The Virtual Homeroom: Utility and Benefits of Small Group Online Learning in the COVID-19 Era.

OBJECTIVE: During COVID-19, Harvard Medical School pivoted to online learning. A large student cohort took a completely virtual Radiology clerkship with daily programming including virtual small group teaching sessions or "homerooms." MATERIALS AND METHODS: One hundred and eleven medical students were divided into 12 virtual small group sessions which emphasized foundational concepts. Uniform teaching materials were used across all homerooms in order to deepen understanding and allow insight into the working methods of radiologists. Students evaluated the homeroom learning and teachers for utility and benefit to their educational experience. RESULTS: Most students (93%) felt the homerooms provided an educational benefit and reinforced topics studied (77%). Most students (84%) felt the leaders created an environment conducive to learning. Despite being virtual, students were able to form interpersonal connections with the homeroom leaders. CONCLUSIONS: Incorporating virtual small group learning can be a valuable component of a virtual or hybrid Radiology clerkship, solidifying foundational concepts with the homeroom leaders playing a major role. While developed by necessity due to COVID-19, virtual small group learning with engaged leaders is an educational strategy whose benefit can continue even as there is return to in-person learning.

Medical Student Education Roadblock Due to COVID-19: Virtual Radiology Core Clerkship to the Rescue.

RATIONALE AND OBJECTIVES: Medical schools were upended by the COVID-19 pandemic, resulting in suspension of all in-person educational activities, and leaving clinical clerkships on hold indefinitely. A virtual curriculum and novel teaching methods were needed to fulfill curricular requirements. We developed a comprehensive virtual radiology clerkship and evaluated the efficacy of this novel method of teaching. MATERIALS AND METHODS: A 4-week virtual radiology clerkship was designed to accommodate medical students who had not yet completed the required clerkship. The design included online flipped classroom modules, large group didactic lectures, and small group homeroom activities. Student performance was assessed via a standardized online final exam. Feedback from students was collected using online surveys. Student performance was compared to the in-person radiology clerkship. RESULTS: One hundred and eleven medical students were enrolled in the virtual radiology clerkship. Final exam scores were similar to the in-person clerkship. Students indicated that small group homeroom activities had the highest overall satisfaction. Students recognized enthusiastic teachers regardless of class format. Exceptional course content and organization were also noted. Course weaknesses included didactic lecture content which was repetitive or too advanced, the limited opportunity to build personal connections with faculty, and scheduling conflicts with other competing school activities. CONCLUSION: A completely virtual radiology core clerkship can be a successful educational experience for medical students during a time when remote learning is required. A small group learning environment is most successful for student engagement. Personal connections between faculty and students can be challenging in a virtual course.

Nivolumab-induced small bowel obstruction and perforation: a rare but life-threatening side effect of immunotherapy.

We present a case of a 58-year-old female with anti-PD-1 immunotherapy-related small bowel perforation. The patient was on long-term therapy with nivolumab for metastatic non-small cell lung cancer. She presented to the emergency department with acute abdominal pain, in which the CT revealed a short segment of dilated distal ileum proximal to a very short segment of bowel with mural thickening and a perforation near the transition point. The patient underwent subsequent laparotomy, which confirmed the CT findings and revealed a short-segment of friable and dilated loop of distal ileum proximal to a stricture and a small perforation at the transition point. Pathological analysis revealed mural thickening at the site of stricture without evidence of malignancy with focal necrosis and perforation at the transition point. Bowel perforation in the setting of anti-PD-1 immunotherapy is rare, but life-threatening complication, and should be considered in oncology patients on immunotherapy presenting with severe abdominal pain.

CT in the Emergency Department: A Real-Time Study of Changes in Physician Decision Making.

PURPOSE: To determine how physicians' diagnoses, diagnostic uncertainty, and management decisions are affected by the results of computed tomography (CT) in emergency department settings. MATERIALS AND METHODS: This study was approved by the institutional review board and compliant with HIPAA. Data were collected between July 12, 2012, and January 13, 2014. The requirement to obtain patient consent was waived. In this prospective, four-center study, patients presenting to the emergency department who were referred for CT with abdominal pain, chest pain and/or dyspnea, or headache were identified. Physicians were surveyed before and after CT to determine the leading diagnosis, diagnostic confidence (on a scale of 0% to 100%), alternative "rule out" diagnosis, and management decisions. Primary measures were the proportion of patients for whom the leading diagnosis or admission decision changed and median changes in diagnostic confidence. Secondary measures addressed alternative diagnoses and return-to-care visits (eg, to emergency department) at 1-month follow-up. Regression analysis was used to identify associations between primary measures and site and participant characteristics. RESULTS: Both surveys were completed for 1280 patients by 245 physicians. The leading diagnosis changed in 235 of 460 patients with abdominal pain (51%), 163 of 387 with chest pain and/or dyspnea (42%), and 103 of 433 with headache (24%). Pre-CT diagnostic confidence was inversely associated with the likelihood of a diagnostic change (P < .0001). Median changes in confidence were substantial (increases of 25%, 20%, and 13%, respectively, for patients with abdominal pain, chest pain and/or dyspnea, and headache; P < .0001); median post-CT confidence was high (95% for all three groups). CT helped confirm or exclude at least 95% of alternative diagnoses. Admission decisions changed in 116 of 457 patients with abdominal pain (25%), 72 of 387 with chest pain and/or dyspnea (19%), and 81 of 426 with headache (19%). During follow-up, 70 of 450 patients with abdominal pain (15%), 53 of 387 with chest pain and/or dyspnea (14%), and 49 of 433 with headache (11%) returned for the same indication. In general, changes in leading diagnosis, diagnostic confidence, and admission decisions were not well explained with site or participant characteristics. CONCLUSION: Physicians' diagnoses and admission decisions changed frequently after CT, and diagnostic uncertainty was alleviated.

