MR Cholangiopancreatography: Comparsion of Single Shot Fast Spin Echo Technique and Heavily T2-weighted Fast Spin Echo Technique

Song, Sang Gook; Kim, Hyeong Kil; Chung, Tae Woong; Jeong, Yong Yeon; Kim, Yun Hyeon; Seo, Jeong Jin; Kim, Jae Kyu; Park, Jin Gyoon; Kang, Heoung Keun; Jeong, Gwang Woo; Kim, Sei Jong; Kim, Hyeun Su; Park, Seung Jin; Yoon, Jong Hoon

Abstract

The purpose of this study is to compare the usefulness of single shot fast spin echo(SSFSE) sequence and heavily T2-weighted fast spin echo(FSE) sequence in magnetic resonance cholangiopancreatography(MRCP) in the diagnosis of pancreatobiliary diseases. Twenty-eight patients with suspected pancreatobiliary diseases were examined on 1.5T MR scanner using single- and multi-slice SSFSE and FSE technique. FSE images were obtained with 4 mm slice thickness and reconstructed using maximum intensity projection. The data acquisition techniques of SSFSE were as follows : 1) single-slice acquisition with 80 mm slice thickness, 2) multi-slice (8 slices) acquisition with 10 mm slice thickness, followed by maximum intensity projection. Two radiologists evaluated the MRCP images using the three techniques qualitatively and quantitatively. The results were as follows. For visual conspicuity of hilum of both intrahepatic bile duct, multi-slice SSFSE was superior to single-slice SSFSE and FSE(p< .05). However, for pancreatic duct, single-slice SSFSE was superior to multi-slice SSFSE and FSE(p< .05). But there were no statistically significant differences in visualization of other biliary structures(p> .05). The overall image quality with multi-slice SSFSE was significantly better than that with single-slice SSFSE and FSE(p> .05). For diagnosis of causative lesion, there were no significant differences in three techniques. For quantitative assessment, contrast ratio was the highest in single-slice SSFSE, but statistically not significant(p> .05) and contrast-to-noise ratio was the highest in multi-slice SSFSE, statistically significant(p< .05). In conclusion, SSFSE technique not only provides better conspicuity of intrahepatic bile duct and pancreatic duct with very short scan time, but also gives no difference in iagnosis of causative lesion than does FSE in MRCP . Especially multi-slice SSFSE gives excellent image quality, and is subsequently essential in diagnosis of the patients with marked bile duct dilatation. Also, single-slice SSFSE can be very useful for evaluation of pancreatic duct lesion.