Improvement of MR cholangiopancreatography at .5 T: three-dimensional half-averaged single-shot fast spin echo with multi-breath-hold technique.
The purpose of this study was to determine the advantage of a three-dimensional (3D) single-shot fast-spin-echo (SSFSE) sequence to obtain MR cholangiopancreatography (MRCP) with a .5-T MR unit by comparison with a two-dimensional (2D) SSFSE sequence. MRCP with 2D-SSFSE and with 3D-SSFSE with 128 echo train lengths was performed on 15 volunteers and 38 patients with pancreatobiliary disease using a .5-T MR unit. For maximum intensity projection (MIP) reconstruction, the section thickness of source images was 4 mm in the 2D-SSFSE and 3 mm in the 3D-SSFSE. 3D volume data in 3D-SSFSE were obtained using repeated short breath-hold of 2 seconds for every repetition time throughout the examination. The image quality, duct conspicuity, signal-intensity ratio (SIR), and contrast-to-noise ratio (CNR) were evaluated. In 23 of the patients who underwent both MRCP and direct cholangiopancreatography (endoscopic retrograde cholangiopancreatography [ERCP]/percutaneous transhepatic cholangiography [PTC]), a comparison between these two modalities was also conducted. The image quality of the MIP image with 3D-SSFSE (49 of 53, 92.5% graded excellent or good) was superior to that with 2D-SSFSE (31 of 53, 58.4%). Duct conspicuity, SIR, and CNR were significantly higher with 3D-SSFSE than with 2D-SSFSE. 3D-SSFSE also showed a stronger relationship with the ERCP/PTC findings compared to 2D-SSFSE. 3D-SSFSE provided satisfactory quality, SIR, and CNR of MRCP images, even when a .5-T MR unit was used, because the breath-hold technique used during 3D data sampling minimized all types of motion effects.
Ichikawa
T
T
Department of Radiology, Yamanashi Medical University, Nakakoma, Japan.
Haradome
H
H
Hanaoka
H
H
Kassai
Y
Y
Nitatori
T
T
Hachiya
J
J
Araki
T
T
D000293:Adolescent; D000328:Adult; D000368:Aged; D001659:Biliary Tract / Q000473:pathology*; D001660:Biliary Tract Diseases / Q000175:diagnosis*; D002760:Cholangiopancreatography, Endoscopic Retrograde; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D010179:Pancreas / Q000473:pathology*; D010182:Pancreatic Diseases / Q000175:diagnosis*; D018709:Statistics, Nonparametric