The value of quantitative multiple?phase CT radiomic features analysis in differentiation of clear cell renal cell carcinoma from fat?poor angiomyolipoma / 中华放射学杂志

Objective To explore the CT dominant phase and optimal classification model in differenting clear cell renal cell carcinoma (ccRCC) from fat‐poor angiomyolipoma (fpAML) through quantitative multiple‐phase CT radiomic features analysis. Methods Clinical and imaging data of 195 cases pathologically confirmed ccRCC (n=131) and fpAML (n=64) were retrospectively studied. All the patients underwent non‐contrast enhanced CT scans and dynamic multi‐phase (corticomedullary phase, medullary phase and excretion phase) contrast‐enhanced CT scans. Regions of interest (ROIs) were manually delineated based on the selected image slices with the maximal diameter of the lesion using ITK‐SNAP software, followed by the acquisition of candidate CT radiomic feature sets from each phase with statistically significant differences by using Mann‐Whitney U test. Then, using the synthetic minority oversampling technique (SMOTE), 232 classification models which are composed of 29 different feature selection algorithms (top 10 features were chosen by the backward elimination method) and 8 different classifiers were constructed. Employing the 5‐fold cross‐validation method, the performance of each classification models for each phase was evaluated using accuracy (ACC), sensitivity (SEN), specificity (SPE) and area under receiver operating characteristic curve (AUC), to acquire dominant CT phases and the optimal classification models for distingushing ccRCC and fpAML, along with the key imaging radiomic features. Results In this study, the mean maximal diameter of ccRCC and fpAML lesions were (3.9±1.4) cm, and (3.5±1.7) cm, respectively, and there was no statistically significant difference in the size of the tumor between two groups (P>0.05). From 102 initial imaging feature sets, the total number of candidate imaging feature sets (P<0.05) were:non‐enhanced phase (n=26), corticomedullary phase (n=71), medullary phase (n=68), excretion phase (n=62). Among the 232 classification models through different combination of classifiers and feature selectors, the amount of classification models which achieved the maximum of AUC value (AUCmax) from different CT phases were: non‐enhanced phase (n=106, 45.7%), corticomedullary phase (n=94, 40.5%), medullary phase (n=23, 9.9%), excretion phase (n=9, 3.9%). Imaging features from non‐enhanced phase and corticomedullary phase yielded higher performance compared with medullary phase and excretion phase, with the corresponding optimal prediction models were SVM‐fisher_score (AUC: 0.897, ACC: 83%, SEN: 84%, SPE:80%) and Logistic Regression‐RFS (AUC: 0.891, ACC: 83%, SEN: 81%, SPE: 89%), respectively. Conclusions The quantitative imaging features from non‐enhanced and corticomedullary phase have better performance among proposed classification models than that from medullary phase and excretion phase. Furthermore, it is feasible to acquire proper combination of feature selection and classifiers to achieve high performance in identifying ccRCC and fpAML.

CT/MRI features and pathological analysis of primary renal rare benign tumors / 实用放射学杂志

Objective To improve the diagnostic accuracy of primary renal rare benign tumors by exploring and analyzing the CT/MRI and clinical pathologic features.Methods 9 patients with primary renal rare benign tumors pathologically proven lesions after operation who had CT or MRI exams with contrast were enrolled in our hospital.The radiological and clinical pathological features of all tumors were analyzed respectively.Results The cases were the mixed epithelial and stromal tumor of kidney (MESTK),cystic nephroma(CN),renal leiomyoma(RL)and renal oncocytoma(RO)respectively.Location:6 cases were in left kidney and 3 in right kidney.Size:long diameter 2.5-8.9 cm,mean 5.7 cm;short diameter 2.5-8.4 cm,mean 4.9 cm.The tumor shape included oval(n=7) and irregular(n=2).9 cases protruded from the renal surface.MESTK showed polycystic lesions on preconstrast,various degrees of cystic wall and septum enhancement were detected on enhancement scans.CN showed cystic lesions and calcification on preconstrast, slight septum enhancement were detected on enhancement scans.RL showed heterogeneous density or signal with patchy necrosis and clear border on precontrast,the obvious enhancement was found on cortex and medullary phase and slight washout enhancement was detected on excretory phase.RO showed heterogeneous hypointense on T1 WI,hyperintense on T2 WI and mixed isodensity and hypodensity on CT precontrast.Slight delayed enhancement was found in central scar and washout enhancement was detected in parenchyma on three phases.Conclusion There are some special CT/MRI characteristics for primary renal rare benign tumors,which could improve their diagnosis and differential diagnosis combined with the clinical pathological features.

