Objective To compare the efficacy of spectral CT imaging and 64 slice CT in assessment of carotid artery atherosclerotic plaque.Methods Thirty-eight patients with carotid plaque were detected retrospectively in this study (plaque,n=46) by using spectral CT.The composition of atherosclerotic plaque was measured by iodine-based images,lipid-based images with spectral CT imaging.Intraplaque hemorrhae,lipid components were also evaluated on spectral CT imaging and compared with pathology and specimen.Statistical comparison was performed with the Kappa value,independent-sample t test and exact test.Results The degree of carotid artery stenosis was (63.3 ±3.1)％ on spectral CT imaging whereas (61.6 ± 3.8) ％ on 64 slice CT.Two imaging modalities were in good consistency in evaluation of the degree of stenosis (Kappa=0.993,P＜0.01).There was no statistical difference in detecting fibrous cap rupture on spectral CT imaging and 64 slice CT (12 plaques vs 11 plaques,respectively,P＞0.05).Furthermore,spectral CT imaging showed 11 plaques within intraplaque hemorrhage,however,no case was found on 64 slice CT (P＜0.05).The plaque iodine concentration were (6.365 ± 1.937) and (1.573 ±0.776) mg/cm3 with or without internal hemorrhage(t=16.39,P＜0.05).Spectral CT imaging showed 9 plaques within intraplaque liquid whereas only 2 plaques showed intraplaque liquid on 64 slice CT (P＜0.05).Twenty-eight plaques within calcification in the plaque were found on spectrl CT imaging and 27 on 64 slice CT(P＞0.05).Conclusion Spectral CT imaging is a reliable tool in detecting intraplaque hemor-rhage and liquid component.

Pancreatic sarcomatoid carcinoma is an extremely rare malignant tumor.The clinical data and computed tomography images of 8 patients with pancreatic sarcomatoid carcinoma who were admitted to the Subei People's Hospital from March 2001 to January 2013 were retrospectively analyzed.The results of computed tomography showed that 8 tumors were cystic and solid,showing exophytic growth.Two tumors were located in the pancreatic head,1 in the pancratic neck,3 in the body of pancreas,and 2 in the tail of the pancreas.The shape of the tumors were round or ellipse,and the mean tumor diameter was (7.2 ± 1.8)cm (range,6.3-9.6 cm).The plain scan of computed tomography showed that the attenuation of the tumors was mild hyperdense (7 cases) or equal to pancreatic tissue (1 case).Tumors were solid with cystic components,and no hemorrhage within the tumor was detected.Small calcification nodule wasdetected in 1 case.The enhanced scan of computed tomography showed that the enhancement of the tumor was moderate; the enhancement of the tumor was higher than that of normal pancreatic parenchyma during venous phase and delayed phase,while lower than that of normal pancreatic parenchyma on arterial phase; the enhancement of tumors was significantly lower than that of aorta during all the enhanced phases.All the tumors had complete capsule,and abnormal enhancement of the capsule was not detected.Three tumors had peripancreatic lymphadenectasis,2 had infiltration of splenic artery,2 had infiltration of splenic flexure of colon and 1 had infiltration of duodenal serosa or muscle.Familiarity with the imaging features of the pancreatic sarcomatoid carcinoma can help surgeons to make a suggestive diagnosis.

Objective To investigate clinical,endoscopic and CT characteristics in Crohn's disease (CD),intestinal tuberculosis(ITB) and primary small intestinal lymphoma (PSIL).Methods In this study,39 cases of CD,24 cases of ITB and 23 cases of PSIL were retrospectively analyzed.Clinical and CT data were collected in all patients,23 CD cases,20 ITB cases and 20 PSIL cases underwent endoscopic exam.Chi-square tests or analysis of variance were used to evaluate and differentiate characteristics.Results Diarrhea,perianal disease,intestinal obstruction occurred significantly more in CD than in ITB and PSIL (x2 =10.134,6.769,8.000,P ＜ 0.05).Febrility,night sweating,pulmonary tuberculosis and ascites occurred more in ITB than in CD and PSIL (x2 =25.696,19.194,35.133,P ＜0.05).Abdominal mass,hematochezia and enterobrosis occurred more in PSIL than in CD and ITB (x2 =19.562,17.708,12.647,P＜0.05).Longitudinal ulcer,cobblestone sign were found more in CD than in ITB and PSIL(x2 =6.283,11.592,P ＜ 0.05).Transverse ulcer and rodent ulcer were found more in ITB than in CD and PSIL(x2 =15.633,19.686,P ＜ 0.05),but lump eminentia were found more in PSIL than in CD and ITB(x2 =26.120,P ＜0.05).Layering thickening,mural gas,fat,edema,enteric cavity stenosis,abscess were discovered more in CD than in ITB and PSIL (x2 =17.472,10.346,7.773,6.867,16.325,10.994,P＜0.05),single layer thickening and hollow lymph nodes were discovered more in ITB than in CD and PSIL(x2 =17.997,12.475,P ＜ 0.05).Multi segmental lesions was discovered more in CD and ITB than in PSIL (x2 =28.460,P ＜ 0.05),while single segmental lesions,mural single eccentric layer thickening and intussusceptions were discovered more in PSIL than in CD and PSIL (x2 =28.460,P ＜0.05).The intestinal wall thickening and lymph nodes enlargement in ITB and PSIL were higher than the CD (F =8.661,7.166,P ＜ 0.05),while the intestinal wall enhancement at CT imaging in PSIL was lower than CD and ITB (F =10.179,P ＜ 0.05).Conclusions Comprehensive analysis made on clinical,endoscopic and CT features of CD,ITB and PSIL may facilitate correct diagnosis.

