Significance Of 7.0T Magnetic Resonance DWI In Assessment Of The Intervertebral Disk Degeneration Of SD Rats

Objective: To assess intervertebral disc degeneration using diffusion weighted imaging(DWI)with 7.0T magnetic resonance imaging.Methods: A.Groups of SD rats ranging in age from 4 to 10 weeks were scanned with 7.0T MRI T2 WI,T1WI imaging sequence and DWI functional imaging sequence.The data and reconstructed ADC charts were collected,then the nucleus pulposus and the annulus fibrosus regions were identified.Several regions of interest(ROI)were chosen and ADC values obtained.ADC values were compared with statistical method.B.After imaging,the intervertebral disks(L1~L6)were isolated,and proteoglycan and type II collagen content was analyzed with statistical method.Results: ADC values in the intervertebral disks decreased in the different rat age groups and same segment to the growth of the rats(P<0.05);ADC values in nucleus pulposus in the same group and different segments also decreased gradually from L1 to L6 segments,while ADC values in annulus fibrosus of the same group and different segments was not statistical significant(P<0.05);The content in intervertebral disks of proteoglycan and type II collagen between different groups also decreased with age(P<0.05);The mean ADC values of different regions of the intervertebral disks was positive correlated with proteoglycan and type II collagen content(P<0.01).Conclusion:It is of a certain significance in assessment of intervertebral disk degeneration of SD rats with 7.0T Magnetic Resonance DWI,and it can be used for investigating early intervertebral disc degeneration.