Value of T2WI histogram analysis in differential diagnosis of glioblastoma and solitary metastatic brain tumor / 中国医学影像技术

Objective To investigate the value of T2WI histogram analysis in differential diagnosis of glioblastoma multiform (GBM) from solitary metastasis.Methods Data of 103 patients with pathologically confirmed GBM (GBM group,n=57) and solitary brain metastasis (solitary brain metastasis group,n =46) were retrospectively reviewed.All patients underwent conventional MR scanning,including axial T1WI,T2WI,FLAIR and contrast-enhanced T1WI before surgery.The histogram metrics,including mean,standard deviation (SD),median,kurtosis and skewness were calculated from ROI,which were manually placed on the maximal section of the solid part of tumors on T2WI by using Image J software.ROCs were generated to evaluate differential diagnostic performance of the histogram metrics with significant difference between both groups.Results The values of mean,SD and median were significantly higher in GMB group than those in solitary brain metastasis group (P＜0.05).The areas under ROC curve of mean,SD and median was 0.772 (95％ CI [0.681,0.862],P＜0.001),0.719 (95％ CI [0.616,0.822],P＜0.001) and 0.767 (95％ CI [0.674,0.860],P＜0.001),respectively;and the diagnosis cutoff value of mean,SD and median was 509.575,58.844 and 550.500,respectively.The sensitivity of the three parameters was 0.719,0.702 and 0.719,and the specificity was 0.783,0.652,and 0.826,respectively.Conclusion The value of mean,SD and median of T2WI histogram analysis can be helpful to differentiating GBM and solitary brain metastasis,of which the mean value is the best for differential diagnosis.

The CT findings and its pathological basis of gastrointestinal neuroendocrine tumors / 实用放射学杂志

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.

Synthesis of a novel long-circulating dual-receptor targeting and dual-modal molecular probe：an in-vitro study / 中华放射学杂志

Objective To explore a novel long-circulating dual-receptor targeting and dual-modal molecular probe and investigate its physicochemical properties and targeting effect on breast cancer cells in vitro. Methods Dual-receptor targeting and dual-modal molecular probe RGD@BBN-lipo(QDs)-SPIO was synthesized in the following steps: long-circulating liposome was prepared by film dispersion method;water-soluble superparamagnetic iron oxide (SPIO) nanoparticles and Quantum dots (QDs) were loaded in the hydrophilic and hydrophobic layer of liposome, respectively;RGD and BBN polypeptides were coupled on the former functional magnetic/fluorescent liposomes. Stability of the probe in different physiological solutions was investigated. Transmission electron microscopy (TEM) and particle size analyzer were used to measure nanoparticle sizes and the Zeta potential. Characterization of RGD and BBN was investigated through 1H-NMR and elemental analysis. The MRI T2 relaxivities (1/T2) of RGD@BBN-lipo(QDs)-SPIO was measured through T2 map scanning on 3.0 T MR system. HUV-EC-C cells were used for assessment of cells viability by MTS assay. Prussian blue staining and fluorescence imaging were carried out to determine the targeted breast cellular uptake of RGD@BBN-lipo(QDs)-SPIO nanoparticles. Results The targeting magnetic/fluorescent dual-model molecular probes appeared spherical or para-spherical,with a mean diameter of(118.2±3.9)nm,Zeta potential of (-24.78±1.68) mV,MR T2 magnetic relaxation rate of 0.498 1× 106 M-1 · s-1.RGD and BBN polypeptides were successfully coupled on the former functionally magnetic/fluorescent liposomes with the bind rates of 33.05%and 45.06%, respectively. There was low cytotoxity of the molecular probe on human umbilical vein endothelical cells(HUV-EC-C)by MTS study. Prussian blue staining and fluorescence imaging studies showed that the RGD@BBN-lipo(QDs)-SPIO nanoparticles could target any αvβ3 or gastrin releasing peptide receptor overexpression breast cancer. Conclusions RGD@BBN-lipo(QDs)-SPIO is a novel long-circulating dual-receptor targeting and dual-modal molecular probe and has excellent physicochemical properties and stability, high T2 relaxivities and strong targeting effect on cancer cells and has laid a solid foundation for early diagnosis of breast cancer.

