Author: Logan Young

_{Published March 16, 2021}

In early 2020, as the coronavirus disease (COVID-19) epidemic spread, numerous articles appeared on imaging for the diagnosis of COVID-19. Descriptions were often discordant and confusing because of small sample sizes and selection biases. Those discrepancies have been largely resolved. As clinical experience and testing improved, imaging’s role has largely switched from diagnosis to aiding prognosis and clinical management.

Asymptomatic/mildly symptomatic patients: The Fleischner Society (Radiology: Cardiothoracic Imaging, Vol. 2, No. 3) and others see no role for chest x-ray (CXR) or CT for diagnosis, unless comorbidities exist or testing is otherwise limited.

Moderately/severely symptomatic patients: CXR is often negative early, only to turn positive subsequently. The most characteristic findings are basilar and peripheral ground-glass opacities (GGOs) (Fig. 1).

• 

Unfortunately, only a minority of patients have this typical COVID-19 pattern. In most patients, the disease is located more diffusely or elsewhere. Consolidation may be present initially with more severe illness or duration (Fig. 2).

• 

Early on, CT may be positive when the CXR is negative. The typical GGO distribution is similar, but usually more extensive than on CXR (Fig. 3).

• 

Adenopathy, cavitation, and effusion are uncommon early on. Compared to other viral pneumonias, peripheral lower-lobe GGOs are more common in COVID-19, whereas other pneumonias tend to have more diffuse disease. There is considerable overlap, however.

Reporting guidelines: Many templates have been proposed. Radiological Society of North America guidelines (Radiology: Cardiothoracic Imaging, Vol. 2, No. 2) define:

• CXR = negative, COVID-19-like; regular pneumonia, other disease
• CT = negative, typical of COVID-19; indeterminant, not COVID-19

Both show moderate interobserver reproducibility.

• 

Follow-up of established disease: On CXR and CT, GGOs and focal area of consolidation often progress and may evolve into a bilateral acute respiratory distress syndrome-like pattern when cytokine storm develops. Less common CT findings include dilated peripheral pulmonary vessels, adenopathy, rounded infiltrates, and signs of bronchial inflammation. Hospital-acquired bacterial pneumonia may complicate COVID-19 and vice versa. Preexisting lung disease (e.g., chronic obstructive pulmonary disease, interstitial lung disease, etc.) further complicate interpretation. Clearing usually starts after 2 weeks.

COVID-19 may cause hypercoagulability, leading to an increased incidence of both emboli and in situ thrombi and deep vein thrombosis.

Pleural effusions may appear late, and barotrauma causing pneumothorax appears to be more common than in other viral pneumonias.

Beyond the thorax: COVID-19 affects more than the lung. It is now clear that this is a systemic disorder affecting many organs.

As with lung involvement, patients with comorbidities (e.g., diabetes, cardiopulmonary disease, etc.) appear more likely to develop extrapulmonary diseases—summarized briefly below.

Cardiac disease: A significant minority of patients develop cardiac disease, evidenced by elevated troponins and other cardiac markers. Imaging may show evidence of heart failure, myocarditis, coronary vasculitis, mural thrombi, and pericardial effusions. Cardiac MRI has an important role, since it can identify myocardial inflammation. Myocarditis has been associated with poor outcomes, including cardiac dysfunction and mortality (either related to COVID-19 or other cause).

Neurological disease: Approximately 15–20% of hospitalized patients develop altered mental status or more focal symptoms. Imaging is positive in a minority, however. Ischemic infarcts are the most common imaging findings, probably related to coagulopathy. Reported infrequently are hemorrhagic stroke, cranial nerve inflammation, encephalopathy, and worsening of multiple sclerosis plaques.

Renal disease: Elevated renal function tests are not uncommon, and acute renal failure has been reported in some cytokine storm patients. Ultrasound may show increased renal echogenicity.

Gastrointestinal disease: Diarrhea and other gastrointestinal symptoms are not uncommon. Imaging may show ileus, dilatation, bowel loops (diffuse/focal), and CT may reveal contrast-enhanced bowel wall. Liver function tests are often abnormal, but failure is uncommon.

Long haulers: A significant minority of patients have residual vague or specific symptoms. Cough and dyspnea are frequent and often clear with supportive therapy within 30 days. Imaging is suggested for symptoms lasting beyond 30 days. Approximately a third of post-hospital patients will have residual signs of “fibrosis” and other residual ground-glass patches. Signs and symptoms in other organ systems may also linger. Clinical and imaging understanding are still evolving and may change as second- and third-wave infections hit, mutations occur, and vaccinations alter immunity. Stay tuned.

This piece first appeared in ARRS’ SRS Notes.

• 

_{Published in InPractice, Spring 2021: Volume 15, Issue 2}

Ancient Egyptians believed in an afterlife, that it was necessary to preserve the body after death. They perfected the process of mummifying the dead and buried them with their treasures in deep underground burial shafts, as in the Saqqara necropolis, or in expertly crafted mountain tombs, such as The Valley of Kings.

Paleoradiology: Imaging the Insides

In 1896, only a few months after the discovery of radiography, prior to its use on living humans, the first tests of the mysterious form of radiation were done on Egyptian mummies: one of a human and one of a cat. For the first time, x-ray film showed what was inside a mummy—without the need to dissect or even unwrap it. This event marked the birth of paleoradiology. The term refers to the use of non-invasive medical imaging modalities to study ancient human and animal remains or objects. Paleoradiology has evolved alongside medical imaging methods since its first uses. Today, a wide array of imaging modalities can be applied in archaeological work: conventional radiography, computed radiography, direct digital radiography, CT, micro-CT, endoscope, and MRI.

• 

Latest Findings in Saqqara

The Saqqara necropolis had been an ancient burial site since the Old Kingdom (ca. 2686–2181 B.C.) and was in use through much later periods for royalty, noblemen, priests, and even common people. Located about 30 kilometers south of present-day Cairo, Saqqara is a United Nations Educational, Scientific, and Cultural Organization (UNESCO) World Heritage Site, hosting several archaeological excavations. Our recent mission at Saqqara, near the pyramid of King Teti (2323–2291 B.C.), unearthed great discoveries, including the temple of Queen Naeret, wife of King Teti. We also discovered 52 burial shafts (1522–1069 B.C.), containing coffi ns and a large number of rare artifacts: statues, board games, jewelry, amulets, stellas, as well as a papyrus 3 meters long by 1 meter wide with inscriptions from The Book of the Dead.

• 

Field Paleoradiology: Imaging With Archaeological Context

Paleoradiology can give us important information regarding the condition of a mummy or other ancient artifacts. Imaging mummies in a proper facility provides the optimum technical conditions. However, during excavations, it is often impractical to transport mummies to an imaging facility; it may even be harmful to vulnerable mummies. Instead, we use dedicated mobile imaging equipment to reach the mummies inside their tombs, a nondestructive option by which we can accomplish the same goals.

Traditional radiography has been used in field paleoradiology, but it is a cumbersome process to develop x-ray film in situ. Therefore, we use computed radiography and direct digital radiography technologies that have the advantage of being filmless systems, allowing for instant review and further manipulation of displayed images.

Conquering Technical Challenges

Careful site inspection is crucial preparation for the use of these field paleoradiology techniques. First, we determined the topography of the site—type, position, and relationship of the burial objects—and the data we intended to collect. We then identified any safety concerns, like applying radiation protection measures to conduct responsible field paleoradiology. The burial shaft in Saqqara was narrow, located 10 meters underground, leading to a room jammed with more than 50 coffins stacked atop one other. To better navigate this architecture, we designed detachable, lightweight radiography accessories that we could bring down and mount inside the burial shaft. These included a tube holder, a framed mummy bed with a plexiglass top, as well as a cassette holder for lateral viewing.

We x-rayed the closed coffins, altering radiographic exposure settings and positioning according to the mummification style and the structures we aimed to visualize: bony skeletons, dense amulets, or soft tissues.

• 

Interpretation Issues

Unlike patients, mummified remains do not have clinical history, and their historical context is often questionable. In fact, we identified a female mummy via radiograph that had been placed inside a coffin bearing inscriptions of a male’s name. The interpretation of mummy radiography also requires awareness of the ways in which the desiccation of human tissue affects its morphology, as well as the changes that resulted from different mummification practices. Additionally, some mummified bodies could be covered by artifacts that might be misinterpreted as pathology.

Thus far, our field paleoradiology study has been successful, resulting in valuable details regarding the sex, age at death, and possible cause of death for the mummies in the Saqqara burial shaft. We were also able to identify jewelry, amulets, and embalming materials inside many of the mummies that reflected their socioeconomic status. Moreover, we gained new perspectives in to the health status and diseases of the studied mummies, which can provide a better understanding of the natural history of disease, itself.

