What’s New in Gastrointestinal Imaging – August 2021

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Imaging of drug mules

Malhotra R, Singh A. Imaging of drug mules. Emerg Radiol. 2021 Aug;28(4):809-814.

 

This article by a group from Massachusetts General Hospital details imaging findings of drug mules, individuals who internally smuggle illicit substances. The authors state that cocaine, heroin, methamphetamine, and hashish are the most prevalent drugs transported by drug mules. Plain radiography has a sensitivity of up to 90% in evaluating concealed drugs, with low-dose CT also accurate in locating internal packages. The article begins by discussing the worldwide drug epidemic, and then details the importance of radiologists in detection of smuggled substances. The authors state that false negatives pose risk of internal harm to the drug mule, as well as allow contraband to be released to the community. Next, smuggling techniques are discussed in-depth, and include swallowing, rectal, and vaginal stuffing. The article states smugglers have become wise to radiology detection and employ techniques to decrease the radiodensity difference between drugs and surrounding stool. The authors recommend plain radiography as an initial scan, followed by CT to validate diagnosis, and rule out complications, bowel obstruction and perforation are highest concerns. The article discusses different imaging findings, most commonly the “tic tac sign,” smooth oblong figures outlined by air. The appearance of different drugs is discussed, hashish has the highest density, followed by cocaine, then heroin. In conclusion, the authors state that a multimodal approach is needed to accurately identify and treat the internal smuggling of illicit substances.

 

Imaging findings of benign and malignant pediatric splenic lesions

Ozkale Yavuz O, Ozcan HN, Oguz B, Ayaz E, Ekinci S, Ciftci TT, Haliloglu M. Imaging findings of benign and malignant pediatric splenic lesions. Abdom Radiol (NY). 2021 Jul;46(7):3245-3252.

 

This article focuses on pediatric imaging of the spleen, which can contain a wide variety of pathology, some benign and some malignant. Cysts are the most common benign splenic lesions, followed by hemangiomas and lymphatic malformations. The vast majority of malignant conditions of the spleen are related to leukemia and lymphoma, with angiosarcoma as the most common primary splenic malignancy. The article discusses imaging findings of each of these pathologies, as well as less common findings such as sclerosing angiomatoid nodular transformation (SANT), inflammatory myofibroblastic tumors, and hamartomas. As this article relates to pediatric imaging, the manuscript predominantly focuses on ultrasound and MRI findings.

 

A review of optimal evaluation and treatment of suspected esophageal food impaction

Lake M, Smoot D, O’Halloran P, Shortsleeve M. A review of optimal evaluation and treatment of suspected esophageal food impaction. Emerg Radiol. 2021 Apr;28(2):401-407.

 

This article discusses contrast-guided fluoroscopy to evaluate and treat esophageal impactions. The article states that while proximal and mid esophageal impactions require ENT and GI intervention, obstructions distal to the arch may be managed by the radiologist with a fluoroscopic disimpaction. The authors describe a technique using a combination of effervescent material, glucagon injection, and water to dislodge the obstruction. Glucagon relaxes the esophageal smooth muscle, the effervescent agent dilates the esophagus, and water increases hydrostatic pressure above the bolus. The authors cite a 56% disimpaction success rate in 252 attempts over the past 32 years at their institution. The authors describe in-depth their indications, technique, and contraindications for fluoroscopic esophageal disimpaction. Besides location, the main contraindications include obstruction due to strictures or sharp foreign body.

 

Traumatic abdominal wall injuries—a primer for radiologists

Steenburg SD, Padilla-Jones B, Lee JT, Petersen MJ, Boutselis AG, Lay SE, Dunkle JW, Chong S. Traumatic abdominal wall injuries-a primer for radiologists. Emerg Radiol. 2021 Apr;28(2):361-371.

