In “Words of Wellness” on www.radfyi.org/, read—and listen!—to members of the ARRS Wellness Subcommittee regarding what “wellness” and “wellbeing” mean in their own clinical practices, research focuses, and everyday lives.
Jessica Wen, MD, PhD
Stanford
“Hello, everyone! My name is Jess Wen, and I am a current PGY-3 IR/DR resident at Stanford. My journey towards wellness has its roots in yoga. My yoga practice started in college, and during graduate school, I became a certified yoga instructor. During medical school, I taught yoga classes for my fellow medical students, weaving concepts of presence and self-awareness into my classes.”
“As a trainee, I find that training and wellness are often difficult to reconcile; not just for myself, but also for my colleagues. The aspect of wellness that I struggle with the most is self-love. In medicine, we are trained with the expectation to place the hospital’s needs always before our own. Our training culture has classically praised the individual who finds more of themselves to give, without reprieve or compensation. The internalization of this culture manifests as a loss of self-worth. To balance this, I have found that the pillars of self-love can be derived from both the physical principles of yoga—flexibility and strength—in addition to the yogic principle of community.”
“Flexibility, strength, and community are the mental and social foundations on which I build my self-love and self-acceptance. How do you foster self-love?”
Dr. Wen’s ARRS “Sound of Wellness” Playlist Selection:
The ARRS Professional and Practice Improvement Committee has been charged with overseeing our professional development programs, cultivating leadership opportunities, as well as initiating several practice quality improvements. Jay Parikh, MD (UT MD Anderson), chairs the new ARRS Wellness Subcommittee: a six-person working group with an overarching charter of promoting both workplace wellness and personal wellbeing to ARRS members of each practice type, private or academic, at every stage of their career, from residency to fellowship to active practice and beyond.
The opinions expressed on RadTeams are those of the author(s); they do not necessarily reflect the viewpoint or position of the editors, reviewers, or publisher.
In “Words of Wellness” on www.radfyi.org/, members of the ARRS Wellness Subcommittee share what “wellness” and “wellbeing” mean in their own clinical practices, research focuses, and everyday lives.
Katerina “Katia” Dodelzon, MD, FSBI
Weill Cornell
“I am a breast radiologist and an associate professor of clinical radiology at Weill Cornell Medicine. As an associate program director for diagnostic radiology residency for the last four years, and associate fellowship director for breast imaging, I have worked on various initiatives to augment our trainees’ work-life integration—a crucial factor in training the next generation of physicians.”
“Building on this work in my recent role as vice chair of clinical operations for our department, I strive to further physician wellness, which has globally taken a hit in recent years. The implications are far-reaching, with direct effect on patient care and health care outcomes.”
Dr. Dodelzon’s ARRS “Sound of Wellness” Playlist Selections:
. . . or “Paint It, Black” by the Rolling Stones—both just as effective
The ARRS Professional and Practice Improvement Committee has been charged with overseeing our professional development programs, cultivating leadership opportunities, as well as initiating several practice quality improvements. Jay Parikh, MD (UT MD Anderson), chairs the new ARRS Wellness Subcommittee: a six-person working group with an overarching charter of promoting both workplace wellness and personal wellbeing to ARRS members of each practice type, private or academic, at every stage of their career, from residency to fellowship to active practice and beyond.
The opinions expressed on RadTeams are those of the author(s); they do not necessarily reflect the viewpoint or position of the editors, reviewers, or publisher.
Over the past two decades, the practice of radiology has changed, with radiologists having become more isolated. With the digital revolution precipitating widespread implementation of both electronic medical records and PAC systems, radiologists have increasingly worked from workstations with less patient contact and decreasing personal interactions with referring clinicians.
The COVID-19 pandemic further isolated radiologists. The initial social distancing requirements, use of PPE, promotion of remote work environments, and reduced meaningful social interactions during this era have amplified the loneliness of radiologists.
As humans, radiologists have a fundamental need to socially connect. And for good reasons: social isolation and loneliness, markers of poor social health, have been associated with multiple adverse psychological outcomes, especially sleep fragmentation, as well as anxiety and depressive symptoms. Studies suggest loneliness is a risk factor for stroke, as well as for hypertension, cognitive decline, and progression of Alzheimer’s dementia. Restoring a sense of community, both at work and beyond, can help radiologists overcome isolation, improve their overall wellness, and mitigate significant health issues.
How does a radiologist do so?
Radiology is a team sport, in which radiologists interact daily with patients, non-clinical staff, technologists, and other radiologists. In the workplace, these interactions can be leveraged to create a sense of community. A positive attitude among teammates can help create a bond of positive energy. Social gatherings organized by the clinical team, both within and outside of the department, can help further create camaraderie between members of the team.
Radiologists also have opportunities to develop connections with referring clinicians. Multidisciplinary tumor boards offer a unique opportunity for radiologists to interface directly or virtually with referring clinicians and become engaged in the care of complex patients. This collaborative atmosphere promotes personal job satisfaction.
Organizations can be instrumental in supporting a culture of community at work. Physician lounges provide a safe space for radiologists to interface with physicians from other specialties. Organization-led social events, such as fundraisers and family outings, may further promote a sense of collegiality.
Beyond the organization, another way for radiologists to connect with other radiologists is to attend regional and national society meetings. A great example is the ARRS Annual Meeting, to be held this year from April 16-20 in the beautiful backdrop of Hawaii. The meeting offers opportunities to not only learn educational content from leading experts, but also to network with other radiologists from around the globe. Opportunities to eat lunch, socialize, and collaborate on research projects with fellow radiologists await. Meanwhile, the inaugural ARRS Radiology Wellness Summit will be a wonderful cultural medium to cross-fertilize ideas, helping us all move forward in the wellness and wellbeing space. Hope to see you there!
Jay Parikh, MD
Professor, Department of Breast Imaging, Division of Diagnostic Imaging, The University of Texas MD Anderson Cancer Center
In “Words of Wellness” on www.radfyi.org/, members of the ARRS Wellness Subcommittee share what “wellness” and “wellbeing” mean in their own clinical practices, research focuses, and everyday lives.
Dr. Parikh’s ARRS “Sound of Wellness” Playlist Selection:
Department of Radiology, Division of Musculoskeletal Imaging Stanford University School of Medicine, Center for Academic Medicine
Amelie M. Lutz, MD
Department of Radiology, Division of Musculoskeletal Imaging Stanford University School of Medicine, Center for Academic Medicine
Kathryn J. Stevens, MD
Department of Radiology, Division of Musculoskeletal Imaging Stanford University School of Medicine, Center for Academic Medicine
Imaging findings in radiology are not always black and white; in between, there are multiple shades of gray. One of the key roles of the radiologist is to identify and differentiate true pathology from pathological mimics that can pose a diagnostic challenge in day-to-day clinical practice. As such, it is important to know the normal imaging anatomy of a joint and be aware of some of the typical anatomic variants that can occur. Most anatomic variants are asymptomatic and are seen as incidental findings on imaging. A few anatomic variants, however, can predispose to symptoms under specific circumstances and can cause pain, sensory loss, or restricted joint function.
In advance of the 2023 ARRS Annual Meeting Categorical Course, “Pitfalls and Challenging Cases: How to Triumph and Make the Diagnosis,” this InPractice article focuses on anatomic variants occurring in and around the elbow and some of the potential pitfalls to be aware of when reading imaging studies.
Normal Anatomy
The elbow is a complex synovial joint formed by the articulation of the distal humerus, proximal radius, and proximal ulna. The bones form three separate joints—the humeroulnar, radiocapitellar, and proximal radioulnar joints—contained within a single joint capsule lined with synovium and supported by groups of muscles, tendons, and ligaments [1–3]. The humeroulnar joint is a hinge joint formed between the humeral trochlea and the sigmoid notch of the ulna. The sigmoid notch of the ulna (also known as the trochlear notch or groove or semilunar notch) is a crescent-shaped depression along the proximal ulna lined with articular cartilage [1–4]. The radiocapitellar joint is the articulation between the humeral capitellum and radial head. The radial head has a central concavity that allows smooth articulation with the rounded, anteriorly directed capitellum or capitulum of the humerus. The surfaces of both the radial head and capitellum are covered with hyaline cartilage [1, 2]. The proximal radioulnar joint is formed by the radial head and radial notch (or lesser sigmoid notch) of the proximal ulna, which is a shallow depression distal and lateral to the coronoid process [1–3].
Osseous Anatomic Variants
Supracondylar Process
The supracondylar process, or avian spur, is a congenital bony protuberance along the anteromedial aspect of the distal humerus. It ranges in size from 2 to 20 mm and is located 5–7 cm above the medial epicondyle. The spur grows toward the elbow, unlike an osteochondroma, which is directed away from the elbow. A supracondylar process is present in 1–3% of the population, more commonly found in men and boys and on the left [2, 3]. The spur may be connected to the medial epicondyle by a fibrous band called the Struthers ligament, which creates a fibroosseous tunnel. A supracondylar process is usually asymptomatic but can fracture or cause mechanical compression of the median nerve or brachial artery, where the neurovascular bundle passes through the fibroosseous tunnel formed by the supracondylar process and Struthers ligament. The symptoms include pain, paresthesia, and weakness in the distribution of the median nerve and can be aggravated by continuous movement or local compression at the elbow [1, 2].
A supracondylar process can be seen on lateral or oblique radiographs obtained with the elbow internally rotated and can be misinterpreted as a bony exostosis or osteochondroma. However, the typical location of the supracondylar process along the anteromedial aspect of the distal humerus and direction of growth toward the joint differentiate it from an osteochondroma, which typically occurs in the metaphysis and grows away from elbow (Fig. 1A). CT angiography can show the supracondylar process and deviation, compression, or thrombosis of the brachial artery (Fig. 1B). MRI and ultrasound can depict the Struthers ligament and any compression on the neurovascular bundle. Surgical decompression is usually the preferred approach over conservative treatment of patients who have symptoms [1–8].