Objective To investigate the diagnostic value of computed tomography,X ray enterography and digestive endoscopy for intestinal Crohn's disease in active and chronic phase.Methods The clinical data of 39 patients with Crohn's disease who were admitted to the Subei People's Hospital from June 2008 to August 2011 were retrospectively analyzed.All patients were divided into the active phase group (28 patients) and the chronic phase group (11 patients).The results of computed tomography,X ray enterography and digestive endoscopy of the 2 groups were compared.The accuracy of the 3 diagnostic methods was assessed by consulting the operative findings.The enumeration data were analyzed using the chi-square test.Results The incidences of intestinal wall stratification,intesitnal edema strap,severe enhancement,ulcers,intestinal stenosis,intestinal fistula,phlegmon,swollen lymph nodes and comb sign in patients with active phase of Crohn's disease were significantly higher than those with chronic phase of Crohn's disease (x2 =10.700,3.954,22.025,7.661,10.700,7.661,6.810,7.661,4.592,P＜0.05).The incidences of intestinal wall thickening,intramural fat,mild enhancement,unenhancement,inflammatory polyps,abscesses and inflammatory masses in patients with chronic phase of Crohn's disease were significantly higher than those with active phase of Chrohn's disease (x2=17.475,11.345,18.050,5.366,22.856,12.662,5.846,P ＜ 0.05).Computed tomography was effective in detecting intestinal wall thickening and extraintestinal complications of Crohn's disease,but it was difficult in demonstrating ulcers and inflammatory polyps.X ray enterography and digestive endoscopy were effective in detecting ulcers and inflammatory polyps,but they were difficult in detecting intestinal wall thickening and extraintestinal complications of Crohn's disease.Conclusion Computed tomography combined with X ray enterography and digestive endoscopy is helpful in demonstrating the presentations of Crohn's disease in active and chronic phase.

Objective To investigate the MSCT features of the renal cell carcinoma associated with XP11.2 translocation-TFE gene fusion ( XP11.2-TFE Ca).Methods The MSCT features of XP11.2-TFE Ca in six patients were retrospectively analyzed,which were confirmed by postoperative histopathology.All the tumor features were recorded and compared to the histopathological findings.Variance test analysis was performed to compare the CT values among tumor,normal renal cortex and normal renal medulla.Results XP11.2-TFE Ca appeared as a solitary lesion in all the 6 patients,which limited in the medulla in 3 patients and infiltrated both medulla and renal pelvis in other 3 patients.The tumor diameter ranged from 3.8 to 5.2 cm [mean diameter,(4.2 ± 1.3) cm],And the adjacent renal cortex was compressed or involved.Four lesions were oval,2 lesions were irregular shape.Tumor capsule showed in all lesions in the six patients.Cystic component and retroperitoneal lymph node metastasis respectively occurred in one patient.In all lesions,calcification was not detected.On unenhanced CT scan phase,the CT values of the normal cortex,normal medulla and XP11.2-TFE Ca were (42 ±5),(38 ±4) and (48 ±4) HU respectively,with no significant statistical difference ( F =1.267,P ＞ 0.05 ) ; on cortical nephrographic phase after contrast injection,they were ( 174 ± 10 ),( 72 ± 8 ) and ( 100 ± 9) HU respectively,with significant statistical difference among the three groups (F =6.588,P ＜ 0.01) ; on parenchymal nephrographic phase,they were (207 + 12),(109 +8) and ( 121± 11) HU respectively,with significant statistical difference (F =7.172,P＜0.01) ; and on the excretory phase,they were (148 ± 12),(67 ±8) and (83 ±7) HU respectively,with significant statistical difference ( F =2.678,P ＜ 0.05 ).On each phase of contrast-enhanced MSCT scan,the enhancement of XP11.2-TFE Ca was higher than that of the medulla and lower than that of the cortex.Conclusions XP11.2-TFE Ca had some characteristic MSCT features.Comprehensive analysis of its MSCT features may help for improving the diagnosis.

