Objective To evaluate the value of diffusion weighted imaging (DWI) and apparent diffusion coefficient(ADC) in diagnosing pancreatic carcinoma. Methods DWI was performed in 25 cases of pancreatic cancer, confirmed by pathology, and 20 normal persons. Five sequences of echo planar diffusion imaging were used, b value (?10-3s/mm2 ) was 50, 100, 300, 500, and 700 respectively. Then the ADC values in tumor area, non-tumor area and normal pancreatic area were calculated.Results ADC values of tumor tissue were significantly different from that of the tissue in the same pancreas, when b value were 100 and 300 s/mm2; there was statistically significantly difference between tumor group and normal group when b value were 100, 300, 500 and 700 s/mm2. ADC values of the tissue except for tumor tissue in the same pancreas were significant different from that of normal group when b value were 500 and 700 s/mm2. Conclusion DWI is a rapid and feasible method in detecting pancreatic cancer.

Purpose cerebral venous sinus thrombosis (CVST) has no specific manifestations in clinic, it is often misdiagnosed and the treatment is delayed. This paper aims to evaluate magnetic resonance venography (MRV) in the detection of CVST by meta-analysis. Materials and Methods The articles concerning the diagnosis of CVST by using MRV were searched in the databases such as Cochrane Library, PubMed, Embase, Web of Science, CBM, VIP, Wanfang and CNKI. The QUADAS items were used to evaluate the quality of the included studies. The results were analyzed with software Metadisc1.4 and RevMan 5.0. The pooled weighted sensitivity, specificity, and the diagnostic odds ratio were calculated, and complete summary receiver operating characteristic curve (SROC) was drawn. Results Twelve studies of eight articles met the inclusion criteria. The pooled sensitivity, specificity, diagnostic odds ratio and area under SROC curve for the MRV were 0.86 (0.80-0.91), 0.87 (0.83-0.93), 29.65 (12.48-70.47), and 0.9125, respectively. Conclusion MRV can be used as an effective method with its high value in the diagnosis of CVST.

Objective To compare the nephrotoxicity of the iso-osmolar contrast media (iodixanol) to low-osmolar contrast media (LOCM) in intravenous contrast-enhanced CT.Methods Randomized controlled trials (RCTs) of iodixanol or low-osmolar contrast media in intravenous contrastenhanced CT were searched in the database of VIP,CBM,CNKI,Wanfang,PubMed,EMBASE,Web of Science,Cochrane Library from their start year to July 2012.Screening and information extracted were did by two researchers independently.The quality of the included documents was evaluated by the criterion of Cochrane handbook.Revman software (version 5.0) of the Cochrane collaboration was used in data analysis.Results There was no significant difference in the incidence of contrast-induced nephropathy (CIN) among 6 trials recruited 907 patients between the iodixanol group and the LOCM group [RR =0.64,95％CI (0.31-1.32),P=0.22] by using serum creatinine increased by more than 44 μmol/L (0.5 mg/dl) as the diagnostic criteria.No considerable difference was existed by using serum creatinine increased by more than 25％ as the diagnostic criteria between the two groups [RR =0.79,95％CI (0.48-1.30),P =0.35].Subgroup analysis showed there was no obvious difference [RR =0.57,95％CI (0.30-1.10),P =0.09] between the two groups in patients with increased baseline of serum creatinine.No obvious difference were gained in normal baseline group [RR =1.28,95％CI (0.57-2.86),P =0.55].Conclusion Compared with low-osmolar contrast media,iodixanol is not associated with less CIN in intravenous contrast-enhanced CT.

Objective To investigate the difference of colon length between patients with intractable constipation and normal peo-ple.Methods 40 patients with intractable constipation and 35 cases of normal control group received air enema CT scan,post-pro-cessing techniques-curved planar reformation and volume rendering were used to measure the length of colon.Results Colon length of normal people and constipation patients were (1 230±33)mm and (1 605±47)mm,respectively.There was significant difference between normal people and constipation patients (t=163,P=0.015).Conclusion CT air enema technique can be used to measure the length of colon obj ectively for diagnosing and treating redundant colon.

Early small hepatocellular carcinoma (SHCC) can be cured by surgery and interventional operation to improve the survival rate of paitents,so the accurate diagnosis of SHCC is of great significance.Presently,the dynamic contrast-enhanced MR scan could only obtain single arterial phase imaging by single breath hold,and it had breathing motion artifact because of the long scanning time.The early arterial transient enhancement of SHCC was easy to be misdiagnosed.The CAIPIRINHA-Dixon-TWIST-VIBE (CDT-VIBE) sequence couldobtain high-quality multiple arterial phases images and hepatic arterial dominant (HAD) images in short-time scanning.And it could not only detect small focal lesions which were difficult to find by other imaging examination,but also find the start enhanced difference between lesions which were relevant to lesions property and blood supplement.The CDT-VIBE has a high clinical value in diagnosis and treatment of SHCC.The research progresses of CDT-VIBE in diagnosis of SHCC was reviewed in this article.

Objective To analyze the value of dual-source computed tomography (DSCT)in the diagnosis of complex congenital heart disease(CCHD).Methods DSCT angiography and transthoracic echocardiography (TTE)were retrospectively assessed in 46 patients who were confirmed by surgery with 107 deformities.Results There were 49 intracardiac deformities and 58 extracardiac deformities.The diagnostic accuracies in detection of intracardiac malformation were 81.63%(40/49)on DSCT and 93.88%(46/49) on TTE,those in detection of extracardiac malformation were 94.83%(55/58)on DSCT and 58.62%(34/58)on TTE,and the overall accuracies of cardiovascular malformations were 88.79%(95/107)on DSCT and 74.77%(80/107)on TTE,respectively,exhibting statistical differences.The diagnostic accuracy of DSCT in combination with TTE in detection of intracardiac and extracardiac malformation was 94.39%(101/107),which was higher than DSCT or TTE with statistical differences.Conclusion The combination of TTE and DSCT is helpful to improve the diagnostic accuracy of CCHD.

