Imaging by the SSFSE single slice method at different viscosities of bile

The single shot fast spin echo single thick slice method (single slice method) is a technique that visualizes the water component alone using a heavy T2. However, this method is considered to be markedly affected by changes in the viscosity of the material because a very long TE is used, and changes in the T2 value, which are related to viscosity, directly affect imaging. In this study, we evaluated the relationship between the effects of TE and the T2 value of bile in the single slice method and also examined the relationship between the signal intensity of bile on T1- and T2-weighted images and imaging by MR cholangiography (MRC). It was difficult to image bile with high viscosities at a usual effective TE level of 700-1,500 ms. With regard to the relationship between the signal intensity of bile and MRC imaging, all T2 values of the bile samples showing relatively high signal intensities on the T1-weighted images suggested high viscosities, and MRC imaging of these bile samples was poor. In conclusion, MRC imaging of bile with high viscosities was poor with the single slice method. Imaging by the single slice method alone of bile showing a relatively high signal intensity on T1-weighted images should be avoided, and combination with other MRC sequences should be used. (author)