Rectal and perirectal CT findings in patients with monkeypox virus infection.

Ola D, Dane B, Shanbhogue K, Smereka P. Abdominal Radiology (2023) 48: 2284-2291

Monkeypox has long been limited to sporadic outbreaks in Africa until a global outbreak in April of 2022. Monkeypox infection can present with rash, fever, lymphadenopathy, and rectal pain has been a reported symptom in the most recent outbreak. This study aimed to quantify the imaging findings of proctitis in patients with laboratory confirmed Monkeypox infection. 21 patients with confirmed Monkeypox infection and CT imaging of the pelvis were included in the study for imaging findings and clinical information. 2 patients presented with fever, and 3 patients presented with elevated white blood cell counts. 14 patients had concomitant HIV infection with average CD4 count of 290 cells/ul. Imaging was obtained for clinical complaints including abdominal pain, perianal pain and rectal bleeding. Mean maximum rectal wall thickness measured 1.1 +/- 0.5 cm in the axial plane. Patients with complaints of rectal pain or bleeding had an increased mean rectal wall thickness of 1.2 +/- 0.5 cm compared to other complaints of 0.6 +/- 0.2 cm. HIV patients had an increased rectal wall thickness of 1.2 +/- 0.5 cm compared to 0.7 +/- 0.2 cm in patients without HIV. 17 patients had abnormal perirectal lymph nodes and 20 patients had perirectal fat stranding. This study demonstrates the high prevalence of proctitis in patients with Monkeypox infection and this infection should be considered on the differential of patients with imaging findings of rectal wall thickening.

Strategies for improving colorectal cancer detection with routine computed tomography.

Johnson CD, Flicek KT, Mead-Harvery C, Quillen JK. Abdominal Radiology (2023) 48: 1891-1899.

Despite data supporting the use of routine screening to reduce incidence and mortality of colorectal cancer, only about 70% of patients are up to date with recommended screenings. The use of CT in the United States has increased in the last 20 years and therefore provides an opportunity for detection of colorectal cancer in unsuspecting patients. 209 patients who were diagnosed with colorectal cancer within one year of receiving an abdominopelvic CT were included in the study and separated into groups which were prospectively diagnosed (106 patients), retrospectively diagnosed (66 patients), or undetected (37 patients) on CT. Asymmetric bowel wall thickening and polypoid masses were present more often in the retrospective group (27% and 26%) than the prospective group (10.5% and 17.1%). Ascending colon location was more likely to be diagnosed retrospectively. Undetected tumors were on average smaller than retrospective or prospectively diagnosed tumors. The prospective group had more pericolonic abnormalities, lymph node involvement, and distant metastases than the retrospective group. The use of iodinated contrast was lowest in the group with undetected colorectal cancer.

Crohn’s disease phenotype analysis with iodine density from dual‑energy CT enterography.

Dane B, Li X, Goldberg JD, O’Donnell T, Megibow A. Abdominal Radiology (2023) 48: 2219-2227.

This study utilized dual energy CT enterography obtained iodine density as a method for identifying phenotype in patients with Crohns disease. 50 patients with CD underwent dual source dual energy CT enterography. Patients were separated into groups based on presence of inflammation, luminal narrowing, stricture and penetrating disease, as defined by the Society of Abdominal Radiology and American Gastroenterological Association consensus statement. Iodine density is a measurement only obtainable using multi energy CT and has been shown to be a marker of Crohns disease activity. Software was used to determine the iodine density and iodine density normalized to the aorta. The means were used to compare groups, and the authors found that iodine density increased with increasing phenotype severity.

Effect of the COVID‑19 pandemic on emergency department utilization of computed tomography scans of appendicitis and diverticulitis.

Collins BW, Robart A, Lockyer EJ, Fairbridge NA, et al. Emergency Radiology (2023) 30: 297-306

This study examined the effects of the COVID lockdown on incidence of diverticulitis and appendicitis presenting to the ED. Retrospective analysis of time periods before, during, and after lockdown was performed. The authors found that significantly fewer patients presented to the ED during lockdown. Despite this decrease in patient volume abdominal CT scans did not drop in proportion to the decrease in patient volume. Appendicitis presentations were found to have not decreased, while diverticulitis presentations decreased. However, the decrease in diverticulitis presentations was not a statistically significant result. No difference in the complicated case presentation was found.

Utility of dual energy CT angiography in the evaluation of acute non‑variceal gastrointestinal hemorrhage: comparison with digital subtraction angiography.

Agarwal A, Kumar KP, Madhusudhan KS. Abdominal Radiology (2023) 48: 1880-1890

This study examined the utility of dual energy CT angiography in acute non-variceal GI hemorrhage and compared it to digital subtraction angiography in patients who underwent both procedures. The authors looked at the attenuation of major abdominal arteries, suspected vascular lesions, and the artery feeding the lesion and calculated contrast to noise and signal to noise ratios. Virtual monochromatic images at 10keV increments from 40 to 70 keV and blended arterial phase images were analyzed. The image quality was qualitatively assessed. The authors found that the vascular lesion was identified in 79.3% and 78.4% of patients by two separate readers on DECTA, compared to 82.9% with DSA. The CNR and SNR of the arteries and vascular lesions was significantly higher at 70 keV compared to the other images. The sensitivity and specificity of blended images and virtual monochromatic images for lesion detection was not significantly different.