• 

Field paleoradiology allowed us to determine the mummies’ levels of preservation—to avoid moving vulnerable mummies unnecessarily. This enabled us to carry out a type of triage; mummies whose images suggested were in good condition and needed further investigations could be moved to a nearby medical facility for a CT scan, while those in more delicate condition were left in situ.

An invaluable tool to unlock the mysteries of mummification, paleoradiology puts us face-to-face with the men and women of ancient Egypt. Even thousands of years after their deaths, we’re still gaining remarkable insights into their lives simply from imaging their remains. Our work at the excavation site at Saqqara has not ended, of course, as what we have unearthed to date is merely a fraction of what we expect to exist.

This is my fourth and final column in an intense and unforgettable year. I have heard many opine that, somehow, we are going to be stronger and smarter and more evolved as a result of the many trials and tribulations we have faced. I don’t know so, but I do certainly hope so—hoping that something positive comes out of fear, pain, suffering, and uncertainty. In a certain way, I suppose we as physicians must possess such an optimistic mindset to survive and keep moving forward, despite the human misery and pain which we as radiologists literally see on a daily basis. As I think about the year, I can’t help but generate a list of questions for every challenging and engrossing topic, questions that I believe are intuitive, and questions that command my attention and test my optimism.

In this year, there has been no dearth of challenges, large and small, that affect and threaten to derail our daily lives and, therefore, the practice of our specialty. Our year opened with COVID-19, affecting our lives like an unpredictable and interrupted set of explosions. It affected the financial security of our department, our salaries, our personal sense of security (affecting ourselves and our families), and our ability to serve our patients, who were either sheltering at home or suffering from a disease which we incompletely understood. Just when we thought we had turned a corner, a larger wave comes crashing on top of us. We followed a handful of models telling us what to expect for a wave, insofar as magnitude and timing were concerned, realizing these predictions may as well have been science fiction. We congratulated ourselves for having several vaccinations, then realized that we could not effectively manage distributing and administering these vaccinations at anything faster than a trickle. As I write this column, we have administered 20 million vaccinations. By some estimates, we have to give 229 million doses to reach 70% of our population of 328 million for effective immunity, if conventional models hold. That means we are 8% of the way there, in the one year and five days since the first U.S. case was reported, on January 19, 2020. Are we committed to social distancing, as I drive up the Pacific coast and see numerous outdoor restaurants open, including some with maskless servers? Have we understood how we will ensure sufficient supply chain management to optimize vaccination production, delivery, and inoculation? Do we know what the longterm effects will be on our businesses and our children’s education, and have we established plans to address the fallout?

Before we could even gain our bearings in dealing with this new pandemic reality, we had to deal with the reality of race riots burning our streets, evidencing centuries of outrage and anger, threatening to tear us apart. As an occasional visitor who picks up fragmented and incomplete impressions of communities I have visited over the years, I never thought I would see Minneapolis in flames, or Seattle. I never imagined Portland as a city under siege. Did we divert to a better place after the Watts riots, or have we learned nothing? Did we resolve any of the contributory factors? Do we have a plan? Did we agree on a course of action that would address divergences and prevent future race riots?

Perhaps all of our problems are really only psychosocial, since we are clearly masters of the natural world, so we may have thought as we debated the validity or existence of global warming. Then, we blinked, and life and earth reminded us of our hubris and fallibility: massive, unprecedented forest fires choked our newly darkened ochre skies in California, we wiped ash off of our windshields in the mornings before going to work, burning flames took away every material possession our friends and families cherished. Homes and property disappeared with a snap of Thanos’ finger. What are we going to do during next year’s fire season? Have we done anything to better address those seemingly inevitable forest fires? Did we solve this problem? Are we ready to take on the next series of forest fires with greater effectiveness, confidence, and less loss of property and life?

And then, after a pandemic, race riots, and forest fires, the fourth horseman of the apocalypse turned out to be an angry mob, numbering in the tens of thousands, breaking into our seat of government while it was in session, intending to kill or physically harm our vice president, our senators, and our representatives. Despite the historic siege of the U.S. Capitol and all that it implied, the sun rose the following morning. In one fortnight, a peaceful transfer of power took place, and both the relevance and power of our systems and processes were reinforced. Are we now committed as a society to respectful disagreement? Will we need 20,000- plus troops in Washington, D.C., for inaugurations and legislative sessions to maintain law and order? Is the pendulum going to slow down and stop swinging way to the left, then way to the right?

So, I can’t help but ask these questions. I would presume you, too, have at least one question: what relevance does any of this have to the ARRS and this column? I would respond as follows: we do not have control over many external factors in our daily life, and we may not be able to easily address external questions; however, we do have the power to mobilize our societal membership to create a better future for our patients and society through the improved delivery of health care—the scope and scale at which we operate, that is—and we have to aspire to work as a committed group of colleagues to positively influence our professional future, which is in our control. Oddly enough, we also have the opportunity to address some of those external big questions through our society, particularly the aspects that overlap with our professional lives.

No matter what, we show up every day, and we do our best to help our fellow citizens. We are part of a group of compassionate, professional, and knowledgeable citizens. And even if the skies are on fire, if there is a literal plague among us, if there is revolution in the streets, if the future of our government is in question, we do our job to the best of our ability. Because we are hopeful, because we are committed, and because we have faith in our processes and our systems.

Our professional society reflects the same collective ethic. Our central belief hinges on having faith in the power of our collective. We hope to educate each other, support each other, and facilitate our collective progress, so that we may become the very best that we can be at what we do. It doesn’t matter if we have to convert the in-person ARRS Annual Meeting to an all-virtual convening, if we must distribute our educational materials in a more effective way, if we need to focus our practice communications on the realities of pandemic management, if we need to share fast-breaking scientific communications regarding COVID-19 to help you work better and smarter, or if we utilize our platforms and publications as a bridge to timely and essential topics, such as diversity in health care. This professional society tirelessly does what it has to do to inspire and empower you.

As I hand off this column to my dear successors, please allow me to ask three things of you, dear reader. I ask you to care, I ask you to engage, and I ask you to volunteer.

I ask you to care because that will fuel your efforts. Caring creates motivational reserves that are virtually limitless. Caring provides purpose, and purpose allows us to muscle through uncertainty in the quest to find solutions. Everything that happens should matter to you, be it race riots or forest fires. Whether or not they are in your backyard, you should care, and you should want to care. Once you care, you will think of solutions, you will share these solutions, and, ultimately, we will collectively iterate and address our problems. It starts with caring. Great things are only possible when we care about the world around us and the events that affect our lives.

I ask you to engage because not one of us is an island, and no individual one of us has the answers. Answers are generated by groups and teams. This means choosing to effectively establish dialogue, which is bidirectional information fl ow necessitating transmitting and receiving. If I’m only listening, then I’m not contributing to the conversation. If I’m only speaking, then I’m not listening suffi ciently to contribute to the conversation in a meaningful way. I have to train myself to listen, and I have to train how to express myself. When we connect with each other—and we translate our caring into effective communication—if we are prepared to both listen and speak, then we leverage the cooperative wisdom of the crowd into a powerful understanding. No matter how fascinating and experienced a single life may be, it cannot compare with the shared experiences and gained lessons and perspectives of a dozen lives. Great things are only possible when we communicate with each other.

I ask you to volunteer, so we can all be part of something bigger, so we can align our efforts and energies, so we can not only imagine positive change, but we can realize it. Part of the beauty of professional societies is the remarkable power evidenced in likeminded individuals standing side-by-side with their shoulders to the wheel, pushing hard, and doing the best they can to create a better future. Sometimes, this testbed demonstrates remarkable returns. As one small example, I can see a brief line of succession where our societal executive leadership is concerned, and I am inspired by the depth of character, thoughtfulness, and energy I see for the next several cycles and years. We have great leaders moving into their ranks, who will serve our society exquisitely well. Great things are only possible when we work together.

Please care, engage, and volunteer. You secure our brightest future, and you validate all that we do. And for that, I owe you all an unrepayable debt of gratitude.

_{Published March 16, 2020}

First used as a hashtag and codified more than a decade ago, altmetrics present a more comprehensive alternative to the traditional citation impact criteria of scientific publishing. Mainstream media, online-first publications, social and academic networks, public policy documents, post-publication forums, Wikipedia even—these complementary bibliometrics help to paint a truer picture of engagement with scholarly work, especially work that finds second, often third lives beyond the towers of academia.

