Author: Logan Young

A Commitment to Remain Engaged and Awoke
^{Published August 18, 2020}
Alexander Norbash
2020–2021 ARRS President
Do you believe that a radiologist deserves to comment on social inequities in a column such as this? Today, I believe that it is appropriate for me to do so. I do believe that, as a physician, I have a perspective that allows me to have an informed opinion where public health is concerned. And I believe that inequity, poverty, and racism are all public health problems. Whether or not they are solvable is beyond my understanding, given the human condition and history. If you feel that I have no right opining on such as this, I pray that you will forgive me this deviation.

On Thursday, April 9, I sent my last editorial to our InPractice editor. At the time, the focus of my thoughts dealt with the COVID-19 crisis and all that we saw, anticipated, and feared at the time as a direct result. I thought we were facing a once-in-a-lifetime problem that would demand our full attention, cost us many lives and considerable hardships, and might take two or three years to address. I even assumed at the time that we would be facing some type of large-scale societal financial crisis, above and beyond the imminent financial crisis I thought our health system would be facing. We thought we would figure this out. I did not imagine I would see a bigger crisis than COVID in my time, and I certainly could not imagine my commenting on a bigger crisis in my three remaining editorials. I was mistaken.

That was a very long time ago. George Floyd was alive on that day, and he continued to walk, breathe, and live among us for the next six and one-half weeks. And then, everything changed for a brief time. We all stirred to awaken—and I fear we have rolled over and fallen asleep again—back into our highly factionalized and outraged dreams. Summed up, the consequences and impact of perpetual, persistent, and unrelenting racism subjugates the COVID crisis to pale by comparison.

In this phase of my life, I believe that, as a healer, I should care about the health of individuals and society. Perhaps my span of interest should expand beyond just minding my business as an imager. Perhaps I should try to at least voice my thoughts about social inequities, and how those inequities erase multiple lifetimes of my professed service to society.

Mr. Floyd was killed, and we witnessed his death. Many of us gathered around our understanding that over 400 years of oppression, we have been either beneficiaries, perpetrators, victims, or bystanders. If victims, we are rightfully outraged. If perpetrators, I have a difficult time characterizing or understanding the defensive sentiment. If bystanders and beneficiaries, then we are faced with the leaden and heavy realization of our complicity, and our contribution to the ongoing racial crisis. Collectively, the end result has been neglect and denial of a purely man-made evil, where we have literally failed to lift a finger to solve this crisis over the centuries. With Mr. Floyd’s killing, many of us were now embarrassed into some temporary form of consciousness, and sought to right 400-plus years of a wrong. Perhaps momentarily, we recognized that the overt outrage of human ownership had been allowed to transform into the covert insidiousness of multigenerational oppression, poverty, disempowerment, and irreversible disadvantage. And now, we thought ourselves awoken, and we almost mobilized to do something real. Closer than ever before. Then again, maybe not so close. I don’t know. Memory is brief and incomplete.

Watts was big, with nearly a thousand buildings destroyed or burned over five days in 1965. Did anything substantive change after Watts? If so, why are there less black male medical students in 2020 than there were in 1973? Does that not shock us? Did Mr. Floyd also die in vain, as one of thousands? You would think that shock charges us to concrete and actionable charges to society. I don’t see the crisis seized upon, nor the corrective actions enabled. I saw large groups of committed individuals mobilized in the streets with my own eyes, propelled by the strength of their convictions and their fearlessness. And I don’t see where all that energy and passion was constructively directed.

We are physicians and health care workers, which means that we not only care for the human physic, we realize the irreducible entanglements that the body has with society, spirit, and soul. Can we be radiologists and not care about lead levels in water supplies, intentional violence, and child hunger because we are only interested in the latent image? Can we be disinterested by social inequity? Can we be untroubled by injustice, when such injustice neutralizes multiple lifetimes of our collective best radiologist efforts?

