Sigmoid diverticulitis; Ultrasound and CT findings

Clinical History

A 47-year- old male patient was admitted to our hospital reporting acute onset of severe left iliac fossa pain. Past medical history was unremarkable. Physical examination revealed abdominal tenderness and a slight elevation of body temperature. An abdominal ultrasound was requested.

Imaging Findings

Sonographic examination of left iliac fossa demonstrated hypoechoic wall thickening of a colonic segment surrounded by ill defined hyperechoic pericolic fat changes. Short axis view of colon showed thickened gut wall creating a target pattern.
Further evaluation of the findings was decided and a CT was performed. The examination revealed wall thickening of the sigmoid colon with intense inflammatory changes of pericolic fat, and a small fluid collection in the left paracolic sulci. A small number of diverticula could be observed at the involved segment. Findings were indicative of sigmoid diverticulitis. Surgical exploration confirmed the radiological findings and also demonstrated a tiny diverticular perforation.

Discussion

Diverticula are sac-like protrusions of mucosa through the colonic wall, along the natural openings created by intramural nutrient vessels. Due to higher intraluminal pressure, they are more frequently observed at the level of sigmoid colon. Diverticulosis indicates the presence of multiple diverticula and diverticulitis the inflammation of a diverticulum [1].
Most patients with diverticulosis have few or no symptoms and the condition may be incidentally diagnosed. Clinical manifestations are usually associated with complications such as inflammation, acute or chronic bleeding, fistula formation, intestinal stenosis and micro or macroperforation. Depending on the complication, a patient may present with signs and symptoms that include constipation or diarrhoea, abdominal pain and tenderness (usually in left iliac fossa), fever or urinary tract infection [2].
CT with oral and intravenous contrast is considered the imaging modality of choice for assessing the disease and may demonstrate segmental thickening of the bowel, enhancement of the colonic wall, pericolic fat stranding, extravasation of air and fluid into the pelvis and peritoneal cavity, abscesses and signs associated to fistula formation (such as gas in the bladder). Transabdominal ultrasonography is an alternative technique, not as accurate as CT (the bowel is often poorly visualised due to presence of gas and feces), but wider available, safer (lack of radiation exposure) and with lower cost. Indications for other imaging modalities such as contrast enema or MRI are limited [3, 4].
Treatment options depend on the stage of the disease and the eventual presence of complications and include diet measures, antibiotics, surgery and interventional radiology techniques (such as CT-guided percutaneous abscess drainage) [5].

Differential Diagnosis List

Final Diagnosis

Sigmoid diverticulitis

URL:	https://eurorad.org/case/9840
DOI:	10.1594/EURORAD/CASE.9840
ISSN:	1563-4086