膝関節軟骨における脂肪抑制ｔｈｒｅｅ−ｄｉｍｅｎｓｉｏｎａｌ ｃｏｈｅｒｅｎｔ ｏｓｃｉｌｌａｔｏｒｙ ｓｔａｔｅ ａｃｑｕｉｓｉｔｉｏｎ ｆｏｒ ｔｈｅ ｍａｎｉｐｕｌａｔｉｏｎ ｏｆ ｉｍａｇｅ ｃｏｎｔｒａｓｔ（３Ｄ−ＣＯＳＭＩＣ）シーケンスの基礎的検討

Abstract

Fat-suppressed three-dimensional coherent oscillatory state acquisition for the manipulation of image contrast (3D-COSMIC) is a sequence that is based on fast imaging employing steady state acquisition (FIESTA) of balanced steady-state free precession (balanced SSFP). Since the data acquisition of steady-state transition is filled up with the center of k-space, improvement in the contrast of the cartilage, which is a low T₂/T₁ value domain, is expected. This time we report on the usability in applying the above sequence to cartilage imaging of the knee joint and comparing and examining this sequence with the sequence in the past from the viewpoints of the contrast and scan time. As a result, compared with fat-suppressed three-dimensional spoiled gradient echo (3D-SPGR), the contrast of marrow and synovial fluid was equivalent to that of the cartilage, and imaging time was shorter than half of that with the cartilage. Compared with a fat-suppressed two-dimensional proton density weighted image (2D-PDWI), the contrast of the cartilage and synovial fluid was significantly improved, and spatial resolution was also excellent. As a short imaging time and a high resolution image pick-up are possible for fat-suppressed 3D-COSMIC, and it can describe minute damage of the cartilage since it depicts synovial fluid as high-level signals, I think this technique is useful.