Fig. 1—Supracondylar process or avian spur. Left, Lateral radiograph of elbow shows bony protuberance (arrow) along anteromedial aspect of distal humerus approximately 5 cm above medial epicondyle and directed toward joint. Right, Volume-rendered 3D CT angiographic image of elbow shows mild deviation of brachial artery as it courses along and deep to spur (arrow).
Supratrochlear Foramen
In the supratrochlear portion of the distal humerus, a thin plate of compact bone called the supratrochlear septum usually separates the olecranon and coronoid fossae. This bony septum can be opaque or radiolucent, is lined by a synovial membrane, and is present until approximately age 7. After this time, it is occasionally absorbed, forming a supratrochlear foramen (also known as the olecranon foramen, septal aperture, intercondylar foramen, and epitrochlear foramen) [3]. It is important to report the presence of a supratrochlear foramen (Fig. 2) and provide information about the shape and dimensions, because these factors can influence preoperative planning and surgical outcome. The presence of a supratrochlear foramen is commonly associated with a narrow medullary canal and anterior angulation of the distal humerus and gracile bones, which can predispose to fracture when instrumentation is placed in the distal humerus. Additionally, a large supratrochlear foramen may be misinterpreted as an osteolytic or cystic lesion, if the radiologist is unaware of this normal variant [9–12].
Fig. 2—Supratrochlear foramen. Frontal oblique radiograph of elbow shows small lucency (arrow) through supratrochlear region of distal humerus.
Pseudodefect of the Capitellum
The capitellum is a hemispherical protuberance along the anterior and lateral aspects of the distal humerus. The anterior 180° of the capitellum is round, smooth, and covered by articular cartilage. As the capitellum curves distally and posteriorly, it tapers in width. The posterolateral aspect of the capitellum is devoid of articular cartilage and often has a rough and irregular appearance. A groove is normally present between the posterolateral aspect of the capitellum and the lateral epicondyle [3, 4].
The abrupt change in contour of the articular capitellum at the junction with the lateral epicondyle can create a pseudodefect of the capitellum on coronal MR images. This finding is more pronounced in contrast to the smooth articular surface of the radial head or in the presence of a joint effusion where fluid outlines the groove. The pseudodefect can simulate an osteochondral lesion, particularly when there is accompanying fibrocystic change. However, the two can easily be distinguished by their anatomic location on sagittal images: the pseudodefect will be along the posterior nonarticular surface of the capitellum (Fig. 3), whereas an osteochondral lesion will be located along the anterior capitellum and is commonly accompanied by subchondral cystic change, bone marrow edema, and a joint effusion [1–4].
Fig. 3—Pseudodefect of capitellum. Left,Coronal fat-saturated proton density–weighted MR image shows cystic change (arrow) along capitellum suspicious for osteochondral lesion. Right,Sagittal fat-saturated T2-weighted MR image shows cystic change (arrow) along posterior nonarticular portion of capitellum.
Pseudodefect of the Trochlear Groove
The trochlear groove is constricted at the junction of the olecranon and coracoid process with inward tapering that results in subtle cortical notches peripherally, which can simulate cortical disruption on sagittal MR images. These pseudodefects of the trochlear groove can simulate a fracture (Fig. 4). However, the well-defined margins, absence of bone marrow edema, and midtrochlear location differentiate the pseudodefect from a true fracture, which usually extends into the medullary cavity [1, 2, 13].
Fig. 4—Pseudodefect of trochlear groove. Left, Sagittal fat-saturated T2-weighted MR image shows a cartilage-free osseous ridge (straight arrow) through center of trochlear groove. Right, Sagittal T1-weighted MR image more peripherally shows inward tapering (curved arrow) of cortex, mimicking fracture line.
Transverse Trochlear Ridges
The midtrochlear groove is partially or completely traversed by a nonarticular transverse bony ridge at the junction of the olecranon process and coronoid process. The bony ridge is devoid of articular cartilage and best seen on sagittal MR images. The bony elevation may be misinterpreted as an intraarticular osteophyte or sequela of a healed fracture; however, the absence of bone marrow edema and characteristic location help differentiate the midtrochlear groove from pathology [1, 3, 4, 13].
Accessory Ossicles
Patella cubiti—A patella cubiti (also known as an os sesamum cubiti or os sesamoideum tricipitale) is a rare sesamoid bone located within the distal triceps brachii tendon that develops when part of the olecranon or the entire olecranon remains separated from the proximal ulna [3]. On radiographs, the patella cubiti is seen as a well-corticated ossicle with a smooth contour adjacent to the olecranon process. The ossicle can mimic an ununited avulsion fracture of the olecranon tip or a nonunited olecranon apophysis. However, a history of trauma and the presence of irregular sclerotic margins in both the parent bone and fracture fragment favors a chronic fracture. In preadolescent or adolescent athletes involved in overhead throwing activities, such as baseball, a widened physis and sclerotic margins on imaging favor an ununited olecranon apophysis [14–16]. A fractured olecranon enthesophyte or calcium hydroxyapatite deposition in the distal triceps tendon can also mimic a patella cubiti [3].
Os supratrochleare dorsale—The os supratrochleare dorsale is an accessory ossicle found in the olecranon fossa; it is commonly seen in the dominant arm of men and boys age 15–40 [1, 17]. Its appearance has been described as a medallion on a frontal radiograph. This finding is characterized by a thick sclerotic border of bone around an ossicle related to stress changes with a thin rim of surrounding lucency due to deepening of the olecranon fossa. Repetitive impaction by the olecranon process during elbow extension can lead to osseous remodeling or fragmentation of the os with secondary osteoarthritis. It is important to differentiate the os supratrochleare dorsale from its common mimickers, such as patella cubiti, intraarticular joint body, and fragmentation of the olecranon tip in patients with valgus extension overload. Surgical removal is the treatment of choice of both os supratrochleare dorsale and the joint body [1, 17].
Prominent Radial Tuberosity
The radial tuberosity along the ulnar aspect of the proximal radius serves as the attachment site of the distal biceps tendon. Cancellous bony trabeculae are sparse subjacent to the radial tuberosity and may produce an exuberant or bubbly osseous prominence that can simulate a pathologic lucent lesion when seen en face on radiographs. An adjacent osseous fossa anterolateral to the biceps tendon insertion can also appear lucent when seen en face. Knowledge of the distal biceps insertional anatomy can prevent mistaking this physiologic structure for a lucent bone lesion [18].
Offering 18 total CME credits for ARRS members, the “Pitfalls and Challenging Cases: How to Triumph and Make the Diagnosis” Categorical Course will also tackle challenging cases in abdominal, chest, and neuroradiology. Didactic lectures will emphasize clinical scenarios and interpretative skills across a true diversity of findings, enhancing the radiologist’s role in patient management. Together, we look forward to presenting more information—especially about nonosseous normal variants in elbow imaging—during the “Pitfalls in Upper Extremity in MSK Imaging” session at the ARRS Annual Meeting Categorical Course. Please join us and other expert faculty in Honolulu, virtually, or on demand to help diagnose your future shoulder, wrist, and hand imaging cases, too.
References
Tomsick SD, Petersen BD. Normal anatomy and anatomical variants of the elbow. Semin Musculoskelet Radiol 2010; 14:379–393
Stein JM, Cook TS, Simonson S, Kim W. Normal and variant anatomy of the elbow on magnetic resonance imaging. Magn Reson Imaging Clin N Am 2011; 19:609–619
Antil N, Stevens KJ, Lutz AM. Elbow imaging: variants and asymptomatic findings. Semin Musculoskelet Radiol 2021; 25:546–557
Rosenberg ZS, Bencardino J, Beltran J. MR imaging of normal variants and interpretation pitfalls of the elbow. Magn Reson Imaging Clin N Am 1997; 5:481–499
Shon HC, Park JK, Kim DS, Kang SW, Kim KJ, Hong SH. Supracondylar process syndrome: two cases of median nerve neuropathy due to compression by the ligament of Struthers. J Pain Res 2018; 11:803–807
Grayson DE. The elbow: Radiographic imaging pearls and pitfalls. Semin Roentgenol 2005; 40:223–247
Newman A. The supracondylar process and its fracture. AJR 1969; 105:844–849
Pećina M, Borić I, Antičević D. Intraoperatively proven anomalous Struthers’ ligament diagnosed by MRI. Skeletal Radiol 2002; 31:532–535
Singhal S, Rao V. Supratrochlear foramen of the humerus. Anat Sci Int 2007; 82:105–107
Erdogmus S, Guler M, Eroglu S, Duran N. The importance of the supratrochlear foramen of the humerus in humans: an anatomical study. Med Sci Monit 2014; 20:2643–2650
Hirsch IS. On a foramen in the lower extremity of the humerus. Radiology 1928; 10:199–208
Nayak SR, Das S, Krishnamurthy A, Prabhu LV, Potu BK. Supratrochlear foramen of the humerus: an anatomico-radiological study with clinical implications. Ups J Med Sci 2009; 114:90–94
Rosenberg ZS, Beltran J, Cheung Y, Broker M. MR imaging of the elbow: normal variant and potential diagnostic pitfalls of the trochlear groove and cubital tunnel. AJR 1995; 164:415–418
Mittal R, Kumar VS, Gupta T. Patella cubiti: a case report and literature review. Arch Orthop Trauma Surg 2014; 134:467–471
Khomarwut K, Sutthisast W, Vasuntaraporn U, Arpornchayanon O. Bilateral patellar cubiti: a case report. Bangk Med J 2019; 15:91–93
Pavlov H, Torg JS, Jacobs B, Vigorita V. Nonunion of olecranon epiphysis: two cases in adolescent baseball pitchers. AJR 1981; 136:819–820
Obermann WR, Loose HW. The os supratrochleare dorsale: a normal variant that may cause symptoms. AJR 1983; 141:123–127
Freyschmidt J, Sternberg A, Brossmann J, Wiens J. Koehler/Zimmer’s borderlands of normal and early pathological findings in skeletal radiography, 5th ed. Thieme, 2003
Melvin E. Clouse Professor of Radiology, Harvard Medical School Chair, Department of Radiology, Beth Israel Deaconess Medical Center
Lea Azour, MD
Clinical Assistant Professor, Department of Radiology, NYU Grossman School of Medicine Director of Wellness, Department of Radiology
Jonathan Goldin, MD, PhD
Professor of Radiology, Medicine, and Biomedical Physics, UCLA David Geffen School of Medicine
Imagine for a moment a lighthouse, perhaps alone among cold, crashing waves casting light and deep, bellowing sounds for passing ships in the foggy night. A beacon of safety, of hope, a navigation pathway, guiding distant faceless and shrouded ships through dark and treacherous passages into safe harbors and beyond. No expressions of gratitude or appreciation for this pillar of rock and time and relief. Sturdily constructed on a foundation of bedrock, built to survive the daily ebbs of moon-pulled tides and cruelly lashing, crashing cold storms. When activated, light-generated heat escapes from the lantern light room through vent balls on top of the cupola. Passing ship horns are spied from the watching gallery deck, which sits atop the cramped living quarters and the kitchen, repair, exercise, and communications rooms. Our tall tower is constructed to meet the many personal needs of the timeless keeper, all alone. Hanging ladders, spiral stairs, a signaling room, escape exits, and tide-safe entrances provide safety nets of protection against battering tides and time and loneliness
So, where are we going with this analogy? In our opinion, the lighthouse symbolizes the four essential ingredients of a wellbeing strategy: foundational elements, safety nets, as well as cultural and personal wellbeing [Fig. 1].
