Objective To investigate the correlation between middle cerebral artery (MCA) atherosclerotic plaques and single subcortical infarction (SSI) using high-resolution magnetic resonance imaging (HR-MRI).Methods The patients with SSI received HR-MRI examinations at the ipsilateral MCA horizontal segment stenosis from January 2012 to November 2014 were analyzed prospectively.They were divided into proximal SSI (pSSI) and distal SSI (dSSI).The longitudinal and transverse diameters and volume of different types of infarction pattern as well as the degree of luminal stenosis of MCA deep perforating parent artery,plaque distribution,plaque enhancement or not,white matter lesions,and general information of both groups were documented respectively.Results A total of 78 patients with SSI were enrolled,including 40 (51％) in the pSSI group and 38 (49％) in the dSSI group.The proportions of Fazekas scale grade 3 white matter lesions (63.5％vs.40.0％;x2 =4.183,P=0.041) and deep white matter lesions (50.0％ vs.15.0％;x2 =10.961,P =0.001) in the dSSI group were significantly higher than those in the pSSI group.The proportions of MCA plaque in the opening (35.0％ vs.13.2％;x2=3.930,P=0.047),plaque enhancement (87.5％ vs.30.0％;x2 =25.447,P ＜ 0.001) and posterosuperior wall plaques (42.5％ vs.21.4％;x2 =9.491,P ＜ 0.001) and the degree of luminal stenosis (60.38％ ± 10.20％ vs.45.00％ ±6.44％;t =3.625,P =0.031) in the pSSI group were all significantly higher than those in the dSSI group.In addition,the longitudinal and transverse diameters and volume of the infarcts in the pSSI group were significantly larger than those in the dSSI group (all P ＜ 0.001).Multivariate logistic regression analysis showed that MCA enhanced plaques on the lesionipsilateral sides (odds ratio[OR] 11.764,95％ confidence interval[CI] 2.081-66.511;P =0.005) and posterosuperior wall plaques (OR 6.131,95％ CI 1.012-23.339;P =0.037) were independently associated with pSSI,while deep white matter lesions (OR 0.280,95％ CI 0.203-0.648;P=0.012) was independently associated with dSSI.Conclusions The atherosclerotic plaques of MCA deep perforating parent artery are common in both the pSSI group and the dSSI group.pSSI is mainly associated with the location of atherosclerotic plaques of deep perforating parent artery and enhanced plaques,while dSSI is mainly associated with deep perforating artery vasculopathy.

Objective To investigate the imaging findings with pathologic correlation in patients with acquired immune deficiency syndrome(AIDS).Methods Imaging findings,autopsy and pathological data were retrospectively analyzed in eight patients with AIDS.Routine CT scanning of different body parts was performed during their hospitalization.CT scanning was performed from the skull to the pelvis immediately following their death.After routine formalin fixing,7 cardevers were cross sectioned for autopsy in freezing state and 1 for gross autopsy.Tissues were obtained from each sections and organs for pathological examinations.Results The autopsy data showed parasitic infections(5 cases),bacterial infections (3 cases),fungal infections(2 cases),virus infections(2 cases),lymphoma(1 case)and cerebrovascular diseases(1 case)in eight patients with AIDS.The CT scanning demonstrated symmetrical ground glass liked shadows with pulmonary hilus as the center in 5 cases of pulmonary PCP infection; pulmonary patchy shadows,scattering distribution of nodular shadows,extensive military nodular shadows with even distribution and tuberculous pleurisy; cloudy shadows for 2 cases of fungi infection with multiple foci of chronic inflammation;pulmonary net-like parenchymal changes for 2 cases of pulmonary CMV infection;thickened intestinal wall and narrowed intestinal lumen for 1 case of intestinal tumor; low density shadows of brain tissue for 1 case of CMV encephalitis and MRI findings of high T_1 and high T_2 signals as well as MRA findings of broken vascular channels in liquefied areas of brain tissues; patchy low density areas inside a cyst of brain for one case of brain toxoplasmosis infection:multiple small patchy low density areas in cerebral basal ganglia for one case of brain cryptococcus infection.Conclusions In AIDS patients,infection and tumor may occur in various organs resulting in complex symptoms,which makes it more complicated and difficult to make accurate diagnosis.A correlative study of imaging findings and pathological manifestation of AIDS patients at autopsy could be helpful for clinical diagnosis.