Review of Ingested and Aspirated Foreign Bodies in Children and Their Clinical Significance for Radiologists.

Ingested and aspirated foreign bodies are a common occurrence in children and are important causes of morbidity and mortality in the pediatric population. Imaging plays an important role in the diagnosis of ingested and aspirated foreign bodies in children and can be crucial to guiding the clinical management of these patients. Prompt identification and localization of ingested foreign bodies is essential to determining the appropriate treatment, as several types of commonly ingested foreign bodies require urgent removal and others can be managed conservatively. In particular, disk batteries impacted in the esophagus carry a high risk of esophageal injury or perforation; multiple ingested magnets can become attracted to each other across bowel walls and cause bowel perforation and fistula formation; and sharp objects commonly cause complications as they pass through the gastrointestinal tract. Accordingly, these ingested foreign bodies warrant aggressive clinical management and therefore radiologists must be familiar with their imaging appearances and clinical implications. Prompt recognition of secondary radiographic signs of foreign-body aspiration is also crucial, as clinical symptoms can sometimes be nonspecific and most aspirated foreign bodies are radiolucent. Overall, radiography is the most important modality in the evaluation of ingested or aspirated foreign bodies; however, fluoroscopy and computed tomography play an ancillary role in complicated cases. It is essential that every radiologist who interprets imaging examinations of children be aware of the imaging appearances of commonly ingested and aspirated foreign bodies and their clinical significance.

The clinical significance of isolated loss of lordosis on cervical spine computed tomography in blunt trauma patients: a prospective evaluation of 1,007 patients.

BACKGROUND: A negative computed tomographic (CT) scan may be used to rule out cervical spine (c-spine) injury after trauma. Loss of lordosis (LOL) is frequently found as the only CT abnormality. We investigated whether LOL should preclude c-spine clearance. METHODS: All adult trauma patients with isolated LOL at our Level I trauma center (February 1, 2011 to May 31, 2012) were prospectively evaluated. The primary outcome was clinically significant injury on magnetic resonance imaging (MRI), flexion-extension views, and/or repeat physical examination. RESULTS: Of 3,333 patients (40 ± 17 years, 60% men) with a c-spine CT, 1,007 (30%) had isolated LOL. Among 841 patients with a Glasgow Coma Scale score of 15, no abnormalities were found on MRI, flexion-extension views, and/or repeat examinations, and all collars were removed. Among 166 patients with Glasgow Coma Scale less than 15, 3 (.3%) had minor abnormal MRI findings but no clinically significant injury. CONCLUSION: Isolated LOL on c-spine CT is not associated with a clinically significant injury and should not preclude c-spine clearance.

Acetabular fractures: what radiologists should know and how 3D CT can aid classification.

Correct recognition, description, and classification of acetabular fractures is essential for efficient patient triage and treatment. Acetabular fractures may result from high-energy trauma or low-energy trauma in the elderly. The most widely used acetabular fracture classification system among radiologists and orthopedic surgeons is the system of Judet and Letournel, which includes five elementary (or elemental) and five associated fractures. The elementary fractures are anterior wall, posterior wall, anterior column, posterior column, and transverse. The associated fractures are all combinations or partial combinations of the elementary fractures and include transverse with posterior wall, T-shaped, associated both column, anterior column or wall with posterior hemitransverse, and posterior column with posterior wall. The most unique fracture is the associated both column fracture, which completely dissociates the acetabular articular surface from the sciatic buttress. Accurate categorization of acetabular fractures is challenging because of the complex three-dimensional (3D) anatomy of the pelvis, the rarity of certain acetabular fracture variants, and confusing nomenclature. Comparing a 3D image of the fractured acetabulum with a standard diagram containing the 10 Judet and Letournel categories of acetabular fracture and using a flowchart algorithm are effective ways of arriving at the correct fracture classification. Online supplemental material is available for this article.