Fig. 1—All four ingredients symbolically coexist in this tower of light and beacon of hope, providing guidance to those in need, as well as those who don’t yet realize they need help.
Let’s consider and expand on components and opportunities encapsulated within the four ingredients below. We invite ARRS members and your colleagues to do the same. For those who might not be experiencing optimal fulfillment in work at this time, do you have your proverbial lighthouse? Might you have colleagues who would clearly benefit from you serving in this capacity?
Foundational Elements
In the clinical imaging realm, foundational elements include a redesign of the work environment itself, as well as reliable assessment tools to provide longitudinal estimates of individual states of wellbeing and the impacts of burnout mitigation efforts. We must recognize that to make real change in individual wellbeing, the foundation must be rebuilt. We are well aware of the impacts of leadership effectiveness (or lack thereof!) on staff morale and burnout [1], and on the importance of building collaborations and providing opportunities for social connections. We can all easily list those several “pebbles in our shoes” that detract from our professional fulfillment and may result in additional negative impacts. An important foundational component is the ability to identify, then remove these pebbles effectively, and to keep them out. Don’t we all aspire to be pebble-removal scientists? Examples of the many recognized “pebbles” in our radiologist’s shoes include call requirements, compensation plans, staffing challenges, malpractice risks, work isolation, job security, low meaning in work, clerical burdens, and inefficient work environment. This list is much longer.
Safety Nets
The stigmas associated with burnout, stress, and mental health among physicians is harmful and underserved.We offer up simple advice: providing top-level care to our patients requires first that we do the same to ourselves. Simply said, always put your own mask on first. Has your practice invested in developing wellbeing peer support? Who really checks in on you at work? Who do you check in on at work, and what training did you receive for this? We’d suggest reminding yourself how to provide stress first aid, both for peer support and self-care [2]. Consider the “first-aid” that a lighthouse provides, correlated with options for managing sources of anxiety in health care professionals during challenging times [3]. We are all experiencing: “hear me, protect me, prepare me, support me, and care for me.”
Personal Dimensions of Wellbeing
An intricate list of dimensions contributes to our overall wellbeing: emotional, psychological, financial, social, spiritual, occupational, physical, intellectual, and environmental. Each of these, while complex and complicated, embraces a wide expanse of opportunities for fostering a state of wellbeing. One cannot just address each individually in isolation, but collectively. For example, the symptoms of burnout include emotional detachment, and might easily overlap those of clinical depression, and both conditions have fundamentally different treatment approaches [4].
Instilling a Culture of Wellbeing
Finally, instilling a culture of wellbeing is not quite as simple as the title suggests. Instilling this culture implies prioritizing employee wellness, being open and transparent about goals, sharing a roadmap of progress, embracing different opinions—especially from our multigenerational workforce [5]—and commitment from and active participation by leaders. Efforts should be made to align values with those of the larger organization. This helps employees to find and experience meaning and joy in work, to build a sense of community and collegiality, to ensure that employees feel valued, to show compassion and appreciation, to ensure that policies support wellbeing, such as flexible work and transparency, to resource and provide efficient workflow solutions, to enable all employees to be heard. The list goes on, of course.
Above, we have briefly addressed the four components of a radiologist wellbeing strategy, certainly not comprehensively, but intended to stimulate conversation, consideration, and contemplation. We are convinced that there will be as many putative suggestions as there are practices. And we plan to continue this conversation this April 16–18, 2023, during the inaugural ARRS Radiology Wellness Summit in Honolulu, HI [6]. A final thought to consider: Is the House of Radiology ready, willing, and resourced to serve as our wellbeing lighthouse?
Shanafelt T et al. Understanding and addressing sources of anxiety among health care professionals during the COVID-19 pandemic. JAMA 2020; 323:2133–2134
Sen S. Is it burnout or depression? expanding efforts to improve physician Well-Being. N Engl J Med 2022; 387:1629–1630
Kruskal J, Azour L, Goldin J. Introducing the ARRS Radiology Wellness Summit in Hawaii—Time to Get Serious! ARRS InPractice website. www.radfyi.org/radiology-wellness-summit-arrs-2023-hawaii. Published August 1, 2022. Accessed November 9, 2022
In our current topsy-turvy world, characterized by political divisiveness, challenges to reproductive rights, gun violence, global warming, and the Russia-Ukraine War, how can we improve our state of affairs? With so many problems, where do we begin? Should we just acquiesce and retreat to our comfortable cocoons?
As radiologists and as members of the American Roentgen Ray Society (ARRS), I believe that we have an obligation to repair and improve the world. Repairing the world is the ancient Jewish concept of tikkun olam—based on acts of kindness. While we may be unable to solve every problem, we can try to repair our world by working towards the betterment of our patients, our colleagues, and ourselves [1].
As we aim to improve our spheres of influence, our three main tools are kindness, improved communication, and flexibility. Kindness goes a long way in establishing human connections. Improved communication can solve a lot of problems, as many problems arise mainly from impaired communication. Flexibility is critical as we try to emerge from the COVID-19 pandemic. Just think of all the changes in our lives and our world since January 10, 2020, when the World Health Organization announced that a disease outbreak in Wuhan, China was caused by the 2019 novel coronavirus [2]. Furthermore, flexibility is critical as practice patterns and organizational structures change. John Wooden, the record-setting coach of the men’s basketball team at the University of California, Los Angeles, noted that “things work out best for those who make the best of the ways things turn out” [3].
Working towards the betterment of our patients reinforces the notion that we as radiologists are not film critics; rather, we are physicians actively engaged in clinical care, consulting with other health professionals and advocating for our patients. What we do each and every day—interpreting images and performing image-guided procedures—affects nearly all of our patients in nearly every area of medicine. In other words, our patients and many of our clinical colleagues would be lost without us. Just think of our role in patient care, with major roles in diagnosis, staging, screening, monitoring response to therapy, predicting prognosis, and risk assessment. In fact, what we as radiologists do every day has a major impact on what treatments are given and what surgeries are performed.
As we go about our daily work, we can always do a better job at doing our jobs, including making life better for our colleagues. Small acts of kindness can have major positive impacts. Even though we are all busy, taking a little time to engage with others can be helpful in establishing a collaborative milieu. As we talk with each other and establish dialogues, we will probably find that we have more in common that we might have thought. Furthermore, you probably do not want to be the person who reaches out to others ONLY when you need something.
As we live our lives, inside and outside of radiology, it is important that we take care of ourselves. In 2022, about half of all practicing radiologists endorsed symptoms of burnout—a state of chronic physical and mental exhaustion, increased negativity or cynicism, and reduced professional efficacy, due to an imbalance between occupational demands and available resources [4, 5]. Burnout may be exacerbated by radiologists’ isolation in an environment with low ambient lighting and pressure to read cases and finalize reports quickly [5].
We need to take care of ourselves, our colleagues, and our patients. If we are physically and mentally exhausted, we will be less effective as radiologists and as members of our communities and our families. I hope that you will join us for the 2023 ARRS Annual Meeting, April 16–20, in beautiful Honolulu, HI (with virtual and on-demand programing). During the Annual Meeting, we will feature the first-ever Radiology Wellness Summit, directed by Drs. Jonathan Kruskal, Lea Azour, and Jonathan Goldin. Our Summit will be a great program, and all of us have a lot to learn about workplace wellness from an individual, as well as an institutional perspective.
Even though our challenges are weighty, we can and should strive to repair and improve the world. With kindness, improved communication, and flexibility, we can make the world better for our patients, our colleagues, and ourselves. In fact, according to the Talmud and the Quran, whoever saves a single life is considered to have saved the whole world [6, 7]. We can and should incorporate tikkun olam into our busy, hectic, unpredictable lives. We can repair the world. Every (small) act helps. The time is now. As Rabbi Hillel said, “if not now, when?” [8].
References
Fine L. The Pittsburgh Attack Inspired Calls for Tikkun Olam. What to Know About the Evolution of an Influential Jewish Idea. TIME Magazine website. time.com/5441818/pittsburgh-tikkun-olam-history. Published November 1, 2018. Accessed November 3, 2022
CDC Museum COVID-19 Timeline. Centers for Disease Control and Prevention website. www.cdc.gov/museum/timeline/covid19.html. Updated August 16, 2022. Accessed November 3, 2022
Associate Professor, Radiology Boston University Medical Center
Course Director 2023 ARRS Global Exchange Featuring Korean Society of Radiology (대한방사선학회)
The mission of ARRS’ Global Partner Society (GPS) program is to build long-standing relationships with key leaders and organizations in the worldwide imaging community—increasing awareness of our society’s services in specific nations, while raising the stature of Global Partner Societies among ARRS members. Every year, the ARRS Annual Meeting Global Exchange incorporates one partner society into the educational and social fabric of our meeting. ARRS members then reciprocate at the partner society’s meeting that same year.