Objective To study the diagnostic value of achilles tendon injury(ATJ) and the diagnostic standards for different severities of the injury by MRI.Methods Twenty-six cases of traumatic ATJ proved both clinically and surgically and had complete MRI materials were selected.The characteristic MRI appearances were summed up and retrospectively compared with that of 10 normal achilles tendons.Results The results were as follows :(1) MRI appearances of 10 normal achilles tendons : regular course,smooth margin,homogenous hypointensity on T_1WI and T_2WI;(2) MRI appearances of 17 partial ATJs:tendon thickening,decreased ratio of wide/vertical diameter,localized hyperintensity in tendon on T_1WI and T_2WI,crude and irregular fibrous bundles but at least keeping one continuous layer on sagital view;(3) MRI appearances of 9 total ATJs: tendon thickened and irregular appearance,totally discontinuous fibrous bundles,"brush" or "pestle" change and mixed hyperintensity on T_1WI and T_2WI;(4) 7 cases with bone contrusion and soft tissue injury,2 cases with ligament injury,2 cases with bone and cartilage injury and 11 cases with fluid collected around tendon.Conclusion MRI can accurately judge thenature,range,degree and complications of ATJ and is of great value for preoperative plan of the treatment program and the postoperativeanalysis of the therapeutic effect.

Objective To investigate the clinical applied value of the early slope value of MR contrast-enhancement in differentitating benign from malignant musculoskeletal neoplasms.Methods 48 patients with benign or malignant musculoskeletal masses(26 benign,22 malignant) confirmed by pathology underwent dynamic contrast-enhanced scanning.The largest slope of dynamic enhancement in early stage and SI-Time curve type were gained and the difference of them in benign and malignant musculoskeletal tumours were analysed.Spearman rank correlation analysis was used to determine the relation between slope and microvessel density of tumor tissues.Results There were 3 SI-Time curve types in all cases with typeⅠ(precipitous rise) in 22 cases,type Ⅱ(slow rise) in 21 cases and type Ⅲ(slight rise) in 5 cases.The average early slope value of enhancement was(4.23?2.68)% per second(range 0.96%~10.53%)in malignant tumors,and(1.44?0.99)% per second(range 0.36%~3.76%)in benign tumors.There was an apparent statistical significance between benign and malignant tumors(P

Objective To observe the clinical efficacy of screwing via the paraspinal muscle approach plus single-segment laminectomy decompression via the dorsomedian approach for thoracolumbar fractures complicated with spinal cord injury.Methods From February 2013 to September 2015,21 patients with thoracolumbar fracture plus spinal cord injury were treated at our department.They were 15 men and 6 women,aged from 20 to 54 years (average,33.2 years).The injury was located at T1 1 in 2 cases,at T12 in 6,at T12 and L1 in one,at L1 in 7 and at L2 in 5;the injury was rated as grade A in one case,grade B in 3 cases,grade C in 8 and grade D in 9 according to the American Spinal Injury Association (ASIA) grading system.A1 the patients were treated by screwing via the paraspinal muscle approach followed by single-segment laminectomy decompression via the dorsomedian approach.Results The operation time averaged 116.1 + 24.5 minutes and the amount of bleeding 580.7 + 80.8 mL.At 3 days after surgery and the final follow-up,their visual analogue scale (VAS) score,anterior vertebral height and cobb angle were significantly improved in comparison with the preoperative values (P ＜ 0.05).At the final follow-up,their Japanese Orthopaedic Association (JOA) the score were also significantly better than the preoperative one (P ＜ 0.05),giving 12 excellent cases,6 good ones and 3 fair ones.Their ASIA grading at the final follow-up showed one case of grade B,2 cases of grade C,6 cases of grade D and 12 cases of grade E.Conclusion Treatment of thoracolumbar fractures complicated with spinal cord injury by crewing via the paraspinal muscle approach plus single-segment laminectomy decompression via the dorsomedian approach is a good way due to limited invasion,less bleeding,simple operation,excellent reduction,reliable fixation and rapid recovery.

