Abstract

Objectives T(2)mapping of the intervertebral disc (IVD) can depict quantitative changes reflecting biochemical change due to loss of glycosaminoglycan content. Conventional T(2)mapping is usually performed using a 2-dimensional multi-echo-spin echo sequence (2D-MESE) with long acquisition times that are generally not compatible with clinical routine. This study investigates the applicability of GRAPPATINI, a T(2)mapping sequence combining undersampling, model-based reconstruction, and parallel imaging, to offer clinically feasible acquisition times in T(2)mapping of the lumbar IVD. Materials and Methods Fifty-eight individuals (26 female; mean age, 23.3 +/- 8.1 years) were prospectively studied at 3 T. GRAPPATINI was conducted with the same parameters as the 2D-MESE while shortening the acquisition time from 13:18 to 2:27 minutes. The setup was also validated in a phantom experiment using a 6.48-hour-long single echo-spin echo sequence as reference. The IVDs were manually segmented on 4 central slices. Results The median nucleus pulposus showed a strong Pearson correlation coefficient between T(2GRAPPATINI)and T-2MESE(r(p)= 0.919;P< 0.001). There was also a significant correlation for the ventral (r(p)= 0.241;P< 0.001) and posterior (r(p)= 0.418;P< 0.001) annular regions. In the single spin-echo phantom experiment, the most accurate T(2)estimation was achieved using T(2GRAPPATINI)with a median absolute deviation of 15.3 milliseconds as compared with T(2MESE)with 26.5 milliseconds. Conclusions GRAPPATINI facilitates precise T(2)mapping at 3 T in accordance with clinical standards and reference methods using the same parameters while shortening acquisition times from 13:18 to 2:27 minutes with the same parameters.

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