What’s new in Gastrointestinal Imaging – June 2021

1 year ago

 

Intraperitoneal Barium From Gastrointestinal Perforations: Reassessment of the Prognosis and Long-Term Effects 

Ghahremani GG, Gore RM.  

AJR Am J Roentgenol. 2021 May 6:1-7. 

This article from AJR discusses a complication of intraperitoneal barium leak during radiologic evaluations of the gastrointestinal tract. This retrospective study from UCSD looked at 18 patients over a 30 year period, with leakage from a GI perforation that was not suspected before the procedure. Complications occurred during barium enemas, upper GI studies, and small bowel series. The article then presents in detail the cases of four of the patients to demonstrate the long term radiographic appearance of intraperitoneal barium leak. The most common complications of barium spill were peritoneal adhesions and fibrotic granulomas. The authors cite animal studies which show instillation of sterile barium into the abdominal cavity do not incite an inflammatory reaction or peritonitis, however when perforations combine barium with intestinal contents and fecal material with bacteria, this is when peritonitis occurs. All 18 patients in the case series underwent urgent laparotomy with peritoneal lavage and antibiotic therapy. All patients in the case series had unremarkable recoveries, even though they often retained a significant amount of barium in the abdominal cavity, as demonstrated by follow-up imaging studies. The article concludes by stating that as fluoroscopic exams are decreasing in volume, new radiologists will be less familiar with their complications, which still may be seen in clinical practice. 

 

Differentiation between complicated and uncomplicated appendicitis: diagnostic model development and validation study  

Kim HY, Park JH, Lee SS, Jeon JJ, Yoon CJ, Lee KH. 

Abdom Radiol (NY). 2021 Mar;46(3):948-959.  

This article discusses a retrospective analysis which helps to differentiate complicated from uncomplicated appendicitis. Nonoperative management of uncomplicated appendicitis is becoming more common and can reduce the morbidity associated with surgical intervention. The authors state that once appendicitis becomes complicated, antibiotics alone can not reverse the disease process due to perforation or gangrene. The study analyzed 1153 patients with positive CT findings of appendicitis. The authors found that appendiceal wall defects, abscess, moderate to severe periappendiceal stranding, appendiceal diameter >10mm, and extraluminal air were associated with complicated appendicitis. The authors found that if any of these criteria are present on contrast enhanced CT, complicated appendicitis could be predicted with 95% sensitivity. 

 

Segmental Bowel Hypoenhancement on CT Predicts Ischemic Mesenteric Laceration After Blunt Trauma 

Boscak AR, Bodanapally UK, Elshourbagy T, Shanmuganathan K.  

AJR Am J Roentgenol. 2021 Apr 28:1-7.  

This AJR article discusses the performance of CT in diagnosing ischemic mesenteric laceration after blunt trauma. The article begins by discussing the details of ischemic mesenteric lacerations and the clinical significance. The authors state this is a difficult injury to detect on CT, quoting a study which reported an approximately 60% miss rate. Other statistics quoted include a 45% sensitivity but 95% specificity. The authors performed retrospective analysis of 147 patients, 33 of whom had mesenteric laceration, and found CT signs to correlate with ischemic mesenteric laceration. The authors found abdominal wall injury, mesenteric contusion, free fluid, segmental bowel hypoenhancement, and adjacent bowel hyperenhancement were associated with increased risk of ischemic mesenteric laceration. Further analysis identified segmental bowel hypoenhancement and abdominal wall injury as independent predictors with significance to identifying injury. There was no correlation with mesenteric vascular lesions, pneumoperitoneum, focal bowel wall defects, or bowel wall thickening. The authors conclude with a discussion, and acknowledging the difficulty in diagnosing ischemic mesenteric laceration in the setting of blunt trauma. 

 

Dynamic fluoroscopic defecography: updates on rationale, technique, and interpretation from the Society of Abdominal Radiology Pelvic Floor Disease Focus Panel  

Palmer SL, Lalwani N, Bahrami S, Scholz F.  

Abdom Radiol (NY). 2021 Apr;46(4):1312-1322.  

Fluoroscopic defecography is a simple examination used to evaluate pelvic floor abnormalities. This article provides a summary of defecography and describes the indications for, techniques of, and common pathologies encountered. The authors state defecography is the best imaging study to evaluate patients with symptoms of obstructed defecation. The rectal lumen is filled with a contrast paste that approximates the consistency of stool, which is then evacuated under fluoroscopic imaging. The article describes  technique, interpretation, and then commonly encountered pathologies, which include rectocele, enterocele, hernia, intussusception, prolapse, and anismus. The authors conclude by stating that although MRI defecography is gaining prevalence, they prefer fluoroscopic defecography. 

