Correlation Of’H-Proton MR Spectroscopy And Diffusion Weighed Imaging With Bone Mineral Density Measured By Quantitative CT On The Lumbar Spine

Objective：To investigate the correlation between vertebral1H-MR spectroscopy (MRS) and diffusion weighted imaging (DWI) and bone mineral density (BMD) measured by quantitative computed tomography.Observe the difference between the different age and gender groups and inwomen after menopause.Methods: A sum of124subjects(49cases of male,mean age52.9±16.6years,range20-82years;75cases of female,mean age55.6±15.7years,range21-90years) with lumbocrural pain underwent1H-MR spectroscopy anddiffusion weighted imaging and volumetric bone mineral density measurement.Gender by age group:20-40group (15male and14female),41-60group (17male and31female),older than60years group(17male and30female),Premenopausal23cases and postmenopausal52cases. inclusion criteria(1) No endocrine metabolic disease.(2) No taking hormone drugs are known to change the bone metabolism.(3) No history of tumor chemotherapy and radio therapy,(4) Without form and abnormal signal by MRI imaging.Informed consent was obtained from all subjects.Routine MRI examination (Sagittal T2WI, T1WI and Axial T2WI) wereunderwent by Siemens3.0VERIO MR system. Single voxel was chosen for the1H-MRSacquisition at L2-4vertebral body with PRESS sequence to get the valueof lipid water ratio(LWR)、fat fraction (FF%)、Water peak and fat peakline with(LW). DWI was performed with single shot spin-echo planarimaging sequence (b=0,600s/mm2) and apparent diffusion coefficient (ADC) value were measured. QCT were underwent by Siemens16-slice CTscanner with five standard cylindrical phantom Produced by the U.S. Mindways company at the site lumbar spine(L2-4).Then volumetric BMD w as measure by the software of QCTPRO provided by the U.S. Mindways company’s.According to the diagnostic criteria established by the(ISCD) in2007,all subjects were divided into three groups(normal,BMD=120mg/cm3,DXA T value=-1.0SD;osteopenia;osteoporosis, BMD=80mg/cm3,DXA T value=-2.5SD).Compare the relationship of LWR、FF、LW and ADC of different BMD groups and analyze the correlation between LWR,FF, LW，and ADC. Finally, observe the changes ofMRS and DWI measurements between the different age and gender groups in women aftermenopause.Results：All subjects were divided into three groups (normal, osteopenia，osteoporosis). Normal bone density group(22cases of male,meanage45.5±16.9years,range20-76years,26cases of female,mean age39.6±12.6years,range21-65years); Osteopenia group (17cases of male,meanage453.1±13.5years,range26-72years,21cases of female,mean age62.5±9.9years,range41-90years); Osteoporosis group(10cases of male,mean age68.9±6.9years,range57-82years,25cases of female,mean age65.0±9.1years,range50-84years).1The differences in age groups:（1）Bone density gradually decreased and fatcontent increased with age in both male and female groups, ADC valuesdecreased and water LW broadend in female.(2) Only LWR and FF wassignificant difference in age group41-60and over60years and water LW andfat LW and ADC value were no significant difference among all groups inmale.(3) LWR、FF and ADC values were significant difference in age group20-40and40-60years and LWR、FF、Water LW and ADC values weresignificant difference in age group20-40and Over60years in female, ADCvalues were differences significantly in age group41-60and over60years.2The differences between BMD groups:（1）In male, FF%was signifcantly increased in osteoporosis group when compared with normal group (32.80±20.60%vs17.05±10.47%, p <0.01). LWR、LW and ADC values were no significant difference.(2) In female,when compared with the normal bone group, LWR（0.150±0.15）、FF(11.62±9.10)%、Water LW(66.3±9.8HZ)、Fat LW(48.4±12.2HZ) and ADC value(0.45±0.13×10-3mm2/s) were signifcantly difference in the osteopenia group LWR（0.331±0.254）、FF（22.76±11.11）%、Fat LW（57.6±11.3HZ）、Water LW(75.6±5.8HZ）and ADC value（0.302±0.07）×10-3mm2/s and osteoporosis group LWR（0.433±0.33）、FF（27.16±12.63）%、Fat LW（56.2±14.9HZ）、Water LW（77.6±4.8HZ）and ADC（0.287±0.05）×10-3mm2/s), p <0.05.3The differences between gender groups: LWR and Fat LW in male washigher than that in female in three BMD groups. FF in male was higher thanthat in female in normal and osteoporosis group and was lower in Osteopeniagroup; ADC values in female was higher than that in male in normal andosteopenia groups and lower in osteoporosis group. LWR、WaterLW andADCvalues were significant difference in normal group and no difference inosteopenia and osteoporosis groups between sexs.4The difference between premenopausal and postmenopausal in female:LWR、FF、Water LW、Fat LW and ADC values were significant differencein premenopausal and postmenopausal groups. There was no significantdifference between the two groups in normal group.5The correlation of MRS and DWI with BMD:(1) There was no correlationFF、LWR、Water LW、Fat LW and ADC value with BMD and LWR withADC value in male.(2)LWR、FF、Water LW、Fat LW negatively correlatedwith BMD (r=-0.641、-0.639、-0.524，-0.272respectively, p<0.001) and ADCvalues positively correlated with the BMD (r=0.545, all p<0.001) in female.LWR、FF、Water LW negatively correlated with ADC value (r=-0.484、-0.482、-0.387respetively, p=0.000、0.000、0.002) in female.Conclusion: MRS and DWI parameters have a good correlation withBMD measured by QCT. MRS and DWI can evaluate osteoporosisnoninvasively by studying the pathological changes of vertebral bone marrowin fat content and molecules motion.