Objective To investigate the imaging and clinical characteristics of reversible posterior leukoencephalopathy syndrome (RPLS). Method The imaging and clinical data of 6 patients with RPLS were analyzed retrospectively. Results CT and MRI examination in 6 patients revealed symmetry white matter lesions of occipital lobe in 4 patients, widely white matter edema of fronto-parietal subcortieal white matter in 4 patients, mesencephal and thalamencephal involved in 1 patient, caudate nucleus involved in 1patient. Venous sinus thrombosis was not found in 2 patients of pregnancy-induced hypertension syndrome with magnetic resonance intravenous angiography.All patients were given active treatment,including controlling blood pressure and seizure disorder,dehydration and supporting therapy.The symptom of 5 patients disappeared. One patient left with hemiparesis of right body.Nobody died. Condusion Diagnosis of RPLS isn't difficult as long as clinical history,imaging characteristics and clinical tetrad in the patients of hyperten-sion,eclamptism or renal inadequacy is combined to consider.

Objective To investigate the relation of the MR manifestations and the pathological characteristics of dissociated discherniation.Methods Characteristics of pathology and MRI of 23 cases of dissociated disc herniation were retrospectively analysed.Results Of 23 cases,the dissociated disc was low signal intensity(compared with spinal cord) on T_1WI and T_2WI with distinct margine in 7 cases,the adhere and inflammation were slight on pathology;iso-or hypo-signal intensity on T_1WI,low signal intensity in the center and slight high signal intensity at periphery on T_2WI with an distinct margine in 13 cases,while the adhere and inflammation were obvious on pathology;on T_1WI slight high signal intensity on T_1WI and iso-intensity on T_2WI in 3 cases,and fibroplasia was showed on patholgy.In the 12 cases with enhanced MRI,the lesions were slight enhancement at periphery and enhancement in the center in 7 cases,no enhancement in 3 cases,slight enhancement in 2 cases.Conclusion MRI signal characteristic can reflect pathologic changes expressly of the dissociated disc herniation.

Objective To discuss the relationship between the injury patterns of medial patellofemoral ligament(MPFL) and injury degrees of vastus medialis obliquus(VMO) after acute patellar dislocation(PD). Methods Knee joint MRI was performed in 79 patients with acute PD. Images were acquired and evaluated using standardised protocols. Injury patterns of MPFL were grouped by severity (partial tear and complete tear)and location (isolated patellar-side tear (PAT), isolated femoral-side tear (FEM) and combined tear (COM) ) for analysis of the prevalence of VMO injury. The VMO elevation was calculated on sagittal and coronal planes. Results The prevalence rates of MPFL tear and VMO lesion were 96.2%(76/79)and 54.4%(43/79)after acute PD.The prevalence rate of VMO lesion was 40.6%(13/32)and 68.2%(30/44)in the partial and complete MPFL tear subgroups,respectively.Complete MPFL tear subgroup showed higher prevalence rate of VMO lesion when compared with partial tear subgroup(χ2=5.727, P=0.017). The prevalence rates of VMO lesion in the PAT, FEM and COM subgroups were 31.8% (7/22), 67.7% (21/31) and 70% (14/20), respectively. There were statistically significant differences among them(χ2=8.549,P=0.014).About the mean VMO elevation,there were statistically significant differences between the complete and partial MPFL tear subgroups, the FEM and PAT subgroups, and the COM and PAT subgroups (P=0.00). Conclusions Compared with partial MPFL tear, complete tear predisposes to VMO lesion and has a higher elevation of the torn VMO after acute PD.The femoral-sided and combined MPFL tears predispose to VMO lesion and have higher elevations of the torn VMO.