So, what are we supposed to do? Perhaps, at the least, we have to commit to not only work on equity in our immediate environment, we have to also recognize the insidious permanence of the condition. Yet there are also specific steps and actions that we can take.

What are concrete steps we can take? Where our immediate environment is concerned, we are all in need of implicit bias training and bystander training. How else can we change our immediate environment unless we understand what is hurtful, and unless we each believe our duty includes stepping in and clearly addressing inequity? There are dozens of online implicit bias training modules that can remind us that each and every one of us suffers from implicit bias, and that this awareness of our implicit bias is the first step in controlling it.

Bystander training is more complicated. It demands an understanding from each of us about when and how we would step in when we see something heinous, or even something just slightly hurtful. Alternatively, would we prefer to lower our heads and walk away to save ourselves? And then, following that, could we look at ourselves in a mirror? Learning about microaggressions and interventions is time consuming, and another ingredient that contributes to establishing a fair and equitable society.

A higher level of commitment is that of outreach and pipeline creation, where we choose to go to such groups as disadvantaged elementary and high school students and tell them about radiology—taking along team members such as technologists and nurses, so these students can envision an alternative future for themselves. Even if we only touch a small number of lives, in and of itself, that has meaning and substance, and may result in further cycles of engagement and economic salvation. It takes so little additional effort to positively affect the lives of others.

Only through vigilance and an understanding of the need for durable and enduring change can we hope for improvement. More than 400 years of inequity demand continuous and unrelenting pressure for change to occur. This is not a moment, or a project, or an initiative. It is a commitment for life to remain engaged and awoke, in order to better the condition of our brothers and sisters. For many of us, it is our understood duty.
August 18, 2020
Pediatric COVID-19 and MIS-C: What Lies Beyond Pneumonia?
^{Published August 10, 2020}
Alexandra M. Foust
Department of Radiology
Boston Children’s Hospital, Harvard Medical School
Ricardo Restrepo
Department of Radiology
Nicklaus Children’s Hospital, Florida International University
Edward Y. Lee
Department of Radiology
Boston Children’s Hospital, Harvard Medical School
Since the publication of our initial AJR article, “Pediatric SARS, H1N1, MERS, EVALI, and Now Coronavirus Disease (COVID-19) Pneumonia: What Radiologists Need to Know”, the coronavirus disease (COVID-19) pandemic has continued to grow—more than 15.7 million cases and 640,000 deaths worldwide, as of July 26, 2020. During this time, understanding of the imaging manifestations related to pediatric COVID-19 pneumonia, and the more newly defined COVID-19-related entity multisystem inflammatory syndrome in children (MIS-C), has continued to increase; however, substantial uncertainty regarding the imaging findings of pediatric COVID-19 and MIS-C still exist. Our article highlights a few key points regarding what is currently known about the imaging findings of pediatric COVID-19 and MIS-C for practicing radiologists.

What is Typical Pediatric COVID-19?

A recent meta-analysis of 7,780 pediatric patients positive for COVID-19 found that the mean age of patients was 8.9 years with a slight male predominance (55.6%). Underlying comorbid medical conditions were identified in 35.6% of patients. Overall, pediatric patients demonstrated a more mild clinical course than adults with 19.3% of patients completely asymptomatic, 3.3% requiring intensive care, and only 7 reported deaths (0.09%). The most commonly observed clinical complaints among symptomatic patients were cough and fever, and elevated inflammatory markers such as C-reactive protein, procalcitonin, and interleukin-6 were frequent.

Radiographically, typical imaging findings of pediatric COVID-19 pneumonia have been characterized as bilateral peripheral and/or subpleural ground-glass opacities and/or consolidation in a lower-lobe predominant distribution.

Fig. 1—13-year-old female with obesity and positive COVID-19 reverse transcription–polymerase chain reaction test who presented with fever and severe shortness of breath. (A) Frontal chest radiograph shows bilateral lower lung zone-predominant consolidation and ground-glass opacities, which are typical chest radiographic findings of pediatric COVID-19 pneumonia. (B) Axial lung window CT image demonstrates diffuse peripheral predominant ground-glass opacities in both lungs.

