Objective To investigate the CT findings of histocyticnecrotizing lymphadenitis(HNL)in the neck.Methods CT data of 10 patients with pathologically confirmed HNL in the neck were retrospectively analyzed,7 males and 3 females,aged from 4 to 75 years old(median age 26 years old).Nine patients had plain CT scans and 5 of them had contrast scans.One case had only contrast CT scan.Results Totally,127 lymph nodes were identified in the neck,mainly located in the area of Ⅱ,Ⅲ,Ⅳ and Ⅴ.The maximum diameter of the involved lymph nodes ranged from 0.5-3.6 cm,1.3 cm in average.One hundred and eight lymph nodes were homogeneous and 8 were heterogeneous in plain CT images.Seventy nine lymph nodes had homogeneous enhancement and 27 had heterogeneous enhancement One hundred and ten lymph nodes had unclear margins and the surrounding fat was blurred.Conclusion CT findings of HNL of the neck are variable and non-specific.Clinical findings and laboratory examination may be helpful for the diagnosis and differential diagnosis.

Objective To assess response of rectal carcinoma to preoperative chemoradiation therapy(CRT)using DWI and tumor ADC values,and to investigate the value of ADC in predicting and monitoring therapeutic effect of CRT.Methods Twenty-six patients with primary rectal carcinoma undergoing preoperative CRT were recruited to the study.DWI was performed on a 1.5 T MR scanner in all patients at the time point of pre-therapy,the end of the 1st,2nd week of therapy and pre-operation,respectively.ADC values of the tumors were calculated on the workstation.Randomized block design was applied to analyze change in ADCs following treatment Results All patients were divided into T-downstaging group(n=12)and T-non-downstaging group(n=14).In T-downstaging group,the mean tumor ADC values were(1.10±0.13)×10~(-3),(1.32±0.19)×10~(-3),(1.35±0.13)×10~(-3),(1.32±1.00)×10~(-3) mm~2/s at the time point of pretreatment,week 1,week 2,pre-operation,respectively(F=16.420,P＜0.01).The mean tumor ADC value in T-non-downstaging had a slight increase from(1.16±0.16)×10~(-3) mm~2/s to(1.23±0.13)×10~(-3) mm~2/s at the time of week 1(P＞0.05).The ADC value in T-non-downstaging group continuously increased to(1.30±0.16)×10~(-3) mm~2/s at the end of the 2nd week of CRT(F=5.023,P＜0.01)and appeared statistical difference.The evolution of tumor ADC values in the two groups was significantly different.Early increases in tumor ADC were observed in T-downstaging group.Regarding the increase percentage of ADC value at 1st week as a diagnostic marker of tumor downstaging,when it was set as 11.6%,the sensitivity,specificity,positive predictive value and negative predictive value is 75.0%,78.6%,75.0% and 78.6% respectively,the area under curve(Az)was 0.774(95% confidence interval:0.583 to 0.964).Conclusions An early significant increase of mean tumor ADC value in rectal carcinoma has a potential to predict therapeutic effect of CRT.One week after beginning CRT is an early time point to monitor therapy efficacy.