Differentiation of glioblastomas and solitary metastatic brain tumors using texture analysis of conventional MRI / 中华放射学杂志

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.

Radical operation on Tetralogy of Fallot and its perioperative outcomes in different ages / 中华实用儿科临床杂志

Objective To explore the feasibility and advantages of early open-heart radical operation on infants and children with Tetralogy of Fallot(TOF) in different ages and to analyze its perioperative outcomes.Methods The clinical data of 390 infants and children with TOF were analyzed, who underwent extracorporeal circulation open-heart surgery from January 2007 to January 2014 at the Department of Cardiovascular Surgery,the Third Affiliated Hospital of Zhengzhou University.The operative age ranged from 3 months to 14 years(mean 3 years).There were 172 infants(＜ 1 year old)and 218 children(≥ 1 year old).Some accompanied abnormalities included atrial septal defect (33 cases),patent ductus arteriosus (17 cases),coronary artery anomalies (8 cases), and multiple ventricular septal defect (5 cases).Results Ten patients died, and the overall mortality during hospital stay was 2.56％.The mortality of the infants group and the children group was 2.32％ (4/172 cases) and 2.75 ％ (6/218 cases), respectively,and there was no significant difference (x2 =0.000, P =1.000).Extracorporeal circulation time was (89.16 ± 74.38) min and (83.14 ± 66.72)min, respectively, aortic clamping time was (59.75 ± 35.20) min and (54.70 ± 38.54)min respectively, operation time were (185.34 ± 168.64)min and (163.35 ± 150.15) min respectively, duration of postoperative ventilation were (57.17 ± 67.46) h and (47.50 ± 58.39) h, respectively, the hospitalization time in the Intensive Care Unit was (5.08 ± 7.93) d and (3.71 ± 5.40) d, respectively, and the postoperative stay averaged (13.82 ± 17.78) d and (9.52 ± 8.74) d respectively in the infants group and the children group;there was no significant differences between 2 groups (t =1.937,1.890, 1.991,1.887,1.951,1.931;P =0.259, 0.713, 0.194, 0.739,0.241,0.308).Conclusions The curative effect of early cardiac surgical treatment on infants with TOF is considerably good with low morbidity and mortality.Early cardiac surgical treatment can avoid delayed development and growth in children, hypoxemic spells,sudden death and some other kind of adverse events.

Influence of different treatment with banked suspended red blood cells on the inflammatory response after cardiopulmonary bypass in infants / 中华实用儿科临床杂志

Objective To compare the influence of washing processed of banked suspended red blood cells (RBCs) by cell saver and the influence by zero-balanced ultrafiltration(Z-BUF) on the inflammatory response after cardiopulmonary bypass(CPB) in infants.Methods Sixty infants with ventricular septal defect (VSD) were randomly divided into a control group (group A,20 cases), group B(20 cases)and group C (20 cases).Banked suspended RBCs were washed by cell saver before priming in group B,in group C the banked suspended RBCs were treated with Z-BUF and in group C the banked suspended RBCs were primed directly without any pre-treatment.Samples of the arterial blood were obtained respectively before the start of the CPB (T1), when the CPB stopped(T2) ,2 h after CPB (T3), 12 h after CPB (T4) and 24 h after CPB (T5).The levels of tumor necrosis factor-α (TNF-α), interleukin(IL)-6, IL-8, IL-10 were detected and analyzed comparatively among 3 groups.Results The levels of TNF-α, IL-6, IL-8 ,IL-10 in 3 groups at T2,T3 ,T4 showed a rising trend markedly,and the above four indicators of A,B and C at T4respectivelywere:(110.3±14.0) ×10-9g/L,(90.6±10.3) ×10-gg/L,(103.3±9.7) ×10-9g/L;(54.1 ± 6.5) ×10-9 g/L,(39.3±4.2) ×10-9 g/L, (46.2±5.7) ×10-9 g/L;(96.8 ±9.2) ×10-9 g/L, (82.5 ±6.5) × 10-9 g/L,(88.4±5.1) ×10-9 g/L;(228.4 ±42.9) ×10 9 g/L,(171.5 ±26.4) ×10-9 g/L,(202.9 ±42.8) × 10-9 g/L.The levels of TNF-α and IL-8 in group B and group C were significantly lower than those in group A at T2, T3 ,T4 and T5(all P ＜0.05) ,but there was no significant differences in the levels of IL-6 and IL-10 among 3 groups at T5;the levels ofTNF-α,IL-6,IL-8 ,IL-10 in group B were significantly lower than those in group C at T2,T3 and T4(all P ＜ 0.05).Conclusions Processing of banked suspended pre-RBCs with cell saver and Z-BUF can relieve systemic inflammatory response, and the effect of washing with cell saver is better compared with that of Z-BUF.