Although a unilateral or bilateral distribution of parenchymal abnormality may be observed in pediatric COVID-19 pneumonia, the differential for unilateral disease is somewhat broader. Thus, a unilateral distribution has been defined as indeterminant. The halo sign, a rounded consolidation surrounded by a rim of ground-glass opacity, can be seen during the early phase of pediatric COVID-19. Therefore, the halo sign is also considered typical when present in an immunocompetent patient, as it has a narrow differential. Additional important considerations for radiologists are atypical imaging findings that raise concern for alternative diagnosis, including centrilobular nodules, focal segmental/lobar consolidation, cavitary lesions, pleural effusion, and lymphadenopathy.

What is Multisystem Inflammatory Syndrome in Children (MIS-C)?

As suggested by the name, MIS-C is a post-viral inflammatory syndrome observed in pediatric patients with prior COVID-19 infection (within the past 4 weeks) that results in injury to multiple organ systems, most frequently involving > 4 systems. Some researchers have called MIS-C a “Kawasaki-like” disease due to the potential overlap in clinical presentation, including fever, conjunctivitis/rash, cardiac dysfunction + coronary artery dilation, and hemodynamic instability. Unlike pediatric COVID-19 pneumonia, children who develop MIS-C demonstrate a more severe clinical course, requiring intensive care management in up to 85% of cases, and have a higher death rate of 4%. As might be expected, the imaging findings in MIS-C differ from those observed in typical pediatric COVID-19 pneumonia.

Clinical Case-Based Review of Pediatric Imaging Online Course

What Are Important Differences Between Typical Pediatric COVID-19 and MIS-C?

Thoracic Findings

Chest imaging studies in pediatric patients with MIS-C may be normal or may demonstrate abnormalities, mainly related to underlying cardiac dysfunction. On chest radiograph, this may manifest as cardiomegaly, increased prominence of pulmonary vasculature, interstitial edema, or pleural effusions.

Fig. 2—15-year-old male, reverse transcription–polymerase chain reaction test positive for COVID-19, who presented with MIS-C associated with COVID-19, with symptoms including fever, vomiting, and diarrhea. Frontal chest radiograph shows cardiomegaly. Subsequently obtained echocardiogram demonstrated dilated left ventricle and moderate systolic dysfunction.

Chest CT may show similar findings and, in some cases, may demonstrate pericardial effusions, coronary artery dilation, and/or pulmonary embolism. Echocardiograms often demonstrate left ventricular dysfunction and/or reduced ejection fraction, as well as pericardial effusion, and/or coronary artery dilation.

Whereas typical COVID-19 pneumonia presents with bilateral peripheral and lower-lobe predominant ground-glass opacities and consolidation, the distribution of pulmonary parenchymal abnormality in MIS-C tends to be central and perihilar in distribution and more frequently presents as increased pulmonary vascularity, although airspace consolidation may be seen in advanced stages of cardiac failure. Additionally, cardiomegaly and pleural/pericardial effusions are often observed in MIS-C, but they are rare in pediatric COVID-19 pneumonia.

Extra-thoracic Findings

Extra-thoracic manifestations are not generally observed in pediatric COVID-19 pneumonia. However, as may be expected in an inflammatory disorder involving multiple organ systems, extra-thoracic findings are not uncommon in MIS-C—especially in the abdomen. Reported intra-abdominal abnormalities in MIS-C include bowel wall thickening, ascites, right lower quadrant fat stranding and/or lymphadenopathy, hepatomegaly, gallbladder sludge and/or pericholicystic fluid, and increased renal cortical echogenicity.

Fig. 3—7-year-old girl, reverse transcription–polymerase chain reaction test positive for COVID-19, who presented with MIS-C associated with COVID-19, with symptoms including fever, vomiting, abdominal pain, and hypotension. Transverse grayscale ultrasound image of the right lower quadrant shows thickened bowel loops (arrows) and ascites (asterisk).