 

While internal organs need to be evaluated in cases of blunt trauma, this article discusses the importance of evaluating the abdominal wall and spectrum of injuries that may occur. Abdominal wall injuries occur in around 10% of blunt trauma patients, and can range from abdominal wall contusions and muscle strains, to hematomas and abdominal wall rupture. The authors discuss clinical evaluation, imaging findings, and surgical approach to these injuries. Traumatic abdominal wall hernia is the most severe form of abdominal wall injury, and may be seen in up to 1.5% of patients with blunt abdominal trauma. This most commonly occurs at the inferior lumbar triangle and as the result of being a restrained passenger in a motor vehicle collision. Identification of traumatic hernias is important, as up to 25% of patients will develop incarceration or strangulation if unrepaired. The authors state that the radiologist should not be biased by satisfaction of search with injuries to the internal organs, as these may signal increased risk for high-grade abdominal wall trauma.

 

Appendicitis and beyond: a pictorial review of various appendiceal abnormalities

Fenwick AKC, Hartery A. Appendicitis and beyond: a pictorial review of various appendiceal abnormalities. Emerg Radiol. 2021 Jun;28(3):651-664.

 

While appendicitis is the most common process to affect the appendix, this article reviews a wide range of additional appendiceal pathology, benign and malignant. The authors start by discussing the anatomy of the appendix, which is vital to understand the pathology that can occur. Acute appendicitis is discussed first, with the authors presenting clinical and imaging features as well as complications such as perforation. The authors then discuss other inflammatory changes to the appendix such as appendiceal diverticulitis, stump appendicitis, foreign body appendicitis, Crohn’s disease, and appendiceal hernias, which can occur both through the abdominal wall and into the inguinal canal. Neoplastic conditions are then discussed, including neuroendocrine tumors, mucinous and non-mucinous epithelial neoplasms, and lymphoma.

 

Hemorrhagic cholecystitis: ultrasound and CT imaging findings—a retrospective case review series

Ramírez Calderón JZ, Martínez Chamorro E, Ibáñez Sanz L, Albillos Merino JC, Borruel Nacenta S. Hemorrhagic cholecystitis: ultrasound and CT imaging findings-a retrospective case review series. Emerg Radiol. 2021 Jun;28(3):613-620.

 

This article discusses one of the complicated presentations of acute cholecystitis, hemorrhagic cholecystitis. The authors collected 11 cases over a six-year period as confirmed by pathology report. The authors found hemorrhagic cholecystitis was most commonly seen in patients with cholelithiasis and on anticoagulation therapy. The etiology is first presented, described as likely due to inflammatory changes of the gallbladder wall which may lead to wall infarction and hemorrhage. In their case series, while ultrasound was a first line imaging modality for several patients, all eventually underwent CT, with one patient undergoing MRI. The authors state that ultrasound may reveal typical signs of acute cholecystitis, additional findings may include hyperechoic debris within the lumen which may signify blood products. CT may demonstrate hemobilia or intraluminal material with a hematocrit level. Hemoperitoneum may suggest perforation in the setting of hemorrhagic cholecystitis. MRI is typically not performed for suspicion of hemorrhagic cholecystitis due to the clinical scenario and the ability of CT and ultrasound to diagnosis cholecystitis, but MRI is the best imaging test to differentiate hemorrhage. Urgent cholecystectomy is the treatment of choice due to the high morbidity and mortality of hemorrhagic cholecystitis.

 

CT appearance of gastrointestinal tract mucormycosis

Ghuman SS, Sindhu P, Buxi TBS, Sheth S, Yadav A, Rawat KS, Sud S. CT appearance of gastrointestinal tract mucormycosis. Abdom Radiol (NY). 2021 May;46(5):1837-1845.

 

Mucormycosis is commonly thought to affect the sinuses and lungs, however this article reviews the imaging findings as it affects the gastrointestinal tract. Mucormycosis is most commonly seen in patients with an impaired immune system. Within the GI tract, the stomach is the most commonly affected organ, followed by colon, small intestine, and esophagus.

