Descending colon diverticulitis diagnosed by ultrasound

Clinical History

A 43-year-old female presented at our department due to acute paraompalic pain radiating to the right illiac fossa. The patient underwent ultrasound and CT examination and one month later colonoscopy.

Imaging Findings

A 43-year-old female presented at our department due to acute paraomphalic pain radiating to the right illiac fossa. A similar experience in the past which was treated conservatively was also reported. During the clinical examination the right inguinal fossa and the left abdomen were tender. An ultrasound examination to exclude appendicitis was performed.

An upper abdominal examination was performed with findings within the normal limits, negative for hydronephrosis or free intraperitoneal fluid. A small right periovarian fluid collection (Fig. 1) was observed and was compatible with ovulation (14th day of menstrual cycle). The appendix presented as a small, easily compressible, concentrically layered, mobile, blind-ending, sausage-like structure, with a diameter < 7mm. Power Doppler revealed no vascular signal and there was no inflamed fat around the appendix.

Then the left abdominal side was also scanned since the patient was complaining of radiating pain. The lower descending colon wall visualized thickened and with the classic ‘pseudo-kidney’ sign (Fig. 2-5). CT examination showed an oedematous lower descending colon and sigmoid colon wall. Also the inflamed diverticulum was revealed as well as the pericolic adipose tissue infiltration (Fig. 6). An intravenous antibiotic treatment was administered and an ultrasound follow up examination was performed 15 days later with the patient almost symptom-free. Pus and faecal material have completely evacuated to the sigmoid lumen, leaving an empty diverticulum (Fig. 7). A colonoscopy was performed 15 days later confirming the diagnosis.

Discussion

Diverticular disease in the younger age group occurs more commonly in men, with obesity being a major risk factor. The disease trend in this patient group is toward more recurrence and an increased incidence of poor outcomes, ultimately requiring surgery.
In patients with appropriate clinical findings, sonographic diagnosis of diverticulitis can be made by demonstrating hypoechoic thickening of the wall of the colon, even in the absence of intramural or intraperitoneal abscess. The wall of the inflamed segment of the colon appears hypoechoic and thickened with maximum thickness of the wall ranging from 5 to 17 mm and length of the most severely inflamed segment of the colon ranging from 6 to 9 cm. Abdominal ultrasound, with a sensitivity of 84% to 98% and a specificity of 80% to 97%, is a noninvasive screening tool with the potential drawback of the interpretation of the study, which may differ from one examiner to another. It is helpful, especially in female patients, to exclude pelvic and gynecologic pathology.
CT, with a sensitivity of 69% to 95%, a specificity of 75% to 100%, and a low false-positive rate, is generally superior to contrast studies. In addition to the identification of complications such as phlegmon, abscess, adjacent organ involvement and distant septic complications, it also is a useful therapeutic tool for percutaneous drainage of intra-abdominal abscesses, providing the opportunity to downstage the intra-abdominal pathology so that it can be treated with a single-stage surgical procedure. Severity staging by CT scanning may allow not only the selection of patients most likely to respond to conservative treatment, but may also predict the risk of failure of medical therapy and of secondary complications after initial conservative treatment. Stage I—diverticulitis with confined paracolic abscess as in the presenting case, stage II—diverticulitis with distant (pelvic, retroperitoneal) abscess, stage III—diverticulitis with purulent peritodiverticular disease is relatively uncommon before the age of 40 years and constitutes only 2% to 5% of the total number of patients in multiple large studies.
Although endoscopy is rarely indicated in an acute setting, if required, it should be done with gentle and cautious insufflation and manipulation because of the risk of perforation of an acutely inflamed colon, either by insufflation of air or by the instrument itself. It can be performed more safely after the patient recovers from the acute attack.

Differential Diagnosis List

Final Diagnosis

Descending colon divericulitis

URL:	https://www.eurorad.org/case/7949
DOI:	10.1594/EURORAD/CASE.7949
ISSN:	1563-4086