Five Take-Home Points for Diagnostic Radiologists
1. “Typical” pediatric COVID-19 pneumonia presents as bilateral peripheral and lower-lobe predominant ground-glass opacities/consolidation + halo sign.
2. Centrilobular nodules, parenchymal cavitation, focal lobar/segmental consolidation, pleural effusion, and lymphadenopathy are atypical in pediatric COVID-19 pneumonia.
3. MIS-C has a more severe clinical course than pediatric COVID-19 pneumonia, often involving > 4 organ systems, with up to 85% of patients requiring intensive care.
4. Thoracic imaging findings observed in MIS-C, including cardiomegaly, pleural/pericardial effusion, coronary artery dilation, or pulmonary embolism, differ from typical findings in pediatric COVID-19 pneumonia.
5. Extra-thoracic manifestations are not uncommon in MIS-C and generally are a manifestation of inflammatory change (bowel wall thickening, lymphadenopathy, fat stranding, pericholicystic fluid, ascites) and/or organ dysfunction (hepatomegaly, increased renal cortical echogenicity).
As our understanding of pediatric COVID-19-related disease continues to grow, it is essential for practicing radiologists to be aware of the imaging findings in this patient population. Additionally, as the imaging features are quite different, awareness of the differences between pediatric COVID-19 pneumonia and MIS-C are critical to accurate diagnosis and optimal management of pediatric patients.
August 10, 2020
New Rituals for Radiology Residents During COVID-19
Lekui Xiao
Mayo Clinic
The COVID-19 pandemic began to impact our program (Rochester, MN) in mid-March, requiring rapid and near constant changes to the entire curriculum. Our chief residents divided us into teams—with one team responsible for call coverage and mandatory rotations, and others on back-up and remote learning. Our program organized daily case-based teaching sessions with staff and distance curricula. This time felt eerily reminiscent of the first two years of medical school, due to being somewhat removed from significant clinical duties! Regular communication with program leadership and co-residents helped alleviate a lot of the stress brought forth by COVID-19.

Around mid-May, we began transitioning back into clinical rotations. Although it is terrific to be back in the reading rooms, it is clear that we’re in a “new normal” for at least the immediate future. The number of people in attendance at noon conference is limited to accommodate social distancing, with many residents watching remotely. Masks, face shields, and meticulous sanitation have become a ritual.

The month of July has been uniquely different because our new first-year residents just started. They would usually interact with the upperclassmen and staff through informal gatherings and welcome parties outside of work. However, because of institutional COVID-19 precautions, social opportunities to welcome them have been limited.

Now is a memorable and unique time to be a radiology resident, as we have faced many challenges. I am eager to resume pre-COVID traditions and social activities with a new appreciation for my residency’s supportive learning environment.
August 4, 2020
Radiology Residency Looks Different with COVID-19
Sean Golden
The Johns Hopkins Hospital
The Johns Hopkins Radiology Residency, like most training programs across the country, has been deeply affected by the COVID-19 pandemic.

In late March, our program temporarily transitioned to a skeleton staffing model, where the majority of residents stayed home and were unable to read studies remotely. Key rotations were delayed or cancelled, and two residents were called upon to staff the ICU. To mitigate the diminished case volumes, faculty and fellows created daily virtual didactic sessions to supplement our regular morning conferences and independent study. Special emphasis was placed on preparing the first-year residents for independent overnight call, which we begin in July of our second year at Hopkins. An innovative online call-prep curriculum was created by our associate program director, where first-years independently reviewed DICOM images of previous overnight studies, submitted an impression to an online dropbox, and then reviewed the pertinent findings with an attending radiologist.

In May and June, COVID-19 numbers in Maryland began to decline, and our program gradually returned to a relative state of normalcy (albeit socially distanced). Now, as numbers in Maryland once again climb, the hospital leadership has asked for another group of volunteers to assist in the ICU and on the floors.

