What’s New in Gastrointestinal Imaging – January 2022

4 months ago

Gastrointestinal – Richard Fagan

Abdominal imaging findings on computed tomography in patients acutely infected with SARS‑CoV‑2: what are the findings? Michio Taya. Viktoriya Paroder . Gil Redelman‑Sidi . Natalie Gangai . Jennifer S. Golia Pernicka . Marc J. Gollub . Sidra Javed‑Tayyab . Iva Petkovska . David D. B. Bates. Emergency Radiology (2021) 28:1087–1096. https://doi.org/10.1007/s10140-021-01986-3

 

Authors investigated what findings on contrast enhanced CT of the abdomen and pelvis were new in patients infected with COVID19. Patients were selected retrospectively from a tertiary oncologic center if they were scanned 3 days prior to 45 days after COVID 19 was diagnosed. This study is unique in that the authors only included patients who had a recent prior contrast enhanced CT of the abdomen and pelvis for comparison in order to truly highlight new findings. 63 patients aged 24 to 85 were selected, with 34 males and 29 females being included. The most common new abdominopelvic findings were thickening of the stomach, small bowel, colon or fluid filled colon seen in 14/63 patients (22%), new small volume ascites seen in 7/63 patients (14.3%), gallbladder distention without prior cholecystectomy in 3/43 patients (7.0%). A single case each (1/63, 1.6%) of new acute pancreatitis and new portal vein thrombosis were seen. No patients had hepatomegaly or splenomegaly. Interestingly, although COVID19 infection presenting with predominantly abdominal symptoms is well documented, only 10/63 patients reported abdominal symptoms such as pain, distension or diarrhea. COVID19 uses the angiotensin-converting enzyme 2 receptor for entry into alveolar cells of the lung, and this receptor is present in the small bowel and colon as well. These abdominal findings are important for radiologists to know as radiographic findings are occasionally the first suggestion that a patient is infected with COVID19.

Prediction of epithelial-to-mesenchymal transition molecular subtype using CT in gastric cancer

Dong Ik Cha, Jeeyun Lee, Woo Kyoung Jeong, Seung Tae Kim, Jae-Hun Kim, Jung Yong Hong, Won Ki Kang, Kyoung-Mee Kim, Seon Woo Kim, Dongil Choi. European Radiology (2022) 32:1–11. https://doi.org/10.1007/s00330-021-08094-3

 

The authors of this study attempted to make a CT based prediction model and a nomogram for individualized estimation of epithelial-to-mesenchymal transition (EMT) subtype gastric cancers. Aberrant gastric EMT activation can lead to more aggressive features in gastric cancers and lead to treatment resistance, and EMT subtype has extremely poor prognosis, high recurrence rate after treatment, young age of onset, and high rate of peritoneal seeding. While molecular subtype is important, gene expression profiling is expensive and not implemented routinely, which provides an important need for a predictive model to guide risk stratification for EMT subtype. The authors used known clinicopathologic variables to build a nomogram, and developed a predictive model including CT assessment of infiltrative gastric wall thickening, hypertrophied stroma and unclear differentiation between tumor and stroma. The predictive model developed by the authors using CT had high accuracy with an AUC of 0.865, which was significantly higher than the comparative model that did not use CT which had an AUC of 0.750. The authors nomogram also had good predictive results. This prediction model using CT can serve as a screening test to identify gastric cancer patients with a high probability of EMT subtype which can guide utilization of gene expression profiling.

 

Automatic detection of Crohn’s disease using quantified motility in magnetic resonance enterography: initial experiences. A. Arkko, T. Kaseva, E. Salli, T. M€akel€a, S. Savolainen, M. Kangasniemi. Clinical Radiology 77 (2022) 96e103.

 

Currently magnetic resonance enterography is used to assess disease extent and severity in Crohns disease, but not often used for primary diagnosis. This study explored the utility of automatic detection of Crohn’s disease (CD) using quantified motility in magnetic resonance enterography. Motility aberrations have been shown to correlate with inflammatory biomarkers and symptoms, so the authors targeted altered motility as an indicator of Crohns disease. The MRE imaging of 302 patients at two medical centers were retrospectively reviewed. The population had equal proportions of confirmed CD and excluded CD, and the authors did not exclude patients based on other concurrent GI conditions or other health conditions in order to give a realistically representative population. Free breathing protocols with automatically generated region of interests (ROI) of small bowel, all bowel, non-bowel, and full image ROI were used. If multiple cine rates were available, the smallest repetition time group was used. The authors found that the highest AUC (0.78) was reached using the full image ROI with the highest cine series length. The ability to suggest probability of Crohns as a by product of MRE offers a cost and time efficient diagnostic aid. The authors note that most of the included patients had some underlying GI condition, and that the inclusion of a healthy population may have led to even more significant results.

 

Retrospective Assessment of the Impact of Primary Language Video Instructions on Image Quality of Abdominal MRI. Myles T. Taffel, MD, Andrew B. Rosenkrantz, MD, Jonathan A. Foster, MD, Jay A. Karajgikar, MD, Paul N. Smereka, MD, Felicia Calasso, Kun Qian, MS, Hersh Chandarana, MD. J Am Coll Radiol 2021;18:1635-1642.

 

Respiratory motion artifact is a routine challenge in acquiring high-quality abdominal MRI examinations, and requires communication between the technologist and the patient. The authors of this study created instructional videos for patients undergoing abdominal MRI in their native language to assess the impact on image quality and respiratory motion. 2.5 minute instructional videos were made in Mandarin Chinese and Spanish, and were viewed prior to imaging by patients for whom English is a second language (ESL). These patients were retrospectively compared to English speaking patients, and to ESL patients who did not view the video but used on site or telephone translation services. The study found that the ESL without a native language video had significantly lower scores for T2WI for respiratory motion and overall image quality, than ESL with a native language video, or English speaking patients. The study also found that T1WI for respiratory motion and overall image quality were not statistically different between the groups. T2WI acquisition requires the patient to follow technologist timing for their breathing and respiratory depth, and the T1WI protocol employs an acquisition technique that can acquire images more rapidly, which explains the difference in findings between the T2 and T1 groups.

 

Postoperative complications of colorectal cancer. A. Pallan, M. Dedelaite, N. Mirajkar, P.A. Newman, J. Plowright, S. Ashraf. Clinical Radiology 76 (2021) 896e907.

 

Colorectal cancer is the third most common cancer, and surgery is usually performed as part of treatment. Each surgical option has its unique anatomic changes and possible complications. Recognition of the anatomy and timely identification of complications is vital for effective management of these patients. The article starts with a review of the surgical techniques including segmental resections, Hartmann’s, anterior resections, abdominoperineal resections, micro and minimally invasive surgeries, exenterative and cytoreductive surgeries. The authors then detail the common complications of colon cancer resection including anastomotic leak, fistula, stricture post operative bleeding, adhesions, ileus, hernia, urological injury, and pneumonia with a recently noted increase in pulmonary complications in patients diagnosed with COVID within 7 days before or 30 days after surgery. It is important to recognize these complications and to be able to distinguish them from tumor recurrence. Given the common occurrence of these cancers and operations, radiologists should be familiar with the appearance and complications following surgery in order to provide efficient diagnosis.

 

 

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