Altmetric.com is a data science company uniquely leveraged to capture this full array of online sources and collate all the disparate activity accordingly. In fact, just to the right of the abstract for every AJR article published on AJRonline.org, you will now see a multicolored “donut” badge visualizing a real-time summary of the attention that article is receiving (red for news outlets, orange for blogs, blues for social media, etc.) For numerical context, you will notice the data output gets assigned an Altmetric Attention Score, a high-level assessment of both the quality and the quantity of attention said AJR article is receiving, weighted according to the relative reach of each attention source, itself.

Perhaps most importantly, if you click anywhere on the embedded donut, then you will be directed to a dedicated AJR Altmetric details page. Here, you, too, can follow the myriad conversations this specific AJR article is engendering—geographic and demographically—in one convenient, shareable URL.

Want to be notified whenever someone shares or discusses the details for a certain AJR article? You can sign up for e-mail alerts under the Summary Tab of any AJR Altmetric details page. While you are free to sign up for notifications regarding multiple AJR Altmetric research outputs, you will only receive a single email alert, sent via once-a-day digest.

_{Published on January 22, 2021}

Although we have known for many decades that radiologists do make errors and the number of these can be significant, continuing educational solutions rarely recognize the practicalities facing modern-day clinicians. These practicalities include: proven effectiveness, methods of delivery that align to busy clinical workloads, modules that are compatible with any technological display, and tailoring education to reflect the unique errors each radiologist makes. Also, under the current climate of pandemic and travel restrictions, the tremendous difficulties of physically attending conferences and other educational venues must be recognized.

The current article focuses on education using clinical test sets, which contain data sets on normal and abnormal cases with known truth that the clinician must diagnose. We aim to summarize what busy radiologists in 2020 require from continuing educational solutions, illustrating how effective, relevant, available, and tailored education can be delivered to all using the DetectED-X platform (Sydney, Australia). 

So, What Is Needed?

High Quality Data Sets Combined With Performance Algorithms

Radiologists need effective and clinically relevant education that is available at all times. One solution that has been shown to work focuses on the provision of high-quality radiologic test sets that are specifically selected and designed to improve diagnostic efficacy. Via their local workstations, clinicians can view and judge sets of usually up to 60 DICOM cases at full native resolution, with higher than normal prevalence, and search for clinically relevant lesions validated by pathology findings using the DetectED-X platform. This way, it is possible to encounter in 1 hour the number of specific abnormalities only presented over periods of years. Radiologists should be able to judge these cases the same way they do clinically, so expert behaviours are relatively unaffected, and once all cases are judged and suspicious areas of interest are marked, clinicians should receive instant results on their performance using well-known and benchmarked metrics, such as sensitivity, specificity, lesion sensitivity, ROC, and jackknife alternative free-response ROC (JAFROC) (Fig. 1). Algorithms should then support these judgments by enabling the presentation of all errors made by each radiologist and identifying specific areas for immediate improvement (Fig. 2).   

• 

• 

Accessible and Recognised Education

To improve accessibility, it is essential that continuing medical education using test sets is available 24/7, regardless of clinicians’ location, must be completed in timeframes that align to busy clinical workloads, and should provide immediately much needed continuing medical education (CME) credits or continuing professional development (CPD) points. Also, to maximize ease of use, educational solutions should be compatible with all types of mobile devices, should involve test sets with smaller number of cases that can be completed in as little as 20 minutes, and must ensure that every activity is rewarded with CME or CPD—regardless of whether the clinician is located in the United States, Europe, or Asia.

Tailored Solutions

Tailoring to each clinician’s needs is required. No longer should clinicians receive test sets or other material that is common for everyone: Dr. Brady will make different mistakes from Dr. Cusack, so why should the two receive the same education? Artificial intelligence (AI) technology is now sufficiently mature to offer a robust educational solution. Elsewhere, in the entertainment industry for example, AI is now being utilized for the personalization of viewing platforms based on previously collected data to improve user experiences. Such advances can now be applied to online medical education, facilitating customized educational materials that accurately recognize each clinician’s strengths and weaknesses. By combining algorithms previously developed for the general-purpose recommender system, such as movie recommendation tools, with radiology-specific knowledge driven from research on factors defining case difficulty for specific clinicians, AI models can predict and access cases most suitable for each user.  

One Potential Solution

Test set technologies have been available over the last 3 decades, particularly in the United Kingdom, Australia, and New Zealand, and these have shown demonstrable mean improvements in diagnostic performance of 34%. However, these test sets can take up to 2 hours to complete and are usually only available via high-quality clinical workstations with images loaded locally. A new approach to address accessibility has been launched by DetectED-X, a University of Sydney startup, where high-quality cases are now available through modules (the smallest of which take only 20 minutes to complete), are available on any mobile device, and are immediately certified with CME credits or CPD points available for every activity. To ensure that this education is available at fast speeds, regardless of wherever in the world the radiologist is located, DetectED-X is working with GE Healthcare, Volpara Solutions, and Amazon Web Services to ensure robust and widespread distribution. Highly accurate tailoring based on tens of thousands of interactions with radiologic images is part of the DetectED-X approach, so that each clinician, regardless of training or experience, has an optimized educational experience. Its evidence-based AI algorithms for recognizing clinical error-making patterns have been tested using more than 600 clinicians reading mammograms or lung CT images, with an accuracy of 80% and 83% for predicting the positive and negative cases that each clinician has difficulty with, respectively. Once case difficulty for a clinician has been set, this is coupled to the clinician’s learning objective (e.g., whether they want to see a test data set, oversampled with calcifications or denser breasts), then a personalized test data set is presented to the clinician. Radiologists need a new approach so that effective, relevant, and tailored education is available everywhere and at all times. The COVID-19 pandemic has brought this need to the forefront.

_{Published on January 22, 2021}

I cannot get the image of the raging forest fires out of my head, even though I saw the carnage from the safety of my sofa on my iPad. Even so. And a close friend of mine lost his house and everything within it, leaving with only the clothes on his back and what little he and his family could carry. And he is grateful that his family lost no lives that day. Literally today, 12,600 firefighters are fighting 14 major wildfires in California, which have already claimed more than 4 million acres. Twelve-thousand firefighters in California alone. That is about half the number of radiologists in the entire U.S. And 4 million acres? Rhode Island has a surface area of less than 1 million acres, Delaware slightly under 1.6 million acres. Even Connecticut is slightly below 3.6 million acres. Our country is on fire, and we go about our daily lives…

What do forest fires have to do with radiology? I submit that health care may be more akin to an uncontrolled forest fire, rather than the controlled and carefully harnessed fire in a foundry that allows us to forge steel and alloy.

Natural questions include pondering the nature and distinction of solvable and unsolvable problems, as well as attribution. When do you stand by and watch a forest fire consume your house, and when do you fight it without endangering your life and health? Couldn’t anything have been done to prevent this? Can’t anything be done to fix this? If solvable, is the solution really cleaning forest floors, ridding them of combustible biomass before flames have a chance to perform the same function? Is this really attributable to global warming, and is it too late to do anything? Are forest fires even a necessary evil that allows renewal and rebirth, despite the massive sorrow accompanying the human experience?

Although a raging forest fire is terrifying, especially when you are fighting the fire and sense it closing in on you from all sides, a single candle’s dancing flame is hypnotizing, and its generation of light and energy is magical. A collection of votive candles can be moving and sacred. A campfire can be comforting and protective. I recall many campfires I sat around as a boy scout, where we shared stories, enjoyed each other’s company, and felt both close to nature while safe and comfortable. Even though there was a dark silence surrounding us, inside that cylinder of light and warmth projected by the campfire was the illusion of safety. If you will forgive the analogy, although our health care ecosystem from a 30,000-foot perspective may be a forest fire, the single flame of an individual patient interaction or single health care encounter is sacred and at times life-affirming for those of us who are moved by the nature of trust patients place in our hands.

For those who have not visited San Diego, we are arid and considered a coastal desert, and our terrain is varied, including steppes, buttes, mesas, and multiple valleys. As you would surmise, we are situated in close proximity to a number of mountain ranges. As you ascend on drives in these mountains, at higher elevations, you encounter beautiful forests. Whether driving to Mount Palomar, which houses a spectacular astronomical observatory on top of a peak, or the Anza-Borrego Desert 90 minutes northeast, the majesty of nature is undeniable. As you drive through our pine forests, spectacular vistas come into view, and off to the sides of the roads, you can’t help but notice groves with massive trees showing charred trunks. Where these charred trunks are found, the undergrowth is different. There is little brush, there is filtered and streaming light, and oddly enough, one finds fields of wildflowers in these clearings. Many decades ago, I recall reading Norman Maclean’s Young Men and Fire, regarding the 1949 Mann Gulch Fire. This book is a management mainstaple regarding tactics, leadership, communication, and learning systems. Several of the preventable fatalities were attributed to firefighters refusing to chuck their equipment and heavy packs in order to lighten and therefore save themselves. So many unnecessary casualties—a costly lesson for future literal and figurative firefighters. Do we learn from each other? Are we willing to jettison our heavy and cumbersome conventions to save ourselves?

