title: Intestinal lesions in pediatric Crohn disease: comparative detectability among pulse sequences at MR enterography.
abstract: BACKGROUND
  Variable sequences can be used in MR enterography, and no consensus exists for the best protocol in children with Crohn disease.
  
  
  OBJECTIVE
  To compare the lesion detectability of various MR enterography sequences and to correlate the findings of these sequences with the Pediatric Crohn's Disease Activity Index (PCDAI) in children with Crohn disease.
  
  
  METHODS
  Children with clinically or pathologically confirmed Crohn disease underwent MR enterography, including a single-shot fast spin-echo (SSFSE) sequence, motility imaging (coronal 2-D balanced fast field echo), diffusion-weighted imaging (DWI), and dynamic contrast enhancement imaging (including arterial, portal and delayed phases). The lesion detectability of each sequence was graded 0-2 for each involved bowel segment. The lesion detectability and PCDAI result on different sequences were compared using the weighted least squares method and Student's t-test, respectively.
  
  
  RESULTS
  Fifteen children (11 boys, 4 girls, mean age 13.7 ± 1.4 years) with a total of 41 lesions were included in this study. All lesions detected in more than two sequences were visible on the single-shot fast spin-echo (SSFSE) sequence. The relative lesion detection rate was 78.1% on motility imaging, 90.2% on DWI, and 92.7% on arterial, 95.1% on portal and 95.1% on delayed phase imaging. Compared to the SSFSE sequence, motility imaging (P < 0.001) and DWI (P = 0.039) demonstrated lower detectability. The mean PCDAI result in the detected lesions was statistically higher only on dynamic enhancement imaging (P < 0.001).
  
  
  CONCLUSIONS
  All MR enterography sequences were found to have relatively high lesion detectability in children with Crohn disease, while motility imaging showed the lowest lesion detectability. Lesions detected on dynamic enhancement imaging showed a higher PCDAI result, which suggests that this sequence is specific for active inflammation.
authors.affiliation: Department of Radiology and Research Institute of Radiological Science, Severance Children's Hospital, Yonsei University, College of Medicine, 50 Yonsei-ro, Seodaemun-gu, 120-752, Seoul, South Korea.
authors.forename: Beomseok
authors.initials: B
authors.lastname: Sohn
authors.forename: Myung-Joon
authors.initials: MJ
authors.lastname: Kim
authors.forename: Hong
authors.initials: H
authors.lastname: Koh
authors.forename: Kyung Hwa
authors.initials: KH
authors.lastname: Han
authors.forename: Mi-Jung
authors.initials: MJ
authors.lastname: Lee
mesh_terms: D000293:Adolescent; D003287:Contrast Media; D003424:Crohn Disease / Q000473:pathology*; D005260:Female; D006801:Humans; D007089:Image Enhancement; D007422:Intestines / Q000473:pathology; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008536:Meglumine; D009942:Organometallic Compounds; D012189:Retrospective Studies
chemical_list: D003287:Contrast Media; D009942:Organometallic Compounds; D008536:Meglumine; C072417:gadoterate meglumine