Objective To investigate the diagnosis and interventional therapeutic technology for the obstruction of hepatic vein(HV)or inferior vena cava(IVC)after liver transplantation.Methods In the 831 patients who received orthotopic liver transplantation(OLT)and 26 patients who received living donor liver transplantation(LDLT),11 cases were confirmed with HV or IVC obstruction by venography and received interventional treatment from 2 to 111 days after liver transplantation.Of the 11 patients,five had the obstruction of HV anastomosis,five had the obstruction of IVC anastomosis,and one had the obstruction of HV and IVC anastomosis.In the eleven patients,five patients underwent OLT,four patients underwent LDLT,and two pediatric patients underwent reduced-size OLT.Before interventional treatment,9 patients received CT enhanced scans,2 received MR enhanced scans.Follow-up evaluations included liver or renal function tests,clinical symptom,and monitoring of HV or IVC flow.Pressure gradients before and after interventional treatment were compared by using a paired t test.The imaging data and interventional therapeutic technology of 11 cases were retrospectively analyzed.Results In all 11 patients,CT or MRI could clearly show congested areas of the liver,and the location and degree of HV or IVC obstruction.Of the 11 patients,four with HV obstruction and five with IVC obstruction were treated with stent placement,one with HV obstruction was treated with percutaneous transluminal angioplasty(PTA),one with HV and IVC obstruction was treated with HV PTA and IVC stent placement.Interventional technical success was achieved in all patients.The venous pressure gradient across obstruction was significantly reduced from(16.5±4.1)mm Hg(1 mm Hg=0.133 kPa)before the procedure to(2.9±1.7)mm Hg after the rocedure(t= 11.5,P＜0.01).Clinical improvement was noted in 10 patients except one pediatric patient who died of multiple-organs failure at the 9 th day after the treatment During the follow-up period of 9 to 672 days,two patients with PTA treatment had recurrent HV stenosis within one month after treatment,no patient with stent placement developed venous restenosis.No major complications occurred during the procedures.Conclusions Stent placement is safe and effective for HV or IVC obstruction after liver transplantation.CT or MRI before treatment is of important value for the diagnosis of congested areas of the liver,and the observation of HV or IVC obstruction.

Objective To probe the clinical application of CT in the diagnosis of criss-cross heart(CCH).Methods Five patients with CCH confirmed by operation were retrospectively analyzed.Enhanced 64-slice spiral CT was performed in 2 patients and enhanced single-slice electron beam CT was performed in 3 patients.Three dimensional reconstructions were applied for the fully display of anatomic malformations,and the results were compared with that of echocardiogram and angiocardiogram with Chi-square test Results(1)Visceroatrial situs solitus,twisted and concordant atrioventricular connection,horizontally oriented ventricular septum,ventricular septum defect and pulmonary stenosis were found in all patients on CT.The ventriculoarterial connection was discordant,including double-outlet right ventricle in 4 patients and complete transposition of great arteries in 1 patient In addition,associated anomalies including persistent left superior vena cava(n=2),coarctation of the aorta(n=1)and right aortic arch with right descending aorta(n=1)were detected as well.(2)Total 33 anomalies in 5 cases were found during operation.The diagnostic accuracy of CT,angiocardiogram and echocardiogram was 93.9%(31/33),81.8%(27/33)and 54.5%(18/33)respectively.There was a significant difference between CT and echocardiogram(X~2=13.39,P＜0.01),and no significant difference between CT and angiocardiogram(X~2=1.29,P＞0.05).Conclusion CT is an excellent imaging technique for the diagnosis of CCH.

Objective To study the morphological appearance and pathological basis of the fine pulmonary reticulation at HRCT.Methods One hundred and seven patients were analyzed about the morphology findings and dynamic changes on pulmonary HRCT.Twenty-four coal worker's pneumoconiosis(CWP)specimens were examined to make comparison between CT and pathology.The data was analyzed by using the Chi-square test.Results The reticular gap was less than 3 mm in diameter.The morphology of reticulation was round or irregular.Pulmonary parenchyma was seen between the gaps.The reticular wall was smooth or coarse.The thickness was less than 1 mm.One hundred and seven patients had accompanying signs including ground-glass opacity(68.2%,73 patients),crazy paving(23.4%,25 patients),interlobular septal thickening(84.1%,90 patients),emphysema(32.7%,35 patients),interface sign(58.9%,63 patients),traction bronchiolectasis(41.1%,44 patients)and honeycombing(26.2%,28 patients).The differences of the honeycomb,traction bronchiolectosis,interbobular septal thickening,interface sign and paving were statistically significant between the fibrotic group and pneunonia(P＜0.01).Pneumonia showed extensive area of ground-glass opacity(GGO)with fine reticulation.Fine reticulation with both interlobular septal thickening and small nodules were observed more frequently in lmphangitic carcinomatosis.Idiopathic pulmonary fibrosis(IPF)showed fine reticulation among the honeycombing.Connective tissue disease (CTD)showed fine reticulation with rarely honeycombing and it could be partly absorbed.Fine reticulation with emphysema was seen in chronic bronchitis.In the 58 follow-up patients,the fine reticulation increased in 26 patients,decreased or disappeared in 22 patients and showed no change in 10 patients.The major pathological basis of the fine reticulation was intralobular interstitial thickening,including fibrosis hyperplasia,inflammatory cells and tumor cells infiltration,effusion filling,smut deposition and so on.Conclusions The fine reticulation was caused by intralobular interstitial thickening including inflammation,interstitial hyperplasia,pulmonary fibrosis and tumor.The fine reticulation is helpful to prompt the diagnosis of these diseases,but the diagnosis need its combination with the other CT findings and dynamic changes.