The GPS partner to be featured at the 2023 ARRS Annual Meeting on the stunning island of Oahu in Honolulu, HI, will be our longtime colleagues from the Korean Society of Radiology (KSR). Established in 1945, KSR remains the official society representing all physicians of Korea working in the field of radiology. With a membership of more than 3,000 practicing imaging professionals—including 500 in-training members—KSR also publishes two scholarly journals: the Korean Journal of Radiology and Journal of the Korean Society of Radiology.
The 2023 ARRS Global Exchange Featuring KSR, “Changing Paradigms in Tumor Response Assessment,” will be the latest in a very long succession of successful educational partnerships between the Americans and Koreans. These two vaunted societies joined forces to present a GPS symposium on breast imaging back in 2017. For that fourth KSR/ARRS online collaboration, respective faculty curated 15 lectures across five breast imaging topics that were delivered during the 72nd Korean Congress of Radiology and the 2016 ARRS Annual Meeting in Los Angeles, CA [1].
On Sunday, April 16, live, virtually, and on-demand from Hawaii, the ARRS Annual Global Exchange Program will deliver a panel of experts from both the United States and Korea discussing a variety of topics and approaches regarding the quickly evolving role of radiologists in tumor response assessment. All participants, regardless of registration type, will gain functional familiarity with treatment response criteria across a wide swath of tumors, treatments, and techniques, learning from esteemed ARRS faculty from Brigham & Women’s Hospital, Memorial Sloan Kettering Cancer Center, and Rhode Island Hospital. I know I speak for the entire ARRS leadership and membership when I note how much we are all looking forward to hosting KSR’s leading experts from Seoul National University Hospital, Yonsei University Health System, Soonchunhyang University College of Medicine, and the Catholic University of Korea. Our Korean friends will help us understand locoregional treatment response evaluation for hepatocellular carcinoma (HCC).
Immune Checkpoints: No Inhibitions?
Be it in America, across the Pacific, or anywhere else in the world for that matter, a chief radiological concern moving forward is recognizing the spectrum of responses and progressive diseases typically encountered in patients treated with immunotherapies, especially immune checkpoint inhibitors (ICI). Right now, indications for ICI therapy already include more than 16 different cancers. As this number will only continue to increase in the coming years, academic and private practice imagers (in addition to radiology residents and fellows) need to know the hang-ups of ICIs.
Recently, on the AJR Podcast episode “Chest CT Findings of Immune Checkpoint Inhibitor Therapy-Related Adverse Events,” Kerem Ozturk, MD, discussed why awareness of early chest CT findings is required for early detection and accurate diagnosis of ICI therapy-related adverse events [2]. Said events are myriad, including pneumonitis, new consolidation, worsening thoracic tumor burden, pleural/pericardial effusion, and pulmonary emboli in the emergency department.
We need to know about combinations, too. Promising results have been published in KSR’s own Korean Journal of Radiology regarding ICI combination therapy and ICI combined with radiotherapy. Specifically, as Kim et al. pointed out in their systematic review and meta-analysis, ICI combination therapy or ICI combined with radiotherapy can work wonders, showing better localized efficacy than ICI monotherapy for treating melanoma brain metastasis [3]. Inevitably, the ever-increasing adoption of ICIs will lead to more and more practical applications.
HCC: Mimics and Machine Learning
Due to its distinct imaging, HCC can be diagnosed noninvasively, typically via multiphasic CT and MRI. As Yoon et al. reminded us in their survey and pictorial review for the Journal of the Korean Society of Radiology, while imaging features like arterial phase hyperenhancement and washout on portal or delayed phase images is classic for HCC, the ability to distinguish HCC-mimicking lesions (e.g., arterioportal shunts, combined HCC-cholangiocarcinoma, intrahepatic cholangiocarcinoma, hemangioma, etc.) on initial imaging examinations is critical for management and treatment alike [4].
Radiologists of tomorrow will need to recognize more than just mimics. We must become familiar with multiple machine learning models, as applied to presently underutilized imaging features that could help construct more reliable criteria for organ allocation and liver transplant eligibility. Apropos, recent findings suggest that machine learning-based models can predict recurrence before therapy allocation in patients with early-stage HCC initially eligible for liver transplant.
As described in AJR OnTrend, 120 patients diagnosed with early-stage HCC, who were initially eligible for liver transplant and underwent treatment by transplant, resection, or thermal ablation, underwent pretreatment MRI and post-treatment imaging surveillance. Imaging features were extracted from postcontrast phases of pretreatment MRI examinations using a pretrained convolutional neural network. Pretreatment clinical characteristics (including labs) and extracted imaging features were integrated for recurrence prediction to develop three ML models: clinical, imaging, combined. Ultimately, all three models predicted posttreatment recurrence for early-stage HCC from pretreatment clinical, MRI, and both data combined [5].
Paradigm and Response Changes
Fortunately, the many recent advances in oncologic patient care are allowing physicians to move beyond nonselective cytotoxic therapies. Increasingly, our specialty will come to rely upon more targeted and personalized treatments for cancer: immunotherapies, stereotactic radiation, image-guided interventions, and theranostics. Alongside these novel approaches to cancer treatment, all houses of radiology will need to prop the door open for our specialty to evolve beyond tumor size measurement—recognizing the cumulative variability in the appearance of treatment responses and associated treatment toxicities by CT, MRI, PET, and a host of hybrid imaging. Given the proliferation of still evolving precision treatment pathways, abdominal, gastrointestinal, and genitourinary subspecialists must stay vigilant and informed. “Changing Paradigms in Tumor Response Assessment” aims to provide precisely that—a contemporary, rigorous update regarding the changing appearances of tumor response on multiple modalities and across a wide spectrum of tumors. I cordially invite you to join Jin-Young Choi, Joon-Il Choi, Natally Horvat, Katherine Krajewski, Jeong Min Lee, Sanghyeok Lim, Don Yoo, and me for the 2023 ARRS Global Exchange Featuring Korean Society of Radiology (대한방사선학회).
Kim PH et al. Immune checkpoint inhibitor with or without radiotherapy in melanoma patients with brain metastases: a systematic review and meta-Analysis. J Korean Soc Radiol 2022; 83:808–829
Yoon J et al. Atypical manifestation of primary hepatocellular carcinoma and hepatic malignancy mimicking lesions. Korean J Radiol 2021; 22:584–595
On Friday, December 9, the final ARRS Virtual Symposium for 2022, Update on Breast Imaging and Multimodality Biopsy, will address timely topics, including digital breast tomosynthesis (DBT), breast ultrasound (US), breast MRI, molecular breast imaging (MBI), and contrast-enhanced mammography (CEM). Didactic lectures will emphasize the most appropriate biopsy methods and procedures for every one of these aforementioned breast imaging modalities—allowing multiple opportunities for radiologists to improve patient outcomes, using current technologies available for early detection of breast cancer.
Digital Breast Tomosynthesis
I will begin the presentation at noon, Eastern Time, on December 9. Focusing on clinical implementation of DBT, I will review DBT technology and important factors to consider for practical application, such as improved breast cancer detection, synthetic digital mammography, and workflow for screening and diagnostic populations.
Recognizing the need for DBT-guided breast biopsy, Sarah M. Friedewald, MD, of Northwestern University will present on advantages and disadvantages of prone and upright biopsy systems, as well as interpretive outcomes for biopsy-proven, DBT-only findings. Earlier this summer in AJR [1], Dr. Friedewald coauthored the first study of its kind comparing pathologic outcomes between patients with single and multiple architectural distortion visualized by DBT. Ultimately, for those patients with multiple architectural distortions identified on DBT, biopsy of all areas may be warranted, given the variation of pathologic diagnoses.
Breast Ultrasound
Liane Philpotts, MD, of the Yale School of Medicine will describe how to optimize breast US in symptomatic patients, pointing out tools to enhance correlations between sonographic, mammographic, and DBT findings. Additionally, Dr. Philpotts will describe methods for reducing false positives (false negatives, too). Meanwhile, 2004 ARRS Scholar Jessica W. T. Leung, MD, of MD Anderson Cancer Center [2] will help us define the clinical indications, benefits, and limitations of US-guided procedures of the breast, while assessing the post-biopsy imaging/pathologic concordance.
Breast MRI
As recent clinical perspectives have affirmed [3], MRI remains the most sensitive tool for detecting breast cancer; however, cost and acquisition time continue to be deterrents in adopting the technology for routine screening purposes. Following our first question and answer session of the afternoon, fellow InPractice breast imaging contributor [4] Linda Moy, MD, of NYU Langone Health will discuss the present role of screening breast MRI, alongside the roles that AI is poised to play in the very near future. Dr. Moy will also bring everyone up to speed on abbreviated or “ultrafast” MRI protocols for supplemental screening [5]. For her session, Laurie R. Margolies, MD, of Mount Sinai will detail the equipment and techniques required to perform MRI-guided breast biopsy procedures, pointing out both pearls and pitfalls to improve the overall patient experience.
Molecular Breast Imaging and Contrast-Enhanced Mammography
Increasingly, MBI continues its integration into routine breast imaging practice. Haydee Ojeda-Fournier, MD, from University of California San Diego Health will present on this topic, describing the variety of MBI indications for use in clinical practice. Her lecture will incorporate discussions of the MBI lexicon, which is well-timed given that, as AJR acknowledged in July [6], we shouldn’t have to wait too much longer for the American College of Radiology’s BI-RADS committee to initiate its own incorporation of MBI lexicon into the BI-RADS Atlas. Finally, Janice S. Sung, MD, of Memorial Sloan Kettering Cancer Center will deliver a must-see session regarding a relatively new breast imaging modality that is quickly gaining acceptance: CEM [7]. CEM renders density and morphologic information on low-energy images in conjunction with physiologic enhancement via the recombined (i.e., subtracted and processed) images. CEM-guided biopsy is not only FDA-approved, as noted in the most recent issue of InPractice [8], it is frequently necessary for proper patient management. Dr. Sung will detail real-world considerations for setting up a CEM program at your institution and practice, followed by another high-impact question and answer session with the entire faculty.
