Objective To investigate the MRI characteristics of the tumor of optic pathway and damage degree of visual function. Methods Analysis of 119 cases surgically and pathologically proved tumor suffering from optic pathway was carried out retrospectively. The patients included:36 ones with tumors in anterior segment of optic pathway,70 ones in middle segment of optic pathway,and 13 ones in posterior segment of optic pathway. The MRI examination series were transverse T 1WI SE,transverse and coronal T 2WI TSE,coronal T 2WI SPIR,and transverse,sagittal,coronal T 1WI SE after Gd DTPA enhancement. Results The tumors of optic pathway included:the primary tumors of the optic pathway and the tumors of any other part of the body which invaded the optic pathway. There was a special MRI feature on the each tumor suffering from optic pathway,but the pituitary adenoma which affects visual function was the most common tumor. Conclusion MRI is an effective method in the diagnosis of optic pathway tumor.

Objective To investigate multi-slice spiral computer tomography(MSCT)images of gastrointestinal lymphoma.Methods MSCT data of 23 cases with primary gastrointestinal lymphoma verified by pathology were retrospectively analyzed. Results Non-Hodgkin'S lymphoma was confirmed in all of the 23 cases.For all of the cases a B-cell origin was in 22 cases and a T-cell origin in 1 case localized in transverse colon.CT images of gastric lymphoma included three kinds:diffuse thickening(n=13,81.2%),segmental thickening(n=2,12.5%),and mass(n=1,6.3%).Median thickness of gastric wall was 3.3cm (0.6～6.8 cm).CT scan of intestinal lymphoma showed irregular thickening of intestinal wall,and mass was visualized in I case of ileum lymphoma and I case of ileocecal lymphoma.Median thickness of intestinal wall was 2.8cm(0～7.0 cm).Of all the cases lesions appeared a common density by conventional CT scan,and low or moderate intensification by contrast-enhanced CT. Conclusions With its character-istic information MSCT remains the method of choice for the diagnosis of gastrointestinal lymphoma.

Objective To explore the role of extracellular signal-regulated kinase(ERK)in the apoptosis of hepatic stellate cells(HSC) induced by Arg-Gly-Asp-Ser (RGDS) tetrapeptide. Methods The cultrued HSC cells were divided into six groups including untreated control, fibronertin (FN), FN+RGDS (25 mg/L), FN+RGDS (50 mg/L), FN+RGDS(100 mg/L) and FN+Arg-Gly-Glu-Ser(RGES, 100 mg/L) groups. 3H-thymidine incorporation, transmission electron microscopy and TUNEL were employed to estimate the influence of RGDS on proliferation and apoptosis of HSC. The HSC adhesion rates were observed by toluidine blue colorimetric assay. The expressions of ERK mRNA and ERK protein in HSC were detected by RT-PCR and Western blotting. Results Compared with control and fibronectin groups, RGDS tetrapeptide at concentrations of 25 mg/L, 50 mg/L and 100 mg/L inhibited the proliferation of HSC(P

As a carrier for MRI contrast agent,active targeting liposome demonstrates distinct advantages in tumor diagnosis and treatment due to its characteristics of biocompatibility,non-toxicity and targeting ability.Tumor targeting imaging with liposome labeled with molecular recognition system,or liposome sensitive to pH value or temperature is a popular research topic.The application of various types of active targeting liposome for tumor magnetic resonance imaging is reviewed in this review.

