Performance of a fast and high‐resolution multi‐echo spin‐echo sequence for prostate T2 mapping across multiple systems

• Published in: Magnetic resonance in medicine Vol. 79; no. 3; pp. 1586 - 1594
• Main Authors: Houdt, Petra J., Agarwal, Harsh K., Buuren, Laurens D., Heijmink, Stijn W.T.P.J., Haack, Søren, Poel, Henk G., Ghobadi, Ghazaleh, Pos, Floris J., Peeters, Johannes M., Choyke, Peter L., Heide, Uulke A.
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc 01.03.2018
• Subjects: Bias; Coefficient of variation; k‐space undersampling; Magnetic resonance; Mapping; multicenter; Patients; Performance evaluation; Prostate cancer; prostate cancer imaging; quantitative; repeatability; Reproducibility; Spatial discrimination; Spatial resolution; Systems analysis; T2 mapping
• ISSN: 0740-3194; 1522-2594; 1522-2594
• DOI: 10.1002/mrm.26816

Purpose To evaluate the performance of a multi‐echo spin‐echo sequence with k‐t undersampling scheme (k‐t T2) in prostate cancer. Methods Phantom experiments were performed at five systems to estimate the bias, short‐term repeatability, and reproducibility across all systems expressed with the within‐subject coefficient of variation (wCV). Monthly measurements were performed on two systems for long‐term repeatability estimation. To evaluate clinical repeatability, two T2 maps (voxel size 0.8 × 0.8 × 3 mm3; 5 min) were acquired at separate visits on one system for 13 prostate cancer patients. Repeatability was assessed per patient in relation to spatial resolution. T2 values were compared for tumor, peripheral zone, and transition zone. Results Phantom measurements showed a small bias (median = −0.9 ms) and good short‐term repeatability (median wCV = 0.5%). Long‐term repeatability was 0.9 and 1.1% and reproducibility between systems was 1.7%. The median bias observed in patients was −1.1 ms. At voxel level, the median wCV was 15%, dropping to 4% for structures of 0.5 cm3. The median tumor T2 values (79 ms) were significantly lower (P < 0.001) than in the peripheral zone (149 ms), but overlapped with the transition zone (91 ms). Conclusions Reproducible T2 mapping of the prostate is feasible with good spatial resolution in a clinically reasonable scan time, allowing reliable measurement of T2 in structures as small as 0.5 cm3. Magn Reson Med 79:1586–1594, 2018. © 2017 International Society for Magnetic Resonance in Medicine.