Image evaluation of 320 multi-slice spiral computed tomography angiography in the diagnosis of nutcracker syndrome / 实用放射学杂志

Objective To summarize the image features of nutcracker syndrome (NCS)on 320 multi-slice spiral computed tomo-graphy angiography (CTA).Methods The clinical and CTA data of 1 5 cases with NCS were analyzed retrospectively.The angle(α) between superior mesenteric artery (SMA)and abdominal aorta(AA)was measured.The ratio(a/b)of the diameters of the most narrow and the most wide at the hilus of left renal vein (LRV)was calculated.Results The angel(α)of 1 5 cases were ranged from 15.5°to 27.6°.The range of a/b was from 0.22 to 0.35.Left renal enlargement were observed on four cases.Collateral circulation were detected on two cases.Duodenal stasis was detected on one case.Conclusion CTA findings of NCS is characteristic,which can noninvasively,rapidly and comprehensively display the surrounding anatomy of LRV.It is helpful in clinical diagnosis.

Synthesis of hyaluronic acid coated magnetic nanoparticles for highly efficient tumor CD44 cell labeling and in vitro study / 中华放射学杂志

Objective To explore a promising system for tumor CD 44 receptor-targeted imaging and to investigate their physic-chemical properties and targeting effect on CD 44 abundant cancer cells in vitro.Methods The superparamagnetic iron oxide ( SPIO) nanoparticles were prepared by a coprecipitation in alkaline media starting from a mixed of the ferrous and ferric solution.And then the surface of the SPIO nanoparticles were modified with APTMS by a reaction with the hydroxyl groups.Finally, the hyaluronan-modified SPIO ( SPIO-HA) nanoparticles were prepared.Control and experimental groups were established after adding SPIO or SPIO-HA as agents respectively.Transmission electron microscopy ( TEM) and particle size analyzer were used to measure these nanoparticle sizes and the hydrodynamic diameters.Thermogravimetric analysis ( TGA) was carried out to evaluate the HA-content on the surface of SPIO-HA.The MRI T2 ralaxivities (1/T2 ) of the two groups at different Fe concentrations (0.09, 0.18, 0.27, 0.36, 0.45 mmol/L ) were measured on a 3.0T MR system.HepG2 cells and HL7702 cells were used for assessment of cells viability by methyl thiazolyl tetrazolium ( MTT ) assay.Prussian blue staining , immunoassay fluorescence image and flow cytometry were carried out to determine the targeted cellular uptake of SPIO-HA nanoparticles.MRI were performed to show the MR T 2 value changes after incubating with HepG2 cancer cells by using T 2 WI sequences at a clinical 3.0 T MR system.One-way analysis of variance was performed to determine significant changes in MR T 2 values of blank control , SPIO-HA and SPIO groups.Results The SPIO-HA and SPIO NPs were fairly homogeneous with an average core size of 18.2 and 22.4 nm, hydrodynamic diameter of 91.1 and 103.2 nm, Zeta potential of (-45.00 ±0.86) mV and (-18.50 ±0.73) mV, and magnetic relaxivity of 0.212 ×106 M-1 · s-1 and 0.191 ×106 M-1 · s-1.Based on the TGA data , HA accounted for 24%weight of each SPIO-HA.The internalization of the SPIO-HA was confirmed by prussian blue staining , while the cells showed no obvious blue stains with SPIO , incubation of SPIO-HA with tumor cells led to blue color inside the cells.After that, we examined cancer cell binding of FITC-SPIO-HA by immunoassay fluorescence image and flow cytometry.The green fluorescence resulting from FITC-SPIO-HA was observed inside the cells in both the cytoplasm and the plasmalemma.Tumor cells treated with SPIO-HA exhibited higher fluorescence signals with 7.97-fold enhancement observed for HepG 2 cells over control particles.In vitro MR, mean T2 values of blank control , SPIO and SPIO-HA groups were ( 115.20 ±0.36 ), ( 115.07 ±0.81 ) and ( 21.67 ±0.21 ) ms, respectively.There was significant difference among those three groups (F=31 703.339,P<0.01), MR T2 values of HepG2 cells treated with the SPIO-HA NPs were lower than blank and SPIO group.In comparison, SPIO did not generate any MRI signal changes compared with blank group.Conclusion The tumor CD44 receptor-targeted MR molecular probe SPIO-HA had a good physic-chemical property and well targeted HepG2 cells.

