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.
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.
Yamashita
Shuhei
S
Department of Radiology, Seirei Hamamatsu General Hospital, Shizuoka, Japan. shuheiy@hama-med.ac.jp
Masui
Takayuki
T
Katayama
Motoyuki
M
Sato
Kimihiko
K
Yoshizawa
Nobuko
N
Seo
Hidekazu
H
Sakahara
Harumi
H
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