Perhaps health care is somewhat analogous to a forest fire raging out of control. Some of us feel a sense of anxiety about the unpredictable winds of the future and how they will affect us. There are many changes perched on our doorsteps, preparing to hit us hard. Whether planned evaluation and management code adjustments threatening us with over 10% of our income this coming year, Rad Partners and MEDNAX merging 10% of all U.S. radiologists into one consolidated supergroup redefining the structural nature of practice, or large-scale venture capitalist and hedge fund purchasing of radiologist practices affecting our autonomy, we lack control and fear for our safety. Similar to a clearing forest fire, perhaps we’re in for rupture of our status quo as an essential step in reordering the foundation and practice of radiology.

Certainly, the COVID pandemic has significantly changed our academic practices, and who knows which of the changes we are seeing will be durable and which will be enthusiastically thrown out at the earliest possible opportunity. Have the COVID pandemic, civil unrest, and financial crisis all served as combustible agents where health care and, more specifically, imaging are concerned? The COVID pandemic has directly affected our financial practices and our procedural practices, underscoring inequities in care that have resulted in extraordinary mortality rates where the disenfranchised are concerned. Civil unrest has reminded us of these same persistent inequities in care. The financial crisis; more of the same. It is natural following a crisis, perhaps even more so following multiple simultaneous crises, to discuss and understand what we have learned. We are midstream and in no way past our crises, nevertheless, it helps to elevate our vision and see where we are heading as an essential exercise and to grant us temporary respite from today’s challenges. If nothing more, at least it allows us to lift our optimistic spirits, instead of suffocating under the weight of what is undeniably present in today. Perhaps in looking to tomorrow and moving toward action we should focus collectively on how we can provide the best possible care to the largest number of patients. I submit that the central reason for the forest fire which is health care could well be inequity in care delivery, misbalanced and at times exaggerated profitability, and a lack of effective population health. Does the public know about radiology, care about it, and fight to protect and elevate it? This repair work necessitates my personal engagement as a single radiologist. This demands my involvement in driving down costs, attempting to ensure the propriety and efficiency of imaging in each case, and eradicating inequities as much as possible. No one else is picking up the ball and confidently addressing the issues. Regrettably, these actions are neither natural, nor have they really been expected of me to date. My job to date, as an individual radiologist, has been to manage worklists, ensuring that individual dictations are correct. That said, if I focus on my work RVUs and bonus, and do not ensure the essential and full appreciated value of my contributions as a radiologist, will I be effectively valued?

I’m sorry to end with a cliffhanger; a question to which I do not have a ready answer. What can I do, apart from drilling down on my worklist as an individual radiologist, to serve the largest number of patients most effectively, or has my campfire already contributed to the creation of a massive and clearing forest fire? I fear the response to this question will determine whether we become giant redwoods, or whether we will feed fields of flowers.

_{Published January 4, 2021}

The coronavirus disease (COVID-19) pandemic is now the most significant pandemic in over a century. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus that causes COVID-19, affects multiple body systems by binding to the angiotensin-converting enzyme 2 (ACE2) receptors on cells. Although pulmonary manifestations of COVID-19 have garnered much attention, its neurological impact can be as devastating. Neurological manifestations include ischemic stroke, intracranial hemorrhage, encephalopathy, and peripheral neuropathy. Neurological symptoms are common and include headache, dizziness, myalgia, seizures, weakness, strokes, and alterations of consciousness. Although rarely isolated, disorders of smell and taste have also been seen in COVID-19. For some patients, cognitive symptoms have been found to last for months following infection. Radiologists must be attuned the neurological manifestations of COVID-19, as early identification of these findings may help to guide management and reduce disease transmission.

Ischemic Stroke

The incidence of ischemic stroke associated with COVID-19 in hospitalized patients is between 0.4% and 2.7% but may vary with infection severity. The association between ischemic stroke and COVID-19 has been proposed since the outset of the outbreak, fueled by the rationale that infectious processes like COVID-19 are prothrombotic through an endotheliitis-mediated mechanism [Fig. 1].

• 

Initial concern was raised following an increased incidence in large vessel occlusion (LVO) strokes. In April 2020, an early case series published in the New England Journal of Medicine highlighted five cases with LVO stroke in New York City and suggested that LVOs may be a presenting feature of COVID-19 in young adults. A case-control study from New York City published in AJR showed that LVOs were present in 32% of code stroke patients with COVID-19, compared to 15% without COVID-19. Recently, a systematic review by Canadian researchers confirmed that 1.5% of patients admitted to hospitals with COVID-19 suffered an ischemic stroke with a resultant mortality of 35% for all stroke types. More concerning, in patients younger than 50, half had no other symptoms of infection at the time of ischemic stroke onset, and 69% presented with LVO.

By contrast, 17 stroke centers in Europe and North America reported a 32% reduction in endovascular thrombectomy (EVT) procedures during the pandemic. The number of patients undergoing neuroimaging for stroke in the United States also decreased by 39%. Proposed reasons for this discrepancy include reluctance of patients to seek care due to fear of contracting COVID-19 and an overwhelmed health care system. With this divergent data, strong epidemiological studies are needed to determine the underlying reasons for these statistics.

Intracranial Hemorrhage

A growing number of studies have investigated the relationship between COVID-19 and intracranial hemorrhage (ICH). The incidence of ICH in COVID-19 ranges from 0.2% to 0.9%. ICH has a much higher likelihood of occurring in hospitalized patients with COVID-19 who receive anticoagulation or extracorporeal membrane oxygenation.

Intracerebral and subarachnoid hemorrhage, as well as hemorrhage from cerebral venous thrombosis, have been reported in COVID-19. The majority of intracerebral hemorrhages are lobar with deep structure and infratentorial hemorrhages being less common. Microhemorrhages in the juxtacortical white matter and corpus callosum (particularly the splenium), multilobar microhemorrhages, and single large lobar hemorrhages have been observed.

At this time, it is unclear if ICH seen with COVID-19 is causative or coincidental. Two prominent hypotheses suggesting causation point to the pathophysiology of sepsis and the activation of the renin-angiotensin system leading to endovascular disruption. A retrospective case series, which suggested these findings are coincidental, showed that most patients with ICH and COVID-19 could be attributed to prior trauma and known suspected hemorrhage before contracting the virus. This highlights the challenge in accurately attributing ICH events to COVID-19 [Fig. 2].

• 

Encephalopathy

Encephalopathies have gained increasing attention as unusual manifestations of COVID-19 and harbingers of more severe disease. Similar coronavirus disease, such as severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome (MERS), have shown a similar propensity to cause acute encephalopathy. The prevalence of this condition ranges from 0.04% to 0.2% for COVID-19 patients. Acute encephalopathy was associated with more severe infection and worse clinical outcomes in hospitalized patients, which makes identification important.

The etiology of acute encephalopathy associated with COVID-19 is not entirely clear. Cases have been reported in the literature. Meningoencephalitis was shown in a young adult patient without significant respiratory disease. Leukoencephalopathy and acute hemorrhagic necrotizing encephalopathy were noted in case reports. Encephalitis was also seen in an adolescent patient with severe infection. 

The primary imaging finding of encephalopathy was nonspecific cortical T2/FLAIR hyperintensities with associated restricted diffusion. Bilateral FLAIR hyperintense thalamic lesions have been characteristically described in acute necrotizing encephalopathy. Imaging features of posterior reversible encephalopathy syndrome and hypoxic-ischemic encephalopathy, as well as exacerbation of demyelinating disease, were also seen. Kihira et al. described multiple cases of white matter disease related to hypoxic leukoencephalopathy, acute disseminated encephalomyelitis, and direct viral encephalitis attributed to COVID-19. A serious condition linked with COVID-19 known as multisystem inflammatory syndrome in children (MIS-C) can cause neurocognitive symptoms, and in four cases, MRI revealed signal abnormalities in the splenium. Consequently, radiologists must have a high index of suspicion for a variety of encephalopathies in patients with COVID-19.

Peripheral Neuropathy

Various studies have identified peripheral neuropathy related to COVID-19. Indeed, since ACE2 receptors are found in the olfactory epithelium, the neuroinvasive potential of SARS-CoV-2 has been a topic of investigation.