Preliminary study of MR diffusion weighted imaging in nude mice models of hepatic Bel7402 tumors after adenovirus-mediated cytosine diaminase-thymidine kinase gene therapy / 中华放射学杂志

Objective To study the characteristics of DWI in nude mice models of hepatic Bel7402 tumors after treatment with adenovirus-mediated cytosine diaminase-thymidine kinase ( Ad.CD-TK) double suicide gene therapy, and then to identify whether DWI can be used for assessing curative effect of postoperative tumors.Methods Thirty nude mice models of hepatic Be17402 tumors were successfully created using cell suspension method,after the tumor grew to more than 1 cm in diameter,20 tumor models were treated by intratumoral administration of Ad.CD-TK for 3 days plus intraperitonea( i.p.) treatment with 5-Fc and GCV for the duration of the study.Then they were randomly divided into three groups during 5-Fc and GCV treatment.The remaining 10 tumor models were used as controls.MR scanning were performed in 10th day before and after tumor implantation in all models by using EPI-SE series and SENSE technology for treatment group. Tumor volumes and ADC values were calculated pretreatment and posttreatment. Cell apoptosis were determined by using TUNEL method.Analyze the change of ADC and apoptosis index (AI) in different times,t test was used for comparison the difference of AI and ADC values respectively. Results After 10 days,the tumor volumes of the treatment groups and controls were respectively (724.16 ±57.45 ) mm3,( 754.57 ± 66.84 ) mm3,with no significant difference ( t =0.488,P ＞ 0.05 ).The ADC values of the treatment groups were (0.98 ±0.11 ) × 10-3 mm2/s,the ones of the control groups were (0.68 ±0.04) × 10 -3mm2/s;AI of the treatment groups were(23.25 ±6.57)％,the ones of the control groups were (2.57 ± 0.58) ％.There were difference in both groups ( t =4.473,5.874 ; P ＜ 0.01 ).Conclusion DWI can be effectively to monitor the early pathological changes of hepatic Bel7402 tumors after Ad.CD-TK double suicide gene therapy,and provide experimental evidences for clinical application.

~1H-MRS in rabbit models of hepatic VX2 carcinoma after high intensity focused ultrasound treatment / 中国介入影像与治疗学

Objective To observe imaging characteristics and changes of vivo two-dimension multi-voxel proton magnetic resonance spectroscopy (~1H-MRS) in the rabbit models of VX2 hepatic carcinoma after high intensity focused ultrasound (HIFU) treatment. Methods VX2 hepatic carcinoma models were established in 20 New Zealand rabbits. Routine MR and 2-dimentional ~1H-MRS scanning were performed before and after HIFU treatment. The central regions of interest (ROI) of the VX2 tumor, tumor border and paratumor normal liver tissues were selected. The Cho/Cr and Lip/Cr of the same ROI before and after HIFU treatment were compared. Results Total 28 satisfied spectrogram diagram of ~1H-MRS were brought into statistical analysis. Of all the spectra, 6 metabolite peaks were detected as lipids (Lip), glutamine and glutamate complex (Glx), choline (Cho), lactate (Lac) and creatine (Cr). Cho and Lac peak in tumor center and tumor border regions after HIFU treatment were higher than those before HIFU treatment. Lip peak was lower than before, and major metabolites of paratumor normal liver tissues did not changed significantly. Statistical differences of Cho/Cr and Lipid/Cr of tumor center and border region were found between before and after HIFU treatment (P＜0.05). Conclusion Two-dimension multi-voxel ~1H-MRS can reflect major changes in the level of metabolites of different ROI for hepatic VX2 carcinoma after HIFU treatment.