The COVID-19 pandemic has created unprecedented challenges for our faculty and residents alike, but it has also highlighted the department’s ability to adapt. Our reading rooms and conferences may look a little different than last year, but our commitment to education, research, and patient care carries on.
August 4, 2020
New Words for Radiology Residents During COVID-19
Joshua T. Olson
Mayo Clinic
The coronavirus disease (COVID-19) pandemic brought with it a new lexicon of phrases to describe daily resident life. At our radiology residency program at the Mayo Clinic in Rochester, Minnesota, we don appropriate “personal protective equipment,” or “PPE,” for clinical encounters and at the reading station. We also practiced “distance learning” for a month, rotating between essential rotations and studying from home as our institution prepared for COVID-19. We came away with a renewed appreciation for the value of one-on-one teaching and the irreplaceable learning that comes from the patients we are humbled to serve. We understand the concept of “hyper-locality” and how our local COVID-19 environment is radically different from others.

Similarly, we have been presented with new challenges. The rescheduling of the American Board of Radiology Core Exam has necessitated multiple redesigned call schedules. With the necessity for safe distancing practices, residents have found creative strategies to collaborate and celebrate milestone personal and professional achievements. Attentiveness and flexibility in meeting the ongoing and changing educational and personal needs during this stressful time have promoted cohesiveness and trust between residents and our program’s leadership.

Integrating these adaptations will allow us to grow stronger as we look toward the post-COVID-19 resumption of a “new normal” residency environment. The Mayo Clinic’s history is one of perseverance and innovation, borne in the wake of a devastating tornado which nearly destroyed the town almost 140 years ago. Together, I am confident our residency will persevere through the present pandemic—maintaining our strong tradition of innovation to ensure a world-class training environment, prioritizing resident wellness and the old adage that “the needs of the patient come first.”
July 27, 2020
An Action-Based Radiology Residency for COVID-19
Lei Yu
University of Nebraska Medical Center
Unprecedented times call for unprecedented actions. The past few months have been the most uncertain and challenging time in our lives, and we are all doing the best to adapt.

In mid-February, Nebraska Medicine quarantined 13 passengers of the Diamond Princess cruise ship in our National Quarantine and Biocontainment Units. The awareness and preparedness for COVID-19 started early among our institution, including focused refresher training on PPE use for all the residents to ensure safety during patient care.

Our department and the residency program reacted to the pandemic with a proactive mindset, including postponing non-urgent outpatient imaging studies and procedures, adopting structured virtual didactics, and altering our reading room layout to follow social distancing guidelines. As COVID-19 cases rapidly climbed nationwide in late March, rotational changes were made based on the waves of teams approach. We divided our residents into two teams: one working in the hospital to fulfill clinical duties, the other working from home to ensure a healthy workforce as a backup. Our schedule was very flexible and gave special considerations to residents who were in need of childcare due to closure of schools and daycares, as well as for family emergencies. In order to facilitate our educational program during these trying times, many online educational resources were made available. Our department always kept our wellness in mind—arranging for snacks and beverages to be brought into the reading room every afternoon, which was something we all looked forward to.

Lack of information can be unsettling in times of uncertainty. To keep us informed, our program sent out timely COVID-19 communications to provide updates and policy changes at both local and national levels, along with wellness resources to help cope with both internal and external stresses.

A silver lining from this pandemic is that it allowed us to pause and appreciate our life, our health, and our families. In the wise words of Marcus Aurelius, “The impediment to action advances action. What stands in the way becomes the way.” Look forward to the post-pandemic time, when we shall become stronger.
July 27, 2020
Radiology Residency in the Midst of COVID-19
^{Published July 15, 2020}
Ian Y.M. Chan
Chief Radiology Resident, Western University
Chair, ARRS Resident Advisory Subcommittee
_{Published July 15, 2020}

Like many facets of life, radiology residency has not been immune to a new reality wrought by the coronavirus disease (COVID-19) pandemic. As one of the first cities in Canada to have a confirmed case of COVID-19, the novel coronavirus was certainly top of mind among our residents, fellows, faculty, and staff at Western University in London, Ontario, Canada. As residents, we worked closely with our program director to advocate for necessary changes to our program to ensure our safety while continuing our education during this pandemic.

