Comparison of Modern 3D and 2D MR Imaging Sequences of the Wrist at 3 Tesla

Abstract

Purpose: To compare the image quality of modern 3D and 2D sequences for dedicated wrist imaging at 3 Tesla (T) MRI. Materials and Methods: At 3T MRI, 18 patients (mean age: 36.2 years) with wrist pain and 16 healthy volunteers (mean age: 26.4 years) were examined using 2D proton density-weighted fat-saturated (PDfs), isotropic 3D TrueFISP, 3D MEDIC, and 3D PDfs SPACE sequences. Image quality was rated on a five-point scale (0-4) including overall image quality (OIQ), visibility of important structures (cartilage, ligaments, TFCC) and degree of artifacts. Signal-to-noise ratios (SNR) and contrast-to-noise ratios (CNR) of cartilage/bone/muscle/fluid as well as the mean overall SNR/CNR were calculated using region-of-interest analysis. ANOVA, paired t-, and Wilcoxon-signed-rank tests were applied. Results: The image quality of all tested sequences was superior to 3D PDfs SPACE (p<0.01). 3D TrueFISP had the highest combined cartilage score (mean: 3.4) and performed better in cartilage comparisons against 3D PDfs SPACE in both groups and 2D PDfs in volunteers (p<0.05). 3D MEDIC performed better in 7 of 8 comparisons (p<0.05) regarding ligaments and TFCC. 2D PDfs provided constantly high scores. The mean overall SNR/CNR for 2D PDfs, 3D PDfs SPACE, 3D TrueFISP, and 3D MEDIC were 68/65, 32/27, 45/47, and 57/45, respectively. 2D PDfs performed best in most SNR/CNR comparisons (p<0.05) and 3D MEDIC performed best within the 3D sequences (p<0.05). Conclusion: Except 3D PDfs SPACE, all tested 3D and 2D sequences provided high image quality. 3D TrueFISP was best for cartilage imaging, 3D MEDIC for ligaments and TFCC and 2D PDfs for general wrist imaging.