Diffusion-weighted MR and apoptosis research in rabbit models of hepatic VX2 tumors after radiotherapy / 中华放射学杂志

Objective To investigate the imaging characteristic of DWI in rabbit models of hepatic VX2 tumors after three-dimensional stereotactic conformal radiation therapy, and the characteristics of apoptosis after radiotherapy. Methods Sixty hepatic VX2 tumor models were successfully created. After the tumor grew to more than 1 cm in diameter, 40 tumor models were treated with SCRT and then divided into four groups using random number table. The remaining 20 tumor models were used as controls and randomly assigned to each group. MR scanning were performed at different time points ( 1 st day, 5 th day, 10 th day, 15 th day) for each group respectively. ROIs of the VX2 tumor tissues and normal liver tissue were taken and ADC values were measured to calculate their ratios. Cell apoptesis were determined by using TUNEL method. ADC values with their ratios and the apoptotic index were analyzed using one-way analysis of variance and SNK test was used for comparison among different time points of groups, while two sample t test was used for comparison between the groups. Results On the 1 st day, 5 th day, 10 th day, and the 15 th day, the ADC ratios of the radiotherapy groups were 0.74 ±0. 15(n =8), 1.04 ±0.09(n =7), 1.43 ±0. 12 (n = 7 ), 1.25 ± 0. 23 (n = 8 ) (F = 24. 221, P ＜ 0. 01 ), the corresponding ADC ratios of control groups were 0. 78 ±0.07(n =5), 0.79 ±0.07(n=4), 0.83 ±0. 14(n =4), 0.97 ±0. 19(n =4). The ratios of ADC values for radiotherapy groups and control group were compared, and the t value was 0. 569 ( P ＞0.05), 4.417(P＜0.05), 7.259(P ＜0.01), 1.957(P＞0.05) respectively for each time point. On the 1 st day, 5 th day, 10 th day, 15 th day, the apoptotic index of the radiotherapy groups were 0. 39 ±0. 13(n=8), 0.29 ±0.08(n=7), 0.28 ±0.07(n=7), 0.58 ±0. 19(n=8,F=8. 128,P＜0.05), while the corresponding apoptotic index of control groups were 0. 26 ±0. 13(n =5), 0. 18 ±0. 03(n =4), 0. 16 ±0. 06(n =4), 0. 18 ±0. 08(n =4,F= 1. 006,P ＞0. 05). The apoptotic index value for radiotherapy groups and control group were compared, with t value of 1. 716 ( P ＞ 0.05 ), 2. 348 ( P ＜ 0. 05 ), 2. 386 ( P ＜0. 05 ), 3. 756( P ＜0.01 ) respectively. Conclusion DWI ADC values can reflect the dynamic changes of cell apoptosis in hepatic VX2 tumors after radiotherapy at different time points.

Mechanism of recovery of dysphagic patients caused by stroke:A fMRI study / 中华物理医学与康复杂志

Objective To study the recovery mechanism of dysphagic patients after stroke using functional magnetic resonanee imaging(fMRI). Methods Thirteen patients with dysphagia caused by unilateral cortical or subcortical lesions were recruited into a dysphagia group,and eight age-matched healthy volunteers were recruited as controls.Both grouDs performed experimental volitional swallowing tasks during fMRI studies.All patients of the dys-phagia group received rehabilitation treatment targeting dysphagia.Of the 13 dysphagia patients,7 reached almost complete recovery and were identified as recovered in follow-up fMRI studies.A 3.0 T MR scanner and echo planar imaging(EPI)T_2 WI sequence were employed to obtain the fMRI data.SPM2 software was used for post-processing of the fMRI data and displaying activated brain maps.Lateral index(LI)was calculated as LI:(C-1)/(C+I).Paired t tests were used to compare activated brain volume before and after complete recovery. Results Consistent activation of the bilateral primary sensorimotor cortex,anterior cingulated gyrus and the bilateral insular cortex were observed in the control group. Activation of the pons,medulla,left cerebellum,left prefrontal area,right occipital area and the left insular cortex were observed in the dysphagia group.Activation was observed in the bilateral primary sensorimotor cortex.bilateral prefrontal area,bilateral superior temporal gyrus,left insular cortex,bilateral frontal o-pereulum and anterior cingulated gyrus in the recovered patients.The total activated volume before recovery in the ip-silesional hemisDhere was significantly less compared with the contralesional hemisphere in the dysphagia group.In the recovered patients,both the activated brain volume of the ipsilesional hemisphere and value of LI were significant-ly larger than those at the initial examination.Conclusions Decreased activation in the sensorimotor cortex,the in-sular lobe and the cingulate gyms might be causes.of dysphagia.Compensation by the contralesional hemisphere in the early stages and then the restoration of the ipsilesional hemisphere after recovery may be mechanisms of dysphagia recovery in stroke patients.

