Preliminary Research Of MR Diffusion Weighted Imaging And MR Perfusion In Diagnosing Vertebral Diseases

PURPOSE: Combined with the conventional series of MRI, we assessed diagnostic values of MR-DWI and MR-PWI in difference of benign vertebral diseases and metastasis.MATERIALS AND METHODS: 64 vertebral diseases were studied in MR-DWI, include 12 osteoporotic fractures,8 traumatic fractures,8 inflammations,2 tuberculosis and 34 metastasis. 16 vertebral diseases of the total were studied in MR-PWI, include 3 osteoporotic fractures,2 traumatic fractures,2 inflammations and 9 metastasis. We used the following methods: Ⅰ.MR-DWI1.Examination methods: All MR-DWI were scanned with GE signa 1.5T MR/i. In order to localize central slice of disease, we performed vertebral usual scan with T1WI and T2WI sequences at first, then we used spine surface coil and performed with EPI-DWI technique, the "b" is 70 s/mm2,100 s/mm2,165 s/mm2,300 s/mm2,500 s/mm2. The slices were same with the conventional series.2.Analysis methods: After obtained the original images, we did some analysis with the Functool 2 software. Selected the region of interested (ROI), then we can know the apparent diffusion coefficient (ADC) and exponential diffusion coefficient (EDC) of the disease directly.Ⅱ.MR-PWI1.Examination methods: All MR-PWI were scanned with GE signa 1.5T MR/i. We used phase coil and performed PWI with GRE-EPI fast scan technique when the contrast-enhanced agent was injected. Besides these, we used high-pressure syringe, the dosage is 0.2 ml/kg and the injecting rate is about 2.5 ml/s. The others were same with MR-DWI. 2.Analysis methods: After obtained the original images, we did some analysis with the Functool 2 software. Selected the ROI, we obtained the time-intensity curve (TIC). At the same time we can know the Maximum slope of descending (MSD) and Maximum slope of increasing (MSI) of the TIC.Ⅲ.Imaging analysis and statistics methodsTwo experienced doctors who didn't know the results evaluated MR-DWI and MR-PWI to decide the property of signals and the quality of images. Using ANOVA Variance Analysis in 10.0 SPSS software, we statistics the parameters as ADC,EDC,MSD and MSI. All results were described with x±s.RESULTS:Ⅰ.MR-DWI1.The signal INTENSITY in diffusion imaging of metastasis and benign vertebral diseases have no statistically significance.2.When b>=300 s/mm2, the signal-noise ratio of DWI images is worse; When b<=100 s/mm2, THE diffusion effect is too small for us to do related analysis. When b is 165 s/mm2, the diffusion images are good enough to make clinic diagnose. 3.When b=165 s/mm2, the ADC of metastasis and benign vertebral diseases are (1.87±0.12)×10-4 mm2/s and (3.19±0.33)×10-4 mm2/s. The EDC of metastasis and benign vertebral diseases are (1466.25±41.69)×10-3 and (715.68±28.36)×10-3. The ADC and EDC in benign diseases are separately higher and lower than metastasis.Ⅱ.MR-PWI1.The quality of MR-PWI images is the best when we put the gradient stage in the head-feet direction.2.TICs are similar "V" in metastasis and like shallow "Z" in benign diseases, which two ARE obviously different in the shape.3.MSD is (69.52±8.23) and MSI is (48.73±8.89) in metastasis; thus in benign diseases, MSD is (25.66±3.12) and MSI is (9.28±1.66). The MSD and MSI in metastasis are obviously higher than benign vertebral diseases.CONCLUSION: Ⅰ.MR-DWI1.The signal intensity in diffusion imaging of metastasis and benign vertebral diseases have no statistically significance. So we can't distinguish benign disease and metastasis just with the signal intensity of diffusion imaging.2.When mentioned EPI-DWI of vertebra, we should use "b" from 100 s/mm2 to 300 s/mm2, which will give us satisfactory diffusion images.3.When b=165 s/mm2, the ADC of metastasis and benign vertebral diseases are (1.87±0.12)×10-4 mm2/s and (3.19±0.33)×10-4 mm2/s. The EDC of metastasis and benign vertebral diseases are (1466.25±41.69)×10-3 and (715.68±28.36)×10-3. The ADC and EDC in benign diseases are separately higher and lower than metastasis. So the ADC and EDC ar...