Objective To explore the value of high-resolution MRI(HR-MRI) on clinical application in the differential diagnosis between Moyamoya disease(MMD) and atherosclerosis-related Moyamoya syndrome (A-MMS). Methods Seventeen cases of patients with MMD and 18 cases of patients with A-MMS in our hospital from January 2014 to September 2015 were prospectively enrolled in the study. Record the clinical data and the proximal middle cerebral artery (M1 portion) performance on HR-MRI, the max-vessel area, the min-vessel area, the max-lumen area, the min-lumen area, the wall max-thickness, the styles of M1 portion thickening (eccentric or concentric), whether the wall was enhanced or not, and analysis the recorded data statistically, t test and χ2 test were used for the statistical analysis. Results The wall max-thickness of MMD group was (0.94 ± 0.17) mm, which was smaller than that in A-MMS group (1.23 ± 0.42) mm, there was statistic significance (t=-2.977, P=0.006). The cases of M1 portion non-enhancement was 15, slight enhancement 2, strong enhancement 0 in MMD group, and non-enhancement 5, slight enhancement 5, strong enhancement 8 in the A-MMS group, the difference was significant statistically (χ2=9.794, P=0.001). The cases of M1 portion concentric thickening was 16, 9 cases in the A-MMS group, there was statistic difference between them (χ2=6.317, P=0.012). Wall concentric thickening diagnose the MMD with a sensitivity of 94.1% (16/17), specificity of 50.0% (9/18), accuracy of 71.4%(25/35). Wall strong enhancement appear in the A-MMS with a sensitivity of 44.4%(8/18), specificity of 100%(17/17), accuracy of 71.4%(25/35).With a cut-off the maximum wall thickness of 1.2 mm could be used to noninvasively differential diagnose the MMD and A-MMS with a sensitivity of 55.6%(10/18), specificity of 88.2%(15/17), accuracy of 71.4%(25/35). Conclusion HR-MRI is a good tool for the differential diagnosis between MMD and A-MMS.

Objective To investigate the diagnostic value of ADC in the evaluation of small round cell malignant tumors(SRCMT) of nasal and paranasal sinus.Methods This study included 143 patients with surgically confirmed SRCMT and Non-SRCMT of nasal and paranasal sinus between 2008 and 2015, all patients underwent diffusion weighted MRI at 3.0 T with a b factor of 0 and 1 000 s/mm2.Quantitative analysis of ADC values was performed.Difference in ADC values between SRCMT and Non-SRCMT was evaluated using the independent samples t test.One-way analysis of variance(ANOVA) test was performed to compare the ADC values of SRCMT.Receiver operating curves (ROC) were developed to determine the cutoff points to differentiate SRCMT from Non-SRCMT.Results There were 98 SRCMT, of which 20 lesions were rhabdomyosarcoma(RMS), 19 lesions were non-Hodgkin's lymphoma(NHL), 4 lesions were malignant melanoma(MM), 14 lesions were neuroendocrine carcinoma(NEC), 12 lesions were Ewing sarcoma or primitive neuroectodermal tumor(EWS or PNET), 11 lesions were extramedullary plasmacytoma(EMP), and 8 lesions were olfactory neuroblastoma(ON).There were 45 Non-SRCMT, of which 28 lesions were squamous cell carcinoma(SCC) and 17 lesions were adenoid cystic carcinoma(ACC).The mean ADC value of SRCMT[(0.66 ± 0.12) × 10-3mm2/s] was significantly different (t=14.97, P＜0.01) from Non-SRCMT [(1.02± 0.16)× 10-3mm2/s].All of 7 kinds of SRCMT were divided into 3 groups according to ADC values: NHL,MM, NEC,EMP;RMS,EWS,PNET;ON.There was statistically significant difference among all 3 groups(F=39.743, P＜0.01), and the differences between any 2 groups were still statistically significant.The area under the ROC of ADC values diagnosing SRCMT was 0.975.Compared with pathological results, an ADC value of 0.82 × 10-3mm2/s was used as the threshold for diagnosing SRCMT with a sensitivity of 97.8％ (44/45),specificity of 89.8％(88/98), and accuracy of 92.3％ (132/143).ADC value had high correlations compared with pathological results (Kappa value was 0.831).Conclusion The ADC value is a non-invasive imaging parameter that can be used to effectively assess SRCMT of nasal and paranasal sinus.