Objective To explore the application value of CT perfusion imaging for predicting the tiny lymph nodes metastasis and micrometastasis of squamous cell carcinoma in cervix after neoadjuvant chemotherapy.Methods The clinical data and CT perfusion parameters of 46 patients with cervical squamous cell carcinoma who underwent neoadjuvant chemotherapy followed by surgery were enrolled in the study.Based on the surgical pathology findings and short-term follow up,the cases were divided into without tiny lymph nodes metastasis (short axle diameter of lymph nodes＜10 mm) group (n=32) and with tiny lymph nodes metastasis group (n=14).All perfusion data were analyzed retrospectively and the diagnostic value were investigated.Results Blood flow (BF),blood volume (BV) and the maximum diameter of tumor per-chemotherapy in with tiny lymph nodes metastasis group were higher than those in without tiny lymph nodes metastasis group (all P＜0.05).The differences of the maximum diameter of tumor after chemotherapy,permeability,time to peak (TTP) between two groups were not statistically significant (all P＞0.05).Multivariate Logistic regression analysis showed BF and the maximum diameter of tumor per-chemotherapy were independent predictors of the tiny lymph nodes metastasis in cervix after neoadjuvant chemotherapy.ROC showed BF (AUC=0.86,P＜0.001,95％CI [0.75,0.96]) had higher predictive value than maximum diameter of tumor per-chemotherapy (AUC=0.70,P=0.02,95 ％ CI [0.54,0.88]).Conclusion CT perfusion imaging shows the significant predictive value for the tiny lymph nodes metastasis of squamous cell carcinoma in cervix after neoadjuvant chemotherapy.

Objective To observe the appearances of decussation of superior cerebellar peduncle (SCP) on MR diffusion tensor imaging (DTI) with different parameters of scanning and reconstruction. Methods Twenty healthy volunteers were examined on Siemens 3.0T MR DTI (b=0, 1000 s/mm~2), post processing were made in Siemens Leonardo workstation using Siemens Standar 6 dirs software to reconstruct the white matter fibers with different fractional anisotropy (FA) threshold value (0.04-0.20), angle threshold value (20°-89°) and voxel size (1.2 mm×1.2 mm×3.0 mm-1.6 mm×1.6 mm×5.0 mm). Results Crossing fiber was presented each voxel group on diffusion tensor tractography (DTT). The types of crossing fiber in the small voxel were more than those of big voxel image obviously. Reduced along with the FA threshold value, the number of crossing fiber increased gradually. After the peak value (FA=0.08), the number of crossing fiber reduced along with the FA threshold value reduced gradually. Increased along with the angle threshold value, the number of crossing fiber increased gradually. The number of crossing fiber reduced along with the angle threshold value increased gradually after the peak value (the angle threshold value＝80°). There were 5 kinds of MR fiber tracking appearances at the level of decussation of SCP on DTT. The fiber crossed to the opposited red nucleus in anterior-posterior style, superior-inferior style and single main bundle fiber. Kissing fiber and missing fiber sign was shouw in all subjects, which mainly located in the center of the decussation. Conclusion DTT FACT can show the descussation of SCP in most health subjects with five typical appearance. The descussation of SCP has the obvious appearances, may be causing by individual difference. For the crossing fiber of SCP, voxel size 1.2 mm×1.2 mm×3.0 mm, FA 0.08 and the angle 80° are recommended.

Objective To observe the CT and MR features of hepatic hydatid cyst, and to evaluate the diagnostic value of CT and MR. Methods CT and MR images were retrospectively analyzed in 42 patients with pathologically proved hepatic hydatid diseases, and the relative articles were reviewed. Results Hepatic echinococcosis granulosus occured in 85.71% patients, among which ring like pattern calcification, the ribbon calcification, multiple daughter vesicles and detached membranes within cyst were the main findings. Hepatic echinococcosis alveolaris occured in 14.29% patients, whereas the main finding included calcification, small vacuoles, peninsula sign, geographic sign and colliquative necrosis. For the diagnosis of hepatic hydatidosis, MR was better than CT in the judgement of the cyst wall, detached membranes and fibrous septum, but was inferior to CT in displaying calcification sign. Conclusion Hepatic hydatidosis can be diagnosed either with CT or MR, CT is superior to MR in integrated diagnosis of this disease.

Purpose With the progression of brain tissue aging, the transport and drainage characteristics of metabolites and secretory products for neurons in extracellular space occurs irreversible change. This paper aims to investigate and quantify MR tracer diffusion characteristics in cerebral interstitial fluid of elderly SD rats. Materials and Methods MR contrast agent Gd-DTPA was injected into the caudate nucleus of two groups of rats including 8 in experimental group (15-17 month old) and 15 in control group (7-10 month old). MR scan was performed at 0.25 h, 0.5 h, 1 h, 2 h, 3 h and 4 h to observe the dynamic distribution in the caudate and measure the diffusion and clearance rate. Results There was no statistically significant difference in diffusion rate and D* between control group with (3.32±0.70)×10-4 mm2/s and experimental group with (3.25±0.46)×10-4 mm2/s (t=1.739, P>0.05). The clearance rate k' was significantly different between control group (0.62±0.12)×10-4/s and experimental group (0.29±0.08)×10-4/s (t=11.602, P<0.05). Conclusion The degeneration of aging brain tissue changes the composition of extracellular space resulting in decreased speed of ISF clearance. This may cause accumulation of metabolites which eventually triggers a variety of age-related diseases.