PET/MR Versus PET/CT Imaging: Impact on the Clinical Management of Small-Bowel Crohn's Disease

J Crohns Colitis. 2016 Mar;10(3):277-85. doi: 10.1093/ecco-jcc/jjv207. Epub 2015 Nov 15.


Background and aims: The aim of this study was to compare the accuracy and clinical impact of hybrid positron emission tomography [PET]/magnetic resonance-enterography [MR-E] and PET/computed tomography-enterography [CT-E] in patients with Crohn's disease [CD].

Methods: A total of 35 patients with symptomatic small-bowel CD who were scheduled to undergo operation were evaluated before operation by same-day PET/CT-E and PET/MR-E. PET/MR-E was also compared with MR-E alone. Imaging accuracy for detecting pathological sites and discriminating between fibrotic and inflammatory strictures was assessed. Treatment was adjusted according to imaging findings and change in medical/surgical strategy was also evaluated.

Results: PET/CT-E, PET/MR-E, and MR-E were equally accurate in detecting CD sites. PET/MR-E was more accurate in assessing extra-luminal disease [p = 0.002], which was associated with higher need for stoma [p = 0.022] and distant localisation [p = 0.002]. When the latter was observed, laparoscopy was started with hand-assisted device, reducing operative time [p = 0.022]. PET/MR-E was also more accurate in detecting a fibrotic component compared with PET/CT-E [p = 0.043] and with MR-E [p = 0.024]. Fibrosis was more frequently classified as inflammation with MR-E compared with PET/MR-E [p = 0.019]. Out of 8 patients with predominantly inflammatory CD who received medical treatment, 6 [75%] remained surgery free. Overall, 29 patients received surgery. At median follow-up of 9 [6-22] months, no recurrences occurred in either the medical or the surgical group.

Conclusions: Preoperative PET/MR-E imaging is highly accurate for assessing CD lesions before operation and contributed to clinical management of patients with small-bowel CD more often than PET/CT-E.

Keywords: Crohn’s disease; diagnosis; surgery; fibrosis; inflammation; magnetic resonance imaging; pathology.

Publication types

  • Clinical Trial
  • Comparative Study

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Crohn Disease / diagnostic imaging*
  • Crohn Disease / pathology
  • Crohn Disease / surgery
  • Female
  • Follow-Up Studies
  • Humans
  • Intestine, Small / diagnostic imaging*
  • Intestine, Small / pathology
  • Intestine, Small / surgery
  • Laparoscopy
  • Magnetic Resonance Imaging* / methods
  • Male
  • Middle Aged
  • Positron Emission Tomography Computed Tomography*
  • Preoperative Care / methods*
  • Prospective Studies
  • Young Adult