Diffusion weighted imaging and B-cell lymphoma/leukemia-2 gene-related research in rabbit models of hepatic VX2 tumors after radiotherapy / 中华放射学杂志

Objective To study the DWI characteristics,Bcl-2 gene expression and the relevance of the DWI and Bcl-2 in rabbit models of hepatic VX2 tumors after three-dimensional conformal radiation therapy(3D-CRT).Methods Forty hepatic VX2 tumor models were successfully created.After the tumor grew to more than 1 cm in diameter,28 tumor models were treated with 3D-CRT and then divided into four groups using random number table.The remaining 12 tumor models were used as controls and randomly assigned to each group.MR scanning were performed at different times(1st day,5th day,10 th day,15 th day) for each group respectively.ROIs of the VX2 tumor tissue and normal liver tissue were taken and ADC values measured with calculation of their ratio.Expression of apoptotic Bcl-2 gene was determined by using Rt-PCR method.ADC value with their ratio and the relative gray value of Bcl-2/β-actin were calculated using one dimensional analysis of variance and two samples t-test at different times,compared within the group and between groups.Results On the 1st,5 th,10 th and 15 th day,the ADC ratios of the radiotherapy groups were 0.55±0.13,1.32±0.27,0.96±0.34,0.72±0.17 respectively,the corresponding ADC ratios of control groups were 0.69±0.20,0.78±0.24,0.71±0.23,0.79±0.21.The ratio of ADC values for radiotherapy group and the control group were compared,t value was 1.283(P＞0.05),4.974(P＜0.01),3.191(P＜0.01),0.776(P＞0.05)respectively for each group.On the 1st,5 th,10 th and 15 th day,the Bcl-2 gene relative gray value of the radiotherapy groups were 0.92±0.31,0.56±0.28,0.42±0.24 and 0.31±0.15 respectively,the corresponding Bcl-2 gene relative gray value of control group were 1.18±0.50,1.15±0.43,1.16±0.41,1.46±0.19.The Bcl-2 gene relative gray value for radiotherapy groups and the control groups were compared,with t value 0.987(P＞0.05),3.863(P＜0.01),5.401(P＜0.01),5.894(P＜0.01)respectively.The ADC value ratio and Bcl-2 gene relative gray value correlation analysis showed that there was significant negative correlation(r=-0.493,P＜0.01).Conclusion DWI ADC values can reflect the dynamic changes at the molecular level for hepatic VX2 tumors after radiotherapy at different times.

The experimental study of MR perfusion weighted imaging in rabbit models of hepatic VX2 tumors after high intensity focused ultrasound / 中华放射学杂志

Objective To discuss the imaging technology and characteristic of perfusion-weighted imaging in rabbit models of hepatic VX2 tumors. Methods Twenty-eight New Zealand rabbits were implanted in liver with VX2 tumor by tissue block. After routine scans were performed on 1.5 T MR scanner, 28 New Zealand white rabbits with VX2 carcinoma were divided randomly into treatment group and control group. Treatment group was divided randomly into group A, group B and group C, 7 animals per group. Perfusion weighted imaging(PWI) was performed in day 14, 25 and 35, respectively, after tumor implantation in all animals. Select the regions of interest (ROI) of the VX2 tumor center, tumor border and pars-tumor parenchyma. Maximal signal reduction slope ( SRSmax ) of the signal intensity versus time curves were created as quantitative variable, and the parameters were calculated and compared in all groups. Results Maximal signal reduction slope ( SRSmax ) of the signal intensity versus time curves were studied in 4 groups, 23 VX2 rabbits,7,5 and 6 in group A , B and C, respectively. The SRSmax of tumor center were ( 12. 6 ± 3.4), ( 9. 8 ± 2. 6 ) and ( 1.0 ± 0. 4 ), the difference was significant ( F = 10. 855, P < 0. 05 ). The SRSmax of tumor border were(48. 3 ± 2.4), (46. 2 ± 1.5 ) and (43. 6 ± 1.8 ) ( P > 0. 05 ). The SRSmax of para-tumor parenchyma were ( 14.4 ± 3.0 ), ( 12. 2 ± 1. 4 ) and ( 14. 8 ± 5.0 ) ( P > 0. 05 ). The difference was significant in different ROI in treatment groups( F value was 7. 435,8. 625 and 12. 595, respectively, P < 0. 05 ). Conclusion PWI can be used in evaluating the liver tumor angiogenesis and angio-degeneration with the treatment of HIFU. It will be possible for qualitative analysis of rabbit models of hepatic VX2 tumors by different treatments.