Objective To investigate the differential diagnostic features of subtypes of renal cell carcinoma(RCC) using dynamic contrast-enhanced MRI(DCE-MRI).Methods The MRI appearances of 77 RCCs, including 55 clear cell RCCs(CCRCC),14 papillary RCCs(PRCC) and 8 chromophobe RCCs(CRCC), were retrospectively analyzed and compared with findings of pathology. DCE-MRI was conducted in each case after intravenous administration of contrast agent. Region of interest measurements (cortical, nephrographic and delayed Phases) of signals within tumor and uninvolved renal cortex were used to calculate percentage signal intensity change and tumor-to-cortex enhancement index, and the data was analyzed by AVONA and t test. Results On unenhanced and enhanced MRI, most CRCCs showed homogeneous signal(7/8). CCRCC and PRCC often show inhomogenous signal with necrosis(36/55, 7/14). Hemorrhage and cystic degeneration were often found in PRCC (9/14). On the cortical, nephrographic and delayed phase images, CCRCCs showed greater signal intensity change[(296.15±60.27)%, (236.33±58.31)% and (216.83±46.72)%,respectively than PRCCs (79.70±18.84)%, (122.81±27.35)% and (117.55±20.63)%, respectively], and CRCCs showed intermediate change [(119.56±40.76)%, (163.06±33.91)% and (179.72±32.89)%, respectively].A phenomenon of quick staining and quick fainting was observed in CCRCCs. Both of CRCCs and PRCCs showed delayed enhancement. The tumor-to-cortex enhancement index at the cortical, nephrographic and delayed phases was highest for CCRCCs (1.26±0.34, 0.92±0.23 and 0.76±0.14, respectively), lowest for PRCCs (0.33±0.12, 0.41±0.23 and 0.35±0.11, respectively), and intermediate for CRCCs (0.54±0.10, 0.62±0.15 and 0.69±0.12, respectively,P＜0.01). The degree of enhancement was significantly different among the 3 subtypes at the every contrast enhanced phase (F=940.931, 124.515 and 38.194, P＜0.01), so was the tumor-to-cortex enhancement index(F=798.625,78.308 and 73.699, P＜0.01). There was a good consistency between MR appearances of the 3 RCC subtypes and pathological characteristics. Conclusion DCE-MRI could distinctly show imaging features of CCRCC, PRCC and CRCC, which were related to their pathological characteristics, and these features were helpful in predicting a specific subtype of RCC.

Objective To evaluate the double-arterial phase and portal venous phase scanning in the detection of hepatocellular carcinoma with multi-slice sprial CT (MSCT).Methods Ninety-four patients with hepatocellular carcinoma were examined by abdominal plain CT and early areterial phase (EAP),late arterial phase(LAP),portal venous phase(PVP).Contrast agent of 100 ml (300 mg I/ml) was administrated intravenously by 3 ml/s,for scanning of EAP at 20 to 22 s,LAP at 34 to 37s.and PVP at 60 s.Chi-square test was carried out to compare the sensitivity among various phases.Resuits A total 0f 318 1esions was detected pathologically,with 86 lesions less than 3 cm in size and 232 lesions more than 3 cm.For the early arterial phase,late artefial and portal venous phase,the sensitivity was 39.5%(34),67.4%(58),44.2%(38)respectively for the small tumors,which showed significant differences between phases(X2=15.38,P<0.01).For the large tumors,the sensitivity was 89.6%(208),99.6%(231), 99.1%(230),respectively(X2=39.09,P<0.01).All had positive predictive values of 100%.If the tumors were taken together,the sensitivity was 76.1%(242),90.9%(289),84.3%(268).and the positive predictive value was 88.3%(242/274),86.3%(289/335),93.7%(268/286)for the early arterial phase,late arterial and portal venous phase respectively.There was significant difference of sensitivity and positive predictive value between phases(X2=25.62,9.29,P<0.05).Conclusion Double-arterial phase could improve the detection of tumors,especially for small hepatocellular earcinoma. and late arterial phase scanning is particularly important.

Objective Using MR defecography to assess the morphological and functional anorectal anomalies related to female outlet obstruction constipation, and evaluate the joint disease of anterior and mid pelvic. Methods One hundred and seven female patients, aged 20 to 84 years ( average, 55 years), were diagnosed as outlet obstruction constipation based on clinical symptoms and signs. They all received MR defecography in our institution. The high compliance homemade balloon was inserted into rectum to simulate stool Then relevant measurements were obtained during rest, squeezing and straining, respectively. Results In all the 107 cases, 70 ( 65.4% ) presented rectocele on dynamic MRI; 28 ( 26. 2% ) presented anismus;60 (56. 1% ) presented cystocele; 59 presented vaginal or cervical prolapse(55. 1% ); and, 54 (50. 5% )presented descending perineum. In 85 females (79.4%) multiple disorders were detected, involving more than one pelvic compartment. Conclusion MR defecography allowed to accurately evaluate the morphological and functional anorectal anomalies related to female outlet obstruction constipation, and the joint disease of anterior and mid pelvic.

