What’s New in Gastrointestinal Imaging – March 2022

2 months ago

Gastrointestinal Imaging ACORE

Is the Mixed-Use of Magnetic Resonance Enterography and Computed Tomography Enterography Adequate for Routine Periodic Follow-Up of Bowel Inflammation in Patients with Crohn’s Disease? – J Ha et al. Korean Jor of Radiology

Both CT enterography (CTE) and MR enterography (MRE) are considered appropriate for therapeutic monitoring of Chron’s disease (CD), specifically for the assessment of the small bowel. This article evaluates the reliability and accuracy in mixing CTE and MRE for the assessment of small bowel inflammation versus MRE alone in the routine follow-up of Chron’s disease. 258 patients with CD who had an MRE done between July 2016-June 2017 (called the “anchor MRE” in this study) were chosen. The patients had either a CTE or MRE done for follow up of CD, in addition to the anchor MRE. These patients were subsequently divided into two groups: MRE only follow up of CD and mixed MRE/CTE follow up of CD. Three gastrointestinal radiologists interpreted the images and determined whether the CD-related inflammation had decreased, not changed, or increased. The authors found that inter-reader agreement was significantly greater for the MRE only group. The authors concluded that MRE alone is favored over mixed use of CTE/MRE for the follow up of CD.

Ha J, Park SH, Son JH, et al. Is the Mixed Use of Magnetic Resonance Enterography and Computed Tomography Enterography Adequate for Routine Periodic Follow-Up of Bowel Inflammation in Patients with Crohn’s Disease?. Korean J Radiol. 2022;23(1):30-41.

The impact of social distancing during the COVID-19 pandemic on rates of pediatric idiopathic intussusception – A Handa et al. Pediatric Radiology

One likely cause of idiopathic ileocolic intussusception is infection. The authors of this paper took advantage of social distancing to investigate if the decreased transmission of infectious disease during the 2019 COVID pandemic lead to a decrease in ileocolic intussusception. To identify patients with clinically significant ileocolic intussusception, the authors used the number of patients receiving air contrast enemas as a surrogate. Hypertrophic pyloric stenosis (HPS) was used as a negative control for the study, given its many commonalities with Ileocolic intussusception. The monthly number of patients with ileocolic intussusception and HPS were divided into prepandemic (24 months prior to March 2020) and pandemic groups (12 months after April 2020, with March being excluded). The authors found that for Ileocolic intussusception there was a statistically significant decline of 72% during the pandemic, while there was no significant change in the number of HPS cases. The authors report that the decline in cases of intussusception during the pandemic strengthen the argument for infection as a possible causative factor.

Handa, A., Callahan, M.J., Kawai, K. et al. The impact of social distancing during the COVID-19 pandemic on rates of pediatric idiopathic intussusception. Pediatr Radiol 52, 453–459 (2022). https://doi.org/10.1007/s00247-021-05211-8

 

Resurgence of intestinal ascariasis among adults: radiological diagnosis and clinical implications – Ghahremani, GG et al.

Ascariasis is one of the most common parasitic infections in the world. Over the past several years ascariasis has become increasingly uncommon in the United States due to improved sanitation, hygiene practices, and public health programs. However, there has been recent concern for a resurgence of ascariasis in the US. This paper reports the authors experiences with 12 patients in whom ascariasis was found on radiological studies. They also review the imaging characteristics associated with the condition. On both CT with intraluminal contrast and fluoroscopic small bowel series, the worms will appear as long, often tubular, filling defects within the small bowel lumen. MR enterography will demonstrate the hypointense ascaris worms within the bowel lumen. The worms themselves can also ingest intraluminal contrast, which causes opacification of the worm’s intestinal tract, which can be a helpful clue in diagnosis. The authors suggest that CT with oral contrast or small bowel series are preferred over MR enterography for evaluation of patients with suspected ascariasis.  The authors also briefly describe the common symptoms patients may exhibit and possible factors which lead to the recent increase in cases.

Ghahremani, G.G., Hahn, M.E. Resurgence of intestinal ascariasis among adults: radiological diagnosis and clinical implications. Abdom Radiol 47, 915–922 (2022).

Comparison of MRI appendix biometrics in children with and without acute appendicitis – Tung EL, et al.

MRI has recently been reported to have comparable performance to CT in the diagnosis of acute appendicitis, with a sensitivity of 96-98% and specificity of 96-97%. However, MRI use for diagnosis of acute appendicitis remains rare, possibly due in part to a lack of MRI specific diagnostic criteria. This study aims to evaluate the performance of MRI features of appendicitis in pediatric patients to improve diagnostic criteria. 384 MRI exams performed for suspected appendicitis were randomly selected and reviewed (104 positive and 280 negative cases). The authors found the sensitivity to be 90.6% and specificity to be 97.7% for this study. An average appendiceal diameter of 10.4 mm and wall thickness of 2.6 mm was found in cases of appendicitis versus 5.8 mm diameter and 1.7 mm wall thickness in patients without appendicitis. Multiple qualitative biometric features were evaluated for appendicitis, which include, but are not limited to hyperintensity of appendiceal wall on T2 and appendiceal wall being distinguishable from intraluminal signal. The authors conclude that MRI is consistently accurate for evaluating children with suspected appendicitis with the presence of peri-appendiceal fatty edema, diameter greater than 7.5 mm, and ability to distinguish appendix luminal hyperintense signal from wall signal being the imaging features of greatest utility in identifying appendicitis.

Tung, E.L., Baird, G.L., Ayyala, R.S. et al. Comparison of MRI appendix biometrics in children with and without acute appendicitis. Eur Radiol 32, 1024–1033 (2022).

 

Evaluating suspected small bowel obstruction with the water-soluble contrast challenge – Lawrence EM et al.

This review article explores the use of the water-soluble contrast (WSC) challenge for the diagnosis and determination of surgical necessity in patients with small bowel obstruction (SBO). The WSC challenge involves giving a patient water-soluble contrast material by mouth and imaging at different time points to evaluate transit through the bowel. When contrast transits to the colon the WSC challenge is considered passed or successful, while challenges where no colonic contrast is observed are considered failed. A successful WSC challenge can be highly sensitive for predicting patients who do not need operative management for SBO. The authors also review evidence suggesting that the WSC challenge may be of therapeutic value for patients with SBO. Proper technique for performing a WSC challenge is also described. If contrast has made it to the colon in 24 hours, the WSC challenge is passed and the patient is unlikely to need surgical management. In general, research on this topic has generally focused on patients with suspected adhesive SBO, with lots of exclusion criteria. Despite this, the authors describe the nuances of WSC challenge use in special populations which haven’t traditionally been included in studies, such as patients with a history of surgery or malignancy. Lastly, the possibility of CT-based WSC challenge is discussed.

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