The experts above continue to enjoy an extensive range of clinical experience with each breast imaging modality presently impacting patient care, so I urge diagnostic radiologists, full-time, or even part-time breast imagers—academic and private practice alike—to join us for Update on Breast Imaging and Multimodality Biopsy on the 9th of December. Offering 4 CME credit hours for ARRS members, the entire program will remain available on demand for practicing radiologists, as well as fellows, residents, and allied medical students, who are unable to attend our live event.
References
Wang LC, Philip M, Bhole S, et al. Pathologic outcomes in single versus multiple areas of architectural distortion on digital breast tomosynthesis. AJR 2022; 1–13:10.2214/AJR.22.27625
Mango VL, Grimm LJ, Harvey JA, Plecha DM, Conant EF. Abbreviated Breast MRI for Supplemental Screening: The Why and How of Clinical Implementation. ARRS InPractice site. www.radfyi.org/abbreviated-breast-mri-supplemental-screening. Published May 13, 2022. Accessed October 29, 2022
Hunt KN, Conners AL, Samreen N, Rhodes DJ, Johnson MP, Hruska CB. PPV of the molecular breast imaging lexicon. AJR 2022; 1–9:10.2214/AJR.21.27047
Division of Musculoskeletal Imaging and Intervention Department of Radiology Massachusetts General Hospital
Joao R.T. Vicentini, MD
Division of Musculoskeletal Imaging and Intervention Department of Radiology Massachusetts General Hospital
Connie Y. Chang, MD
Division of Musculoskeletal Imaging and Intervention Department of Radiology Massachusetts General Hospital
The ankle and foot are challenging areas to image and diagnose, due to complex anatomy. In advance of the 2023 ARRS Annual Meeting Categorical Course, “Pitfalls and Challenging Cases: How to Triumph and Make the Diagnosis,” our InPractice article is a collection of cases that we hope will help you conquer some of these pathologies.
Nearly all ankle and midfoot cases begin with radiographs, because radiography is the modality we usually encounter initially, and x-rays can often give us many clues about the diagnosis, especially in the ankle. In the midfoot, which has more complicated anatomy, cross-sectional imaging, especially MRI, is often required to make the diagnosis.
Case No. 1
For the classic inversion injury or ankle “sprain,” we typically think of lateral ankle ligament injuries, or a fibular avulsion fracture. Since the foot and ankle are relatively flexible, injuries can occur in many places. Our first case is a 27-year-old man who injured his ankle in a rollover car accident. In the lateral aspect of the talar dome—left image above—there is a curvilinear subchondral lucency (dotted curve) seen on the frontal radiographic view, compatible with an osteochondral lesion (arrow).
Osteochondral lesions (OCL) of the talus can be quite difficult to see on x-rays, and OCLs are often missed, especially when they occur with other bony injuries. For example, a patient may have a fibular fracture, which is adequately treated, and then experience persistent pain later on [1]. If the mechanism of injury involves shearing (e.g., tibiotalar subluxation), compression (e.g., falling from a height) or avulsion (e.g., distraction of the tibiotalar joint), the index of suspicion for an osteochondral injury should be higher, although these details may be difficult to ascertain from the patient or the medical record [2]. Impaction of the talus on the distal tibial plafond leads to microfractures in the cartilage and subchondral bone plate, and the increased pressure from weight-bearing can cause osteonecrosis [3]. This process can take a variable amount of time; therefore, presentation may be delayed up to 6–12 months. Even if the OCL is seen on radiographs, cross-sectional imaging is frequently needed. CT may be more helpful to evaluate small or comminuted OCLs, as ossific fragments may be difficult to visualize on MRI [4]. Apropos, the coronal reconstruction CT image of this case—right image above—demonstrates the mildly displaced, dominant osteochondral fragment (solid arrow). There is an additional punctate ossific fragment (dashed arrow) along the lateral aspect of the osteochondral injury, not seen on the x-ray. It would be unlikely to see this fragment on MRI, simply because of the inadequate spatial resolution.
Case No. 2
When an ossific fragment is not displaced, as in this case of a 39-year-old who twisted her ankle on the stairs 6 months ago, MRI can be helpful to evaluate for stability. On the coronal T2 fat-suppressed image—left image above—we can see that the fragment is somewhat irregular at the articular surface, but there is fluid signal intensity completely undercutting the fragment (solid arrow), and bone marrow edema in the adjacent talus, suggesting that the fragment is unstable [5]. There is mild subchondral bony irregularity and depression (dashed arrow), too. Other signs of instability may be cystic change or partial or complete separation of the fragment from the donor site [8].
The sagittal T1 image—right image above—shows that a large portion of the fragment is low in signal intensity, which persists on all sequences, and there is articular surface collapse, suggesting that the portion is at least partially osteonecrotic [8]. Another portion still demonstrates fat signal intensity (solid arrow) on T1 and high signal on the T2 fat-suppressed image, suggesting that tis portion remains viable.
This patient was placed on a trial of conservative treatment, including a lace-up ankle brace and semi-rigid orthosis, which had just begun at the time of writing this article. Management depends on patient symptoms, as well as size and stability of the OCL. In general, small (< 15mm2), stable fragments in ankle fractures are treated conservatively, whereas large, unstable fragments are managed operatively [3, 6–7, 9]. Surgical options include arthroscopic drilling, excision and debridement, or osteocartilaginous grafting [2].
Case No. 3
Our third and final case is a 33-year-old woman, playing tennis two hours prior to presentation, who had planted her foot, tried to run forward, then felt something like “a hit behind her ankle.” The patient could no longer walk without significant pain. The initial radiograph demonstrates distal Achilles thickening, and more proximally, a focally irregular anterior margin, consistent with Achilles tendinopathy and tear. Achilles tendon ruptures account for 20% of all large tendon ruptures [10]. Showing bimodal age distribution, the first peak occurs around the third to the fifth decade of life, due to high-energy injuries, while the second peak occurs in the elderly, due to low-energy injuries to a degenerated tendon. Men are more commonly affected. Achilles tears are more common in sports with forceful and repetitive jumping or “push-off,” often seen in cyclists, gymnasts, runners, and divers, as well as tennis, basketball, and volleyball players. Risk factors include poor conditioning before exercise, prolonged use of corticosteroids, fluoroquinolone antibiotics, and overexertion [11].
Because the Achilles tendon is bound by the Kager fat pad anteriorly and subcutaneous fat posteriorly, an abnormal appearance can often be detected on radiographs [12]. The lateral radiograph—left image above—demonstrates diffuse fusiform thickening of the Achilles tendon (dashed arrow). More proximally, the tendon is irregular anteriorly, consistent with a tear. There is edema in the Kager fat pad (“K”), also indicating acute tear. It can be difficult to determine partial versus full-thickness tear, and in this case, the posterior margin of the tendon appears intact, suggesting that it is a high-grade partial, rather than full-thickness tear, although MRI later confirmed that it was a full-thickness tear. Ossific foci, if present, suggest chronic tears (not seen in this case) [13].
On MRI, we first observe that the foot was placed in plantar flexion, which may underestimate the tendon gap. While this typically does not preclude diagnosis of the tendon tear, it inevitably brings torn pieces of tendon closer together, and the maximum tendon gap cannot be determined.
The sagittal T2 fat-suppressed image—right image above—demonstrates a full-thickness tear (“X”) and severely degenerated proximal (dashed arrow) and distal (solid arrows) tendon. The uniformly thickened and hyperintense distal tendon is probably a combination of chronic tendon degeneration and acute edema from the tear, especially as individual fibers within the tendon are relatively well seen. It is important to comment on tendon quality and the length of tendon, which appears severely degenerated, because this tendon may not be useable for repair [14]. Many of the internal strands appear wavy, compatible with retraction. MRI is considered the gold standard for imaging Achilles tendon tears (sensitivity, 80–100%; specificity, 100%) (8, 15). Ultrasound also has high sensitivity (full thickness, 95%; partial thickness, 94%) and specificity (full thickness, 99%; partial thickness, 97%) for the detection of Achilles tendon tears, given the tendon’s superficial location and possibility of dynamic imaging with the modality (16, 17). This patient’s tear was also well seen on ultrasound (not shown).
Since the patient was only visiting the United States, she was placed in a boot for her trip home, although surgical intervention was required soon after arriving. Management of Achilles tendon ruptures is controversial and evolving. Overall, there has been a general trend moving toward immobilization with functional rehabilitation, rather than treating all ruptures exclusively with surgical repair [18, 19].
Focusing on interpretative skills for avoiding misdiagnoses across a wide spectrum of musculoskeletal imaging pitfalls, the 2023 ARRS Annual Meeting Categorical Course, “Pitfalls and Challenging Cases: How to Triumph and Make the Diagnosis,” will also tackle challenging cases within neuroradiology, abdominal, and chest imaging. Topics will emphasize real-life clinical scenarios, while providing tips and tricks for optimal performance. We invite you to join us on the beautiful island of Oahu in Honolulu, HI (or virtually or even on demand) for this exciting, 18-hour Categorical Course, purposefully designed to enhance your ability to add value to patient management.
