Diagnostic performance of MRI for detection of intestinal fistulas in patients with complicated inflammatory bowel conditions

Abstract

The diagnostic performance of magnetic resonance imaging (MRI) for detection of intestinal fistulas, other than perianal, in patients with known complicated inflammatory bowel conditions (CIBC) was investigated. Our study group consisted of 20 patients (12 women, mean age 43 years) with CIBC, including Crohn's disease (n=13), colonic diverticulitis (n=3), colitis after radiotherapy (n=3) and of postoperative origin (n=1). Eleven surgically proven enteral fistulas were known in ten (50%) of these patients, being of enterovesical (n=3), enterocolic (n=2), enteroenteral (n=2), rectovaginal (n=2), rectovaginovesical (n=1) and of entercutaneous (n=1) localisation. The other ten patients (50%), used as the control group, showed MR features of CIBC, although without any fistulous tract. Multiplanar T1-and T2-weighted sequences had been performed, including gadolinium-enhanced acquisition with fat saturation (1.5 T). MR findings were independently blindly and retrospectively reviewed by three radiologists for the presence and etiology of any fistula, as well as visualization and characterization of the fistulous tract. Results were compared with surgical findings (n=16) and clinical evolution (n=4). Interobserver agreement was calculated. Interobserver agreement kappa for fistula detection was 0.71. Overall sensitivity, specificity and accuracy for fistula detection were 78.6%, 75% and 77.2%, respectively. Sensitivity for fistula characterization was 80.6%, with visualization of the fistulous tract in all cases, whereby T1-weighted gadolinium-enhanced fat-saturated images were considered the most useful sequences. Gadolinium-enhanced MRI is a reliable and reproducible tool for detection of enteral fistulas secondary to inflammatory conditions.

Acute Complications of Crohn’s Disease: Comparison of Multidetector-Row Computed Tomographic Enterography with Magnetic Resonance Enterography

“…Very good diagnostic values among all the pathological signs detected in entero-MRI in our study were disclosed for abscesses and fistulae, the latter in agreement with a previous study [30], and equal to our MDCT enterography results, also in agreement with a similar study [12]. Furthermore, several other authors have obtained similar diagnostic values for enteric fistulae with the techniques of enteroclysis and enterography, either combined with MRI [7,11] or with MDCT [17].…”

Enterovesical fistulas: diagnosis and management

“…In diverticulitis, an abscess is very often seen between the sigmoid colon wall and the superior bladder wall. Focal interruption of the muscular layer of the bladder is also recognised as a key finding [50,51]. Although highly sensitive [50,51], MRI has to date a limited role due both to the lack of its availability in the emergency setting and its cost.…”

MR Imaging of the Small Bowel

“…The fistulizing-penetrating subtype is characterized by transmural extension of the inflammatory process, with resulting fistula formation or perforation (73,87). The features of this subtype include deep fissuring ulcers and sinus tracts, fistulas to adjacent bowel loops or other organs (Fig 8), evidence of an associated abscess (Fig 9), and extraintestinal involvement (57).…”