The clinical data,endoscopic and CT findings of 39 patients with Crohn's disease(CD) and 24 patients with intestinal tuberculosis (ITB) were retrospectively reviewed.Diarrhea,hematochezia,perianal disease,intestinal obstruction,occurred more frequently in CD than in ITB (P ＜0.05 or ＜0.01).Night sweating,febrility,pulmonary tuberculosis and ascites were more common in ITB than in CD (P ＜0.01).The endoscopic findings showed that longitudinal ulcer,cobblestone sign,intestinal stricture were detected more often in CD than in ITB (P ＜ 0.05 or ＜ 0.01),but transverse ulcer and rodent ulcer were more frequently found in ITB than in CD (P ＜0.05 or ＜0.01).On the CT imaging mural gas,fat,enteric cavity stenosis and layering thickening were more common in CD than in ITB (P ＜ 0.05 or ＜ 0.01),but mural single layer thickening and hollow lymph nodes were discovered more frequently in ITB than in CD (P ＜ 0.01).The degree of intestinal wall thickening,enhancement and lymph nodes enlargement of ITB were more severe than that of CD (P ＜ 0.01).The clinical manifestations combined with endoscopic and CT finding may improve the differential diagnosis between Crohn's disease and intestinal tuberculosis.

Objective To investigate the differential diagnostic features of subtpes of renal cell carcinoma (RCC) using CT scan.Methods The CT appearances of 53 RCCs,including 28 clear cell RCCs (CCRCC),6 Xp11.2 /TFE RCCs (Xp11.2 /TFE RCC),7 collecting ducts RCCs (CDC),12 chromophobe RCCs (CRCC),were retrospectively analyzed and compared with finding of pathology.Dynamic contrast-enhanced CT (DCE-CT) was conducted in each case after intravenous administration of contrast agent,and the data was analyzed by AVONA and LSD text.Results On unenhanced and enhanced CT,most CCRCCs and CDCs showed heterogeneous density (23/28,6/7),with necrosis (21/28,6/7),and most Xp11.2/TFE RCCs,CRCCs showed homogeneous density(5/6,8/12).Most CCRCCs,Xp11.2/TFE RCCs and CRCCs had clearly boundaries with well demonstrated at enhanced CT delayed phase (25/28,6/6,10/12),CDCs had unclearly boundaries (6/7),and most CCRCCs had lymph node or other metastasis (19/28).A phenomenon of quick staining and quick fainting was observed in CCRCCs.Xp11.2/TFE RCCs,CDCs,CRCCs showed delayed enhancement.On unenhanced CT,the Xp11.2/TFE RCC attenuation was greater than CCRCC,CDC,CRCC and normal renal cortex (53.7±4.1 vs 45.8±3.6 vs 41.4±2.4 vs 47.7±3.6 vs 41.5±5.1,F=5.458,P＜0.01,respectively).The enhancement degree was highest for CCRCCs,lowest for CDCs,and intermediate for Xp1 1.2/TFE RCCs and CRCCs.The enhancement degree of Xp1 1.2/TFE RCC was higher than that of the CDC and CRCC (P＜ 0.01).The enhancement degree of Xp11.2/TFE RCC and CRCC were higher than that of the normal renal medulla at cortical and medullary phases (P＜0.01),but lower than that of the renal medulla on delayed phase (P＜0.01).The enhancement degree of CDC were lower than that of the normal renal cortex and medulla on cortical,medullary and delayed phases (P＜0.05).Conclusions CT could distinctly show imaging features of CCRCC,Xp1 1.2/TFE RCC,CDC and CRCC,which were related to their pathological characteristics,and these features were helpful in predicting a specific subtype of RCC.

Objectives To explore the value of Silenz MRA in the follow-up assessment of intracranial aneurysms embolization. Methods Fifteen patients underwent coiled embolization were prospectively collected. Silenz and time of flight MRA (TOF MRA) were performed on the same day as DSA examination. Two neuro-radiologists scored the structures of peripheral vascular with a 4-score grading system and evaluate embolism status (two-grade montreal scale). The scores of vascular structures were compared using Wilcoxon signed rank tests. Weighted Kappa statistics was used to assess the inter-observer agreement on each MRA scoring, the inter-modality agreement between MRA and DSA, the inter-modality agreement between the MRA methods. Results There were 11 cases with complete occlusion, 4 cases with residual aneurysm revealed by DSA. For depiction, Silenz MRA was significantly better than TOF MRA [(3.50 ± 0.62) vs. (3.00 ± 0.63), Z=-3.12, P=0.002]. Inter-modality agreement of Silenz MRA and DSA was excellent (Kappa=0.82), while the agreement of TOF MRA and DSA was moderate(Kappa=0.60). Inter-modality agreement between Silenz MRA and TOF MRA was good (Kappa=0.76). Conclusions Silenz MRA is superior to TOF MRA for depiction of vascular structures and evaluation of embolism status, which is highly related with DSA. It has the value in the postoperative follow-up evaluation.