Investigating effect of fusion gene therapy by MR diffusion-weighted imaging in a rat C6 glioma model / 中华放射学杂志

Objective To evaluate the use of diffusion-weighted imaging(DWI)for early detection of tumor response to Angiostatin-Endostatin(Statin-AE)fusion gene therapy in a rat C6 glioma model.Methods Fifty male wistar rats with C6 tumor cells implanted into the striatum were examined by a 3.0T MR scanner,then the rats beating tmors were divided into two groups,treatment group and control group.Rats in the treatment group received 107 plaque forming unit(pfu)recombinant herps simplex viral (R-HSV)mediated Statin-AE fusion gene therapy on day 7,and then the tumors were conformed on MRI.Conventional MR and DWI examination were acquired on 1,2,3 weeks after implantation with a 5-inch surface coil.Two(1 w),eight(2 w)and all the residual rats(3 w)of each group were sacrificed to perform the histopathological examination after each MBI examination.Pretreatment and post treatment tumor volulnes and apparent diffusion coefficient(ADC)values were calculated.Rank sum test and t test were employed for statistical analysis.Results On MRI,43 rats demonstrated tumors on day 7 with a successful rate of 86%,On week 2,the tumor volumes of the controh and treatment group were 90.6 and 91.64 mm3,with no significant difference(Z=-0.14,P＞0.05).On week 3,the tumor volumes of the controls and treatment group were 156.64 and 29.64 mm3,and a significant difference was observed(Z=-3.45,P＜0.01).On week 2.the ADC values of the tumor centers of the treatment group and the control group were (1.20±0.25)×10-3 and(0.99±0.08)×10-3 mm2/s,and the values of the tumor peripheral parts of the two groups were(1.00±0.25)×10-3 and(0.83±0.12)×10-3mm2/s,the ADC values of both tumor centers and peripheral parts of the treatment group were significantly higher than those of the control group (t=-0.82 and-0.46,P＜0.05).On week 3,the ADC values of the tumor centers of the treatment group and the control group were(0.92±0.21)× 10-3 and(0.99±0.09)×10-3mm2/s,and the values of the tumor peripheral parts of the two groups were(0.81±0.19)×10-3 and(0.78±0.11)×10-3 mm2/a,there were no statisfical difference between the two groups(t=0.82,and-0.46,P＜0.05).HE stained slices showed more prominent tumor interstifial edenla.swelling and death of tumor cells in the treated rats than the controls.Conclusions Combination of conventional MRI and DWI can be powerful to monitor tumor progression and therapy effecL Conventional MRI showed that the therapy slow the tumor progression in size while DWI demonstrated the tumor response even earlier than size change.DWI has potential use forthe detection of early response to antiangiogenic gene therapy.

MRI Diagnosis and Differential Diagnosis of Hemangioblastomas / 实用放射学杂志

Objective To study the MRI manifestations of hemangioblastomas.Methods MRI data of 27 cases of hemangioblastomasproved by surgery and pathology were analyzed retrospectively.Results Hemangioblastomas were often located in hemispherium of cerebellum.All cases could be divided into three types : cyst-nodule type cyst-solid type and purely solid mass type.The large cyst and small nodule sign were characteristic manifestations of the cyst-nodule type,the signals of the fluid of the cyst were higher than that ofcerebrospinal fluid on MRI.The nodules or solid potions of the mass were showed as equal or slight long T_1 and slight long T_2 signalintensity,and were obviously enhanced.The blood vessel flow-void-sign around and inside the solid parts of the masses could be seen,and had a close relation with surrounding meninges.Conclusion MRI is a effective method in diagnosing hemangioblastomas,but the atypical cases should be differentiated from cystic astrocytoma,meningioma and metastesis.