Anosmia may be the most common neurological symptom. Inflammatory obstruction of the olfactory clefts is known to impair olfaction. CT and MR images in patients with COVID-19 have shown obstruction of the olfactory clefts, which has been thought to lead to anosmia. Imaging of infected patients has also shown olfactory bulb atrophy and MRI signal changes that can resolve on follow-up imaging. 

Although rare, Guillain-Barré syndrome (GBS) has also been reported in COVID-19. Comprising a heterogeneous group of immune-mediated polyneuropathies, GBS classically presents as rapid symmetrical ascending muscle paresis or paralysis. To date, at least 73 cases of GBS have been reported in patients with COVID-19. GBS associated with COVID-19 has been shown to exhibit asymmetrical thickening and hyperintensity of the post ganglionic roots supplying the brachial and lumbar plexuses on STIR images. Facial nerve, nerve root, and leptomeningeal enhancement have been reported. Of note, MRIs of the brain and spine in these patients are most often normal. Other neuromuscular conditions, such as generalized myoclonus and rhabdomyolysis, have also been rarely reported.

We have highlighted a number of important neurological manifestations of COVID-19. Our understanding of this novel coronavirus and its neurological manifestations continues to improve, and the epidemiology between these conditions and COVID-19 are frequently being refined. We remain hopeful that the management and prevention of COVID-19 will continue to advance with the development of new therapeutics and vaccines in the coming months and beyond. As radiologists, we should be cognizant of the fact that imaging has crucial role to play in diagnosing many of these neurological manifestations. Moreover, long-term sequelae of these conditions will often necessitate further follow-up imaging, ensuring our continued involvement in patient care for the foreseeable future.

_{Published November 23, 2020}

Dual-energy CT (DECT) is a state-of-the-art technology that simultaneously processes data from multiple photon energies in a single CT acquisition. The principle of dual energy dates back to the 1970s, whereas the first clinical DECT scanner was available in 2006. However, the utilization of DECT in routine clinical practice has grown over the past decade owing to increased scanner availability from vendors and multiple new applications of DECT techniques. Furthermore, the postprocessing DECT data using commercially available software have resulted in the generation of virtual monoenergetic or monochromatic images ranging from 40 to 200 keV. These images can also be used to produce spectral attenuation curves, scatterplots, histograms, and effective atomic number (Z_eff). Various technical approaches of DECT imaging are currently available through different vendors, such as single source rapid-kVpswitching DECT (GE Healthcare, WI), single source helical DECT (Siemens Healthineers, Germany), single source twin-beam DECT (Siemens Healthineers), dual source DECT (Siemens Healthcare, Germany), single source sequential DECT (Toshiba, Japan), and dual layer DECT (Philips Healthcare, Netherlands).

In a typical CT, two different materials (e.g., calcium and iodine) may demonstrate similar CT attenuation values when subjected to a single radiation beam; however, these materials behave differently when exposed to different energy levels, as in dual energy CT. Atomic number (i.e., Z) is an important parameter determining the CT attenuation values. For example, higher Z materials are more susceptible to the photoelectric effect than lower ones. The commonly used contrast agent iodine is discernible at low kiloelectron volt values, and these properties can be useful in distinguishing iodine from other body materials, such as calcium and water. Soft tissues, such as muscles and organs, have weak photoelectric effects and less variation in their attenuation values at different energies.

DECT postprocessing techniques produce different types of reconstructed images with multiple clinical functions. These images include mixed material-specific images, such as water, iodine, or fat images, virtual monochromatic and virtual monoenergetic images (VMIs) generated for a single energy level. Spectral attenuation curves display particular ROI energy values on the x-axis (range, 40–140 keV) and mean attenuation values on the y-axis. Scatterplots are generated by comparing the ROI attenuation values with water concentrations. Histogram displays the frequency of values for a single ROI variable. The materials can be differentiated from one another on the basis of their calculated Z_eff values (i.e., virtual atomic numbers). The calculated Z_eff takes into account the unique nature of the materials over the range of energies in DECT (40–140 keV).

Researchers have explored the utilization of DECT in identification and characterization of various tumors in the body. VMIs are more advantageous in identification and characterization of liver lesions than conventional CT. Material-specific images, such as iodine images, aid in assessing hypervascular metastases from uterine sarcomas. In addition, these images may be able to detect remote small subdiaphragmatic perihepatic implants. The retroperitoneal lymph nodes are better visualized on iodine-enhanced images than conventional CT images. Studies have shown lower iodine uptake on DECT in metastatic than in normal and inflammatory lymph nodes, guiding the diagnosis of lymph node metastases. Osseous metastases with soft-tissue components are also better visualized on iodine-enhanced images. VMI has also been beneficial in identifying incidental pulmonary embolism (PE) in oncologic patients. 40-keV VMI images have been shown to improve objective image quality of the pulmonary vessels, along with increased diagnostic confidence in the diagnosis of incidental PE. Virtual unenhanced DECT images offer valuable tools for improving the diagnosis of pediatric abdominal neoplasms—helping to identify or validate the presence of tumoral calcifications and hemorrhage, appropriate lesion delineation, and differentiate an abdominal mass from adjacent contrast- filled bowel or abdominal organs. DECT has also been documented to identify vascular and perfusion abnormalities due to hypoxemia related to coronavirus disease 2019 (COVID-19).

There are few clinical studies in the current literature assessing the diagnostic ability of DECT in gynecological malignancies. These studies support using low energy for assessing endometrial cancer invasion, characterization of ovarian masses with internal septation and mural nodularity, and identification of calcified peritoneal implants and remote serosal perihepatic implants. Iodine maps are useful for assessing response after chemoradiation in cervical cancer patients, peritoneal implants, and nodal and osseous metastases, as well as distinguishing benign and malignant ovarian tumors. Water maps obtained from DECT are useful in distinguishing high- and low-grade ovarian tumors. Currently, there are numerous and amazing new applications of DECT being investigated in clinical studies. Spectral photon-counting CT with enhanced image quality is being translated successfully into clinical studies. There have been recent developments in new nanoparticle contrast agents with specific disease biomarkers for dual-energy and multi-spectral CT. All of that being said, there is a need for more prospective trials to explore the true potential of this innovative and promising technology, so as to make DECT a true multiparametric imaging modality in the future.

Variability in the interpretations of clinical imaging studies is a problem that has been recognized for decades and has been extensively documented in the radiology literature. It’s a problem that pervades all imaging modalities. Patients should get the same result if they go to the radiology department any day of the week. Sadly, that is too often not the case. The reasons for this day-to-day variability are complex and reflect the use of different scanners, software, technologists, local operating procedures, and different radiologists. However, to be in synch with the continuing emergence and maturity of precision medicine, and to meet the expectations of referring physicians and our patients, the field of radiology must more strongly strive to improve the reproducibility of clinical imaging results for each individual patient.

One of the generally accepted benefits of precision medicine is to monitor a patient’s response to therapy and adjust, tailor, or change the patient’s health care plan according to the degree of or lack of response. Unfortunately, the traditional subjective, qualitative interpretation of clinical imaging examinations, based on visual inspection of the images, results in marked interreader and intrareader variability. This frequently makes it difficult to be confident across serial scans when determining whether a given patient’s condition has improved, worsened, or stayed the same.

One strategy to reduce variability is to extract objective, reproducible, quantitative results from clinical imaging scans. Since all clinical imaging studies today are digital, this is feasible. One clinical setting where referring physicians particularly want objective measurements delineating change in the burden of disease is oncology. Oncologists want objective measurements of both tumor size (whether from CT or MRI) and metabolic activity (from FDG-PET scans).

Reproducible, quantitative standardized uptake value (SUV) results from FDG-PET scans are increasingly viewed as important in clinical oncology—both in routine clinical practice, as well as in clinical trials. In 2010, we surveyed several hundred oncologists at National Cancer Institute-funded cancer centers about tumor measurements. Ninety-four percent expected tumor size measurements to be provided routinely, and more than half also expected SUV to be provided from FDG-PET scans.

Recommendations to use FDG-PET scans as part of the staging workup for solid tumors have been included in several chapters of the eighth edition of the American Joint Committee on Cancer’s Cancer Staging Manual. These panels of expert oncologists recognize that SUV from FDG-PET scans likely conveys important diagnostic and/or prognostic information, but lack of standardization makes it impossible at present to determine appropriate thresholds or cut-points to guide clinical decision-making. They therefore recommend that all FDG-PET scan reports in breast cancer patients should contain SUV values for the primary tumor and SUV for the primary tumor, as well as hilar and mediastinal nodes in patients with lung cancer [6]. They further recommend that these SUV values be extracted from the medical record by cancer registrars, so that large databases can be developed to determine relevant thresholds. It is sobering to consider that another medical specialty is promulgating recommendations to collate imaging data to inform their clinical decision-making. One could argue that the radiology profession should be initiating such data collection and analysis.  