CT findings include pneumatosis, decreased wall enhancement, thickening of intestinal wall, and pneumatosis. As these findings are largely nonspecific, clinical history is important. The authors include examples of all of the imaging findings and different manifestations throughout the different parts of the GI tract. While abdominal mucormycosis is rare, it has a high mortality rate, and should be suspected in immunocompromised patients with unexplained bowel ischemia.

 

Caustic ingestion: CT findings of esophageal injuries and thoracic complications

Cutaia G, Messina M, Rubino S, Reitano E, Salvaggio L, Costanza I, Agnello F, La Grutta L, Midiri M, Salvaggio G, Gargano R. Caustic ingestion: CT findings of esophageal injuries and thoracic complications. Emerg Radiol. 2021 Aug;28(4):845-856.

 

Ingestion of caustic substances may be accidental or intentional and can cause severe damage throughout the GI system, this article focuses on the esophageal and thoracic findings. Caustic substances can cause damage by many mechanisms which include liquefaction necrosis, fat saponification, protein denaturation, and thrombosis of blood vessels. The authors cite guidelines from the World Society of Emergency Surgery which state that CT should be the initial imaging study to evaluate for a surgical emergency, followed by endoscopy if none is found. Plain radiographs may also be useful to detect pneumomediastinum or pleural effusions in the setting of perforation. For CT, the authors recommend a triple phase study of noncontrast, arterial, and venous phase contrast-enhanced imaging. The authors also recommend oral contrast administration if perforation is suspected. The article then discusses the different imaging findings which may be seen in acute, subacute, and chronic injuries to the esophagus. Aside from esophageal injury, the authors also discuss mediastinal injuries and respiratory fistulas.

 

A comprehensive radiologic review of abdominal and pelvic torsions

Bonney R, Revels JW, Wang SS, Lussier R, Dey CB, Katz DS, Moshiri M. A comprehensive radiologic review of abdominal and pelvic torsions. Abdom Radiol (NY). 2021 Jun;46(6):2942-2960.

 

This review article goes beyond ovarian and testicular torsion and discusses the various types of torsions that can occur throughout the abdomen and pelvis. Imaging findings are important as some of the less common torsions may not be suspected clinically. The article states that nearly each of the organs is capable of torsion, which can lead to significant morbidity and mortality of not identified and promptly treated. One of the imaging features common to various torsions is the “whirlpool” sign, twisting of the vascular pedicle. The article discusses imaging findings of torsion throughout the gastrointestinal tract from the stomach to the colon, where it is known as volvulus. The article then discusses torsion of the omentum, spleen, gallbladder, pancreas, kidneys, transplant liver, ovaries, fallopian tubes, fibroids, and testicles. In conclusion, the authors declare the importance of radiologists in identifying torsion of abdominal organs, as many of them are rare and likely not clinically suspected in the initial workup of acute abdominal pain.

 

Intraperitoneal focal fat infarction: the great mimicker in the acute setting

Lazaridou E, Aslanidi C, Mellou V, Athanasiou S, Exarhos D. Intraperitoneal focal fat infarction: the great mimicker in the acute setting. Emerg Radiol. 2021 Feb;28(1):201-207.

 

Along the same lines of torsion, this article discusses infarction of intraperitoneal fat, including conditions such as epiploic appendagitis, omental infarction, and perigastric appendagitis.  Most cases of focal fat infarction are related to torsion with vascular occlusion, most commonly venous, which can lead to infarction of the greater omentum, epiploic appendages, and more rarely, the falciform ligament. These self-limiting conditions may mimic other emergent pathologies such as appendicitis or diverticulitis, and imaging is important to prevent unnecessary surgical intervention. The article discusses clinical presentation, as well as ultrasound, CT, and MRI protocols and findings of each of the above conditions. Imaging has high sensitivity and specificity, and proper diagnosis is crucial to prevent unnecessary intervention.

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