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Objective To evaluate the capability of Turbo inversion recovery magnitude (TIRM) magnetic resonance neurography (MRN) in the diagnosie of sacral plexus injury by comparing MRN findings with surgical results.Methods Ten patients with sacral plexus injury confirmed surgically underwent conventional T1WI,T2WI,TIRM and coronal TIRM MRN before operations from June,2011 to December,2012.The MRI data and surgical data were analyzed retrospectively to observe nerve injury.Results The coronal TIRM MRN images displayed 93 trunks of sacral plexus,of which 37 were confirmed injury by operation.The MRI findings were as follows:6 trunks involved continuous nerves,but with thickening and blurred margin,as well as abnormal high signal intensity;22 trunks were continuous,but with distortion,stiffness and adhesion accompanied by heterogeneous signal intensity and structural disorder;3 trunks showed complete loss of continuity,absence of normal signal,accompanied by retraction;and 3 trunks involved formation of traumatic neurofibroma.The coincidence of injured nerve trunks diagnosed by MRN with surgical findings amounts to 81.08％ (30/37).Conclusion MR with coronal TIRM imaging is effective in the diagnosis and depiction of sacral plexus injury,therefore it can be used as conventional sequence in sacral plexus examination to detect sacral plexus avulsion.
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Objective To analyze CT and MR imaging features of dysembryoplastic neuroepithelial tumor(DNT),so that to improve its diagnostic accuracy.Methods CT and MRI fidnings of DNT in 10 cases proved surgically and pathologically were retrospectively reviewed.Results All lesions were located in the super-tentorial gray matter regions or involved the cererbral certex mainly.The lesions were round,lobular,triangular or irregular pseudocystic masses with definite borders mostly.The lesions were hypointense on T_1WI and hyperintense on T_2WI.On fluid attenuated inversion recovery weighted images,the hyperintense "ring sign" and septa of the lesions were seen.On diffuse-weighted images(DWI),the lesions were hypointense or slight hypointense.On MR spectroscopy,NAA of the lesions slightly decreased.There were no peripheral edema and mass effect with well-demarcated.7 lesions had no enhancement and 3 lesions had slight unhomogeneous enhancement after administration of contrast medium.The lesions in 2 cases on plain CT showed low attenuation and one had calcification inside the lesion.Conclusion DNTs are of typical neuroradiologic features,that may be helpful for the diagnosis of which preoperatively.
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Wallerian degeneration of the corticospinal tracts is the anterograde degener-ation of distal axons and myelin caused by the upper motor neuron injury or axonal injury.Stroke is the most common cause of Wallerian degeneration of the corticospinal tracts. Conventional magnetic resonance imaging (MRI) of Wallerian degeneration of the corticospinal tracts is a linear abnormal signal that connects the original lesion along the corticospinal tracts, but the conventional MRI signal does not reveal Wallerian degeneration until 4 weeks after stroke. Diffusion tensor imaging (DTI) detects early Wallerian degeneration of the corticospinal tracts, and dynamically observes the process of pathological changes from early subacute stage to chronic stage. 1his article reviews Wallerian degeneration of the corticospinal tracts on DTI after stroke, especially the effect in early Wallerian degeneration, as well as the values in predicting prognosis and late rehabilitation in patients with stroke.
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Objective To evaluate the accuracy of MR diffusion weighted imaging (DWI) in the diagnosis of hyperacute cerebral infarction. Methods Twenty one patients with onset of strokelike symptoms underwent conventional MRI and DWI within 6 hours. Results DWI indicated cerebral infarction in 16 patients, all of whom had a final diagnosis of acute stroke. DWI was negative in 5 patients, all of whom had a final diagnosis of TIA. The abnormality seen at DWI was confirmed with follow up study. DWI had a sensitivity of 100% and a specificity of 100% in the diagnosis of hyperacute cerebral infarction, and conventional MRI interpretation yielded a sensitivity and specificity of 25% and 100%, respectively. Conclusion DWI is highly accurate in diagnosing hyperacute cerebral infarction and is superior to conventional MRI.
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Objective To study the manifestations of MR of the tumor in jugular foramen area(JFA) and its diagnostic values.Methods 13 cases of tumors confirmed by pathology in JFA were reported,and the characteristics of MR of different kinds of tumor were analysed.Results There were its own MRI manifestations of different tumors in JFA,and the localizing and qualitative diagnosis of these tumors can be accurately made by MRI.Conclusion MRI is of very important diagnostic values in detecting the tumors in JFA.