Objective To explore the value of single source dual energy CT for quantitative measurement of liver fat fraction in the rabbit model of nonalcoholic fatty liver disease(NAFLD).Methods Thirty male New Zealand rabbits were randomly divided into five groups.Six rabbits were fed with standard chow as a control group for 3 weeks.TwentyGfour rabbits were divided into four groups and fed with highGfat, highGcholesterol diet to reach different stage of NAFLD model for 1 ,3 ,4 and 8 weeks respectively before dualGenergy CT scanning.1 40 keV polychromatic CT values (QC),70 keV monochromatic CT values (Mono 70 keV),slope,effective atomic number (EffectiveGZ)and fat concentration based on dualGenergy CT fat decomposition (Fat/Water)were measured.Liver samples were obtained to measure the fat fraction and staged according to Burnt staging system.Correlations between different CT indexes and fat fraction were analyzed.ROC was used to evaluate the diagnosis efficacy of different parameters.Results Correlation between fat concentration based on dualGenergy CT fat decomposition and fat fraction (r＝0.936)was better than that between 140 keV polychromatic CT values (r＝－0.838)and 70 keV monochromatic CT values (r＝－0.906),as well as effective atomic number (r＝－0.858)and slope (r＝0.863).In terms of diagnostic performance of material decomposition fat imaging,the values of area under the curve were 0.944 (stage 0 vs.stage 1 or more severe),0.995 (stage 1 or less severe vs.stage 2 or more severe)and 1 (stage 2 or less severe vs.stage 3)with optimal cutoff values of 59.310,99.5 17 and 22 3.02 3 mg/cm3 ,respectively.Conclusion The dualGenergy CT can quantitatively measure liver fat concentration as a noninvasive surrogate bioGmarker in the rabbit model of nonalcoholic fatty liver disease.DualGenergy CT derived material decomposition fat images can provide more diagnostic information at the early stage of NAFLD.

ObjectiveTo investigate the CT and MRI characteristic features of neuroendocrine carcinoma in paranasal sinuses.MethodsCT and MRI findings of 10 patients with proved neuroendocrine carcinoma by pathology were retrospectively reviewed. All patients underwent plain and enhanced MRI scanning,and 9 patients also underwent CT manning.ResultsThere were 5 males and 5 females with mean age of (48 ± 9 ) years old,ranging from 27 to 57 years.The treatment time after symptoms onset ranged from 1 to 4 months,with the median of 2 months.Clinical symptoms were headache and vision loss,hyposmia and yellow nasal discharge,and exophthalmos.The lesions were located in the ethmoidal sinus ( n =6 ),maxillary sinus ( n =2),and bilateral sphenoid sinus ( n =5 ).The lesions were symmetrical in the sphenoid sinus.Pathology type included typical carcinoid tumor ( n =1 ),atypical carcinoid ( n =1 ),and neuroendocrine carcinoma not otherwise specified ( n =8 ). Immunohistochemical staining showed that neurospecific enolase,synaptophysin,cytokeratin and P53 were all positive.On CT images,lesions showed isointensity (n =1 ),iso- to hypointense (n =4 ),and iso- to hyperintense (n =4 ) with hypointense or hyperintense spots.Bone changes included bony absorption and sclerosis ( n =1 ) with a clear margin in typical carcinoid tumor,and moth-eaten bone destruction in other 8 cases( n =8).The lesions were isointense on T1-weighted images,and isointense (n =4) or mixed iso- to hyperintense on T2-weighted images (n =6).Lesions showed mild to medium heterogeneous enhancement ( n =7 ) or marked enhancement ( n =3 )on gadolinium-enhanced images.Time-signal intensity curve ( TIC ) showed plateau type in 2 cases.The aggressive nature of the tumors was demonstrated by invasion of adjacent structures,involvement of nasal cavity( n =9 ),orbits ( n =7 ),pterygopalatine fossa ( n =4 ),ethmoidalsinus and sphenoid ( n =3 ),clivus ossis occipitalis(n =2),cavernous sinus and internal carotid canal(n =2),optic canal(n =2),jugular fossa ( n =1 ),anterior fossa ( n =1 ),apex partis petrosae ossis temporalis ( n =1 ),meninges ( n =1 ),temporal fossa and infratemporal fossa ( n =1 ),pharyngonasal cavity and parapharyngeal space ( n =1 ).ConclusionsThere are different CT features in different pathological types of neuroendocrine carcinoma of the paranasal sinuses,and MRI can demonstrate the invasive extent accurately. CT combined MRI can provide more comprehensive information in the diagnosis and therapy.