Objective To investigate the diagnostic value of cystic pilocytic astrocytoma by MRI.Methods MRI features of cysticpilocytic astrocytoma proved pathologically in 26 patients were reviewed retrospectively.The location,morphology and signal characteristics of the tumors were analyzed.Results Among 26 cases the tumors localized in cerebellum(n=20) and cerebrum(n=6).This tumor could be divided into simple cystic and cystic type with node on the wall.Conclusion Cystic pilocytic astrocytoma usually occur in children andadolescents with typical MRI features.MRI features in combination with clinical manifestation,it is possible to diagnose cystic pilocyticastrocytoma correctly before operation.

Objective To study the relationship between hepatic resection,hepatic regeneration and hepatic function.Methods Totally 8 cases undergone partial hepatic resection were undergone CT scan pre-and pastoperation.The volumes of the whole liver and the lesions were measured on CT images,and the hepatic resectable rate was calculated before operation.The volume of liver was measured again after operation,and the hepatic regenerative rate at different time was also calculated after operation.The hepatic function was tested before and after operation.Results The negative relation was showed between hepatic resectable rate and hepatic regenerative rate.Conclusion There is postiive relation between hepatic resectable rate and the function of liver.

Objective:To explore the drug application in the postoperative chemotherapy for the patients with non-small cell lung cancer. Methods:The chemotherapy regimens, drug utilization and adverse drug reactions in the non-small cell lung cancer patients received postoperative chemotherapy in 2012 were statistically analyzed in a retrospective study. Results:Totally 8 kinds of chemother-apy regimens were used in 156 cases. The NC( vinorelbine + carboplatin) regimen was used most frequently and the PC( pemetrexed+ carboplatin) regimen was with the highest expense. Proton pump inhibitors, recombinant human erythropoietin and lentinan were the top three in the adjuvant drugs used in the treatment. Conclusion:It is necessary to further standardize the postoperative chemo-therapy for non-small cell lung cancer patients. Thoracic surgeons along with pharmacists should strengthen the drug use monitoring during the whole treatment process to promote the rational drug use.

Objective To discuss the appearances of focal nodular hyperplasia(FNH) of the liver on the muhiphase helical CT scanning, and to improve its diagnostic accuracy with CT. Methods Helical CT scanning of pre- and post- contrast arterial phase,portal venous phase and delayed phase was performed in 10 cases with surgically and pathologically proved FNH. Results On pre- contrast scans,9 of 11 FNH lesions were hypodense(either homo-geneous or non-homogeneous), the other two lesions were isodense. On the arterial phase scans, all lesions were markedly and homogeneously enhanced,except for the central scar area. Tortuous and dilated arteries were seen at the center or peripheral area in 3 out of 11 lesions. On the portal phase and delayed phase scans ,4 of 11 lesions turned to isedanse of slightly hypodense,7 lesions remained slightly hyperdense. Central scar was found in 8 FNH lesions ,2 of them showed no enhancement while the other six demonstrated late enhancement. Conclusion Mulfiphase helical CT scanning can fully reflect the blood supplying and pathologic features of FNH, and it is of great value in diagnosing and differentiating FNH.

Objective To evaluate the clinical efficacy of combined use of Pathfile and Mtwo in the preparation of curved root canals.Methods This study enrolled a total of 90 teeth(313 root canals)that need root canal therapy because of pulpitis or apical periodontitis from December 2013 to February 2014.All root canals were randomly divided into three groups.In group A,both Pathfile and Mtwo NiTi files were used in root canal preparation.In group B,Pathfile and ProTaper were used.ProTaper was employed alone in root canal preparation in group C.The high temperature thermaplasticized inj ectable ver-tical condensation technique was applied in all the three groups.The time of root canal preparation,the number of separated de-vices,root canal transportation and the quality of root canal filling were obtained and compared among the 3 groups.Results In group A,the time of root canal preparation was shortest,(6.01±1.12)min ;there were no instrument separation and ledge for-mation,and the filling rate was highest in group A.The differences were significantly noted in these indexes between group A and groups B,C.Conclusion Combined use of Pathfile and Mtwo for preparation of curved root canals is fast and safe,and the root canal filling is satisfactory.This method is suitable for clinical application.

