MRI-based abnormalities in young adults at risk of adverse bone health due to childhood-onset metabolic & endocrine conditions.
OBJECTIVE
Traditional methods of bone densitometry may not provide a comprehensive assessment of bone health. We aimed to assess bone micro-architecture and bone marrow adiposity (BMA) by MRI in adults with osteogenesis imperfecta (OI) and endocrinopathy including GH deficiency and/or hypogonadism.


METHODS
High-resolution micro-MRI images were acquired at the tibia using 3T MRI to calculate parameters of bone micro-architecture in seven adults with OI and 10 adults with endocrinopathies. MR Spectroscopy was performed in participants to calculate vertebral BMA, which was expressed as percentage fat fraction (%FF). Lumbar spine DXA was performed to assess bone mineral density. The MRI data were compared with a group of 22 healthy adults who were divided into two age-matched control groups.


RESULTS
Intra-operator repeatability was high, with an average CoV of 1% for micro-MRI and 2·5% for MRS. The ratio of apparent bone volume to total volume (appBV/TV) in the endocrinopathy and OI groups was lower than in age-matched control groups (P = 0·003 and P = 0·008 respectively). A weak association between DXA BMD and appBV/TV was also observed (r = 0·5, P = 0·045). %FF was higher in the endocrinopathy group than in the age-matched control group (P = 0·005), but no difference in %FF was observed between the OI group and their age-matched control group (P = 0·26).


CONCLUSIONS
MRI provides valuable detailed information on the micro-architecture and adiposity of bones and is capable of showing clear differences in bone parameters in a range of clinical conditions associated with abnormal bone health.
Department of Clinical Physics, NHS Greater Glasgow & Clyde, Glasgow, UK.
C
C
McComb
A
A
Harpur
C
C
Yacoubian
C
C
Leddy
G
G
Anderson
S
S
Shepherd
C
C
Perry
M G
MG
Shaikh
J
J
Foster
S F
SF
Ahmed
D050154:Adiposity; D000293:Adolescent; D000328:Adult; D015519:Bone Density; D001853:Bone Marrow / Q000473:pathology*; D016022:Case-Control Studies; D005260:Female; D013006:Growth Hormone / Q000378:metabolism; D006801:Humans; D008159:Lumbar Vertebrae / Q000473:pathology; D008279:Magnetic Resonance Imaging / Q000379:methods*; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D008875:Middle Aged; D010013:Osteogenesis Imperfecta / Q000503:physiopathology*; D019047:Phantoms, Imaging; D015203:Reproducibility of Results; D012306:Risk; D055815:Young Adult
D013006:Growth Hormone