References
StatPearls Publishing; www.ncbi.nlm.nih.gov/books/NBK556139. Cited Accessed Aug 18 2022
Badekas T, Takvorian M, Souras N. Treatment principles for osteochondral lesions in foot and ankle. Int Orthop 2013; 37:1697–706
Rikken QGH, Kerkhoffs GMMJ. Osteochondral lesions of the talus: an individualized treatment paradigm from the Amsterdam perspective. Foot Ankle Clin 2021; 26:121–36
Yasui Y, Hannon CP, Fraser EJ, et al. Lesion size measured on MRI does not accurately reflect arthroscopic measurement in talar osteochondral lesions. Orthop J Sports Med 2019; 7:2325967118825261
Rios AM, Rosenberg ZS, Bencardino JT, Perez Rodrigo S, Garcia Theran S. Bone marrow edema patterns in the ankle and hindfoot: distinguishing MRI features. AJR 2011; 197:720–729
Pedersen ME, DaCambra MP, Jibri Z, Dhillon S, Jen H, Jomha NM. Acute osteochondral fractures in the lower extremities–approach to identification and treatment. Open Orthop J 2015; 9:463–474
Gianakos AL, Yasui Y, Hannon CP, Kennedy JG. Current management of talar osteochondral lesions. World J Orthop 2017; 8:12–20
Szaro P, Geijer M, Solidakis N. Traumatic and non-traumatic bone marrow edema in ankle MRI: a pictorial essay. Insights Imaging 2020; 11:97
van Dijk CN, Reilingh ML, Zengerink M, van Bergen CJA. Osteochondral defects in the ankle: why painful? Knee Surg Sports Traumatol Arthrosc 2010; 18:570–580
Shamrock AG, Varacallo M. Achilles tendon rupture. StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; www.ncbi.nlm.nih.gov/books/NBK430844. Cited Accessed Aug 18 2022
Theobald P, Bydder G, Dent C, Nokes L, Pugh N, Benjamin M. The functional anatomy of Kager’s fat pad in relation to retrocalcaneal problems and other hindfoot disorders. J Ana 2006; 208:91
Paoloni J. Tendon injuries–practice tips for GPs. Aust Fam Physician 2013; 42:176–180
Bäcker HC, Wong TT, Vosseller JT. MRI assessment of degeneration of the tendon in Achilles tendon ruptures. Foot Ankle Int 2019; 40:895–899
Dams OC, Reininga IHF, Gielen JL, van den Akker-Scheek I, Zwerver J. Imaging modalities in the diagnosis and monitoring of Achilles tendon ruptures: a systematic review. Injury 2017; 48:2383–2399
Chang A, Miller TT. Imaging of tendons. Sports Health 2009; 1:293–300
Aminlari A, Stone J, McKee R, et al. Diagnosing Achilles tendon rupture with ultrasound in patients treated surgically: a systematic review and meta-analysis. J Emerg Med 2021; 61:558–567
Park SH, Lee HS, Young KW, Seo SG. Treatment of acute Achilles tendon rupture. Clin Orthop Surg 2020; 12:1–8
Deng S, Sun Z, Zhang C, Chen G, Li J. Surgical treatment versus conservative management for acute Achilles tendon rupture: a systematic review and meta-analysis of randomized controlled trials. J Foot Ankle Surg 2017; 56:1236–1243
Since its introduction nearly 20 years ago, score-based peer review has not been shown to have a meaningful impact on or be an accurate measurement of radiologist performance [1]. A new paradigm—peer learning—has emerged, which is a group activity where practicing professionals review each other’s work, actively give and receive feedback in a constructive manner, teach and learn from one another, and mutually commit to improving performance as individuals and as a group. As my colleague, coauthor, and present chair of ARRS’ Professional & Performance Improvement Committee, Nadja Kadom, MD, first noted here in the pages of InPractice back in 2019, peer learning is “a system that uses accuracy of interpretation as a surrogate marker for competency” [2].
Many radiology practices are beginning to transition from score-based peer review to peer learning, but these same practices face distinct challenges and multiple barriers to implementation, especially considering the variety of leadership styles Dr. Kadom has recently detailed [3]. Case in point: nearly half of the 742 members of ARRS who participated in our 2020 AJR Original Research article, “Current Status and Future Wish List of Peer Review: A National Questionnaire of U.S. Radiologists,” reported insufficient learning outcomes from peer review [4]. Clarifying a minimum number of cases that required monthly review, as well as how interpretive discrepancies would be communicated, were two big factors where some level of standardization was clearly needed.
Perhaps most importantly, the demographics of our survey respondents reflected the current composition of this country’s imaging workforce. A total 742 (4.2% response rate) ARRS members replied to our 21-question, multiple-choice questionnaire. Among those respondents, 547 (73.7%) were board-certified, practicing radiologists also participating in a form of peer review. As you can see, most responders were in private practice (51.7%, 283/547), while the next largest cohort was in academic practice (32.4%). The most common practice size was 11–50 radiologists (50.5%), followed by groups of up to 10 radiologists (21.2%). The majority of responders practiced in urban settings (61.6%), too.
Practice Characteristic
No. (%)
Type
Private
283 (51.7)
Academica
177 (32.4)
Hybridb
45 (8.2)
Government
42 (7.7)
No. of radiologists
0–10
116 (21.2)
11–50
276 (50.5)
51–100
85 (15.5)
>100
70 (12.8)
Setting
Urban
337 (61.6)
Suburban
158 (28.9)
Rural
52 (9.5)
aAcademic practices had medical school and radiology residency program. bHybrid practices had radiology residency program without a medical school.
Nonetheless, in this largest nationwide questionnaire to imaging professionals regarding the present state of and their future needs for peer review, most radiologists working in the United States felt a better system is not only necessary, but that said system could even be feasible in daily practice.
To our knowledge, “Updates for Your Peer Learning Activities: Pitfalls, Tips, and Accreditations” remains the only course of its kind. Presented live as a Featured Sunday Session during the 2023 ARRS Annual Meeting in Honolulu, HI, this course is now in its second revised and expanded iteration, packed with practical tips to clinical success, all taught by experts in the field. Summarizing the current status and practice gap in peer review in radiology, sessions will include three didactic lectures to showcase the best practices and challenges of peer learning programs at multiple institutions, including Emory, NYU, Stanford and Mayo Clinic. Esteemed faculty will highlight potential barriers to starting and sustaining peer learning activities in both academic and private practice settings, each instructor sharing their own “top 5 tips” for overcome these challenges. We will also address the latest updates from the American College of Radiology’s Quality and Safety Commission regarding new accreditation pathways for peer learning [5].
The evolution of peer learning is of universal importance for the continuing education of all radiologists—in practice, during fellowship or residency. However, the intersecting concepts of peer learning, just culture, etc. are evolving at a breakneck pace, with brand-new accreditation pathways opening up and multiple acceptable approaches to finding the “right answer” [6]. For imaging professionals already involved in peer learning, come share your experience with our expert panel, ensuring you are getting the most out of your program. For those new to peer learning, come learn how to fish for the pearls, avoid the pitfalls, and hit the ground running. We will conclude with an interactive panel discussion with the audience—there in Hawaii, virtually, or on demand.
References
Larson DB et al. Transitioning from peer review to peer learning: report of the 2020 Peer Learning Summit. J Am Coll Radiol 2020; 17:1499–1508
@OWeaverMD Department of Breast Imaging, Division of Diagnostic Imaging MD Anderson Cancer Center
Contrast-enhanced mammography (CEM) is a relatively new modality which is rapidly gaining acceptance in breast imaging. Many medical centers have already acquired the necessary equipment to implement CEM programs [1], thus creating an ever-increasing demand for trusted CEM educational resources.
At the same time, however, there remains a paucity of quality instructional materials for this emerging tool, a lack of structured, case-based training, and fundamental misconceptions regarding both the technical aspects and the operational/administrative knowledge needed for successful implementation of CEM.
On day one of the 2023 ARRS Annual Meeting, Sunday, April 16, live (and virtually, of course) from Honolulu on the enchanting island of Oahu, HI, Drs. Wendie Berg, Bhavika Patel, and I, will offer a two-hour introductory program on practical CEM for radiologists. Our Featured Sunday Session, “Contrast-Enhanced Mammography: The Essentials and Beyond,” will include interactive didactic and case-based lectures to educate and update practicing radiologists on the important foundational principles of CEM. The course will be supplemented with an optional short pre- and post-test survey to help the audience organize the information and evaluate their learning progress.
CEM Augments Mammography Capabilities in the Digital Era
The strength of CEM is its ability to provide both morphologic information on low-energy images, similar to a standard 2D mammogram, and functional information of contrast distribution on the “recombined” (subtracted and processed) images. This is achieved by software and hardware modifications to modern mammographic equipment and necessitates patient workflow adjustments in breast centers [2]. The course will present the basics of CEM technology, its strengths and limitations, as well as helpful tips on implementing this modality in clinical practice.
Additionally, the course will serve as a guide to CEM image interpretation with a special emphasis on utilization of the newly introduced Breast Imaging Reporting & Data System (BI-RADS®) CEM lexicon [3].
We will also discuss background parenchymal enhancement (BPE) in CEM image interpretation. Similar to breast tissue density of mammography, increased BPE may both mask and mimic cancer on CEM. As on MRI, there are four categories of BPE (Fig. 1), and multiple factors are associated with increased BPE [4]. We will present the audience with a range of appearances for normal BPE on CEM.
Fig. 1—Normal craniocaudal views of recombined images from CEM examination of four patients show different patterns of BPE: minimal (A), mild (B), moderate (C), and marked (D). All enhancement on images caused by normal BPE [4].
Drs. Berg, Patel, and myself will provide a case-based introduction to the most common artifacts and cancer mimics on CEM, too. This topic is continuously evolving. In the July issue of AJR, enhancing cherry hemangioma has been described as a common benign finding that may be misleading (Fig. 2) [5]. It is helpful for the technologist to make note of skin lesions, which can be marked to facilitate recognition.
Fig. 2—52-year-old woman with dense breasts and family history of breast cancer (estimated lifetime risk, 20.4% by Tyrer-Cuzick model version 8) undergoing high-risk screening CEM. 1A: Right craniocaudal (left) and mediolateral oblique (right) CEM obtained 2.5 minutes after IV injection of 125 mL of iopamidol (Isovue 370, Bracco) show superficial 3-mm focus (circle) with medium enhancement in superior aspect of breast approximately 5 cm from nipple. 1B: Clinical photograph shows 3-mm cherry hemangioma (circle) on skin of right breast at 10-o’clock position approximately 5 cm from nipple found clinically by radiologist performing ultrasound. Finding corresponds to enhancing focus in A [5].
