| Objective:Application of ATCC25177of Mycobacterium tuberculosis strains (freeze-dried) established in rabbit lumbar spinal tuberculosis model, and to discuss X-ray, CT and MRI (magnetic resonance imaging) routine scan, Diffusion weighted imaging (DWI) can, Perfusion imaging (PWI) and histopathological examination in the diagnosis of rabbit spinal tuberculosis disease early image application value. Methods:First select the60experimental rabbits according to different operation method and reagent were divided into4groups:A group25rats:TB0.2ml injection5.0mg/ml by operation of drilling fluid of rabbit lumbar vertebral; B group25rats:intradiscal injected directly into the bacterium liquid0.2ml5.0mg/ml; C group5rats:rabbit lumbar vertebral injected normal saline0.2ml; D group5rats:the rabbit lumbar intradiscal injection of physiological saline0.2ml.(C group and D group as negative control). Selected each New Zealand white rabbit as the experimental observation of the lumbar6vertebral body, lumbar4vertebral body can be used as its control vertebral. At1-8weeks after operation were randomly killed A, B two groups of rabbits and fluorescence quantitative PCR examination, HE staining, pus bacterial culture and histological examination and anatomical observation; C, D two groups of experimental rabbits were sacrificed rabbits and the inspection at the same time. Main observation indexes:the positive rate of the comparative analysis of two kinds of operation method of modeling, the success rate of acid fast staining; comparative analysis and positive rate of acid fast staining advantage, PCR fluorescence quantitative method in the early detection of spinal tuberculosis; tuberculosis of bone tissue on the edge of osteoblast and osteoclast number and bone histomorphometry analysis. According to the experimental rabbit survival rate was the highest and the operation methods of vertebral tuberculosis infection optimal planting area, to establish animal model imaging:choose40rabbits according to intraoperative reagent were divided into2groups:A group30:TB0.2ml injection5.0mg/ml by operation of drilling fluid of rabbit lumbar vertebral; group B:10the rabbit lumbar vertebral body inject physiological saline (0.2ml; B group as negative control). Selected each New Zealand white rabbit lumbar vertebral body6as the experiment the intervention of the vertebral body,4vertebral body can be used as blank control vertebral body.After4,6,8weeks, X-ray examination, CT examination of conventional MRI imaging and diffusion weighted MRI-DWI imaging and MRI-PWI perfusion imaging. Analysis of the imaging method of each in the early images of spinal tuberculosis and the scanning method of parameter significance, and will analyze the correlation between MRI-PWI perfusion parameters and MRI-DWI diffusion weighted imaging in the. Comparison of various imaging methods on the advantages and disadvantages of early evaluation of spinal tuberculosis. Results:By comparing the two groups of different operation methods the success rate of the model, experimental rabbit A group of lumbar lateral approach to the lumbar6vertebral tuberculosis drilling fluid injected rabbits operation success rate is higher than the B group of lumbar lateral approach in the lumbar intervertebral disc is injected directly into the5-6bacterial liquid; by fluorescence quantitative PCR method can detect specific the content of TB-DNA tuberculosis in pus, and can detect the lowest TB-DNA content, and better than the acid fast staining method; linear relationship between fluorescence quantitative real-time PCR developed very well, the value of Ct DNA template content and Mycobacterium tuberculosis showed a linear relationship with the linear range is4×102～107Copies/mL, r=0.99503; through the organization pathological staining was observed in spinal tuberculosis destroyed early, mainly histopathological performance to tuberculosis exudative period osteitis and hyperplasia of bone destruction.Through the experiment of imaging studies to prove:group A at8weeks postoperatively, three methods of imaging examination of bone destruction, vertebral abscess, epidural and the diagnosis of spinal cord compression sensitivity are meaningful. At8weeks after operation,, bone destruction caused by MRI of spinal tuberculosis compared with CT examination in the diagnosis sensitivity, P values>0.05, shows both at8weeks after operation, this time has no obvious difference on the sensitivity of the diagnosis of bone destruction, for the diagnosis of vertebral side abscess with hard mold, compression of the spinal cord is the sensitivity of magnetic resonance imaging MRI>CT>X ray; At4weeks after surgery building, MRI and MRI-DWI appeared abnormal signal, and the rabbit spinal imaging DWI sequence of b value to get a clear picture in about600s/mm;46,8weeks of infection group vertebral ADC value higher than normal vertebral body (P<0.05); Based on four kinds of ADC images and ADC values of comparative analysis, concluded that:8b value of the DWI fitted ADCgb graph of the signal noise ratio is the highest, and have the best image quality; ADhigh value can reflect the internal vertebral tuberculosis activity; ADClow value with time increased, in the low the b values of DWI, increase the internal perfusion of the vertebra than water restricted molecular motion on the value contribution to significantly; ADCperf value with Mycobacterium tuberculosis of spine damage and showed gradually increasing trend; Experimental group A rabbit spinal tuberculosis in CT value and the negative correlation between number of osteoclast, trabecular bone volume fraction, and negative correlation between the number of osteoclast.By analyzing MRI perfusion imaging parameters it is concluded that:A experimental groups after4,6,8weeks in peak time (TTP) decreased with the extension of observation time and beyond, other perfusion parameters are increased with the time, increased higher than that in B group and control group, except for the peak time (TTP) was negatively correlated with the DWI in the ADCperf, the first pass enhancement ratio (Efirst), the first pass enhancement rate (Vfirst), early enhancement rate (Ee), early enhancement rate (Ve), maximum signal enhancement ratio (Emax), signal enhancement ratio (SER), peak enhancement (PH), signal high rise slope (MSI), excretion rate (washout) were positively correlated with ADCperf. Conclusion: Through the experimental research directly into the two kinds of operation methods of Mycobacterium tuberculosis in lumbar New Zealand rabbits were local cultivation of Mycobacterium tuberculosis and intervertebral disc, can build a rabbit spinal tuberculosis model, examination by gross anatomy, fluorescence quantitative PCR and histopathology confirmed the model succeed. The local cultivation of mycobacterium tuberculosis in New Zealand white rabbit lumbar spinal tuberculosis model construction method is simple and high success rate, which lays a foundation for animal experimental study of spinal tuberculosis early tissue pathology. Through the X-ray, CT and conventional MRI and MRI-DWI, MPI-PWI imaging examination method in the diagnosis of early spinal tuberculosis complementary advantages can improve the inspection sensitivity. Through the analysis of the parameters and MRI-PWI MRI-DWI in the b value, evaluation can make quantitative index for early hemodynamics of vertebral tuberculosis. To provide image basis for early diagnosis and treatment of spinal tuberculosis clinical department of orthopedics. |
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