Objective To explore the preliminary study of the four-dimensional CT-based respiratory gating applications in the IGRT treatment of lung cancer .Methods 38 patients′ were scanned with 4D-CT ,and could got 10 images:0-90% each one ,and then two kinds of radiation treatment plans :Plan-3D and Plan-4D were used ,respectively .Treatment of the patients in the IGRT mode with Plan-4D and following up were done in two months after treatment to evaluate the efficacy and complication probability . Meanwhile evaluation of the two plans by the volume histogram was done .Results The displacement of lung tumor respiratory mo-tion was different in three dimensions ,especially in the Vertical direction ,about(9 .1 ± 2 .2)mm .Accuracy of the distance was 2 .6 mm .The Plan-4D′s CTV was bigger than Plan-3D ,but its PTV was less than the Plan-3D significantly ,at the same time its lung V20 ,MLD were both less than the Plan-3D ,and the difference was statistically significant(P< 0 .05) .The total efficiency(CR+PR)was 77 .78% (28 case);the incidence of 1 ,2 ,3 acute radiation-induced lung injury were 86 .11% ,11 .11% ,2 .78% ,respectively ;the incidence of 1 ,2 acute radiation esophagitis injury were 80 .56% ,8 .33% .Conclusion The respiratory gating techniques based on 4D CT applied in image guided radiotherapy of lung cancer in clinical is feasible ,and it can reduce the volume of the planning tar-get volume ,and help to improve the accuracy of radiotherapy .The degree of respiratory motion is significantly different in individu-als ,and expanding outside the target ranges should be individualized .

Evidence-based medicine was applied in the clinic teaching and ward inspection of superficial bladder cancer as far as no consensus was reached on its treatment.Some preferred to total cystectomy while others favored transurethral resection of bladder tumor and bladder instillation.In order to solve this problem,evidence-based medicine was applied in our clinic teaching procedure.Students were asked to read relative papers and draw the final conclusions with evidence-based medicine.Clinical guidance was provided for the students to promote clinical application.

Objective To improve the understanding of giant hypertrophy of the gastric mucosa.Methods Giant hypertrophy of the gastric mucosa in 6 cases proved by operation or gastroscopy biopsy pathological examination were reviewed.Barium meal examination was performed in all cases,CT in 3 cases.B-type ultrasound in 2 cases.Results It was ease to be misdiagnosed giant hypertrophy of the gastric mucosa on the basis of the conventional imaging appearances.Laboratory data and gastroscopy biospsy played an important role in diagnosis and differential diagnosis.Conclusion Giant hypertrophy of the gastric mucosa is uneasily to correct diagnosed,comprehensive evaluation is necessary for it.

Objective To investigate the X-ray,CT and MRI features of peripheral primitive neuroectodermal tumors (pPNETs).Methods 14 patients were pathologically diagnosed with pPNETs.The imaging of X-ray (twelve image),Computed Tomography(eleven image) and Magnetic Resonance Imaging(five image) were retrospectively analyzed.Results Of 14 patients,there were two sites of tumour:soft tissue( eight patients) and bones( six patients).For tumoura of the soft tissue region,the appearance of X-ray and CT imaging showed equal or lower density soft mass without dear boundary.In some cases,tumours invaded adjacent bones.The appearance of MRI imaging showed large heterogeneous masses inside soft tissue without clear boundary.Tumours displaced adjacent cortical bone and cavitas medullaris.All masses were heterogeneous enhancement on contrast images.For tumours of bone region,X-ray and CT scan showed large scale osteolysis osteoclasia in bone surrounding with soft tissue masses of various size.The lesions were equal or lower signal on T1 WI.All masses were intermediate or hyperintense signal with heterogeneous midrange or obvious enhancement on T2WI.Conclusion Imaging characteristics of pPNETs were described.X-ray,CT and MRI were useful in understanding the property,extent and staging of tumor and very useful in the diagnosis.

Objective: To discuss the feasibility of using tissue engineered bone to repair large chest wall defects. Methods: Skeletal chest wall defects were reconstructed by tissue engineered bones in five dogs. These tissue engineered bones were constructed by seeding autologous mesenchymal stem cell (MSC) onto xenogenic acellular porcine bone matrix (APBM), a biodegradable scaffold. Within every regenerated bone was and assistant nutrition catheter designed to keep the cell living before reformation of blood supply. This catherter could also maintain the bone regeneration microenvironment through bone morphogenetic protein (BMP) and other growth factors delivered every day. Apparently diminished repair potential may be prevented by periodic administration of MACs. Results: Three-months follow-up showed that sufficient chest wall stability was obtained, and no postoperative complication occurred such as flail chest, infection. Conclusion: Tissue engineered bone is a perfect biomaterial for chest wall defect reconstruction.