Imaging of iatrogenic conditions of the thorax.

Common medical interventions performed by cardiologists, radiologists, surgeons, dentists, and alternative practitioners can result in complications within the thorax that lead to significant patient morbidity. Prompt radiologic identification of iatrogenic complications of medical procedures in the thorax is essential to guide patient triage and treatment. Understanding the approach to common thoracic interventions and the placement of thoracic medical devices can aid radiologists in the evaluation of iatrogenic complications.

Imaging for appendicitis: should radiation-induced cancer risks affect modality selection?

PURPOSE: To compare life expectancy (LE) losses attributable to three imaging strategies for appendicitis in adults-computed tomography (CT), ultrasonography (US) followed by CT for negative or indeterminate US results, and magnetic resonance (MR) imaging-by using a decision-analytic model. MATERIALS AND METHODS: In this model, for each imaging strategy, LE losses for 20-, 40-, and 65-year-old men and women were computed as a function of five key variables: baseline cohort LE, test performance, surgical mortality, risk of death from delayed diagnosis (missed appendicitis), and LE loss attributable to radiation-induced cancer death. Appendicitis prevalence, test performance, mortality rates from surgery and missed appendicitis, and radiation doses from CT were elicited from the published literature and institutional data. LE loss attributable to radiation exposure was projected by using a separate organ-specific model that accounted for anatomic coverage during a typical abdominopelvic CT examination. One- and two-way sensitivity analyses were performed to evaluate effects of model input variability on results. RESULTS: Outcomes across imaging strategies differed minimally-for example, for 20-year-old men, corresponding LE losses were 5.8 days (MR imaging), 6.8 days (combined US and CT), and 8.2 days (CT). This order was sensitive to differences in test performance but was insensitive to variation in radiation-induced cancer deaths. For example, in the same cohort, MR imaging sensitivity had to be 91% at minimum (if specificity were 100%), and MR imaging specificity had to be 62% at minimum (if sensitivity were 100%) to incur the least LE loss. Conversely, LE loss attributable to radiation exposure would need to decrease by 74-fold for combined US and CT, instead of MR imaging, to incur the least LE loss. CONCLUSION: The specific imaging strategy used to diagnose appendicitis minimally affects outcomes. Paradigm shifts to MR imaging owing to concerns over radiation should be considered only if MR imaging test performance is very high.

High attenuation pericardial fluid on CT following cardiac catheterization.

High-density pericardial fluid may be seen on noncontrast CT performed following cardiac catheterization (CC), raising the possibility of hemopericardium. Our goal was to determine the clinical course and associations of incidentally discovered high-attenuation pericardial fluid on noncontrast CT performed soon after CC. Hospital database search over a 7.5-year period identified 211 patients who underwent CT of the chest and/or abdomen within 60 h before or after CC, 150 having CC first. Pericardial fluid volume and attenuation as well as relevant laboratory and clinical parameters were recorded. Bivariate associations with average pericardial fluid attenuation (HUavg) were assessed. Using the 61 patients with CT before CC as controls, 44 of the patients with CC first had attenuation values greater than the mean + 2SD of 22.6 Hounsfield unit (HU) and 19 had attenuation values greater than the maximum control patient value of 39.8 HU. All patients with incidental finding of high-density pericardial fluid followed a benign course. Bivariate correlations showed time gap between CC and CT (rho = -0.50, p < 0.001), estimated glomerular filtration rate (eGFR) (rho = -0.24, p = 0.004), and female gender (median (IQR) 17.4 (13.6, 29.6) vs. 15.8 (9.9, 23.7), p = 0.02) to be associated with HUavg. In multiple linear regression analysis, only time gap and female gender were independently significantly associated with average attenuation (both p < 0.001). The finding that patients with incidentally discovered high-density pericardial fluid followed an uneventful course suggests a benign etiology such as vicarious excretion, and in patients who are otherwise stable, observation rather than immediate intervention should be considered.

Imaging of penile and scrotal emergencies.

Penile and scrotal emergencies are uncommon, but when they do occur, urgent or emergent diagnosis and treatment are necessary. Emergent conditions of the male genitalia are primarily infectious, traumatic, or vascular. Infectious conditions, such as epididymitis and epididymo-orchitis, are well evaluated at ultrasonography (US), and their key findings include heterogeneity and hyperemia. Pyocele and abscess may also be seen at US. Fournier gangrene is best evaluated at computed tomography, which depicts subcutaneous gas. Vascular conditions, such as testicular torsion, infarction, penile Mondor disease, and priapism, are well evaluated at duplex Doppler US. The key imaging finding of testicular torsion and infarction is a lack of blood flow in the testicle or a portion of the testicle. Penile Mondor disease is characterized by a lack of flow to and noncompressibility of the superficial dorsal vein of the penis. Clinical examination and history are usually adequate for diagnosis of priapism, but Doppler US may help confirm the diagnosis. Traumatic injuries of the penis and scrotum are initially imaged with US, which depicts whether the penile corpora and testicular seminiferous tubules are contained by the tunicae albuginea; herniation of contents and discontinuity of the tunica albuginea indicate rupture. In some cases, magnetic resonance imaging may be performed because of its ability to directly depict discontinuity of the tunica albuginea. Radiologists must closely collaborate with emergency physicians, surgeons, and urologists to quickly and efficiently diagnose or rule out emergent conditions of the male genitalia to facilitate prompt and appropriate treatment.

