Quantitative Comparison of 2D and 3D MRI Techniques for the Evaluation of Chondromalacia Patellae in 3.0T MR Imaging of the Knee

Abstract

Methods: Seventy-five knee MRI exams of 69 adult consecutive patients were included in the study. Fat-saturated T2-weighted (FST2), fat-saturated proton density (FSPD), water-only T2-weighted DIXON (T2mD), T2-weighted 3 dimensional steady state (3DT2FFE), merged multi-echo steady state (3DmFFE), and water selective T1-weighted fatsuppressed (WATSc) images were acquired. Quantitative comparison of grade 1 and grade 5 lesions were made using contrast-to-noise (CNR) ratios. Grade 2-4 lesions were scored qualitatively and scorings of the lesions were compared statistically. Analysis of variance and Tukey’s tests were used to compare CNR data. Two sample z-test was used to compare the ratio of MR exams positive for grade 1 lesions noted on T2-mapping and other conventional sequences. Paired samples t-test was used to compare two different pulse sequences. Results: In detecting grade 1 lesions, FSPD, FST2 and T2mD images were superior in comparison to other sequences. FSPD and FST2 images were statistically superior in detecting grade 2-4 lesions. Although all grade 5 lesions were noted in every single sequence, FST2 images have the highest mean CNR followed by 3DT2FFE images. Conclusion: FST2 sequence is equal or superior in detecting every grade of patellar chondromalacia in 3.0T MR imaging of the knee in comparison to FSPD, T2mD, WATSc, 3DT2FFE, and 3DmFFE images.