In 2018, the American College of Radiology (ACR) Quality Measures Technical Expert Panel, recognizing the increasing clinical importance of objective SUV measurement, approved a quality performance measure entitled “Use of Quantitative Criteria for Oncologic FDG PET Imaging”, which says, in part: “Final reports for FDG PET scans should include at a minimum…at least one lesional SUV measurement OR diagnosis of ‘no disease-specific abnormal uptake.’” In other words, providing an accurate SUV result for every patient with cancer is now an expected performance measure by the ACR. Obtaining accurate and reproducible SUV measures requires attention to a range of specifications that target hardware, software, personnel, and procedures. In 2007, the Radiological Society of North America (RSNA) formed the Quantitative Imaging Biomarkers Alliance (QIBA). QIBA now has more than 20 committees developing standards, called Profiles, for a variety of quantitative imaging biomarkers. One QIBA Profile deals with SUV from FDG-PET scans. Rigorous attention must be paid to all potential sources of variance to obtain reproducible, clinically meaningful SUV results.

• 

Adherence to these specifications is entirely possible in nuclear medicine departments that prioritize the quality of their results. Conformance to these specifications would lead to a significant improvement in the reproducibility of SUV measurements, thus greatly improving their clinical usefulness. This will translate into a major benefit to patients in this era of precision medicine.

The comments in this article are focused on the need for accurate and reproducible quantitative results in oncologic FDG-PET scans; however, the medical literature clearly supports the need for similar reproducible quantitative imaging in several other clinical areas Wallis RS, Maeurer M, Mwaba P, et al. Tuberculosis—advances in development of new drugs, treatment regimens, host-directed therapies, and biomarkers. Lancet Infect Dis 2016; 16:e34–46
Loomba R. Role of imaging-based biomarkers in NAFLD: recent advances in clinical application and future research directions. J Hepatol 2018; 68:296–304
Schrantee A, Ruhé HG, Reneman L. Psychoradiological biomarkers for psychopharmaceutical effects. Neuroimaging Clin N Am 2020; 30:53–63
Mobasheri A, Saarakkala S, Finnilä M, Karsdal MA, Bay-Jensen AC, van Spil WE. Recent advances in understanding the phenotypes of osteoarthritis. F1000Res 2019; 12:2091
Thomas MR, Lip GY. Novel risk markers and risk assessments for cardiovascular disease. Circ Res 2017; 6:133–149. All current clinical images contain quantitative information. We must make use of the digital techniques available to us to extract that quantitative data and make radiology more precise.

When performing an imaging study involving the injection of a radioactive compound into a patient, it is implicitly assumed that the compound is injected directly into the circulation, without any infiltration or extravasation into the tissue surrounding the injection site. Failure to achieve this goal will have a number of unintended consequences, depending upon the extent of the extravasation. Unfortunately, until recently, such extravasations have not been monitored, and in the cases where they occurred, the magnitude and extent were unknown.

Recently, I authored an article highlighting that such radiopharmaceutical misadministration resulting in extravasation is exempt from medical event reporting, owing to an outdated 1980 internal policy of the Nuclear Regulatory Commission (NRC). This exemption applies even when the radiation dose to tissue locally exceeds the NRC threshold for event reporting. The policy was based on the assumptions that extravasations are a “frequent occurrence” and are “virtually impossible to avoid”;  assumptions that are no longer valid today.

Since much of my career has been spent developing instrumentation and reconstruction algorithms for PET imaging, let us consider the imaging consequences resulting from the extravasation of an injection of a PET radiopharmaceutical. Obviously, its significance will depend upon the extent of the extravasation: the fraction of the radioactivity that remains locally at the injection site compared with that entering the circulation. Since the interpretation of the PET image assumes that all the radiopharmaceutical entered the circulation at the moment of injection, extravasation may affect the image both qualitatively and quantitatively. The reduced volume of radiotracer in the circulation may increase image noise that then obscures small, low uptake pathologies resulting in misinterpretation. Further, the uptake in a volume of tissue, such as a tumor, is estimated relative to the injected dose per unit weight of the patient, so that if the true dose injected is incorrect due to extravasation, the estimate of uptake in the tumor is also incorrect. This, again, potentially leads to misinterpretation of the study, particularly when it is used to assess response to a specific therapy.   

In addition to these well-known effects on the image quality, there can also be a significant change in the dose distribution of the injected radiopharmaceutical. The majority of imaging studies meet the criteria of low, or very low, radiation dose to the patient. This assumes that the injection is directly into the vein and the radioactivity distributes uniformly throughout the body. Obviously, depending on the radiotracer, uptake in certain organs may be higher than others, but overall, a typical equivalent dose to tissue at the injection site is less than 1 mSv. Extravasation of the injection will change this distribution, resulting in potentially much higher doses at the site of the injection. In a study of 36 significant extravasations of injections for diagnostic imaging, all of them exceeded the NRC medical event reporting threshold of 0.5 Sv, and 80% of them also exceeded the 1-Sv limit that the nuclear medicine community takes as the threshold for an adverse tissue reaction. The dosimetry estimates in this study are based upon patient-specific biological clearance that assesses the dose in a 5-mL sample of tissue. However, as mentioned previously, the outdated 1980 NRC policy does not require such extravasations to be reported as a medical event, even when there is the possibility of tissue damage to the patient.

Within the context of radiation protection, such a contradictory approach makes little sense: a 1-Sv radiation dose externally resulting from radioactivity spilled on the patient is reportable, whereas a 1-Sv dose internally resulting from extravasation of an injection is not reportable. Obviously, a critical consideration is how often do such extravasations arise during the normal practice of nuclear medicine, and is it a significant problem? Almost 20 million nuclear medicine studies are performed in the US each year, and therefore, even a small percentage of extravasated injections represents a large number of patients. However, most centers do not monitor the quality of the injection, and therefore, their extravasation rate is unknown. Twelve centers have published eight studies of 3,254 patients acquired between 2003 and 2017 and identified an average rate of 15.5% Hall N, Zhang J, Reid R, Hurley D, Knopp M. Impact of FDG extravasation on SUV measurements in clinical PET/CT. Should we routinely scan the injection site? J Nucl Med 2006; 47:115P
Bains A, Botkin C, Oliver D, Nguyen N, Osman M. Contamination in ¹⁸F-FDG PET/CT: an initial experience. J Nucl Med 2009; 50:2222
Krumrey S, Frye R, Tran I, Yost P, Nguyen N, Osman M. FDG manual injection verses infusion system: a comparison of dose precision and extravasation. J Nucl Med 2009; 50:2031
Osman MM, Muzaffar R, Altinyay ME, Teymouri C FDG dose extravasations in PET/CT: frequency and impact on SUV measurements. Front Oncol 2011; 1:41
Silva-Rodriguez J, Aguiar P, Sánchez M, et al. Correction for FDG PET dose extravasations: Monte Carlo validation and quantitative evaluation of patient studies. Med Phys 2014; 41:052502
Muzaffar R, Frye SA, McMunn A, Ryan K, Lattanze R, Osman MM. Novel method to detect and characterize (18)F-FDG infiltration at the injection site: a single-institution experience. J Nucl Med Technol 2017; 45:267–271. This work could only include imaging studies where the injection site is within the imaging field-of-view, and therefore, the actual extravasation rates could be higher. This finding was supported by a multi-center study published in 2019, of which I was a co-author, incorporating 2,531 patients from seven centers. 

Such statistics invalidate the assumptions upon which the 1980 NRC policy was based: that extravasations are frequent and impossible to avoid. An average rate of 15% implies many centers have extremely low rates, and some centers have higher rates. The fact that there is a wide disparity of rates suggests that they are not impossible to avoid—some centers avoid them almost entirely. The studies in which I have been involved identified factors such as the tools used for the injection, the technique, and the experience of the technologist that influence the probability of extravasation, rather than any patient-specific factor. Consequently, with better tools, improved technique, and more experience, extravasation rates can be reduced to very low levels. We also showed that such improvements are sustained, and the rates do not increase again over time. If all centers monitored their extravasation rates and implemented an appropriate training program, such rates could be kept extremely low.

