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

BackgroundComparing 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 standardResultsSeventy-five adult patients were enrolled in this study. They underwent MRI examinations then arthroscopy done in 2-4days 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.Conclusion2D FS-PD images showed better diagnostic performance than 3D WATS-c images for evaluating chondromalacia patella.