Objective To prospectively evaluate the influence of average heart rate,heart rate variability and ECG editing on image quality of 64-slice CT coronary angiography(CTCA)in patients with atrial fibrillation(AF).Methods Fifty patients who were diagnosed with AF underwent respective ECG-gating 64-slice CTCA Image quality(good,moderate,poor)were evaluated on vessel segment level pre-and post ECG editing.Chi-square test was performed to compare the image quality in patients with various average heart rate,heart rate variability,and pre-and post ECC editing.Pearson correlation analysis was performed to test the relationship between the image quality and average heart rate and heart rate variability.Sensitivity,specificity,positive predictive value(PPV)and negative predictive value(NPV)were calculated by using the conventional angiography as the standard reference.Results The average heart rate of the fifty AF patients was(89±23)beat/min,with variability of(18.2±6.1)beat/min.Finally,24(3.4%)segments were considered to have poor image quality in 6(12.0%)patients.Image quality decreased significantly(P＜0.05)at the average heart rate of over 100 beats per minute(11 segments)or the standard deviation of heart rate of over 24 beats per minute(11 segments).There was significant correlation between the mean heart rate and the image quality for all segments,the RCA,and distal section of coronary artery(r=0.50,0.55,0.53,0.49,0.42,0.44;P＜0.05).Heart rate variability was also significant correlated with the image quality.There was significant difference on image quality pre-and post ECG editing(P=0.013).The respective overall sensitivity,specificity,NPV,PPV values were 100%(6/6),93.2%(41/44),100%(41/41),and 66.7%(6/9).Conclusion ECG editing can improve the success rate and the image quality of 64-slice CTCA effectively in patients with AF within a certain range of average heart rates and heart rate variability.

Objective To study a rare CT finding of pulsatile tinnitus(FT)caused by sigmoid sinus abnormalities.Methods The imaging data of PT caused by sigmoid sinus abnormalities were analyzed retrospectively in 15 patients(15 female).The median age was 45 years(24 to 63 years).The duration of persistence pulsatile tinnitus was from 0.5 year to 36.0 years(median time,2.0 years).The tinnitus was at left side in 5 patients and right side in 10 patients.Fifteen patients underwent HRCT of the temporal bone.Of them,12 patients underwent cerebral CT angiography and CT venogram(CTA/CTV),and 9 patients underwent cerebral digital subtraction angiography(DSA).Nine patients underwent transmastoid reconstruction surgery of the sigmoid sinus.Of them,the tinnitus was at left side in 2 patients and right side in 7 patients.Paired rank sum test was used to compare the cross-sectional area of the sigmoid sinus of the tinnitus side and normal side.Results On HRCT,focal bony coarse defect is shown in the anterior sigmoid wall in 11 patients and anterolateral sigmoid wall in 4 patients.On CTA/CTV,the sigmoid sinus focally protruded into the adjacent mastoid air cells and formed diverticulum in 10 patients.The pulsatile tinnitus disappeared immediately after transmastoid reconstruction surgery of the sigmoid sinus in all 9 patients.The cross-sectional area of the sigmoid sinus of the tinnitus side was 100.6(41.5-96.2)mm~2,it was 77.0(92.1-122.4)mm~2 in the nonmal side(Z=2.158,P=0.031).Conclusion Focal bony defect of the sigmoid wall with sigmoid sinus diverticula is one of the causes which lead to pulsatile tinnitus,which can be easily identified by imaging examination.