Journal club: How radiation exposure histories influence physician imaging decisions: a multicenter radiologist survey study.

OBJECTIVE: The purpose of this article is to evaluate the influence of patient radiation exposure histories on radiologists' imaging decisions. MATERIALS AND METHODS: We conducted a physician survey study in three academic medical centers. Radiologists were asked to make an imaging recommendation for a hypothetical patient with a history of multiple CT scans. We queried radiologists' decision making, evaluating whether they incorporated cancer risks from previous imaging, reported acceptance (or rejection) of the linear no-threshold model, and understood linear no-threshold model implications in this setting. Consistency between radiologists' decisions and their linear no-threshold model beliefs was evaluated; those acting in accordance with the linear no-threshold model were expected to disregard previously incurred cancer risks. A Fisher exact test was used to verify the generalizability of results across institutions and training levels (residents, fellows, and attending physicians). RESULTS: Fifty-six percent (322/578) of radiologists completed the survey. Most (92% [295/322]) incorporated risks from the patient's exposure history during decision making. Most (61% [196/322]) also reported acceptance of the linear no-threshold model. Fewer (25% [79/322]) rejected the linear no-threshold model; 15% (47/322) could not judge. Among radiologists reporting linear no-threshold model acceptance or rejection, the minority (36% [98/275]) made decisions that were consistent with their linear no-threshold model beliefs. This finding was not statistically different across institutions (p = 0.070) or training levels (p = 0.183). Few radiologists (4% [13/322]) had an accurate understanding of linear no-threshold model implications. CONCLUSION: Most radiologists, when faced with patient exposure histories, make decisions that contradict their self-reported acceptance of the linear no-threshold model and the linear no-threshold model itself. These findings underscore a need for educational initiatives.

Incidental findings in trauma patients: dedicated communication with the primary care physician ensures adequate follow-up.

BACKGROUND: Frequent use of computed tomography (CT) in trauma patients results in frequent detection of non-trauma-related incidental findings (IFs). Inpatient documentation and disclosure at discharge are infrequent, even when they are potentially serious. We aimed to not only identify the incidence of IFs but also to evaluate the effectiveness of an intervention to trigger follow-up. METHODS: In this before-after study, all trauma patients evaluated by the trauma surgery service who underwent CT were admitted for >24 h, had at least one IF requiring follow-up, and had a primary care physician (PCP) employed in our health care system were identified. The historical control period was from January 2006 to December 2008. The intervention period was from December 2011 to September 2012. Intervention consisted of notifying the PCP via email or postal letter. The outcome of interest-the rate of follow-up-was compared between both groups. RESULTS: During the historical period, 364 (20.5 %) of 1,774 eligible trauma patients had 434 IFs requiring follow-up. During the study period, 197 (26 %) of 692 trauma patients had 212 IFs requiring follow-up. Overall, 91 % of study patients with postdischarge PCP follow-up had documented follow-up of the IF. There was a significant improvement in the rate of follow-up in the study group compared to that of the control group (51 vs. 11 %; p < 0.0001). CONCLUSIONS: Detection of IFs is common in trauma patients. A dedicated effort of communicating the presence of an IF to the patient's PCP triggered a follow-up for 91 % of patients who saw their PCP after hospital discharge.

Teeth: what radiologists should know.

Disease of the teeth and their support structures is common and frequently seen at imaging of the head and neck. Recognition of dental disease by the interpreting radiologist has the potential to alter the course of patient care, such as when periapical disease is identified as the cause of sinusitis or pericoronitis is identified as the cause of deep neck infection. Furthermore, incidental recognition of carious lesions in both children and adults who are undergoing CT for other reasons may alert the patient and care team of the need for a dental consultation. In fact, most of the images of dental and periodontal conditions that are used in this article were obtained from CT studies that were performed to investigate other problems. Familiarity with the imaging appearance of common dental conditions, such as hyperdontia and hypodontia, tooth trauma, periodontal disease, caries, periapical disease, odontogenic sinusitis, and deep neck infections, allows the radiologist to render a timely, confident, and specific diagnosis of dental abnormalities, even when such findings are unexpected.