[P3-115] Osteoporosis diagnosis using spinal CT image in patients with Duchenne muscular dystrophy
[Introduction] Dual energy X-ray absortiometry (DXA) measurement is a reference standard for osteoporosis diagnosis. However, Duchenne muscular dystrophy (DMD) patients in advanced stage manifest severe skeletal deformity, and often face difficulty undergoing the study. Recent report suggest that computed tomography (CT) attenuation value (Household units [HU]) at L1 spine trabecular bone obtained from images taken for other reasons have positive predictive value above 68% for osteoporosis, when lower than 100 HU (Pickhardt 2013).
[Aim] Assess applicability of CT attenuation value obtained from images taken for other health issues to diagnose osteoporosis in patients with DMD.
[Methods] Retrospective study. Fifteen patients with DMD (age 15-38, mean 21.1y) who had underwent both DXA BMD and CT images that include L1 within two months period were studied. CT attenuation values measured at L1 trabecular bone were compared with bone mineral density (BMD) from DXA.
[Results] Inter-observer reliability calculated by intraclass correlation coefficients was 0.97. Univariate regression analysis showed statistically significant (p=0.038, r2=0.292) correlation for CT value with BMD. Eight out of fifteen patients had Z-scores, and CT values below 110 HU together with Z-score below -2SD were seen in seven patients, indicating abnormal bone loss in those individuals.
[Conclusions] CT value measurement of L1 spine is technically easy and reproducible, and can be an alternative method to estimate BMD for DMD patients who have difficulty undergoing DXA. When the patient has CT value below 110HU, it is highly likely that the individual has abnormal bone loss.
[Aim] Assess applicability of CT attenuation value obtained from images taken for other health issues to diagnose osteoporosis in patients with DMD.
[Methods] Retrospective study. Fifteen patients with DMD (age 15-38, mean 21.1y) who had underwent both DXA BMD and CT images that include L1 within two months period were studied. CT attenuation values measured at L1 trabecular bone were compared with bone mineral density (BMD) from DXA.
[Results] Inter-observer reliability calculated by intraclass correlation coefficients was 0.97. Univariate regression analysis showed statistically significant (p=0.038, r2=0.292) correlation for CT value with BMD. Eight out of fifteen patients had Z-scores, and CT values below 110 HU together with Z-score below -2SD were seen in seven patients, indicating abnormal bone loss in those individuals.
[Conclusions] CT value measurement of L1 spine is technically easy and reproducible, and can be an alternative method to estimate BMD for DMD patients who have difficulty undergoing DXA. When the patient has CT value below 110HU, it is highly likely that the individual has abnormal bone loss.