As our government mandated physical distancing and temporary business closures, our department also acted in concert and canceled most outpatient imaging. As a result, we noticed a sudden drop-off in cases for residents to report during the day. While after-hours resident call duties remained, we modified our daily work routine for two months by implementing a schedule of alternating a week of working in hospital and a week of self-studying at home. Importantly, we continued to receive dedicated radiology teaching as our “hot seat” case conferences and academic half-day lectures proceeded as scheduled via video conferencing.

There was also the looming anticipation of our redeployment to other clinical services. This has not yet transpired, largely due to public health policies that have slowed community transmission for the time being. Fortunately, we have had access to appropriate personal protective equipment when caring for patients. Stress management has indeed been especially crucial to our wellness during this trying time. I believe that constant, albeit distanced, social interaction with colleagues and friends has helped emphasize our shared experiences and that “we are all in this together.”

The Greek philosopher Heraclitus once said, “change is the only constant in life.” During this harrowing time, this axiom still rings true with our residency training as we adapt to this pandemic.

Stay safe and be well!
July 15, 2020
PET/CT Plays Role in Lung Adenocarcinoma Management

^{Published June 22, 2020}

Xiaoliang Shao
First author

Fluorodeoxyglucose PET (FDG PET) can be used to predict the histopathologic subtypes and growth patterns of early lung adenocarcinoma. “FDG PET, combined with high-resolution CT (HRCT), has value for predicting invasive histopathologic subtypes, but there was no significance for predicting invasive growth patterns,” clarified authors Xiaoliang Shao and Xiaonan Shao from the department of nuclear medicine at Soochow University in Changzhou, China. The team’s retrospective analysis was conducted on the PET/CT data on ground-glass nodules (GGNs) resected from patients with stage IA lung adenocarcinoma, evaluating the efficacy of PET maximum standardized uptake value (SUV_max) combined with HRCT signs in prediction of histopathologic subtype and growth pattern of lung adenocarcinoma. Although SUV_max measured significantly higher in GGNs with invasive HRCT signs, the diameter of GGN, as well as the attenuation value differential between ground-glass components and adjacent lung tissues, were independent predictors of FDG uptake by GGNs. Additionally, SUV_max was higher in invasive adenocarcinoma than in adenocarcinoma in situ (AIS)–minimally invasive adenocarcinoma (MIA), with SUV_max 2.0 the optimal cutoff value for differentiation. Acinar-papillary adenocarcinoma had a higher SUV_max than lepidic adenocarcinoma, with SUV_max 1.4 the optimal cutoff value for differentiation. “In stage IA lung adenocarcinoma characterized by GGNs, the SUV_max of GGNs with invasive CT features was high,” Xiaoliang Shao wrote, adding that HRCT can be used in diagnosing the subtypes of lung adenocarcinoma. “However, it cannot be used to differentiate different growth patterns of lung adenocarcinomas.” As Xiaonan Shao concluded: “The efficacy of FDG PET SUV_max in differentiating lung adenocarcinoma subtypes is similar to that of HRCT signs, however, the diagnostic efficiency of FDG PET combined with HRCT is significantly higher than that of each imaging technique alone.”

