Comparison of dual spin echo echo planar imaging (SE_EPI), turbo spin echo with fat suppression and conventional dual spin echo sequences for T 2-weighted MR imaging of focal liver lesions

Abstract

The performance of T 2-weighted spin-echo version of echo planar imaging (SE_EPI), conventional spin echo (SE) and fat-suppressed turbo spin-echo (TSE_SPIR) sequences for the detection of focal liver lesions was evaluated. Twenty patients that were included in our study, had CT examinations prior to the MR study and were scheduled for surgery for removal of liver lesions. All patients had intraoperative sonographic examinations. Qualitative and quantitative analysis of the images was performed. Overall image quality of SE_EPI sequences was better than SE ( p < 0.001) and similar to TSE_SPIR sequences. There were fewer motion and ghost artifacts on SE_EPI and TSE_SPIR images compared to SE images ( p < 0.001). Susceptibility artifacts were statistically equivalent on SE_EPI and SE images ( p < 0.001) while chemical shift artifacts were equally observed on SE and SE_EPI sequences. Overall image quality of EPI-SE and TSE_SPIR sequences was better compared to SE sequences. There was no significant difference in the number of lesions detected by each of the three sequences. Quantitative analysis showed that liver/lesion contrast-to-noise ratio (CNR) and signal-to-noise ratio (SNR) of liver, lesion, spleen was higher on TSE_SPIR sequences ( p < 0.001) while SE_EPI and SE sequences showed non-significant differences ( p > 0.05). SE_EPI sequences of the liver resulted in fewer artifacts and shorter acquisition times than SE sequences. They provide a diagnostic performance similar to TSE_SPIR and better than that of SE sequences.