Hisanobu Koyama MD, Presenter: Nothing to Disclose

Motoshige Kotera, Abstract Co-Author: Nothing to Disclose

Tetsuya Tamura, Abstract Co-Author: Nothing to Disclose

Kazuro Sugimura MD, Abstract Co-Author: Research grant, Toshiba Corporation Research grant, Koninklijke Philips Electronics NV Research grant, Mitsubishi Corporation Research grant, Bayer AG Research grant, Eisai Co, Ltd Research grant, DAIICHI SANKYO Group Research Consultant, Shionogi & Co, Ltd

To determine the quantitative diagnostic capability of MRI including diffusion weighted imaging (DWI) in comparison with dual-energy x-ray absorptiometry (DEXA) in osteoporosis patients.

Eight male volunteers (mean age, 42.5 years) and eight consecutive patients (two male and six female patients; mean age, 74.7 years) underwent both DEXA and MRI. Results were obtained from L2 to L4 of each volunteer and patient with a total of 48 lumbar vertebrae. Bone mineral attenuation (BMD) was acquired from DEXA, and according to the results of BMD, vertebrae were classified as the following groups; normal (n = 28), osteopenia (n = 0) and osteoporotic vertebrae (n = 20). All MR examinations were performed on a 1.5 T scanner, and T1WI, fat-suppression T2WI (FS-T2WI), and DWI were obtained. The b-values of DWI were 0, 600, and 1000 sec/mm2. As quantitative MR parameters, signal to noise ratios (SNRs) of T1WI and FS-T2WI, and ADC values from DWI were acquired, respectively. To determine the relationship between MRI and BMD, SNRs and ADC values were correlated with BMD. To determine the difference of SNRs and ADC values between normal and osteoporotic vertebrae, SNRs and ADC values were compared each other. Finally, to determine the quantitative diagnostic capability of MRI as indicator of osteoporosis, ROC analyses were performed.

SNRs and ADC values were significantly correlated with BMD (T1WI: r = -0.64, p<0.001; FS-T2WI: r = -0.36, p<0.05; DWI: r = -0.57, p<0.001). SNRs and ADC values had significant difference among normal and osteoporotic vertebrae (p<0.05). Area under the curve (Az) of SNR of T1WI (Az = 0.96) was significantly higher than those of SNR of FS-T2WI (Az = 0.84) and ADC values of DWI (Az = 0.74) (p<0.05). When adapted 30 as the feasible threshold value of SNR of T1WI, sensitivity, specificity, and accuracy were 95.0 % (19/20), 92.9 % (26/28), and 93.8 % (45/48), respectively.

MRI was a useful method on the assessment of osteoporosis, and in particular SNR of T1WI was a reliable diagnostic indicator.

Though MRI is useful method as an indicator of osteoporosis patients, T1WI was quantitatively more reliable diagnostic indicator than fat-suppression T2WI and DWI.

Koyama, H, Kotera, M, Tamura, T, Sugimura, K, The Quantitative Diagnostic Capability of MR imaging in Osteoporosis Patients.  Radiological Society of North America 2009 Scientific Assembly and Annual Meeting, November 29 - December 4, 2009 ,Chicago IL. http://archive.rsna.org/2009/8000839.html