CEM Screening and Diagnostic Applications
Chief among the topics discussed will be the role of CEM, alongside other legacy modalities, in today’s screening and diagnostic guidelines and society-endorsed consensus recommendations for breast cancer imaging. CEM is already recommended as an alternative to MRI in screening of women at high risk of breast cancer and in average-risk women with dense breasts [6]. An AJR article from 2021 demonstrated that CEM shows promise as a breast cancer screening examination in patients with a personal history of lobular neoplasia [7].
Of clinical importance is the fact that enhancing CEM-detected lesions that have an ultrasound correlate are more likely to be malignant. These data were also published by AJR in 2021 [8]. Among 153 enhancing lesions detected on CEM in 144 patients, the authors found ultrasound correlates in 47 (31%). Furthermore, this means that a substantial number of enhancing findings can potentially be sampled with ultrasound-guided biopsy (Fig. 3).
Fig. 3—57-year-old woman with history of left breast excision for lobular carcinoma in situ who underwent CEM. A: Low-energy mammogram shows no abnormality. B: Recombined mammogram shows enhancing 0.4-cm mass in 6-o’clock axis of left breast (arrow). Mass was evident only on recombined images. C: Image obtained during targeted ultrasound-guided core biopsy shows ultrasound correlate (arrow). Pathology result was invasive lobular carcinoma [8].
Diagnostic applications of CEM in breast imaging continue to evolve. In the July issue of AJR, CEM was compared with MRI for neoadjuvant therapy (NAT) response assessment [9, 10]. After NAT for breast cancer, CEM and MRI yielded similar assessments of lesion size (both slightly overestimated vs. pathology) and RECIST categories, and no significant difference in specificity for complete pathologic response. Duly noting that MRI had higher sensitivity for complete pathologic response, Bernardi et al. showed preliminary data suggesting that a delayed CEM acquisition 6 minutes after contrast injection could help detect residual ductal carcinoma in situ (DCIS) [10]. The authors concluded that while MRI remains the preferred test for NAT monitoring, the findings support CEM as a useful alternative when MRI is contraindicated or not tolerated [10, 11].
CEM may be a useful alternative to MRI in women with newly diagnosed breast cancer and breast augmentation. The findings of Carnahan et al. published in AJR last year suggest the plausibility of CEM for disease extent assessment in women with breast augmentation and contraindication or limited access to MRI [12].
The study evaluated 17 female breast cancer patients with breast implant augmentation, who underwent both CEM and MRI for staging. CEM and MRI were concordant for the index cancer in all 17 women. Six additional lesions were demonstrated by CEM and confirmed by MRI in 6 (35%) women: three multifocal, one multicentric, and two contralateral; two (33%) were malignant (one each invasive ductal and invasive lobular carcinoma). MRI did not identify any additional cancers not seen on CEM.
CEM-Guided Biopsy
Perhaps the largest unmet need for expertly curated CEM education surrounds CEM-guided biopsy. Case in point: recently FDA-approved—but not yet widely available—direct CEM-guided biopsy is often a necessary step in patient management. In the absence of CEM-guided biopsy capability, suspicious enhancing findings that have no definite correlate on low energy images, tomosynthesis, or ultrasound require possible MRI-guided biopsy for diagnosis. This increases cost and prolongs diagnostic workup. With the introduction of CEM-guided biopsy technology, this workflow is expected to become more streamlined and efficient. Our subspecialized presenters have personal experience with this technology and will deliver a comprehensive overview of the current state of knowledge and the future directions of CEM-guided biopsies.
CEM Essentials—and Beyond—at the ARRS Annual Meeting
Contemporary breast imagers must become more familiar with the range of indications and contraindications on CEM, such as normal variants, BPE, pathology, and artifacts. Focused sessions will also address interpretative skills in CEM—including appropriate use of the recently released BI-RADS CEM lexicon from the American College of Radiology—giving radiologists in private and academic practices alike applied insights from real-life cases.
Although the target audience for our course is predominantly medical imaging professionals considering or actively implementing CEM in practice, the curriculum presented live on Sunday, April 16 will also be relevant and valuable for recent residency or fellowship graduates, particularly those transitioning to imaging practices with established CEM services.
As the field moves forward, medical centers with established CEM programs will inevitably need to educate an incoming imaging workforce and new trainees who have not experienced enough clinical exposure to this modality in their previous practices or training programs. Apropos, “Contrast-Enhanced Mammography: The Essentials and Beyond” will also offer participants a unique opportunity to test and evaluate a newly developed online teaching module for CEM, purposefully designed to train the radiologists of today and tomorrow in clinical implementation of CEM in their own practices.
Perry H, Phillips J, Dialani V, Slanetz PJ, Fein-Zachary VJ, Karimova EJ, et al. Contrast-Enhanced Mammography: A Systematic Guide to Interpretation and Reporting. AJR 2019; 212:222–223
Breast Imaging Reporting & Data System (BI-RADS®) Contrast Enhanced Mammography (CEM) Supplement. ACR website. www.acr.org/-/media/ACR/Files/RADS/BI-RADS/BIRADS_CEM_2022.pdf. Published 2022. Accessed September 12, 2022
Karimi Z, Phillips J, Slanetz P, Lotfi P, Dialani V, Karimova J, et al. Factors Associated With Background Parenchymal Enhancement on Contrast-Enhanced Mammography. AJR 2020; 216:340–348
Lu AH, Zuley ML, Berg WA. Enhancing Cherry Hemangioma: A Mimic for Breast Cancer on Contrast-Enhanced Mammography. American Journal of Roentgenology. 2022;219(1):160-1.
The ACR Appropriateness Criteria® American College of Radiology Appropriateness Criteria. Supplemental Breast Cancer Screening Based on Breast Density. ACR website. acsearch.acr.org/docs/3158166/Narrative. Published 2021. Accessed September 12, 2022.
Hogan MP, Amir T, Sevilimedu V, Sung J, Morris EA, Jochelson MS. Contrast-Enhanced Digital Mammography Screening for Intermediate-Risk Women With a History of Lobular Neoplasia. AJR 2021; 216:1486–1491
Coffey K, Sung J, Comstock C, Askin G, Jochelson MS, Morris EA, et al. Utility of Targeted Ultrasound to Predict Malignancy Among Lesions Detected on Contrast-Enhanced Digital Mammography. AJR 2021; 217:595–604
Woodard S. Editorial comment: evidence supporting contrast-enhanced mammography (CEM) for monitoring neoadjuvant chemotherapy response and showing the potential of delayed CEM. AJR 2022;11
Bernardi D. et al. Contrast-enhanced mammography versus MRI in the evaluation of neoadjuvant therapy response in patients with breast cancer: a prospective study. AJR 2022; 14:1–11
Carnahan MB et al. Contrast-enhanced mammography for newly diagnosed breast cancer in women with breast augmentation: preliminary findings. AJR 2021; 217:855–856
Division of Pediatric Neuroradiology Orlando Health—Arnold Palmer Hospital for Children
Avery Wright, DO
Division of Pediatric Neuro-Oncology Orlando Health—Arnold Palmer Hospital for Children
Mohit Agarwal, MD
Division of Neuroradiology Medical College of Wisconsin
Lily Wang, MBBS, MPH
Division of Neuroradiology University of Cincinnati Medical Center
Karen L. Salzman, MD
Division of Neuroradiology University of Utah Medical Center
Primary brain tumors are the most common solid tumors in children, second only to leukemia in terms of cancer incidence, and are the leading cause of childhood cancer-related mortality [1, 2]. Tumors may present across all pediatric age groups, including infants, children, adolescents, and young adults, with the majority of cases presenting in the first decade of life. Clinical presentations vary, based upon the type of tumor, location, and patient age; however, the most common presenting symptoms include headaches, nausea and vomiting, and gait abnormalities [3]. In infants and very young children, obstructive hydrocephalus results in macrocephaly with bulging fontanelle [4]. Brainstem tumors commonly have symptoms associated with involved tracts and cranial nerves.
Imaging plays a crucial role in the initial workup, management, and post-treatment follow-up of primary pediatric posterior fossa tumors. Treatment options vary, based upon the tumor type, location, and patient age, and are beyond the scope of this InPractice review. The most common primary posterior fossa tumors in children that we will discuss and illustrate during our 2023 ARRS Annual Meeting Categorical Course session include (in descending order of frequency): medulloblastoma, pilocytic astrocytoma, ependymoma, diffuse midline glioma, and atypical teratoid-rhabdoid tumor.
Medulloblastoma
Medulloblastomas are high-grade (WHO grade 4) embryonal tumors and represent the most common malignant and the most common primary posterior fossa brain tumors in children [5]. Various subcategories of medulloblastomas have been described and used in the past; however, the latest molecular classification lists the following subtypes: wingless/integrated (WNT)—activated, sonic hedgehog (SHH)—activated, and non-WNT/non-SHH (also known as groups 3 and group 4), with additional subcategories for SHH-activated and non-WNT/non-SHH variants [6]. Classically, medulloblastomas were thought of as midline cerebellar tumors, but certain subtypes have a propensity for off-midline presentations.
General Imaging Features
Imaging characteristics for the various subtypes of medulloblastoma are overall similar, reflecting that of densely packed, highly cellular tumors. Masses tend to be spherical in shape and displace adjacent structures, as opposed to the more pliable appearance of ependymomas. Increased density on CT and diffusion restriction on MRI are characteristic of medulloblastomas, reflective of their high cellularity. T2 signal intensity is variable, typically having areas of both increased and decreased T2 signal compared to cerebellar parenchyma. Small intralesional cysts are common, while intralesional hemorrhage and calcification are uncommon, though may occasionally be seen. Enhancement ranges from patchy to more robust solid enhancement [7, 8] (Fig. 1).