Based on these considerations, it is time for the NRC to update their 1980 policy to be consistent with all patient radiation exposure exceeding 0.5 Sv as reportable, whether external or internal. Such a change would be in the interests of patient safety and would encourage centers to monitor their extravasation rates and maintain them at very low levels. In addition, the quality of the imaging study would be improved, both from a qualitative and quantitative perspective. By reducing rates to very low levels, any increased administrative demand on the center to report extravasations would be kept to a minimum.

The NRC is considering a petition to update their 1980 policy, for which they are currently accepting public comment. As stated above, such a change would protect patient safety and improve the quality of imaging studies. Although the petition would require reporting of significant extravasations where the estimated tissue dose exceeds the 0.5-Sv threshold, it also suggests a 12-month regulatory reporting grace period to allow all centers to monitor and improve their injection techniques. It has been shown that even levels of 15% or above can be reduced (and maintained) at less than 1% with appropriate effort. Consequently, supporting this petition for change will introduce consistency into the NRC policy for radiation exposure, and it will further encourage centers to resolve an issue that compromises both patient safety and the diagnostic quality of the imaging study.

As a final point, it should be noted that all the above considerations apply even more so to therapeutics involving injected radioactive compounds, where an extravasated dose may have profound consequences for the patient.

Here are the highlights from #ARRSProstateChat, a tweetchat discussion on how COVID-19 has affected breast imaging.

How did the initial wave (Spring 2020) of COVID-19 impact prostate MRI, targeted biopsy and prostate cancer diagnosis at your institution?

With the initial wave in Spring of 2020, we had to stop doing MRIs and targeted biopsies #ARRSProstateChat

— Baris Turkbey MD (@radiolobt) November 20, 2020

I will share our experience – we (in hindsight) reacted perhaps too cautiously and stopped non-urgent prostate #mri and biopsy in March due to fears of #COVID19

Now we are still trying to catch up with the backlog this created! https://t.co/qwL8gqHpZB

— NickSchieda (@NickSchiedaMD) November 20, 2020

A1: We are encouraging referrers to consider abbreviated bi-parametric prostate MRI, but have gotten little (~10%) buy-in. #ARRSProstateChat https://t.co/yzZte3VtLs

— Daniel Margolis (@DoctorMargolis) November 20, 2020

Biopsies and even prostatectomies were stopped for 2 to 3 months. #ARRSProstateChat https://t.co/veDApQ2Z7C

— Sandeep Arora (@LetDdiceFlyHigh) November 20, 2020

MRI kept going whole time, but We had bad timing for bx – shutdown in March for Covid then moved OP centre May/June and didn’t get prostate Bx going again until late July – backlog going to take a while!

— Adam Tunis (@adamtunis) November 20, 2020

We kept the same imaging protocol, but reinforced in safety measures and health screening. Also reached out to urologists to ask that they only refer urgent or particularly concerning cases.

— Leonardo Kayat Bit.. (@lkayat) November 20, 2020

Which strategies, initially, were used to maintain clinical care while reducing risk of exposure to patients and staff?

We stopped using endorectal coils, keep the appointments as far as possible from each other to avoid crowds in waiting areas and applied deep cleaning in scanner and changing rooms after each case and PPE for our technologists #ARRSProstateChat https://t.co/oYhkRMIVMz

— Baris Turkbey MD (@radiolobt) November 20, 2020

One of the advantages of #bpMRI for #ProstateMRI is no nurse contact. We are also building in spacing between scans – planned down-time. Therefore, we have extended hours and are keeping open older scanners we had planned to decommission. #ARRSProstateChat https://t.co/xiq8bSmrdd

— Daniel Margolis (@DoctorMargolis) November 20, 2020

At my current institution, all pts coming to hospital get a COVID test prior. #ARRSProstateChat https://t.co/uyFf5yvIfg

— Sandeep Arora (@LetDdiceFlyHigh) November 20, 2020

We at first stopped doing prostate MRI on all patients except those with very high PSA at risk for aggressive disease who may be harmed by no treatment. Once we had processes in place to do MRI more safely with adequate PPE we resumed and dealt with the backlog.

— Ben Spilseth, MD (@benspilseth) November 20, 2020

What was the short term impact on prostate MRI, targeted biopsy and prostate cancer diagnosis at your institution after the initial wave of COVID-19?

A3: we got a big backlog and some patients who could not wait us to reopen started to get imaging in other centers and they shipped their imaging studies for us to read. We tried to help them but without biopsies it was incomplete help #arrsprostatechat

— Baris Turkbey MD (@radiolobt) November 20, 2020

A3: Short term impact has been profound! MRI has caught up but biopsy is WAY BEHIND, and we are fighting a losing battle. We do 75% of the biopsied we did before so will need blitzes to catch up / but #COVID19 cases are higher now than before. 🤨#ARRSProstateChat https://t.co/kSZiAhMYJj

— NickSchieda (@NickSchiedaMD) November 20, 2020

A3 #prostateMRI volume had increased 3x in as many years but dropped to nearly zero as we deferred all non-urgent scans. It made sense – they couldn’t get biopsies much less surgery (because they were being used as ICU’s). We wanted scans soon before treatment. #ARRSProstateChat https://t.co/7FV5rfECem

— Daniel Margolis (@DoctorMargolis) November 20, 2020

With a resurgence of COVID-19 cases (Fall 2020), which strategies employed during the initial wave are still being used and which have been modified at your institution?

At my current institution we’re keeping the same health and safety measures that were in effect since march. We’re getting daily updates on use of PPEs and visitation policy. Other interesting measures such as virtual waiting room are being implemented.

— Leonardo Kayat Bit.. (@lkayat) November 20, 2020

We now have returned to 80-85% of pre-covid volumes for MRI and targeted biopsies. It takes more time to finish all day since we work with few team members to avoid crowds and do more detailed cleaning. We keep same deep cleaning and always wearing PPE rules #arrsprostatechat

— Baris Turkbey MD (@radiolobt) November 20, 2020

We definitely did not stop MRI or biopsy in the second wave – patient and staff wear PPE, cleaning +++, verbal consent, volumes are 80-90% normal – seems to be going well for now. We are still struggling to catch up from the Spring. #ARRSProstateChat https://t.co/RcPWhsVtiY

— NickSchieda (@NickSchiedaMD) November 20, 2020

A4 Good question! So far we haven’t changed anything. I imagine we will follow the institution’s guidance regarding elective procedures. We are still trying to catch up mammograms, though, so who knows for #ProstateMRI? It depends if the OR’s become ICU’s again. #ARRSProstateChat https://t.co/m0Fw05oDk9

— Daniel Margolis (@DoctorMargolis) November 20, 2020

A4: With resurgence of COVID, PPE and deep scrubbing after every MRI still remains. However there is a hesitancy to cut down prostate MRIs due to already huge backlogs. https://t.co/1GjjQuy9Qp

— Satheesh Krishna (@Dr_RadioLogic) November 20, 2020

What will be the long term impact on prostate cancer diagnosis, treatment and outcomes for men with prostate cancer due to the COVID-19 pandemic?

There is no doubt there will be delayed #ProstateCancer diagnosis and treatment / what the long term implications are for morbidity and mortality are unknown

So far have not seen any terrible cases due to delays, thankfully #ARRSProstateChat https://t.co/6RKwunXoyY

— NickSchieda (@NickSchiedaMD) November 20, 2020

A5: There has definitely been delay in treatment. At least anecdotally, initiation of chemotherapy was delayed due to delay in biopsy in a patient with strong clinical suspicion of metastatic pCa with patient having to live with the pain. Long term morbidity/mortality unknown! https://t.co/3K6CrwvLWu

— Satheesh Krishna (@Dr_RadioLogic) November 20, 2020

A5 I hope, #ProstateCancer being more indolent than #BreastCancer, there will be little long-term impact. However, the effects of the brief #USPSTF recommendations against #PSA screening are already evident. Worry is warranted. #ARRSProstateChat https://t.co/FhgbhOC1TR

— Daniel Margolis (@DoctorMargolis) November 20, 2020

Here are the highlights from #ARRSBreastChat, a tweetchat discussion on how COVID-19 has affected breast imaging.

Breast Cancer Awareness Month highlights the fact that breast cancer does not go away during a pandemic. How is your institution encouraging continued breast imaging despite the pandemic?

