Investigation of the Possibility to Reduce Susceptibility Artifacts in MRI Knee Examination

The aim of this present study is to evaluate the reduction of susceptibility artifacts by increasing bandwidth (BW) and echo train length (ETL) in proton density turbo spin echo (PD TSE) sequences with and without fat saturation (FS) and in turbo inversion recovery magnitude (TIRM) sequences. We compared: (1) TIRM coronal (COR) with TIRM COR with high (H) BW and Long ETL; (2) PD TSE sagittal (SAG) FS with the PD TSE SAG FS with (H) BW; (3) PD TSE SAG with PD TSE SAG with (H) BW; (4) PD TSE SAG with PD TSE SAG with (H) BW and Long ETL. A quantitative analysis measured the extent of the susceptibility artifacts. A qualitative analysis evaluated the susceptibility artifacts, image distortion and effectiveness of fat suppression. The depiction of cartilage, menisci, muscles, tendons and bone marrow were also qualitatively analyzed. In the quantitative analysis, modified TIRM appears superior. In the qualitative analysis, the modified TIRM appears superior in 8/10 characteristics. The modified PD TSE FS is superior to the conventional regarding the susceptibility artifacts, image distortion and the depiction of bone marrow and cartilage and fat saturation. The modified PD TSE with (H) BW is found to be superior to the conventional PD TSE only in cartilage. In these sequences, when ETL was increased there were significant differences in four characteristics (ghost artifacts, cartilage, menisci and muscles). TIRM sequences with an increased BW and ETL are proposed to be used in daily clinical practice.