title: T2-weighted MRI of rectosigmoid carcinoma: comparison of respiratory-triggered fast spin-echo, breathhold fast-recovery fast spin-echo, and breathhold single-shot fast spin-echo sequences.
abstract: OBJECTIVE
  To compare the abilities of T2-weighted (T2W) imaging using respiratory-triggered fast spin-echo (RT-FSE), breathhold fast-recovery FSE (BH-FRFSE), and BH single-shot FSE (BH-SSFSE) sequences without an endorectal coil to detect rectosigmoid carcinomas.
  
  
  METHODS
  Forty patients (stage: pT0, 1; pTis-2, 15; pT3-4, 24) were included in the study. All examinations were performed on a 1.5T magnet with a phased-array coil and the patients were studied in the prone position with per-anal air injection. Qualitative and quantitative evaluations were performed.
  
  
  RESULTS
  Motion artifact was the most prominent with the RT-FSE sequence, and the least prominent with the BH-SSFSE sequence. Scores for depiction of the rectal wall layer, tumor recognition, and overall image quality were the highest with the BH-FRFSE sequence. On the basis of a receiver operating characteristic (ROC) analysis, the detection rate of tumor invasion through the rectal wall was higher with the BH-FRFSE sequence (Az = 0.9077) than with the RT-FSE (Az = 0.7762, p < 0.05) or BH-SSFSE (Az = 0.8602) sequence. Tumor-to-fat contrast was highest with the BH-FRFSE sequence (P < 0.017).
  
  
  CONCLUSIONS
  The BH-FRFSE sequence may be the first choice for rectosigmoid T2W imaging in the prone position with per-anal air injection for patients who can hold their breath stably.
authors.affiliation: Department of Radiology, Seirei Hamamatsu General Hospital, Shizuoka, Japan. shuheiy@hama-med.ac.jp
authors.forename: Shuhei
authors.initials: S
authors.lastname: Yamashita
authors.forename: Takayuki
authors.initials: T
authors.lastname: Masui
authors.forename: Motoyuki
authors.initials: M
authors.lastname: Katayama
authors.forename: Kimihiko
authors.initials: K
authors.lastname: Sato
authors.forename: Nobuko
authors.initials: N
authors.lastname: Yoshizawa
authors.forename: Hidekazu
authors.initials: H
authors.lastname: Seo
authors.forename: Harumi
authors.initials: H
authors.lastname: Sakahara
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016477:Artifacts; D002277:Carcinoma / Q000175:diagnosis* / Q000473:pathology; D003937:Diagnosis, Differential; D017352:Echo-Planar Imaging / Q000379:methods; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D011446:Prospective Studies; D012372:ROC Curve; D012004:Rectal Neoplasms / Q000175:diagnosis* / Q000473:pathology; D012119:Respiration; D012811:Sigmoid Neoplasms / Q000175:diagnosis* / Q000473:pathology