- Among 74 patients hospitalized for ulcerative colitis, mural stratification on abdominopelvic multidetector computed tomography (MDCT) was independently predictive of the need for inpatient rescue therapy
- Mural stratification was the only independent predictor of the need for rescue therapy, outperforming clinical variables including age, gender, albumin, C-reactive protein and pancolitis
- This study does not suggest that MDCT should be performed routinely in all hospitalized UC patients for prognosis, but it may be a valuable tool for risk prognostication when available
Patients hospitalized for severe ulcerative colitis (UC) are typically treated with an intravenous steroid and have response assessed after three to five days. If steroid therapy is inadequate, the delay in initiating rescue therapy puts patients at risk of protracted morbidity and disease-related complications.
Kelly C. Cushing, MD, former fellow with the Division of Gastroenterology at Massachusetts General Hospital, Ashwin N. Ananthakrishnan, MBBS, MPH, director of the Mass General Crohn's and Colitis Center, and colleagues have determined that mural stratification visualized on abdominal multidetector computed tomography (MDCT) scans is highly predictive of the need for medical rescue and/or colectomy during hospitalization. Their findings are published in Digestive Diseases and Sciences.
The researchers retrospectively studied 74 patients hospitalized for severe ulcerative colitis who were started on intravenous steroid therapy and underwent abdominopelvic MDCT examination within 48 hours of admission. The average age of the patients was 45 (range, 14–86) and 66% were male.
The scans were performed within 24 hours of admission in 89% of the patients. Two radiologists, blinded to clinical data and the primary outcome, reviewed the scans independently. The primary outcome was the need for medical rescue therapy (cyclosporine or a tumor necrosis factor inhibitor) and/or colectomy during hospitalization.
Rescue therapy was required in 28 patients (38%). Of those, 22 patients (79%) required medical therapy, three (11%) required colectomy and three required both.
CT Findings and Rescue Therapy
Mural stratification was the only MDCT feature significantly associated with the need for rescue therapy. It was seen in 92% of patients who needed rescue therapy versus 49% of those who did not (P = .001).
Mural stratification appears on CT and ultrasound as three concentric circles. The inner ring is composed of mucosa, lamina propria and muscularis mucosa, the middle ring is composed of submucosa and the outer ring is composed of muscularis propria. The use of IV contrast is usually necessary to identify mural stratification, but severe submucosal edema may be seen in noncontrast CT.
Other very common MDCT features were:
- Bowel wall thickening, seen in 100% of patients who needed rescue therapy and 98% of those who did not
- Bowel wall hyperenhancement, seen in 96% and 86%
- Bowel wall stranding, seen in 78% and 65%
- Mesenteric hyperemia, seen in 100% and 100%
Predicting the Need for Rescue Therapy
Mural stratification remained significant on multivariable analysis (OR, 14.9; 95% CI, 2.76–80.2; P = .002) when controlling for age, gender, albumin, C-reactive protein and pancolitis. As a diagnostic test, it had a sensitivity of 92%, a specificity of 51%, a positive predictive value of 55% and a negative predictive value of 91%.
The number of positive MDCT findings also predicted the need for rescue therapy (OR, 2.10; 95% CI, 1.06–4.16; P = .03). The median number of positive MDCT findings was five for patients who required rescue therapy and four for those who did not.
Expanding the Value of an Established Test
MDCT is frequently performed in hospitalized UC patients for evaluation of complications such as infection, perforation and toxic megacolon. This study does not suggest that MDCT should be performed routinely in all hospitalized UC patients for prognosis, but considering the increasing availability of low-dose radiation, it may be a valuable tool for risk prognostication when available.
Visit the Crohn's and Colitis Center
Refer a patient to the Digestive Healthcare Center