 

Diurnal variation of major error rates in the interpretation of abdominal/pelvic CT studies  

Kliewer et al 

This article was written in an attempt to identify particular days of the week and times of day when radiologists may be most prone to error. The study utilized abdominopelvic CTs over the course of ten years which continued a major error as listed in the authors’ institution quality assurance database. 252 errors were identified. 58 of these occurred on Monday, more than any other day of the week. Major error rates were highest during the period from 9am-12pm, at a level found to be statistically significant. The most common misses occurred in patients who were being scanned with an indication of neoplasm follow-up. The most common anatomic regions of error were the hepatobiliary system and mesentery. It is important to note that studies performed on weekends and from 5pm-7am were not included in the error data. The authors conclude by suggesting radiologists experience periods through the day where physical and mental resources wax and wane, which can lead to poor concentration. 

 

Locally advanced gallbladder cancer: a review of the criteria and role of imaging  

Gupta et al 

Gallbladder carcinoma is the most common malignancy of the biliary system, this article discusses the imaging of gallbladder cancer and how it is used to stratify patients into resectable and unresectable treatment options. Surgical resection is the definite treatment, however most patients are not eligible for surgery based on disease progression at time of presentation. The article discusses epidemiology and clinical presentation, stating patients commonly present late in the disease process due to obstructive symptoms as the tumor grows and spreads, which the article states is commonly directly into the liver, hepatic ducts, stomach, duodenum, with intraperitoneal metastases commonly occurring too. The authors discuss the role of imaging, which is often multimodal with ultrasound, CT, MRI, and PET. The authors imply that once malignancy has spread from the gallbladder, success rates of resection are dismal, and imaging is important to decrease morbidity of unnecessary operations. 

 

Improving the completeness of structured MRI reports for rectal cancer staging  

Zhao et al 

This article provides information into the detail required to provide a complete report for rectal cancer. Colorectal cancer is the third most common malignancy, with rectal MRI providing valuable information into staging, with treatment options, surgical planning, and prognosis dependent on features seen on MRI. Standardized report recommendations have been published in an attempt to give clinicians a clear guide to all the information needed to make clinical decisions. The authors describe how at their institution, a standardized report for rectal cancer was implemented in 2014, nearly 30% of reports remained unsatisfactory, and they attempted to improve reports. The authors educated the faculty and fellows at their academic institution with regard to why improved compliance with a standardized template could lead to improved patient outcomes, and used an educational module to which they provide a link in the article. Additionally, the authors required that all initial rectal cancer staging studies be reviewed by two faculty radiologists. After their intervention period, the authors found a significant increase in proportion of optimal reports following the template. 

 

Diagnostic approach to primary retroperitoneal pathologies: what the radiologist needs to know  

Czeyda-Pommersheim F, Menias C, Boustani A, Revzin M.  

Abdom Radiol (NY). 2021 Mar;46(3):1062-1081. 

This article discusses a variety of different lesions which may arise from the retroperitoneum, and starts with an overview of retroperitoneal anatomy, which can be divided into smaller spaces. The article then introduces imaging features concerning for malignancy, some of which include fat components, intravascular extension, myxoid stroma, necrotic components, and hypervascularity. The article suggests that most retroperitoneal masses with these components are malignant and resection should at least be considered. The article then discusses imaging features of primary retroperitoneal neoplasms such as liposarcoma, leiomyosarcoma, pleomorphic sarcoma, lymphoma, neurogenic tumors, germ cell tumors, and teratomas. Next, nonneoplastic conditions are presented, and include abscesses, AVMs, hematomas, retroperitoneal fibrosis, and extramedullary hematopoiesis. 

 

Abdominal CT in COVID‐19 patients: incidence, indications, and findings 

Barkmeier DT, Stein EB, Bojicic K, Otemuyiwa B, Vummidi D, Chughtai A, Ellis JH.  

Abdom Radiol (NY). 2021 Mar;46(3):1256-1262.  

This topical study discusses abdominal CTs ordered in evaluation of patients with a positive COVID-19 test. The authors discuss the morbidity and mortality of the COVID virus, in which abdominal symptoms may be overlooked as it is classically considered a respiratory illness. The authors performed a retrospective analysis of 1057 COVID positive patients, of which only 43 had an abdominal CT performed as part of their initial presentation. The authors found that compared to the COVID positive patients without an abdominal CT, the inclusion group was significantly older and more likely to have diabetes mellitus, with 40 of these 43 admitted to the hospital. The most common indications for abdominal CT in the 43 patients were abdominal pain, fever, and abdominal infection. In 63% of studies, no acute abdominal findings were seen. The lung bases showed signs of infection in 76% of the abdominal CTs, with various abdominal findings not statistically significant from pre-pandemic imaging. The authors state that no findings in the abdomen should be used to suggest the possibility of coronavirus infection. 

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