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3T chemical shift‐encoded MRI: Detection of altered proximal femur marrow adipose tissue composition in glucocorticoid users and validation with magnetic resonance spectroscopy
Author(s) -
Martel Dimitri,
Leporq Benjamin,
Saxena Amit,
Belmont H. Michael,
Turyan Gabrielle,
Honig Stephen,
Regatte Ravinder R.,
Chang Gregory
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.26586
Subject(s) - adipose tissue , nuclear medicine , femoral neck , medicine , femur , magnetic resonance imaging , osteoporosis , in vivo magnetic resonance spectroscopy , trochanter , bone marrow , chemistry , pathology , radiology , surgery
Background Osteoporosis (OP) results in weak bone and can ultimately lead to fracture. Drugs such as glucocorticoids can also induce OP (glucocorticoid‐induced osteoporosis [GIO]). Bone marrow adipose tissue composition and quantity may play a role in OP pathophysiology, but has not been thoroughly studied in GIO compared to primary OP. Purpose/Hypothesis Chemical shift‐encoded (CSE) MRI allows detection of subregional differences in bone marrow adipose tissue composition and quantity in the proximal femur of GIO compared to OP subjects and has high agreement with the reference standard of magnetic resonance spectroscopy (MRS). Study Type Prospective. Subjects In all, 18 OP and 13 GIO subjects. Fields Strength 3T. Sequence Multiple gradient‐echo, stimulated echo acquisition mode (STEAM). Assessment Subjects underwent CSE‐MRI in the proximal femurs, and for each parametric map regions of interest (ROIs) were assessed in the femoral head (fHEAD), femoral neck (fNECK), Ward's triangle (fTRIANGLE), and the greater trochanter (GTROCH). In addition, we compared CSE‐MRI against the reference standard of MRS performed in the femoral neck and Ward's triangle. Statistical Tests Differences between OP/GIO were investigated using the Mann–Whitney nonparametric test. Bland–Altman methodology was used to assess measurement agreement between CSE‐MRI and MRS. Results GIO compared with OP subjects demonstrated: decreased monounsaturated fat fraction (MUFA) (–2.1%, P < 0.05) in fHEAD; decreased MUFA (–3.8%, P < 0.05), increased saturated fat fraction (SFA) (5.5%, P < 0.05), and decreasedT 2 *(–3.8 msec, P < 0.05) in fNECK; decreased proton density fat fraction (PDFF) (–15.1%, P < 0.05), MUFA (–9.8%, P < 0.05), polyunsaturated fat fraction (PUFA) (–1.8%, P < 0.01), increased SFA (11.6%, P < 0.05), and decreasedT 2 *(–5.4 msec, P < 0.05) in fTRIANGLE; and decreasedT 2 *(–1.5 msec, P < 0.05) in GTROCH. There was high measurement agreement between MRI and MRS using the Bland–Altman test. Data Conclusion 3T CSE‐MRI may allow reliable assessment of subregional bone marrow adipose tissue (bMAT) quantity and composition in the proximal femur in a clinically reasonable scan time. Glucocorticoids may alter the lipid profile of bMAT and potentially result in reduced bone quality. Level of Evidence : 2 Technical Efficacy : Stage 2 J. Magn. Reson. Imaging 2019;50:490–496.