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Repeatability and reproducibility of variable flip angle T 1 quantification in the prostate at 3 T
Author(s) -
Zhong Xinran,
Shakeri Sepideh,
Liu Dapeng,
Sayre James,
Raman Steven S.,
Wu Holden H.,
Sung Kyunghyun
Publication year - 2019
Publication title -
journal of magnetic resonance imaging
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.563
H-Index - 160
eISSN - 1522-2586
pISSN - 1053-1807
DOI - 10.1002/jmri.26596
Subject(s) - repeatability , reproducibility , concordance correlation coefficient , flip angle , nuclear medicine , coefficient of variation , kappa , correlation coefficient , medicine , mathematics , magnetic resonance imaging , statistics , radiology , geometry
Background Variable flip angle (VFA) imaging is widely used for the estimation of T 1 relaxation in the prostate, but may have limited repeatability and reproducibility due to its sensitivity to B 1 + inhomogeneity. Purpose To assess the repeatability and reproducibility of prostate T 1 estimation with and without compensating for B 1 + variation. Study Type Prospective. Population Twenty‐one volunteers were prospectively recruited and scanned twice on two 3 T MRI scanners, resulting in 84 VFA T 1 exams. Field Strength/Sequence 3 T/2D saturated turbo fast low angle shot (FLASH) and 3D dual‐echo FLASH. Assessment Two B 1 + mapping techniques, including reference region VFA (RR‐VFA) and saturated turbo FLASH (satTFL), were used for B 1 + correction, and T 1 maps with and without B 1 + correction were tested for intrascanner repeatability and interscanner reproducibility. Volumetric regions of interest (ROIs) were drawn on the transition zone, peripheral zone of the prostate, and the obturator internus left and right muscles in the corresponding slices. Statistical Tests The average T 1 within each ROI for each scan was compared for both intra‐ and interscanner variability using concordance correlation coefficient and a Bland–Altman plot. Results Both RR‐VFA‐corrected T 1 and satTFL‐corrected T 1 showed higher intra‐ and interscanner correlation (0.89/0.87 and 0.87/0.84, respectively) than VFA T 1 (0.84 and 0.74). Bland–Altman plots showed that VFA T 1 had wider 95% limits of agreement and a larger range of T 1 for each tissue compared with T 1 with B 1 + correction. Data Conclusion The application of B 1 + correction (both RR‐VFA and satTFL) to VFA T 1 results in more repeatable and reproducible T 1 estimation than VFA T 1 . This can potentially provide improved quantification of the prostate dynamic contrast‐enhanced MRI parameters. Level of Evidence 1. Technical Efficacy Stage 1. J. Magn. Reson. Imaging 2018.