[Three-dimensional isotropic magnetic resonance imaging of the ankle joint].

Objective To compare the image quality of isotropic 3-dimensional fast spin echo(3D-FSE), 3D fast field echo(3DFFE), and 2D fast spin echo(2D-FSE) sequences in magnetic resonance imaging(MRI) of the anatomical structure of the ankle joint. Methods The ankle joints of 10 healthy volunteers were examined with isotropic 3D-FSE, 3D-FFE and 2D-FSE sequences using a 1.5T MR scanner and 3D reconstruction. The signal-to-noise ratio(SNR) and contrast-to-noise ratio(CNR) of the tissues were measured. Two radiologists evaluated the image quality of the 3 sequences using a 5- point Likert scale in a doubleblinded manner. Results The 3D- FSE sequences resulted in the highest SNRs for all the tissues and the highest CNRs for differentiation between cartilage and marrow, between muscle and tendon, and between tendon and fluid. In the estimation of image quality for cartilages, 3D-FFE had the highest score followed by 3D-FSE, and the latter had the highest score among the3 sequences in displaying the tendon. Conclusion 3D- FSE sequence has a high performance in displaying the anatomical structures of complex joints especially for cartilage, ligament, and tendon tissues.