Objective To evaluate the interstital MR lymphography using positive lymphotropic contrast agent for differentiation of metastatic lymph nodes from inflammatory lymph nodes hyperplasm.Methods Eighteen New Zealand white rabbits weighted at 2.0-2.5 kg were used.Inflammatory hyperplastic popliteal lymph node model was established in 9 rabbits by injection of complete freund adjuvant into the interdigitial skin of the dorsal aspect of one hind leg,and tumor-bearing popliteal lymph node model was established in another 9 rabbits by injection of VX~2 tumor cell suspension.The popliteal lymph nodes of another hind leg of all 18 rabbits were assigned to the normal contral group.In each group,every rabbit underwent MR lymphography examination before and after the inoculation.Volumes of 0.2 ml of Gd[DTPA-bis(2-aminoethoxy)ethane]polymeric contrast agent(Gd-poly-DTPA-EOEA)injection were injected subcutaneously into the dorsal feet of both hind legs of two groups of rabbits.T_1-weighted 3D gradient-echo images were obtained,and source images were used to reconstruct images of MIP before and after the administration of agent.The maximum short-axis diameter(MSAD)of each popliteal lymph node was measured on the enhanced 3D MIP images,and the signal-to-noise ratio(SNR)measurement was performed in the largest popliteal node of each rabbit at each time point in delayed scan.Independentsamples t test was used to compare the sizes of popliteal nodes in MSADs between inflammatorily hyperplastic and tumor-bearing nodes after the inoculation,and the values of SNRs of popliteal nodes at each time point between inflammatorily hyperplastic,tumor-bearing and normal popliteal lymph nodes.Imaging results of the popliteal nodes were analyzed and correlated with pathological findings.Results All of the rabbits were successfully inoculated except of the 2 rabbits in tumor-bearing nodal group.The size in MSAD of 13 inflammatorily hyperplastic and 11 tumor-bearing nodes was(1.32±0.14)and(1.33±0.12)cm,respectively.There was no significant statistical difference between the sizes of the two groups(t=0.186,P＞0.05).At the time of 5,15,30,60,90,120 minutes after the injection of the agent,the value of SNR of 9 inflammatorily hyperplastic and 9 contralateral normal nodes was 17.31±0.37 and 17.19±0.29,27.42±0.50 and 27.39±0.48,38.44±0.47 and 38.19±0.27,37.10±0.09 and 36.97±0.10,36.32±0.61 and 36.20±0.80,34.60±0.44 and 34.71±0.32,respectively.There was no significant statistical difference between the values of the two groups(t=0.78,0.14,1.43,1.00,0.36,-0.62,respectively,P＞0.05).The value of SNR of seven tumor-bearing and seven contralateral normal nodes was 6.00±0.22 and 17.21±0.28,7.87±0.16 and 27.17±0.23,8.14±0.24 and 38.16±0.19,8.09±0.28 and 36.94±0.30,7.59±0.20 and 35.96±0.72,7.50±0.14 and 34.81±0.27,respectively.There was significant statistical difference between the values of the two groups(t=-84.00,-182.72,-261.27,-186.48,-100.22,-239.00,respectively,P＜0.01).At each time point,inflammatorily hyperplastic nodes had significantly higher values of SNRs compared to tumor-bearing nodes(t=83.97,174.07,158.49,152.71,96.06,154.57,respectively,P＜0.01).A complete or part signal filling defect occurred in the tumor-bearing lymph node on the MR lymphographic images.Conclusions The internal anatomy and function of the lymph nodes were effectively visualized by interstitial MR lymphography with positive lymphotropic contrast agent,which provide a sensitively diagnostic way for the differentiation of benign lymph nodes from malignant ones.

