RESUMO
OBJECTIVE: (1) To compare older adults stratified by supraspinatus tendon tear status (STT status)-no tear (Intact), partial-thickness (PT) tear, full-thickness (FT) tear-by 3D Dixon fat fraction (3D-FF); 2D fat fraction (2D-FF); and 2D Goutallier grade (2D-GG) at the Y-shaped view, and 1.4 cm and 2.8 cm medial to the Y-shaped view. Stratified by STT status to determine (2) correlation of 3D-FF with 2D-FF and 2D-GG and (3) inter-rater reliability at and medial to the Y-shaped view. MATERIALS AND METHODS: Forty-five volunteers ≥ 60 years recruited prospectively received shoulder MRI. 3D-FF and 2D-FF were measured on 6-point-Dixon MRI by three trainees. Goutallier grade was assessed on T1-weighted MRI by three fellowship-trained diagnostic radiologists. Descriptive, reliability, and correlation analyses were performed. RESULTS: Groups showed no difference in age. The FT group showed higher (p < 0.05) mean 3D-FF (14.09% ± 10.99%), mean 2D-FF (1.4 cm medial to Y-shaped view, 14.91% ± 12.11%; 2.8 cm medial to Y-shaped view, 13.32% ± 9.48%), and mean 2D-GG (Y-shaped view, 1.71 ± 0.78; 1.4 cm medial to Y-shaped view, 1.71 ± 0.69; 2.8 cm medial to Y-shaped view, 1.71 ± 0.72), relative to Intact/PT groups. 3D-FF showed strong correlation with 2D-FF among all groups/all analyses (rho, 0.80-0.98; p < 0.001). 3D-FF showed strong correlation with 2D-GG for all FT group analyses (rho, 0.85-0.91; p < 0.05). 3D-FF showed moderate-to-strong correlation considering all Intact/PT group analyses (rho, 0.51-0.79; p < 0.50). Dixon fat fraction showed excellent reliability for all groups (≥ 0.884, intraclass correlation coefficient). Goutallier grade showed excellent reliability for FT group (0.771, weighted Fleiss's kappa) but poor (0.294) and fair (0.502) for Intact and PT groups, respectively. CONCLUSION: Single slice MR image estimation of 3D supraspinatus intramuscular fatty infiltration has merit for continued use in clinical populations requiring potential rotator-cuff-repair surgery. However, Dixon fat fraction should be prioritized for use in research over Goutallier grade due to superior reliability.
RESUMO
BACKGROUND: A recent report suggests that semi-quantitative two-dimensional Goutallier grade (2D-GG) correlates poorly with quantitative three-dimensional Dixon fat fraction (3D-Dixon-FF) on magnetic resonance imaging (MRI). PURPOSE: To determine whether the finding of poor correlation of supraspinatus 3D-Dixon-FF with 2D-GG is reproducible, and to determine the strength of the correlation of 3D-Dixon-FF with quantitative 2D Dixon fat fraction (2D-Dixon-FF). MATERIAL AND METHODS: Ten adults aged ≥60 years were recruited prospectively received shoulder MRI. 2D-Dixon-FF and 3D-Dixon-FF were measured on 6-point Dixon fat fraction maps. 2D-GG was rated on T1-weighted images. RESULTS: The mean age of participants was 70.7 ± 3.7 years. The mean 3D-Dixon-FF was 8.3% ± 5.7%; the mean 2D-Dixon-FF was 7.3% ± 4.4%; and the mean 2D-GG was 0.9 ± 0.7. There was a strong correlation for 3D-Dixon-FF with 2D-Dixon-FF (rho = 0.90; P < 0.001) and with 2D-GG (rho = 0.73; P = 0.017). Excellent inter-observer reliability was found for Dixon fat fraction (intraclass correlation coefficient = 0.946), which was good for Goutallier grade (weighted kappa = 0.634). CONCLUSION: Supraspinatus 3D-Dixon-FF had a strong correlation with 2D-Dixon-FF and 2D-GG in our study population.
