Comparison of 2D Fat Suppressed Proton Density (FS-PD) and 3D (WATS-c) MRI pulse sequences in evaluation of chondromalacia patellae

Abstract

Abstract Background Comparing the diagnostic performance of widely used 2D FSE technique (fat-suppressed proton density; FS-PD) and the 3D technique (water-selective cartilage scan; WATS-c) in evaluation of the chondromalacia patella by using arthroscopy as reference standard Results Seventy-five adult patients were enrolled in this study. They underwent MRI examinations then arthroscopy done in 2–4 days after it. MRI was done using 2D (FS-PD) and 3D (WATS-c) sequences and MR images were compared by two radiologists separately, then grading of the cartilage lesions was performed according to modified Noyes grading system and comparison between grade 0–1, 2, and 3 lesions was done using arthroscopic findings as a reference. A false-negative result is considered if there was undergrading of chondromalacia and false-positive result if chondromalacia was overgraded. Each sequence sensitivity, specificity, and accuracy was calculated by both readers. For reader 1, the sensitivity is 69% for WATS-c and 80% for FS-PD and the accuracy is 90% for WATS-c and 92% for FS-PD and for reader 2, the sensitivity is 56% for WATS-c and 84% for FS-PD and the accuracy is 88% for WATS-c and 94% for FS-PD. Conclusion 2D FS-PD images showed better diagnostic performance than 3D WATS-c images for evaluating chondromalacia patella.

Keywords

• WATS-c (water-selective cartilage scan)
• FS-PD (fat-suppressed proton density)
• Chondromalacia patella