Qualitative and quantitative assessment of wrist MRI at 3.0T: comparison between isotropic 3D turbo spin echo and isotropic 3D fast field echo and 2D turbo spin echo

Abstract

Background: Isotropic three-dimensional (3D) magnetic resonance imaging (MRI) has been applied to various joints. However, comparison for image quality between isotropic 3D MRI and two-dimensional (2D) turbo spin echo (TSE) sequence of the wrist at a 3T MR system has not been investigated.

Purpose: To compare the image quality of isotropic 3D MRI including TSE intermediate-weighted (VISTA) sequence and fast field echo (FFE) sequence with 2D TSE intermediate-weighted sequence of the wrist joint at 3.0 T.

Material and methods: MRI was performed in 10 wrists of 10 healthy volunteers with isotropic 3D sequences (VISTA and FFE) and 2D TSE intermediate-weighted sequences at 3.0 T. The signal-to-noise ratio (SNR) was obtained by imaging phantom and noise-only image. Contrast ratios (CRs) were calculated between fluid and cartilage, triangular fibrocartilage complex (TFCC), and the scapholunate ligament. Two radiologists independently assessed the visibility of TFCC, carpal ligaments, cartilage, tendons and nerves with a four-point grading scale. Statistical analysis to compare CRs (one way ANOVA with a Tukey test) and grades of visibility (Kruskal-Wallis test) between three sequences and those for inter-observer agreement (kappa analysis) were performed.

Results: The SNR of 2D TSE (46.26) was higher than those of VISTA (23.34) and 3D FFE (19.41). CRs were superior in 2D TSE than VISTA (P = 0.02) for fluid-cartilage and in 2D TSE than 3D FFE (P < 0.01) for fluid-TFCC. The visibility was best in 2D TSE (P < 0.01) for TFCC and in VISTA (P = 0.01) for scapholunate ligament. The visibility was better in 2D TSE and 3D FFE (P = 0.04) for cartilage and in VISTA than 3D FFE (P < 0.01) for TFCC. The inter-observer agreement for the visibility of anatomic structures was moderate or substantial.

Conclusion: Image quality of 2D TSE was superior to isotropic 3D MR imaging for cartilage, and TFCC. 3D FFE has better visibility for cartilage than VISTA and VISTA has superior visibility for TFCC to 3D FFE and the visibility for scapholunate ligament was best on VISTA.