Fig. 1—8-year-old boy with progressive nighttime headache, nausea, vomiting. Surgical pathology confirmed medulloblastoma. Top, left to right: Axial CT image in brain window shows circumscribed hyperdense midline posterior fossa mass (black arrow) with dilatation of temporal horns of lateral ventricles secondary to obstructive hydrocephalus (white arrows); axial T2-weighted image shows mass (arrow) has signal intensity predominantly similar to gray matter, with additional small internal cystic components; axial T1-weighted postcontrast image shows avid enhancement of solid components of mass (arrow). Bottom, left and right: Characteristic restricted diffusion (arrows) is seen as increased signal intensity on DW image and decreased signal intensity on ADC map.
On MR spectroscopy, a high-grade tumoral spectrum is evident with increased choline and decreased N-acetyl aspartate peaks. A taurine peak just to the left of the choline peak may be a specific marker for medulloblastoma in the posterior fossa [9].
The frequency of metastatic disease varies depending upon the molecular subtype, ranging from approximately 10% to up to 45% at the time of initial presentation [5]. It is therefore important to image the spine prior to surgical resection and with subsequent surveillance imaging to evaluate for disseminated disease.
WNT-Activated Medulloblastoma
WNT-activated medulloblastomas are the least common subset and have the best overall prognosis. These tumors commonly present in older children and adolescents and may occur midline or laterally around the foramen of Luschka, cerebellar peduncle, and cerebellopontine angle [6, 7, 10].
SHH-Activated Medulloblastoma
SHH-activated medulloblastomas are a more heterogeneous subset than WNT-activated, with an overall intermediate prognosis. Tumors tend to be located laterally in the cerebellar hemispheres, since they are thought to arise from precursors in the external granule-cell layer of the cerebellum, but they may occur in the midline as well [6, 11]. There is a bimodal presentation, occurring most commonly in infants and then young adults, though they may also occur in children. The infantile variant tends to have extensive nodularity on histology and more frequently metastasizes [11, 12]. Nearly all nodular or desmoplastic variants fall into this category. SHH-activated medulloblastomas are stratified based on their TP53 status as either TP53-wildtype or TP53-mutant, with TP53-mutant portending a worse prognosis [6].
Non-WNT/Non-SHH Medulloblastoma, Groups 3 and 4
Non-WNT/non-SHH medulloblastomas are the most common molecular subsets, have an increased incidence in boys, present as midline vermian tumors, and often have classic or large cell anaplastic features on histology. Group 3 tumors tend to occur in infants and young children, have a higher incidence of metastases, and have the worst overall prognosis of any medulloblastoma tumor subset. Group 4 tumors are the most common subset, occur in older children and adolescents, and have an intermediate prognosis [6, 11]. In terms of distinguishing imaging features, group 3 tumors often have avid enhancement, while hypoenhancement is preferentially seen with group 4 tumors [13].
Pilocytic Astrocytoma
Pilocytic astrocytomas are the most common primary brain tumor in children, accounting for approximately one-third of all gliomas, and the second most common primary posterior fossa tumor in children after medulloblastomas. They are low-grade, WHO grade 1, tumors with an excellent prognosis in the setting of gross total surgical resection. Pilocytic astrocytomas result from MAPK pathway alterations, often with BRAF fusion or BRAF V600E point mutations. BRAF fusion is common in posterior fossa pilocytic astrocytomas and is associated with improved outcomes [14]. BRAF V600E point mutations, on the other hand, tend to be associated with poorer outcomes [15]. Increased frequency of pilocytic astrocytomas is seen in patients with neurofibromatosis type 1 (NF1), most commonly involving the optic pathways, though they may occur nearly anywhere with NF1 [16].
Posterior fossa pilocytic astrocytomas most often arise within the cerebellar hemispheres and are therefore lateral in location. Less commonly, they may be midline, arising from the cerebellar vermis. The classic imaging appearance is a large cystic mass with a peripheral solid nodule. More heterogeneous presentations, including a multicystic mass, predominantly solid mass with central cystic changes, or partially hemorrhagic mass, are less common [7, 17].
On MRI, the cystic component of the tumor is often similar to CSF signal intensity on T1 and T2 sequences, with the T2-FLAIR signal being more variable, based upon internal proteinaceous content. Solid portions of the mass avidly enhance, and there may also be enhancement along the margins of the cyst wall. A helpful distinguishing feature of a pilocytic astrocytoma, compared to other posterior fossa tumors, is the lack of diffusion restriction within the solid components of the tumor [18, 19] (Fig. 2).
Fig. 2—5-year-old boy with ataxia, nausea, vomiting. Surgical pathology revealed pilocytic astrocytoma. Left to right: Axial T2-weighted image shows off-midline cystic and solid posterior fossa mass (arrow) centered within left cerebellar hemisphere and subtle surrounding edema; coronal T1-weighted postcontrast image shows diffuse enhancement of peripheral solid nodular component of mass (arrow); axial DW shows no diffusion restriction.
Ependymoma
Ependymomas are the third most common primary posterior brain tumors, after medulloblastomas and pilocytic astrocytomas. The majority are classic, WHO grade 2, ependymomas, with more aggressive anaplastic ependymomas being WHO grade 3. Ependymomas are soft, pliable tumors that originate in or near the fourth ventricle and squeeze through the outlet foramina into adjacent spaces and cisterns. Because of their pliability, they often surround or encase neurovascular structures.
There are two subgroups of posterior fossa ependymomas: posterior fossa group A (PFA) and posterior fossa group B (PFB) [20]. PFA variants occur most often in infants, are lateral in location, and have a relatively poor prognosis. Because of the lateral location and common extension into the prepontine cistern, gross total resection is often difficult, and radiation therapy is typically avoided in infants because of the potential for morbidity. PFB variants occur in older children and adolescents, tend to arise from the floor of the fourth ventricle, and have a better overall prognosis than PFA variants [16, 21].
On MRI, ependymomas tend to be heterogeneously T2 hyperintense with variable enhancement. Cystic change and calcifications are common, with calcifications occurring in up to 50% of cases, much more common than is seen with medulloblastomas [7]. Given the relative pliability of the tumor, extension through fourth ventricular outlet foramina is characteristic. The presence of reduced or restricted diffusion is variable, but typically less than is seen with highly cellular medulloblastomas. The exception is with anaplastic ependymomas, which may have areas of restricted diffusion that are similar to medulloblastomas. Anaplastic ependymomas tend to have a higher frequency of disseminated metastatic disease and disease recurrence, with a poorer prognosis compared to lower-grade ependymomas [22]. The frequency of disseminated metastatic disease for ependymomas is less than that for medulloblastomas.
Diffuse Midline Glioma
Diffuse midline gliomas (DMGs) “H3K27-altered” are highly aggressive pediatric brain tumors (WHO grade 4) that encompass the majority of lesions previously referred to as diffuse intrinsic pontine gliomas (DIPGs). Prognosis is dismal with a median survival of approximately 11 months from diagnosis [23]. Given the brainstem location, the most common clinical presentations include cranial nerve palsies, pyramidal tract signs (paresis, hyperreflexia, or positive Babinski reflex), and cerebellar signs (dysmetria, ataxia, dysarthria, or nystagmus) [23]. DMGs tend to occur in younger children, with median age at presentation around 6 years [24].
On MR imaging, DMGs present as a diffuse, ill-defined, T2 hyperintense, expansile masses centered within the pons. The degree of enhancement is variable, often absent at initial presentation and typically patchy when present (Fig. 3).
Fig. 3—7-year-old girl with ataxia, nystagmus, torticollis. Patient presumptively treated for DMG. Left and center: Axial T2-weighted and FLAIR images demonstrate infiltrative, expansile brainstem mass (black arrows) centered within pons and extending into brachium pontis on left. Exophytic components engulf basilar artery (white arrows) anteriorly and partially efface fourth ventricle posteriorly. Right: Axial T1-weighted postcontrast image shows mild patchy enhancement along ventral aspect of mass (arrow) on left.
Peripheral enhancement commonly occurs along margins of central necrosis, which occurs more frequently after radiation therapy [25]. Intralesional hemorrhage is uncommon, but areas of hemosiderin deposition may be seen on susceptibility-weighted sequences. Focal areas of restricted diffusion develop in the majority of cases. The presence of central necrosis, diffusion restriction, or enhancement at the time of initial diagnosis has been shown to portend a worse prognosis [24].
Extrapontine spread is common throughout the brainstem, into the thalami and adjacent structures, through the cerebellar peduncles, and into the cerebellar hemispheres. Exophytic components engulf the basilar artery anteriorly and efface the fourth ventricle posteriorly. Disseminated metastatic disease is uncommon, though may be seen occasionally.
Historically, DMGs have been treated presumptively when characteristic imaging features are present, reserving biopsy for cases with nonclassic imaging features or when tissue sampling is required for a clinical trial eligibility. However, more centers are now performing biopsies prior to treatment to confirm molecular classification and histology, shed light on potential prognosis, and help advance investigation of future adjuvant therapies. When biopsy is performed, the posterolateral portion of signal abnormality is typically targeted to minimize potential morbidity. If focal areas of diffusion restriction are present, these areas tend to have the highest diagnostic yield, if they can be safely accessed and sampled [26].
Atypical Teratoid-Rhabdoid Tumor
Atypical teratoid-rhabdoid tumors (ATRTs) are rare and highly aggressive (WHO grade 4) embryonal tumors that tend to occur in infants and young children, with the majority of cases presenting under 3 years of age. As with medulloblastomas, posterior fossa ATRTs may be midline or off-midline and are highly cellular with areas of diffusion restriction. Imaging features significantly overlap with medulloblastoma; therefore, patient age is one of the key features in suggesting ATRT versus medulloblastoma. Compared to medulloblastomas, ATRTs tends to have a more heterogeneous imaging appearance, with a higher incidence of intralesional hemorrhage and calcification, as well as a higher incidence of disease dissemination at the time of presentation [27, 28].
For most cases of primary posterior fossa tumors in children, the correct diagnosis can be suggested based upon distinguishing imaging features, with remaining cases requiring a thoughtful differential diagnosis in the setting of overlapping or nonspecific imaging findings. Our Categorical Course session will focus on recognizing characteristic imaging features for the most common primary pediatric posterior fossa tumors.
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