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Objective@#To evaluate the precision of image registration between MRI simulation (MRIsim) and CT simulation compared to diagnostic MRI(MRIdiag) and to provide information for further application of MRIsim.@*Methods@#A total of 24 patients who underwent both MRIsim and MRIdiag were enrolled, including 8 patients with gliomas, 8 with nasopharyngeal carcinomas and 8 with prostate cancers. MRIsim and MRIdiag images of each patient were fused with CT. The OARs were delineated on three modalities of images and targets were delineated on fusion image of MRIsim with CT (F_CTMsim) and fusion image of MRIdiag with CT (F_CTMdiag) respectively. The concordance index (CI), Dice′s similarity coefficient (DSC) between the OARs and image similarity index (S) based on images from MRIsim, MRIdiag and CT were evaluated. IMRT plans were designed based targets on F_CTMsim and OARs on CT images, and differences in dosimetry of targets and OARs were evaluated subsequently.@*Results@#Volumes of most OAR from three modalities of images showed no statistically significant difference(P>0.05). All the CI and DSC between the OARs derived from MRIsim and CT were higher than those corresponding values from MRIdiag, and a statistically significant difference was achieved in 50% of these OARs (t=2.58-5.47, P<0.05). The S values of MRIsim and MRIdiag compared with CT were 0.89 and 0.83 respectively (t=5.77, P<0.05). MRIsim improved the S value by 10% (2%-56%) compared with MRIdiag. No further differences in dosimetry were found on all OARs and all targets(P>0.05).@*Conclusions@#The precision of image registration can be significantly improved by introducing MRIsim into radiotherapy planning design compared with MRIdiag. However, no significant differences in dosimetry were found on targets produced by rigid registration and manual adjustment method .
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@#Objective To analyze the diagnosis and treatment of cervical spinal cord injury without fracture or dislocation.Methods 38 patients were analyzed retrospectively.Results and Conclusion According to the manifestation of MRI and the symptoms,6 cases accepted conservation treatment,and the other 32 cases accepted surgery with different styles.All the patients recovered in some degrees.
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Objective To analyze and sum up the MRI appearances of osteoporotic acute vertebral collapse(OAVC) or metastatic acute vertebral collapse(MAVC) and evaluate MRI value in both the differential diagnosis .Methods 30 cases of OAVC and 30 cases of MAVC were respectively collected at random according to clinical features,biochemical examinations,conventional radiograghy,and CT scan and all cases were studied with SE,T1-weighted images,gadolinium-enhanced T1-weighted images,and SE,T2-weighted images.Results 11 MRI apperances which were valuable in distinguishing OAVC from MAVC were summed up.Four images suggested that it was OAVC,one of which was specific:retropulsion of a bone fragment of collapsed vertebral body into the spinal canal.Seven images suggested MAVC,four of which were specific:dull-bell shaped body,destruction of pedicles,epidural mass,diffuse high or inhomogeneous signal intensity within the vertebral body on gadninium-enhenced T1-weighted images and T2-weighted images.Conclusion MRI is very useful in the differentiating OAVC from MAVC.