MSCT findings of gastric schwannomas / 实用放射学杂志

Objective To explore the MSCT characteristics of gastric schwannoma (GS).Methods 1 6 patients with pathologically verified GS were included in our study.The MSCT images were analysed retrospectively.Results 1 6 participants were determined with solitary nodule,which located in gastric antrum,body and fundus,respectively with 5 cases,10 cases and 1 case.13 of them showed morphologically as round or ovoid shape,while 3 of them grew irregularly lobulated lesion.For their growth pattern,1 3 tumors presented as bilateral growth,1 lesion appeared intra-cavitary growth,1 grew outside the cavity fields.However,1 case was hard to confirm the growth pattern due to the gastroduodenal intussusception.14 tumors appeared uniform density,1 showed a little necrosis and 1 had dotted calcification,all the lesions were emerged as progressive enhancement with inhomogeneous feature.Conclusion GS mostly located in gastric body or antrum,with round or ovoid appearence,well-defined border,and bilateral growth pattern,necro-sis and calcification are rare,enhanced progressively with homogeneous feature,with no surrounding invasion and metastasis.

Value of dual-source dual-energy CT in differentiating extravasation of iodine contrast agents from secondary hemorrhage after revascularization in acute ischemic stroke / 实用医学杂志

Objective To explore the value of dual-source dual-energy CT (DSDE-CT) in differentiating extravasation of iodine contrast agents from secondary hemorrhage after revascularization in acute ischemic stroke. Methods 46 acute ischemic stroke patients following intra-arterial thrombolysis were examined with DSDE-CT within 2 hours after the procedure. Simultaneous imaging at 80 kV/392 mA and 140 kV/196 mA was employed, and then mixed images, virtual unenhanced non-contrast images and iodine overlay maps were calculated. Mixed images alone, as conventional CT, and DUDE-CT interpretations were assessed separately by two radiologists and compared with follow-up CT. Results 6 of 34 patients were negative cases proven by CT without high density, and another 28 cases were proven positive cases with 3 cases of cerebral hemorrhage, 21 cases of contrast agent extravasation, and the remaining 4 cases of combined cerebral hemorrhage and contrast agent extravasation. The sensibility, specificity, positive predictive value, negative predictive value and accuracy of mixed imaging alone in diagnosing hemorrhage was 66.67%, 100%, 1005, 96.15% and 96.43%, while the sensibility, specificity, positive predictive value, negative predictive value and accuracy of hemorrhage with DUDE-CT was 100%, 96%, 75%, 100% and 96.43% . The diagnostic accuracy of superimposed fusion images for intracranial hemorrhage, extravasation of contrast agent and hemorrhage with extravasation of contrast agent was relatively high, and the difference was statistically significant (P < 0.05). The diagnostic accuracy of superimposed fusion images consistent with clinical follow-up was significantly higher (Kappa=0.815),as compared with that of mixed imaging alone (Kappa=0.0.564). Conclusion DUDE-CT has great value in differentiating hemorrhage from iodinated contrast after intra-arterial thrombolysis in acute ischemic stroke.

Prostatic abscess:MRI findings and ADC value quantitative analysis / 实用放射学杂志

Objective To investigate the conventional MRI and DWI features of prostatic abscess.Methods 8 patients with path-ologically and clinically proved prostatic abscess who were performed MRI examination in our institution were enrolled in this study. Among them,2 patients underwent CT examination and 7 patients were performed DWI examination (b = 0 and 1 000 s/mm2 ). Their CT,conventional MRI and DWI features were retrospectively analyzed.The ADC value between prostatic abscess and normal prostate tissues were compared by using paired t test.Statistical significance was inferred at P <0.05.Results 2 patients with 3 fo-cal abscesses,2 patients with 2 focal abscesses,and 4 patients with only one focal abscess.4 abscesses perforated the prostate cap-sule and involved the fat gap in front of the rectum.Prostatic abscess showed low hypointensity on T1 WI,hyperintensity on T2 WI and DWI.2 focal abscesses with low signal areas consistent both on T1 WI and T2 WI of gas.The mean ADCs of prostatic abscess were (0.854±0.223)×10 -3 mm2/s ,which were significantly lower than those of prostate tissues (1.41 6±0.1 68 )×10 -3 mm2/s (P <0.05).Conclusion Prostatic abscess has characteristic feature on MRI,and shows restricted diffusion on DWI.MRI can clearly display their size,number and invasive condition of the circumambient organs.Thus should be considered as an optimal method in the diagnosis of prostatic abscess.

Assessment of apparent diffusion coefficient in clinicopathologic and prognostic features of rectal cancer / 实用放射学杂志

Objective To assess the value of apparent diffusion coefficient (ADC)in clinic ,pathology and prognosis of rectal cancer. Methods The MRI and DWI findings of 109 patients with pathological proved rectal adenocarcinoma were retrospectively analyzed. DWI with b=0 s/mm2 and b= 1 000 s/mm2 were acquired.Mean tumor ADCs were measured and compared between subgroups stratified by histologic differentiation grades,T-stage,N-stage,mesorectal fascia status and presence of lymphangiovascular or peri-neral invasion.Results Mean tumor ADCs were significantly different when comparing groups stratified by histologic differentiation grades,T-stage,mesorectal fascia status and presence of lymphangiovascular invasion.Tukey’s post hoc test showed that the differences of mean ADCs between good-moderate differentiated group and moderate differentiated group(P =0.996),moderate-poor differentiated group and poor differentiated group(P =0.957)were not significant.The differences among other groups of differentia-tion grades differed significantly(P 0.05).There were no sig-nificant differences among N0,N1 and N2 in N-stage groups(P >0.05).Conclusion ADC values can reflect pathologic and prognos-tic features of rectal cancer.

