A Pilot Study on Feasibility of Ultrashort Echo Time T2* Cartilage Mapping in the Sacroiliac Joints

Abstract

PurposeAssess feasibility of ultrashort echo time (UTE) T2* cartilage mapping in sacroiliac (SI) jointsMethodsProspective magnetic resonance imagings with UTE T2* cartilage maps obtained on 20 SI joints in 10 subjects. Each joint was segmented into thirds by 2 radiologists. The UTE T2* maps were analyzed; reliability and differences in UTE T2* values between radiologists were assessed.ResultsMean UTE T2* value was 10.44 ± 0.60 ms. No difference between right/left SI joints (median, 10.52 vs 10.45 ms; P = 0.940), men/women (median, 10.34 vs. 10.57 ms; P = 0.174), or different anatomic regions (median range 10.55–10.69 ms; P = 0.805). Intraclass correlation coefficients were 0.94 to 0.99 (intraobserver) and 0.91 to 0.96 (interobserver). Mean bias ± standard deviation on Bland-Altman was −0.137 ± 0.196 ms (limits of agreement −0.521 and 0.247) without proportional bias (β = 0.148, P = 0.534).ConclusionsThe UTE T2* cartilage mapping in the SI joints is feasible with high reader reliability.

Assessment of the sacroiliac joint in patients with axial spondyloarthritis via three-dimensional ultrashort echo time magnetic resonance imaging

“…Previous studies have reported that T2 relaxation times of the SIJ cartilage were significantly higher in patients with axSpA than in healthy controls ( 11 , 38 ). SIJ cartilage T2* values of different anatomical regions were not compared in our study because a previous study found there to be no substantial differences across regions in healthy volunteers ( 15 ). The reproducibility of the UTE-T2* measurements of the SIJ cartilage in our study was good, although ROIs may be influenced by the partial volume effect of adjacent bone or ligamentous structures.…”

“…Signals from the short T2* components of the articular cartilage are poorly captured by long TE sequences, which may be useful in determining early cartilage abnormalities ( 13 , 14 ). Although one study reported that 3D-UTE T2* mapping is feasible for SIJ cartilage imaging in asymptomatic volunteers ( 15 ), to the best of our knowledge, 3D-UTE T2* mapping in patients with axSpA has not yet been examined. Therefore, we conducted this study to assess the feasibility of the 3D-UTE sequence for detecting SIJ bone erosion in patients with axSpA using CT as a reference, to evaluate the quantitative T2* mapping from the 3D-UTE sequence in the diagnosis of axSpA, and to compare its performance with that of conventionally clinically available GRE-T2* mapping.…”