June 22, 2020
MRI Predicts Shoulder Stiffness for Rotator Cuff Tears

^{Published June 22, 2020}

Bo Mi Chung
Corresponding Author

Two MRI findings—joint capsule edema and thickness at the axillary recess, specifically—proved useful in predicting stiff shoulder in patients with rotator cuff tears. Studying 106 patients with small to large (≤ 5 cm) full-thickness rotator cuff tears, in addition to joint capsule edema and thickness in the axillary recess, Yoon Yi Kim of Korea’s Veterans Health Service Medical Center assessed obliteration of the subcoracoid fat triangle, fatty degeneration of the torn rotator cuff muscle, and degree of retraction. Tear size and location were determined by MRI findings and operative report, while associations between MRI findings and preoperative passive range of motion (ROM) were evaluated with simple and multiple linear regression analyses and proportional odds logistic regression analysis. As Kim and colleagues wrote: “There was a significant, negative linear correlation between limited ROM at forward elevation and thickness of the joint capsule in the glenoid portion of the axillary recess (p = 0.018), external rotation and joint capsule edema in the humeral portion of the axillary recess (p = 0.011), and internal rotation and joint capsule edema in the glenoid portion of the axillary recess (p = 0.007).” Fatty degeneration (p = 0.003) was an independent predictor of limited ROM on internal rotation. Meanwhile, male sex (p = 0.041) and posterosuperior rotator cuff tear (p = 0.030) were independent predictors of shoulder ROM on external rotation. “This study is important,” Kim et al. noted, “because it is the first to highlight joint capsule abnormality on MRI as a factor associated with stiff shoulder in patients with full-thickness rotator cuff tears.”

June 22, 2020
New CT Scoring Criteria for Timely Diagnosis and Treatment of COVID-19

^{Published June 22, 2020}

Updated CT scoring criteria that considers lobe involvement, as well as changes in CT findings, could quantitatively and accurately evaluate the progression of coronavirus disease (COVID-19) pneumonia. “The earlier that COVID-19 is diagnosed and treated, the shorter the time to disease resolution and the lower the highest and last CT scores are,” concluded lead author Guoquan Huang of Wuhu Second People’s Hospital in China. Assigning CT scores to 25 patients according to CT findings and lung involvement, Huang and colleagues recorded the time from symptom onset to diagnosis and treatment for each patient. Patients with COVID-19 were divided into two groups: (patients for whom this interval was ≤ 3 days) and group 2 (those for whom the interval was > 3 days). Using a Lorentzian line-shape curve to show the variation tendency during treatment, the fitted tendency curves for group 1 and group 2 were significantly different. Peak points showed that the estimated highest CT score was 10 and 16 for each group, respectively, and the time to disease resolution was 6 and 13 days, respectively. The Mann-Whitney test showed that the last CT scores were lower for group 1 than for group 2 (p = 0.025), although the chi-square test found no difference in age and sex between the groups. The time from symptom onset to diagnosis and treatment had a positive correlation with the time to disease resolution (r = 0.93; p = 0.000), as well as with the highest CT score (r = 0.83; p = 0.006). “Sequential chest CT examinations enable qualitative investigation of alterations in COVID-19 infection during the course of treatment,” Huang explained. Because previously proposed CT scoring criteria regarding lobe involvement gave no consideration to changes in CT features (i.e., the change from observation of GGO to a crazy-paving pattern and then consolidation), Huang et al. suggest that such a rubric is not sufficiently accurate to assess the progression of pneumonia. “In the present study,” wrote Huang, “we propose a new version of CT scoring criteria that considers both lobe involvement and changes in CT findings, in an attempt to more comprehensively evaluate COVID-19 pneumonia on sequential chest CT examinations.”

June 22, 2020
Pediatric Coronavirus Disease (COVID-19) Pneumonia Radiography, CT Findings Included in Review of Five New Lung Disorders

