Magnetic resonance fingerprinting for the whole knee articular cartilage assessment using automated pipeline
摘要
To evaluate the feasibility of a prototype MRF sequence in an automated pipeline for T2 extraction of knee cartilage, and to compare it to the same procedure with a conventional T2 mapping sequence.
Materials and methodsSeventeen healthy volunteers and twenty patients with a focal cartilage damage ICRS grade I–III diagnosed via morphological MRI underwent knee MRI examination, including a prototype MRF sequence, a conventional multi-slice multi-echo (MSME) T2 mapping sequence and double-echo steady-state sequence (DESS). Automated cartilage segmentation with a subsequent automated pipeline for T2 extraction from both T2 maps was performed. The methods were compared via correlation analysis. Test–retest analysis was performed on 5 healthy volunteers and evaluated with the intra-class correlation coefficient (ICC). Additionally, the National Institute of Standards and Technology (NIST) phantom was scanned to compare the methods.
ResultsOn average, the MSME method yielded T2 values 12.4 ms higher than MRF in the phantom and 17.3 ms and 16.3 ms higher in healthy volunteers and patients, respectively. The T2 values correlated very strongly in phantom (r = 0.998, p < 0.001) and in pooled in vivo analysis (r = 0.819, p < 0.001 and r = 0.865, p < 0.001 in volunteer and patient group, respectively), but moderately to strongly in global regions (femoral, patellar and tibial). The reliability of the pipeline was excellent for both methods (ICC from 0.823 to 0.958 for MRF and ICC from 0.863 to 0.932 for MSME).
ConclusionsMRF T2 mapping in the knee cartilage in combination with automatic segmentation is feasible and reliable.
Key Points