A Simplified Method of T1ρ Mapping in Clinical Assessment of Knee Joint

Abstract

Purpose: We assessed the clinical utility of our proposed simpliˆed method for T 1 r mapping calculations.Materials and Methods: Ten healthy subjects underwent scanning on a 3-tesla magnetic resonance system using an 8-channel phased-array coil. For each subject, we obtained sagittal T 1 r-prepared images using 5 diŠerent time of spin-lock pulses (TSL＝1, 20, 40, 60, and 80 ms), produced conventional T 1 r maps (cT 1 r maps) using all TSLs, and recomputed our proposed simpliˆed T 1 r maps (sT 1 r maps) using a decreasing number of TSLs (from 4 to 2). We then investigated the diŠerences and correlations in T 1 r values of the tissues obtained using diŠerent numbers of spin-lock times.Results: There was a strong positive correlation (single measure intraclass correlation coe‹cient＝0.948; 95z conˆdence interval＝0.911 to 0.970) in T 1 r values of tissues between the cT 1 r and sT 1 r [1, 80] maps. The 2 maps were comparable, though there was a small diŠerence in T 1 r value between the two. The total scan time to acquire the data from 5 spin-lock times was 16 min 15 s. Similarity of the T 1 r [1, 80] map with the conventional approach reduced scan time by 60z, to 6 min 30 s.Conclusion: The clinical relevance of our proposed simpliˆed method is potentially similar to that of the conventional method, and our method requires a shorter examination time and generally preserves the reliability of the T 1 r relaxation time of the tissues.

High-Resolution Methods for Diagnosing Cartilage Damage In Vivo

“…Quantitative magnetic resonance imaging (qMRI), including T2 mapping, delayed gadolinium-enhanced MRI of cartilage (dGEMRIC), and T1 rho (T1ρ) are useful diagnostic tools for assessing articular cartilage because they objectively evaluate the biochemical properties of tissue. [44][45][46][47][48][49][50] These are useful pulse sequences because they can detect biochemical changes that precede morphological degeneration in tissue and may help hasten early diagnosis and treatment of OA.…”

Diffusion tractography of the rat knee at microscopic resolution

“…T2 relaxation is commonly used in both basic and clinical research because of its sensitivity to the collagen orientation and water content in soft tissues . T 1ρ relaxation based on the spin lock technique has been used in connective tissues studies, because it is sensitive to slow motional interactions between confined water molecules and the macromolecular environment . T1 relaxation has been found to be mostly uniform in the soft tissues .…”