QUANTIFICATION OF ARTICULAR-CARTILAGE IN THE KNEE WITH PULSED SATURATION-TRANSFER SUBTRACTION AND FAT-SUPPRESSED MR-IMAGING - OPTIMIZATION AND VALIDATION

PURPOSE: To assess the reproducibility and accuracy of volumetric quan tifications of articular cartilage in the knee determined with three-d imensional (3D) magnetic resonance (MR) imaging combined with pulsed s aturation transfer subtraction (STS) or T1-weighted fat suppression (F S) imaging. MATERIALS AND METHODS: Eight osteoarthritic knees were ima ged repeatedly with optimized STS and FS sequences. Cartilage volumes were determined from 3D reconstructions of FS and STS images and by me ans of water displacement of surgically retrieved tissue. RESULTS: Mea n over- or underestimation of cartilage volume at STS and FS imaging w as 0.40 mL +/- 0.11 (standard deviation) (8.2%) and 0.31 mL +/- 0.08 ( 5.9%), respectively. Intraobserver reproducibility error was 0.20-0.65 mL (3.6%-6.4%) for STS and 0.21-0.58 mL (4.2%-6.4%) for FS imaging. I nterobserver error was less than 0.62 mL and 7.8%. CONCLUSION: Three-d imensional data analysis of MR images acquired with STS or FS allows a ccurate and reproducible volumetric quantification of articular cartil age in the knee.