To encourage screening MG, we got creative:
📌 created self scheduling
📌extended breast clinic hours
📌 virtual fundraising
📌virtual talks to the community
📌media outreach #ARRSBreastChat https://t.co/tSgoJkQnv0

— Toma Omofoye, MD (@TomaOmofoyeMD) October 28, 2020

A1: Our Breast Imagers and Surgeons at Weill Cornell and NYP have been engaging the community with numerous virtual discussions, lectures, town halls and Q & A sessions addressing the of importance of screening mammography even during COVID-19.#ARRSBreastChat @WeillCornellRad https://t.co/jcUCBcgcsl

— Katia Dodelzon (@KatiaDodelzon) October 28, 2020

Q1:
-Mobile breast imaging
-Virtual Dx in rural areas
-Media Outreach
-Weekend screening#ARRSbreastchat https://t.co/ANGOrDUomd

— DrJackson_RAD (@DrJackson_RAD) October 28, 2020

We @YaleRadiology have screening and diagnostic breast imaging centers open with extended evening & weekend hrs to facilitate delayed exams while increasing distancing. We follow strict masking and cleaning measures to ensure that exams and encounters are safe. #ARRSBreastChat https://t.co/4iFvlvhMDJ

— Faezeh Sodagari (@fsodagari) October 28, 2020

Q1: Social media has been key for us. We are using this outlet to communicate with our patients. We have used videos in which we address the precautions we are taking against Covid and highlight the importance of continued mammo surveillance and diagnostic workups.

— ClaudiaCotesMD (@ClaudiaCotesMD) October 28, 2020

A1: We have also added a video on the @washradiology website showcasing the precautions we have put in place to ease the fears or concerns that patients may have. #ARRSBreastChat #BCAM

— Islamiat Ego-Osuala, MD (@TheMinBreastRep) October 28, 2020

We @YaleRadiology have screening and diagnostic breast imaging centers open with extended evening & weekend hrs to facilitate delayed exams while increasing distancing. We follow strict masking and cleaning measures to ensure that exams and encounters are safe. #ARRSBreastChat https://t.co/4iFvlvhMDJ

— Faezeh Sodagari (@fsodagari) October 28, 2020

What measures have your team put in place to ensure the safety of women who attend screening mammography during the pandemic?

** Publication referenced in video:

Link: https://t.co/WXRKEsxDmy@JeanSeely et al “COVID-19: Safe Guidelines for Breast Imaging During the Pandemic.” May, 2020

“Delays >3 months from symptom onset and start of treatment could be considered excessive” #ARRSBreastChat https://t.co/E09sHCywpJ pic.twitter.com/pNbKf8Xfji

— Toma Omofoye, MD (@TomaOmofoyeMD) October 28, 2020

A1: We have also added a video on the @washradiology website showcasing the precautions we have put in place to ease the fears or concerns that patients may have. #ARRSBreastChat #BCAM

— Islamiat Ego-Osuala, MD (@TheMinBreastRep) October 28, 2020

A2: All patients and healthcare employees wear masks which has shown to be the most effective way to mitigate the spread of disease. #ARRSBreastChat #WearAMask @WeillCornellRad @nyphospital @KemiMDRad https://t.co/qqfOGcsCJ4

— Katia Dodelzon (@KatiaDodelzon) October 28, 2020

A2. We take temperatures of everyone entering the building and supply surgical masks. We practice social distancing and have extended our hours to dedicate more time per patient to promote social distancing. We disinfect the rooms between patients. #ARRSBreastChat @RadiologyUSC https://t.co/eBzjIFKaDG

— USC Breast Imaging (@USCBreastRads) October 28, 2020

Kathy Schilling: using #AI on prior Mammos to assess risk for developing breast cancer, called those patients to encourage return to screening. #ARRSBreastChat https://t.co/E09sHCywpJ

— Toma Omofoye, MD (@TomaOmofoyeMD) October 28, 2020

What changes have your team put in place that you see continuing after the pandemic is over?

I anticipate we will continue to:
🔑Offer extended screening hours to accommodate different patient schedules
🔑Continue enhanced disinfecting protocols
🔑Single use gel
🔑Have a (mostly) Paperless workflow
🔑Continue same day dx/biopsy eval, reduce # of visits#ARRSBreastChat https://t.co/YAoa5EMIJh

— Toma Omofoye, MD (@TomaOmofoyeMD) October 28, 2020

A3. We will continue using social media to communicate with patients. We will continue disinfecting the rooms between patients, as we always have. #ARRSBreastChat @ARRS_Radiology @RadiologyUSC https://t.co/ADyNLwHCff

— USC Breast Imaging (@USCBreastRads) October 28, 2020

A3: We intend to continue to ease and streamline the experience for our patients long after the pandemic, to hopefully encourage greater adherence to screening in our community. #ARRSBreastChat @WeillCornellRad @WeillCornell @nyphospital https://t.co/UfIqF6C00s

— Katia Dodelzon (@KatiaDodelzon) October 28, 2020

@ButlerReni : extended breast clinic hours into evening and weekends to accommodate backlog of patients and enhanced cleaning of @YaleRadiology #ARRSBreastChat https://t.co/AHfNtF1XhE

— Toma Omofoye, MD (@TomaOmofoyeMD) October 28, 2020

A3: Measures put into place to ⬇️ spread on #COVID also helped ⬇️ in person wait time via more online scheduling, electronic check in and information exchange. Patients also benefit from more convenient care & communication. #ARRSBreastChat @NYUImaging @NYUWinthropHosp https://t.co/nBuyW2rjSy

— Monica Sheth, MD (@MonicaSheth) October 28, 2020

I see these to continue even after the pandemic:
Enhanced cleaning measures, expediting check-in process, extended hours, using AI for risk assessment, exploring work from home for breast screening, using media campaigns for increasing awareness.#ARRSBreastChat https://t.co/i6bvRkfiAZ

— Faezeh Sodagari (@fsodagari) October 28, 2020

What advice do you have for women who are eligible for screening mammography?

Miri Sklair-Levy: we’re screening in a way that’s safe for our staff and you!@jeanseely– wear a sear belt in every time. You should screen every year. @paulagordon: Please come get your screening MG#ARRSBreastChat https://t.co/IPlDSnqlzR

— Toma Omofoye, MD (@TomaOmofoyeMD) October 28, 2020

Here @UNCRadiology, the safety of our patients is our priority. Women should be encouraged to begin their screenings as soon as they are eligible. The pandemic should not delay timely access to care. We have learned a lot and put safeguards in place#ARRSBreastChat https://t.co/6FNirQ0yKz

— radrezmama (@drfemiabod) October 28, 2020

Q4: Breast cancer doesn’t go away because of #COVID19. Screening mammography is important to detecting early breast cancer- when it is most treatable.

*Breast Imaging saves lives- one of them could be yours!*#ARRSBreastChat #BCAM @SBIRFS @BreastImaging https://t.co/GLDk2xtqJO

— Jesse Conyers, MD (@jesse_conyers) October 28, 2020

A4: Get it done. Mammography saves lives. It is normal to worry about your risk of exposure to COVID-19. Remember your breast radiologists are concerned about your health and we are putting in significant safety measures to protect you from contracting the virus. #ARRSBreastChat https://t.co/UnmwLIOMl0

— Katia Dodelzon (@KatiaDodelzon) October 28, 2020

A4: @ARRS_Radiology It is important to take control of your health during this time of uncertainty, so if you’re 40 and over or considered HR don’t wait.. #MammogramsSaveLives #ARRSBreastChat @GeisingerHealth #realmamo https://t.co/fhUcNRu2Eb

— DrJackson_RAD (@DrJackson_RAD) October 28, 2020

A4: 🚺 by the time you are 30, speak with your doctor about your risk for #breastcancer & if early screening is indicated (i.e. starting before age 40). If you are 40 or older & average risk, get your mammogram yearly. #Breastcancer doesn’t stop for #CoVID #BCAM #ARRSBreastChat https://t.co/Y03qjkFe2s

— Monica Sheth, MD (@MonicaSheth) October 28, 2020

A4. Please call and make your appointment now for your annual screening mammogram. To schedule a screening mammogram at USC, call 323-865-3463 (option 1). #EarlyDetectionSavesLives #ARRSBreastChat @ARRS_Radiology @RadiologyUSC @KeckMedUSC https://t.co/1dgdkWSeBA

— USC Breast Imaging (@USCBreastRads) October 28, 2020

A4: COVID-19 lockdown does not lock down breast cancer. Lack or delay of screening mammograms will lead to more cancer-related deaths, particularly in minorities with pre-existing health disparities #ARRSBreastChat #BCAM

— Islamiat Ego-Osuala, MD (@TheMinBreastRep) October 28, 2020

Q4- We understand that you’re dealing with a lot these days, but please do not delay your breast care. Early detection saves lives! We are here for you and want to work with you to understand and address your concerns. Let us know how we can facilitate your care.#ARRSBreastChat https://t.co/ihv5VgjVzJ

— Faezeh Sodagari (@fsodagari) October 28, 2020