Fat-suppressed 3D T1-weighted gradient-echo imaging of the cartilage with a volumetric interpolated breath-hold examination.

Abstract

The purpose of our study was to evaluate the feasibility of using fat-suppressed 3D volumetric interpolated breath-hold examination (VIBE) as a substitute for fat-suppressed 3D FLASH in cartilage MRI. Fat-suppressed 3D VIBE and fat-suppressed 3D FLASH were prospectively performed in 82 patients. The acquisition time of these two sequences were 2 minutes 42 seconds and 3 minutes 53 seconds, respectively. Quantitative comparisons were made by calculating signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR), and qualitative comparisons were made on the basis of two subjective scoring systems evaluating image artifacts and cartilage conspicuousness. In addition, in a subgroup of the 43 patients who underwent arthroscopy with cartilage grading, sensitivity and specificity of these two sequences for cartilage lesions were determined in comparison. Fat-suppressed 3D VIBE provided significantly higher cartilage SNR, cartilage-to-synovial fluid CNR, cartilage-to-meniscus CNR, and cartilage-to-bone marrow CNR than fat-suppressed 3D FLASH. Significantly less pulsation artifact and more severe truncation artifact were seen with fat-suppressed 3D VIBE. Deep cartilage surface conspicuousness in fat-suppressed 3D VIBE was better than that in fat-suppressed 3D FLASH, but superficial conspicuousness was relatively worse. In the patients who underwent arthroscopy, sensitivity and specificity for detecting cartilage lesions of grade 2 or higher were comparable for both sequences, with fat-suppressed 3D VIBE at 78.3% and 97.8% and fat-suppressed 3D FLASH at 79.7% and 97.5%, respectively. Fat-suppressed 3D VIBE is a promising substitute for fat-suppressed 3D FLASH as a more effective T1-weighted sequence in cartilage imaging.