Objective To investigate the feasibility of using superparamagnetic iron oxide(SPIO)as MRI contrast agent to assess rat nonalcoholic steatohepatitis Kupffer cells(KC)function.Methods Twenty male SD rats were randomly divided into A and B groups,group A(n=10)was the experimental group fed high fat diet,group B(n=10)was the control group fed normal diet After 8 weeks,plain MR and SPIO enhanced MR were performed in all the rats.Blood lipids were measured,and HE and Perl's blue staining in all livers specimen was done.The related results of the staining were analyzed with t test Results Group A TC and TG levels[(6.58±1.25)and(1.53±0.23)mmol/L respectively]were significantly higher than group B[(1.64±0.22)and(0.55±0.14)mmol/L respectively](t=11.716 and 11.588,P＜0.01).Group A and B groups hepatic signal intensity decreased in all sequences after SPIO enhanced,but in group A the level of decline[(34.78±4.51)% and(60.38±3.49)% respectively]was less than group B[(64.96±2.42)% and(81.08±1.66)% respectively]on PDWI and T_1WI,and statistically significant differences(t=-18.451 and-16.240,P＜0.01)were found.In group A the ratio of signal intensity of liver to spleen(1.002±0.141,5.000±0.516,20.004±1.490 and 2.601±0.077 respectively)was more than group B(0.400±0.102,1.500±0.115,0.503±0.105 and-0.300±0.058)before and after contrast enhancement on PDWI,T_2WI,T_2~* WI andT_1WI(t=10.745,19.800,39.168 and 92.785,P＜0.01).Typical histological hepatic lesions of NASH were observed in group A,Perl's staining-positive particles in group A(2.33±0.50)were fewer than in group B(4)(t=-10.000,P＜0.01).Conclusion The high-fat diet induced model of SD rats was close to the human NASH and was easy to establish.Clinical application of SPIO enhanced MR successfully assessed the phagocytic activity of KC in the study,and it suggested that the pathogenesis of NASH was related to the decreased phagocytic activity of KC.

Objective To quantitatively analyze and testify the diagnostic value of combined MRS and DWI for prostate cancer based on sextant localization.Methods Patients who underwent prostate MR examinations in our hospital had MRS and DWI scanning in addition to conventional MRI.The(choline+creatine)/citrate(CC/C)value in each measurable voxel and the minimal ADC value(ADC_(mini))in each sextant were measured.Taking CC/C of no less than 0.911 as the cutoff value for prostate cancer,the ratios of positive voxel(PVR)in sextants were calculated.The selected patients were divided into 2 groups according to the date of examination,for the quantitative analysis and the verification respectively.Group 1 was from Feb,2006 to Dec,2006,and group 2 from Jan,2007 to Jul,2007.The diagnostic efficacy of PVR,ADC_(mini) and their combination was tested by ROC analysis.Results There were 40 patients in group 1 and group 2 respectively for the linear discrimination of the cluster analysis,including 20 patients with prostate cancer and 20 patients without prostate cancer.The linear discrimination equation calculated from group 1 was 'D=3.264×ADC_(mini)-0.205×PVR-4.407'.The areas under curve(Az)of ROC for PVR,ADC_(mini) and D were 0.769,0.910 and 0.909,respectively.In group 2,the Az of ROC for PVR,ADC_(mini) and D were 0.838,0.912 and 0.915,respectively.There were no statistical difference between ADC_(mini)-alone and D in both groups(X~2=0.32 and 1.50,P＞0.05).Conclusions Quantitative prostate DWI had higher diagnostic value than MRS.The combined use of MRS and DWI was not superior to the DWI-alone in the diagnostic efficacy of prostate cancer.