What’s New in Gastrointestinal Imaging? – November 2022

1 year ago

MRI-Based Characterization of Intestinal Motility in Children and Young Adults with Newly Diagnosed Ileal Crohn Disease treated by biologic therapy: A controlled prospective study.

Dillman JR, Tkach JA, et al. American Journal of Roentgenology. 219, October 2022


Crohn’s disease can lead to alterations in a patients bowel motility. These changes have previously been primarily assessed subjectively. There is a current lack of data assessing if image based measures of motility can detect response to medical therapy in small-bowel Crohn’s disease. The authors of this study aimed to evaluate intestinal peristalsis using MRI-based dynamic cine imaging and assess changes in objective motility in young patients with newly diagnosed ileal Crohn’s disease treated with biologic therapy. These patients were compared to control patients with no known GI conditions. Subjects underwent MRI of the abdomen with dynamic cine sequences. Patients with Crohn’s disease underwent additional imaging at 6 weeks and 6 months following initiation of therapy. The mean intestinal motility scores in patients with Crohn’s disease increased significantly in the early period following therapy initiation compared with baseline in response to biologic therapy. The study showed mixed results for correlation between intestinal motility and ESR and CRP.


Reducing acquisition time of diffusion weighted MR imaging of the rectum with simultaneous multi-slice acquisition: A reader study.

Koeter T, Jongen G, et al. Academic Radiology 2022; 29: 1802-1807


MRI is widely used for primary staging and restaging of rectal cancer. Diffusion weighted imaging is an integral part of the MRI protocols used for assessment of rectal cancer, especially in patients with good response to neoadjuvant chemoradiotherapy who may be offered a ‘watch-and-wait’ approach instead of early resection. A downside of DWI is the long acquisition times. Several methods of speeding up acquisition time can reduce signal to noise ratio. An emerging technique to reduce acquisition time is simultaneous multi-slice acquisition (SMS) in which multiple excited slices can be separated based on individual signals of multiple coil elements. The authors of this study aimed to assess the acquisition time and image quality of SMS DWI imaging versus conventional DWI of the rectum. The SMS-DWI protocol acquisition time was 4:08 minutes versus 7:24 for the conventional DWI. The overall image quality was found to be not statistically different between SMS and conventional DWI.


Clinically optimal protocol for the imaging of enteric tubes: on the basis of radiologist interpreted diagnostic utility and radiation dose reduction.

Klejch WJ, Marshall EL, et al. Academic Radiology 2022; 29:e279-288.


Confirmation of tube placement is one of the most common indications for portable abdominal radiography. Techniques vary for radiation exposure during these abdominal radiographs, but are usually dependent on manual adjustments by technologists as current mobile units do not offer automatic exposure control techniques. The purpose of this study was to develop and assess a dedicated protocol to assess enteric tube position based on the anteroposterior thickness of the patient. Following development of a protocol using Phantom models, the authors implemented their protocol and were able to reduce effective dose by 80% with no significant difference in diagnostic quality of the radiographs.


Outcomes in pediatric patients with documented delays between ileocolic intussusception diagnosis and therapeutic enema attempt: evaluation of reduction efficacy and complication rate.

Williams JL, Woodward C, et al. Emergency Radiology (2022) 29:953-959.


Ileocolic intussusception in pediatric patients is an abdominal emergency, with pneumatic or hydrostatic enema reduction indicated for reduction. Several factors can lead to delay in attempted reduction including presentation to a facility that does not routinely perform enemas, and diagnosis delays among others. Data is limited on how delays can affect reduction and complications, with previous studies showing improved outcomes for delays to transfer patients to a pediatric hospital or to re attempt a reduction prior to surgery. The authors of this study aimed to assess outcomes of intussusception enema reduction after in-hospital delays. The authors found that successful reduction occurred in 72.2% of cases performed within 1 hour of diagnosis, 74.3% between 1 and 3 hours, 73.2% between 3 and 6 hours, and 81.2% greater than 6 hours. There was no association between need for bowel resection and short delay between diagnosis and reduction attempt. These findings suggest that short delays to allow for adequate prepping of the patient and adequate staffing do not lead to an increase in adverse outcomes.


Extramural vascular invasion as an independent prognostic marker in locally advanced rectal cancer: propensity score match pair analysis.

Paul S, Arya S, et al. Abdominal Radiology (2022) 47:3671-3678.


MRI is the gold standard for local staging of rectal carcinoma. Extramural vascular invasion detected on MRI (mrEMVI) has previously been reported as a poor prognostic factor, and plays a role in predicting local recurrence, operability and distant metastasis, but is not yet included in the TNM staging system. The authors of this study aimed to evaluate the role of mrEMVI as an independent prognostic factor in rectal cancer. The authors compared patients with mrEMVI and without mrEMVI at presentation and assessed for other parameters including T stage, mesorectal fascia involvement, and tumor differentiation. After 3 years 59% of the mrEMVI positive group had locoregional treatment failure, distant metastasis or poor response chemoradiation compared to 45% in the mrEMVI negative group. There was no significant difference in local recurrence. Distant metastasis free survival was significantly worse in the mrEMVI group (58.2%) versus the without EMVI group (69.4%). Overall survival was significantly worse in the mrEMVI group (57%) versus the without EMVI group (72.4%). These findings show that mrEMVI is an independent risk factor for distant metastasis in locally advanced rectal cancer and should factor into treatment decisions.



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