^{Published June 22, 2020}

Alexandra M. Foust
Corresponding Author

Although the clinical symptoms of new pediatric lung disorders such as severe acute respiratory syndrome (SARS), swine-origin influenza A (H1N1), Middle East respiratory syndrome (MERS), e-cigarette or vaping product use–associated lung injury (EVALI), and coronavirus disease (COVID-19) pneumonia may be nonspecific, some characteristic imaging findings have emerged or are currently emerging. “Although there are some overlapping imaging features of these disorders,” wrote first author Alexandra M. Foust of Boston Children’s Hospital and Harvard Medical School, “careful evaluation of the distribution, lung zone preference, and symmetry of the abnormalities with an eye for a few unique differentiating imaging features, such as the halo sign seen in COVID-19 and subpleural sparing and the atoll sign seen in EVALI, can allow the radiologist to offer a narrower differential diagnosis in pediatric patients, leading to optimal patient care.” At most institutions, whereas the first imaging study performed in patients with clinically suspected COVID-19 is chest radiography, Foust and colleagues’ review of the clinical literature found that studies on chest radiography findings in patients with COVID-19 were relatively scarce. Regarding the limited studies of pediatric patients with COVID-19, Foust et al. noted chest radiography “may show normal findings; patchy bilateral ground-glass opacity (GGO), consolidation, or both; peripheral and lower lung zone predominance.” Similarly, while the literature describing chest CT findings in patients with COVID-19 are more robust than those describing chest radiography findings, only a few articles have reported CT findings of COVID-19 in children. A study of 20 pediatric patients with COVID-19 reported that the most frequently observed abnormalities on CT were subpleural lesions (100% of patients), unilateral (30%) or bilateral (50%) pulmonary lesions, GGO (60%), and consolidation with a rim of GGO surrounding it, also known as the halo sign (50%). The authors of this AJR article also pointed to a smaller study of five pediatric patients with COVID-19, where investigators reported modest patchy GGO, one with peripheral subpleural involvement, in three patients that resolved on follow-up CT examination.

June 22, 2020
Review of COVID-19 Studies Cautions Against Chest CT for Coronavirus Diagnosis

^{Published June 22, 2020}

Constantine A. Raptis
Corresponding Author

To date, the radiology literature on coronavirus disease (COVID-19) pneumonia has consisted of limited retrospective studies that do not substantiate the use of CT as a diagnostic test for COVID-19. “This is not to say these studies are not valuable,” maintained lead investigator Constantine A. Raptis of Washington University in Saint Louis. As Raptis, Travis S. Henry of the University of California-San Francisco, and nine co-authors from six institutions across the United States noted of the most frequently cited studies on the subject, reporting the various CT features of COVID-19 pneumonia remains “an important first step” in helping radiologists identify patients who may have COVID-19 in the appropriate clinical environment. “However,” they continue, “test performance and management issues arise when inappropriate and potentially overreaching conclusions regarding the diagnostic performance of CT for COVID-19 pneumonia are based on low-quality studies with biased cohorts, confounding variables, and faulty design characteristics.” Because misdiagnosing even a single patient (i.e., obtaining a false-negative finding) could result in large outbreaks among future contacts, understanding the potential effects of selection bias is important in determining sensitivity. As Raptis and colleagues explained, “if a study cohort contains patients who are more likely to have a true-positive finding and less likely to have a false-negative finding, sensitivity will be overestimated.” The specificity and positive predictive value of a laboratory test—in the case of COVID-19, reverse transcription–polymerase chain reaction (RT-PCR)—are based on its ability to limit false-positive findings. Acknowledging false-positive RT-PCR results are possible, Raptis, Henry, et al. maintained they are often caused by contamination and are likely insignificant in the setting of assays for COVID-19. CT, on the other hand, does not test for singular features unique to the disease, and even those features most characteristic of COVID-19 pneumonia—peripheral, bilateral ground-glass opacities typically in the lower lobes—have been reported in a number of other conditions, both infectious and noninfectious. Finally, Raptis and colleagues addressed the hazards of wide deployment of CT: overuse of hospital resources, including the use of PPE already limited in availability but required to safely perform CT studies; clustering of affected and nonaffected patients in the radiology department, increasing the risk of disease transmission among imaging staff. “At present,” the authors of this AJR article concluded, “CT should be reserved for evaluation of complications of COVID-19 pneumonia or for assessment if alternative diagnoses are suspected.”

June 22, 2020