Objective To investgate the value of various parameters obtained from monoexponential, biexponential, and stretched exponential diffusion?weighted imaging models in the differential diagnosis of breast lesions. Methods A retrospective study performed in 54 patients with pathologically confirmed malignant tumors(n=30), benign lesions(n=34) and normal fibroglandular tissues (n=30). All patients underwent T1WI, T2WI, dynamic enhancement and diffusion weighted MRI with multi?b values at a 3.0 T magnetic resonance imaging unit. All parameters were measured at a workstation. ADC was calculated by using monoexponential analysis(b=0, 800 s/mm2). Slow apparent diffusion coefficient (ADC?slow), fast apparent diffusion coefficient (ADC?fast), and perfusion fraction (f) were calculated using the biexponential model. Distributed diffusion coefficient (DDC) and water molecular diffusion heterogeneity index (α) were obtained from diffusion?weighted images using the stretched exponential model. All parameters were statistically compared among normal fibroglandular tissues, benign lesions and malignant tumors using Kruskal?Wallis rank sum test. Mann?Whitney U test were used for further comparisons between specific group pairs. ADC values were compared with ADC?slow and DDC for different groups by paired Wilcoxon test. Correlations between ADC?value, ADC?slow and DDC were assessed by using Spearman rank correlation coefficient. Receiver operating characteristic curve was used to analyze and compare the ability of these parameters in differentiation of benign and malignant breast lesions. Results The ADC, ADC?slow, f, DDC and α values were significantly different among the normal fibroglandular tissues, benign tumors and malignant tumors (P<0.05). Further differential comparisons of the four parameters between each pair showed that the ADC, ADC?slow, f, DDC and α values were significantly lower in malignant tumors than both in normal fibroglandular tissues and benign tumors(P<0.016 7). The ADC values of normal fibroglandular tissues, benign tumors and malignant tumors were significantly higher than ADC?slow and DDC (P<0.05). The f and DDC had higher area under the receiver operating characteristic curve (0.688 and 0.657 respectively). The optimal cutoff values for ADC, ADC?slow, f, DDC and α were 1.235 × 10-3mm2/s, 0.428 × 10-3mm2/s, 57.8%, 1.175 × 10-3mm2/s and 0.721, respectively. Theαvalue showed higher specificity (65.5%) and the f value had higher sensitivity (82.9%). Conclusion The parameters derived from biexponential and stretched exponential DWI could be helpful for differentiation between benign and malignant breast tumors.

Purpose To compare the value of contrast-enhanced ultrasound (CEUS), contrast-enhanced CT (CECT) and contrast-enhanced MRI (CEMRI) in the diagnosis of renal space-occupying lesions. Materials and Methods Seventy-eight patients whose 80 kidney space-occupying lesions were conifrmed by traditional ultrasound underwent CEUS examination. Among those patients, 39 patients also underwent CECT, 28 had CEMRI, and 5 had CECT and CEMRI examination together. Taken pathologic findings as gold standard, the value of conventional ultrasound, CEUS, CECT and CEMRI was compared in the diagnosis of renal space-occupying lesions. Results Among 80 renal masses, 57 lesions were malignant and the rest 23 lesions were benign. The diagnostic sensitivity, speciifcity, positive predictive value and negative predictive value were 93.0%, 69.6%, 88.3%, 80.0%for CEUS;those for CECT were 96.4%, 72.7%, 90.0%, 88.9%respectively;and for CEMRI were 86.4%, 66.7%, 90.5%, 57.1%respectively;and the diagnostic value among the three means showed no difference (P>0.05). Conclusion CEUS, CECT and CEMRI are all effective in the diagnosis of renal space-occupying lesions, We may select suitable examination means for patients according to their features. A combination of these techniques provides more information for the diagnosis of renal space-occupying lesions.

Objective To investigate the assessment value of diffusion-weighted magnetic resonance imaging (DWI)and apparent diffusion coefficient (ADC)in the differential diagnosis of common cerebellar tumors of children.Methods 45 patients with cerebel-lar tumors were retrospectively analyzed,including 23 medulloblastomas,14 astrocytomas,and 8 ependymomas .The ADCmin of parenchyma of different tumors were measured and Receiver operating characteristic (ROC)curve were delineated.The optimum ADC value for differential diagnosis of common cerebellar tumors of children was analyzed and determined.Results The mean ADC-min of medulloblastoma (0.497 ± 0.023 )× 10 -3 mm2/s was lowest,the mean ADCmin of astrocytoma (1.572 ± 0.145 )× 10 -3 mm2/s was highest,while that of ependymoma was (0.784 ± 0.037 )× 10 -3 mm2/s.The optimum ADC to distinguish ependymomas from medulloblastomas was 0.61 1 × 10 -3 mm2/s (100% sensitivity and 95.7% specificity).The optimum ADC to distinguish low-grade astrocytomas from ependymomas was 1.064×10 -3 mm2/s (92.9% sensitivity and 100% specificity).Conclu-sion ADC is very helpful with differential diagnosis of common cerebellar tumors of children.