Objective To investigate the CT findings and its pathological basis of gastrointestinal neuroendocrine tumors (GEP-NETs ). Methods The CT findings of 23 patients with GEP-NETs confirmed by pathology were analyzed retrospectively and compared with the pathological results.Results The GEP-NETs were found on CT in 20 patients,including focal gastrointestinal wall thickening in 4,mass formation in 6,and both in 10.The tumor diameter ranged from 0.9 cm to 5.2 cm with a mean value of (2.6±0.6)cm. Plain CT showed homogenous isodensity in 15 lesions,little necrosis with low density in 4,and hemorrhage with high density in 1. The dynamic contrast-enhanced CT showed the tumors with obvious enhancement in 16 cases and mild enhancement in 4 in arterial phase.In addition,serosa invasion was found in 7,enlargement of mesentery lymph node in 7,and liver metastases in 2.The pathol-ogy showed the location of submucosa and invasion of the tumors.Most small tumors had intact gastrointestinal mucosa,and some large ones had surface or infiltrated ulcer.Conclusion Some specific CT findings of GEP-NETs depend on its pathological character-istics.CT plays an important role in assessment of invasion extent and metastasis of the tumor.

Objective To investigate the MRI features of pleomorphic xanthoastrocytoma (PXA).Methods 1 5 pathologically confirmed PXA cases were analyzed retrospectively.Clinical history and imaging features including location,size,shape,signal intensi-ty,enhancement and surrounding changes of those lesions were analyzed.Results All 1 5 cases were supratentorial and solitary le-sions,of which 9 lesions located in temporal lobe(60%).14 lesions contacted with the leptomeninges,and 1 lesion contacted with lat-eral ventricle wall.All lesions were solid-cystic,with different proportion of solid/cystic components.8 large lesions were predomi-nantly cystic(53.3%),3 small lesions were predominantly solid(20%),and 4 lesions had roughly equal cystic and solid proportions (26.7%).Solid components showed iso-intense or mild hypo-intense on T1 WI,iso-intense or mild hyper-intense on T2 WI,and signif-icant enhancement with contrast.Cyst fluid showed slightly hyper-intense in some cases.Cyst wall or septa enhancement was seen in 7 cases,and leptomeningeal enhancement was seen in 8 cases.Conclusion The MRI features of PXA are the characteristic of suprat-entorial solid-cystic lesions commonly seen in temporal lobe and contacting with leptomeninges.The typical features include “cyst with mural nodule”and “multiple cysts with irregular eccentric nodule”with significant enhancement of solid component and some cyst wall.MRI features of PXA is valuable in diagnosis and differential diagnosis of PXA.

Objective To investigate the diagnostic value of the texture analysis derived from conventional MR imaging in differentiating glioblastomas from solitary brain metastases. Methods Thirty-four patients with pathological diagnoses of glioblastomas and 34 patients with pathological diagnoses of solitary brain metastases were enrolled in our study. All patients underwent conventional MR imaging including axial T1WI, T2WI, fluid attenuated inversion recovery (FLAIR) and contrast-enhanced T1WI before surgery. Texture features were calculated from manually drawn ROIs by using MaZda software. The feature selection methods included mutual information (MI), Fishers coefficient, classification error probability combined with average correlation coefficients (POE+ACC) and the combination of the above three methods. These methods were used to identify the most significant texture features in discriminating glioblastomas from metastases. Then the statistical methods including raw data analysis (RDA), principal component analysis (PCA), linear discriminant analysis (LDA) and nonlinear discriminant analysis (NDA) were used to distinguish glioblastomas from metastases. The results were shown by misclassification rate. Meanwhile, two senior radiologists (who had 5 and 9 years of experience in neuroimaging diagnosis, respectively) analysed the data of the 68 patients. Chi-square test was used to compare the differences in the results between the radiologists' analysis and the texture analysis. Results In the four kinds of sequences, the texture features for differentiating glioblastomas from solitary brain metastases were mainly from T2WI which had the lowest misclassification rate, 8.82% (6/68). The misclassification rates of the feature selection methods were similar in MI, Fisher's coefficient and POE + ACC (10.29%-27.94% for MI;11.76%-44.12% for Fisher's coefficientand 8.82%-38.24% for POE+ACC). However, the misclassification rate of the combination of the three methods (8.82%-33.83% for FPM) was lower than that of any other kind of method. In the statistical methods, NDA (8.82%-11.76% ) had lower misclassification rate than RDA (26.47%-39.71% ), PCA (27.94%-39.71%) and LDA (13.24%-44.12%). Misclassification rate of the radiologists' analysis 14.71%(10/68) was higher than that of the texture analysis, but there was no statistically difference between them (χ2= 10.993, P=0.287). Conclusion Texture analysis of conventional MR imaging can provide reliably objective basis for differentiating glioblastoma from solitary brain metastasis.