Faculty Bibliography

BACKGROUND:COVID-19 commonly presents with upper respiratory symptoms; however, studies have shown that SARS-CoV-2 infection affects multiple organ systems. Here, we review the pathophysiology and imaging characteristics of SARS-CoV-2 infection in organ systems throughout the body and explore commonalities. OBJECTIVE:Familiarity with the underlying pathophysiology and imaging characteristics is essential for the radiologist to recognize these findings in patients with COVID-19 infection. Though pulmonary findings are the most prevalent presentation, COVID-19 may have multiple manifestations and recognition of the extrapulmonary manifestations is especially important because of the potential serious and long-term effects of COVID-19 on multiple organ systems.

RATIONALE AND OBJECTIVES/OBJECTIVE:To use a cine balanced steady-state free precession magnetic resonance enterography (cine MRE) pulse sequence to assess the effectiveness of a sublingual (SL) antiperistaltic agent, hyoscyamine sulfate. MATERIALS AND METHODS/METHODS:Institutional review board approval was granted with an exemption for informed consent in this Health Insurance Portability and Accountability Act-compliant, retrospective, single-institution study. Of the 288 MRE examinations performed between October 1, 2007 and January 15, 2011, 92 using SL hyoscyamine sulfate for antiperistalsis were included for review, each with cine MRE before and after medication. These 184 cine MRE data sets were randomized, blinded for treatment, and independently reviewed by five attending abdominal radiologists, who rated the degree of whole abdomen bowel motility on each cine MRE data set on a 5-point scale. Pre- and postmedication mean peristalsis ratings, standard deviation, mean difference, and treatment effect sizes were calculated. A repeated measures analysis of variance test was performed using a significance threshold of P = .05. Interobserver reliabilities were also calculated. RESULTS:Mean peristalsis ratings ranged 2.63-3.34 and 2.36-3.03, before and after medication administration, respectively. The mean differences ranged from 0.22 to 0.46, which are treatment effect sizes of 0.20 to 0.37. The decrease in peristalsis observed by the five reviewing radiologists after SL hyoscyamine sulfate administration was significant (df = 1/182, f = 7.35, P < .01). The interobserver reliabilities were 0.34 for the pretest and 0.33 for the posttest. CONCLUSIONS:Although cine MRE sequences show decreased bowel peristalsis after the use of SL hyoscyamine sulfate, the small size of the observed treatment effect is likely insufficient to justify its use for MRE.

RATIONALE AND OBJECTIVES/OBJECTIVE:The end point of chemoembolization for hepatocellular carcinoma is qualitative. We intended to determine the feasibility of measuring intra-arterial pressure changes after chemoembolization and hypothesized that pressures would increase in the distal hepatic artery after the procedure. MATERIALS AND METHODS/METHODS:Before and after chemoembolization, systemic (S) systolic and mean pressures were measured along with celiac (C), lobar (L), and distal (D) hepatic artery pressures with a pressure wire. Corrected pressures were defined as a ratio with S as the denominator to account for intraprocedural S changes. Changes in the systolic and mean corrected pressures at each location (C/S, L/S, and D/S) were evaluated using paired t tests. Pressure changes in patients with and without tumor response using the Modified Response Evaluation Criteria in Solid Tumors were also compared. RESULTS:Sixteen tumors were treated in 15 patients. One patient had bilobar tumors with separate supplying arteries. The only significant pressure change was systolic D/S (P = .02), while mean D/S approached significance (P = .08). C/S and L/S did not change significantly after chemoembolization. Eleven of 16 patients had a complete response, whereas the other five had a partial response after chemoembolization. When comparing complete to partial responders, no changes in systolic or mean C/S, L/S, or D/S reached statistical significance (all P > .05). CONCLUSIONS:Measuring change in hepatic artery pressures is feasible. Distal intra-arterial corrected pressures increase significantly after chemoembolization. Further study to determine the ability to predict tumor necrosis at follow-up imaging is warranted.