Research on dynamic contrast-enhanced MR quantitative analysis of pancreatic cancer at 3.0T MR / 实用放射学杂志

Objective To investigate the value of dynamic contrast-enhanced quantitative parameters of pancreatic cancer at 3.0T MR.Methods 27 patients with pathologically proved pancreatic cancers were underwent DCE-MR at a 3.0 T scanner.AToft with Vp model was used to quantify K trans ,k ep ,Ve and Vp in the pancreatic cancer and normal pancreatic tissues.All parameters among different tissues were analyzed and compared by SPSS1 7.0.Results The K trans 、k ep 、Ve 、Vp values of pancreatic cancer were(0.303± 0.321)min,(1.387±1.486)min,(25.07±10.98)%and(3.420±4.692)% respectively ,while those values of normal pancreatic tis-sue were (1.235±0.777)min,(9.277 ± 7.996 )min,(1 7.89 ± 8.882 )%,and(7.1 96 ± 6.704)%,respectively.The differences be-tween the four parameters of pancreatic cancer and normal pancreatic tissue were statistically significant(F =33.188,25.414,6.984, 5.78,P <0.05).Conclusion Quantitative parameters of DCE-MRI accurately reflect changes in tumor blood perfusion and microcir-culation,they may be helpful to differentiate the atypical lesion.

A study on hippocampus injury assessment with apparent diffusion effect of MRI on mouse model / 中华行为医学与脑科学杂志

Objective To determine the utility of apparent diffusion coefficient (ADC) values as an objective method of early detection of traumatic brain injury of the mice models in hippocampus injury.Methods A total of 18 healthy male adult C57/BL6 mice were randomly divided into three groups according to the degree of injury:the mild group,severe group and control group.Conventional images,diffusion-weighted images,ADC were studied.The hippocampal were selected as the interesting area.ADC values were calculated and compared with those in control subjects after 6 h,12 h and 24 h.Student t test was performed for each region to compare the injury groups and the control.Results In control group both sides hippocampal ADC values had no differences(8.65±0.26 and 8.77±0.12) × 10-4 mm2/s,P＞0.05.Abnormalities were detected on ADC values,compared with conventional images in the injury groups.ADC values in mild group and severe group were significantly different from those of control group(6 h ADC values were (8.70±0.50) × 10-4 mm2/s,(6.13± 0.11) × 10-4 mm2/s,and (3.16±0.78) × 10-4 mm2/s in control,mild and severe group respectively),(12 h ADC values (8.23±0.61)× 10-4 mm2/s,(5.92 ± 0.27) × 10-4 mm2/s and (2.64±0.65) × 10-4 mm2/s) and (24 h ADC values (9.01±0.14) × 10-4 mm2/s,(5.99± 0.13)×10-4 mm2/s and (2.58±0.42)×10-4 mm2/s),P＜0.05.Conclusion There are differences among the ADC values on differcnt types of hippocampal brain injury mouse-model.ADC values can identify the degree of damage on brain injury and can detect early craniocerebral injury.

The study of growth and development of normal prostate in 3.0 T MRI / 中华放射学杂志

Objective To study the prostate volume of normal children and adolescents and to evaluate the development of prostate central zone and peripheral zone.To provide the preliminary MRI standards of prostate growth and development for nomal Chinese children and adolescents.Methods Five hundred and fifty eight healthy male volunteers,aged from 2 to 25 years were retrospectively analysed.They were divided into 5 groups by the ages (group A:2 to 5 years,group B:6 to 10 years,group C:11 to 15 years,group D:16 to 20 years and group E:21 to 25 years).All the volunteers underwent conventional MRI examinations at our institution (T2WI axial and coronal image acquisition).The prostate volume of different age groups were measured,the development of the central zone and peripheral zone were scored by two radiologists,and the datas were treated by Nonparametric test.Results Group A children's prostate nearly not development,only individual MRI measurable its size; Group B most not development,only 6 children visible prostate form,but can't distinguish the anatomical division; Group C prostate gland development better,MRI can measure the size,but distinguish its central and peripheral area is difficult ; Group D prostate gland development rapidly,differences are obvious,but only a few central and peripheral area boundary clear; Group E the central and peripheral area boundary clear,form full,T2 WI signal contrast clear.The median prostate volumes of 5 groups were 0.000,0.000,2.450,7.990 and 10.600 cm3,respectively(x2 =215.452,P ＜ 0.01).The median prostate scores of 5 groups were 0.04,0.31,1.34,2.23 and 2.60,the prostate volumes were significant difference among these 5 groups except group A and group B(x2 =127.460,P ＜0.01),there were significant difference among the volumes and the scores of these five groups (P ＜0.01).Conclusions MRI provided the basis of objective and truth for the the measurements of volume and the observations of prostate development in this study,that offers preliminary reference range for normal Chinese children and adolescents prostate development status.