Pitfalls and Pearls of Imaging Non-traumatic Thoracic Aortic Disease.

Imaging of the thoracic aorta is a common request in both the acute and outpatient settings, playing a crucial role in diagnosis and treatment planning of aortic disease. The findings of aortic pathology may be obvious or occult on imaging. Recognizing subtle changes is essential and may lead to early detection and prevention of serious morbidity and mortality. Knowledge of the anatomy and understanding the pathophysiology of aortic disease, as well as selecting the appropriate imaging modality and protocol will enable prompt diagnosis and early intervention of aortic pathology. Currently, computed tomography angiography and magnetic resonance angiography of the aorta are the most commonly used imaging modalities to evaluate the aorta. This review focuses on a spectrum of aortic pathology manifestations on computed tomography and magnetic resonance, including atherosclerosis and acute aortic syndromes, highlighting diagnostic challenges and approaches to aid in image interpretation.

CT Scans Obtained for Nonpulmonary Indications: Associated Respiratory Findings of COVID-19.

Background Atypical manifestations of coronavirus disease 2019 (COVID-19) are being encountered as the pandemic unfolds, leading to non-chest CT scans that may uncover unsuspected pulmonary disease. Purpose To investigate patients with primary nonrespiratory symptoms who underwent CT of the abdomen or pelvis or CT of the cervical spine or neck with unsuspected findings highly suspicious for pulmonary COVID-19. Materials and Methods This retrospective study from March 10, 2020, to April 6, 2020, involved three institutions, two in a region considered a hot spot (area of high prevalence) for COVID-19. Patients without known COVID-19 were included who presented to the emergency department (ED) with primary nonrespiratory (gastrointestinal or neurologic) symptoms, had lung parenchymal findings suspicious for COVID-19 at non-chest CT but not concurrent chest CT, and underwent COVID-19 testing in the ED. Group 1 patients had reverse transcription polymerase chain reaction (RT-PCR) results obtained before CT scan reading (COVID-19 suspected on presentation); group 2 had RT-PCR results obtained after CT scans were read (COVID-19 not suspected). Presentation and imaging findings were compared, and outcomes were evaluated. Descriptive statistics and Fisher exact tests were used for analysis. Results Group 1 comprised 62 patients (31 men, 31 women; mean age, 67 years ±17 [standard deviation]), and group 2 comprised 57 patients (28 men, 29 women; mean age, 63 years ± 16). Cough and fever were more common in group 1 (37 of 62 [60%] and 29 of 62 [47%], respectively) than in group 2 (nine of 57 [16%] and 12 of 57 [21%], respectively), with no significant difference in the remaining symptoms. There were 101 CT scans of the abdomen or pelvis and 18 CT scans of the cervical spine or neck. In group 1, non-chest CT findings provided the initial evidence of COVID-19-related pneumonia in 32 of 62 (52%) patients. In group 2, the evidence was found in 44 of 57 (77%) patients. Overall, the most common CT findings were ground-glass opacity (114 of 119, 96%) and consolidation (47 of 119, 40%). Major interventions (vasopressor medication or intubation) were required for 29 of 119 (24%) patients, and 27 of 119 (23%) died. Patients who underwent CT of the cervical spine or neck had worse outcomes than those who underwent abdominal or pelvic CT (P = .01). Conclusion In a substantial percentage of patients with primary nonrespiratory symptoms who underwent non-chest CT, CT provided evidence of coronavirus disease 2019-related pneumonia. © RSNA, 2020.

Navigating the Pulmonary Perfusion Map: Dual-Energy Computed Tomography in Acute Pulmonary Embolism.

Pulmonary embolism is the third most common acute cardiovascular disease. Dual-energy computed tomography perfusion imaging is a promising adjunct in the detection of acute PE providing simultaneous functional assessment of pulmonary perfusion alongside the high-resolution morphological information from computed tomography pulmonary angiography. We review the evidence to date and common causes of perfusion defects including artifacts, parenchymal, and vascular causes, and discuss its potential in furthering our understanding of physiology and pathophysiology in acute pulmonary embolism.

Imaging findings in systemic childhood diseases presenting with dermatologic manifestations.

PURPOSE: Many childhood diseases often present with skin abnormalities with which radiologists are largely unfamiliar. Knowledge of associated dermatologic manifestations may aid the radiologist in confirming the diagnosis and recommending targeted imaging of affected organs. METHODS: We review the imaging findings in childhood diseases associated with dermatologic manifestations. FINDINGS: Diseases include dermatologic findings which herald underlying malignancy (Neuroblastoma, leukemia/lymphoma, Langerhans cell histiocytosis),are associated with risk of malignancy (Epidermolysis Bullosa, basal cell nevus syndrome, Cowden's syndrome, Tuberous Sclerosis),or indicate a systemic inflammatory/immune disorder (Kawasaki's disease, Henoch Schonlein Purpura, systemic lupus erythematosus, scleroderma, sarcoidosis, dermatomyositis and immune thrombocytopenic purpura). CONCLUSION: Familiarity with pertinent findings in childhood diseases presenting with dermatologic manifestations in childhood diseases aids the radiologist in confirming the diagnosis and guiding imaging workup.

False-Positive Ventilation-Perfusion Studies Due to Nonembolic Pulmonary Artery Compromise.

Ventilation/perfusion (V/Q) scans are highly sensitive in detecting clinically significant pulmonary embolisms; however, V/Q mismatches are not specific to pulmonary embolism alone, and other etiologies can cause false-positive results. We present 3 cases where the pulmonary vasculature was compromised, from either intraluminal narrowing or external compression, with resultant mismatches. This raises the importance of interpreting V/Q scan results in conjunction with a thorough medical/surgical history and careful analysis of the chest radiograph.