Objective To analyze the CT features of orbital bone benign tumor and tumor mimics,so that to improve the diagnostic accuracy of these diseases.Methods CT appearances of orbital bone benign tumor and tumor-like lesion in 32cases proved by surgery,pathology and clinical features were reviewed.The lesions included orbital bone benign tumor(n=17)and tumor-like lesions(n=15).Results On CT,orbital osteomas in 9 cases showed homogeneous high density and cavernous bone-like density or ground glass-like density;ossifying fibroma in 5 cases were well-defined expansion of bone with ossification,cystic areas within the lesions;epidermal cyst in 2 displayed cystic density ;calcification and ossification could be seen in 1 case of chondroma ;10 cases of fibrous dysplasia showed ground glass-like density with cystic areas in poor-defined expansion of bone;the osteolytic destruction with well-defined margin were founded in 3 cases of orbital Langerhans' cell histiocytosis;1 case of aneurismal bone cyst appeared as cystic and expansive lesion with thin bone shell;1 case of osteopetrosis showed homogeneous high density in orbital wall.Conclusion Various orbital bone benign tumor and tumor-like lesions have different CT features.CT scan can clearly demonstrate the extent,density,border and the relationship with adjacent tissue of these lesions.

Gastrointestinal stromal tumors (GISTs) are common mesenchymal neoplasms in the gastrointestinal tract.The results of computed tomography play important roles in the diagnosis,treatment planning and follow up of GISTs. From August 2007 to January 2012,28 patients with GISTs were admitted to the Henan Provincial People's Hospital. Sixteen tumors showed extra-luminal growth,4 showed intra-luminal growth,7 involved both intra- and extra-luminal growth,and 1 showed extra-gastrointestinal growth.After administration of contrast media,9 tumors demonstrated homogeneous enhancement,18 showed heterogeneous enhancement and 1 showed non-obvious enhancement.The enhancement of tumors in arterial and venous phase was 20 Hu higher than that in plain scan.Angiogenesis was displayed in 6 tumors,and feeding arteries were observed in 3 tumors.

Objective To describe the MR appearancses of growth-plate of the developmental long bones,and to study the correlativity of MRI with the anatomy and histology findings.Methods 40 pigs with normal knees were examined by 1.0 T scanning system with various orientations and sequences,MR imagings were compared with the results of sectional anatomy and histology.Results According to MRI,we divided the evolution of growth plate into four developmental stages;the earlier forming stage of growth plate(aged the 80～95 days of pregnancy),the forming stage(aged the 95 days of pregnancy-2 months),the maintaining stage (aged 2 months-3.5 years),the closing stage(aged 3.5～4.5 years).The MRI manifestations of growth plate of knees reflected the findings of sectional anatomy perfectly and histology to a certain extent in each developmental stage.Conclusion MRI is very useful and helpful in dividing the developmental stages of growth-plate,guessing the foundation of anatomy and histology,diagnosing and differentiating all kinds of growth plate lesions.

Objective To investigate the expression of hypoxia-inducible factor-1 alpha (HIF-1 α),vascular endothelial growth factor-A (VEGF-A) and vascular endothelial growth factor-D (VEGF-D)in hypoxic environment as well as the relationship between HIF-lα and VEGF-D.Methods Human esophageal cancer cell line EC9706 was cultured under hypoxia environment for 6,12 and 24 h,the cell radiosensitivity was evaluated by survival curve.HIF-1 α siRNA was constructed and transfected into human EC9706 cells.Protein expressions of HIF-1 α,VEGF-A and VEGF-D were analyzed by Western blot before and after RNA interference.Results EC9706 cells under hypoxia showed radioresistance with a SF2 of 0.62 higher than that of normoxic cells of 0.43.Moreover,the protein expressions of HIF-1α,VEGF-A and VEGF-D were all increased (F =205.24,227.88,130.55,P ＜0.05) due to hypoxia treatment.On the contrary,after HIF-1α siRNA transfer,the protein expressions of HIF-1α,VEGF-A and VEGF-D in EC9706 cells were not influenced by hypoxia treatment.Conclusions EC9706 cells in hypoxic environment was radioresistance,and the upexpressions of HIF1α,VEGF-A and VEGF-D may be involved.

OBJECTIVE: To investigate the factors affecting shoulder joint functions following artificial humeral head replacement. METHODS: A total of 22 patients with complex fracture of proximal humerus, managed by humeral head replacement in Changhai Hospital of The Second Military Medical University from June 2006 to December 2008 were collected, including 12 males and 10 females, with average age of 67 years (52-86 years). During the procedure, soft tissue damage was minimized, the bone of the tuberosity was reserved as much as possible, appropriate matching size of humerus head prosthesis was selected, and early staging functional rehabilitation was performed. Neer's scoring system was used to evaluate the treatment results after replacement. RESULTS: The 22 patients were followed up for 10-30 months, mean 22.6 months. The shoulder joint functions of 14 cases were recovered more quickly through early post-operative staging rehabilitation, No shoulder joint unstable and stiff occurred. The shoulder joint functions of 8 cases were recovered slowly as they complained pain and did not perform early physical therapy after surgery, shoulder joint of 2 cases presented little unstable and 1 case presented stiff. Only 4 cases of all complained occasionally slight shoulder pain, but could continue daily work. The mean movement ranges of shoulder were as follow: mean flexion for 96°(80°-103°), mean extension for 38° (32°-45°), mean abduction for 86°(80°-110°), mean adduction for 31°(30°-35°), mean external rotation for 32°(30°-37°) and internal rotation for 42° (10°-75°). No vasculardamage, nerve damage, lessening prosthesis or prosthesis dislocation was found in all cases. Based on Neer's scoring system, 5 cases were rated as excellent, 11 as good and 4 as fair, with excellent rate of 82% and case satisfaction rate of 87%. CONCLUSION: In order to recover maximally the shoulder joint functions for post-artificial humeral head replacement, we must try our best to avoid soft tissue damage, reserve the bone of the tuberosity, select appropriate humerus head prosthesis, perform early post-operative staging rehabilitation, as well as maintain a normal retroversion of the prosthesis.

Objective To assess the dose reduction potential of adaptive statistical iterative reconstruction(ASiR)and model-based iterative reconstruction(MBIR)in pelvic CT with a standard male phantom.Methods A Fluke Biomedical RANDO standard male phantom was scanned with discovery CT750 HD using different tube currents.CT images were reconstructed with FBP,50％ASiR and MBIR.The CT value,the image noise and the contrast-to-noise ratio(CNR)for the sacral vertebra relative to muscle were measured.The volume CT dose indexes(CTDIvo1)and dose-length product(DLP)were recorded.Results Compared with FBP,using 50％ASiR and MBIR had significant reduced image noise and greater CNR.The effective minimal tube currents for displaying sacral vertebra were 250 mA(FBP),180 mA(50％ASiR),and 100 mA(MBIR).With the similar image quality using FBP,the dose was reduced by 28.0％ and 59.9％ using 50％ASiR and MBIR,respectively.Conclusions Using advanced iterative algorithms can reduce image noise,improve CNR,and reduce the radiation dose in pelvic CT examination.

Objective To explore the imaging characteristics of seminomas and nonseminomatous germ cell tumors (NSGCT) and its pathological foundation. Methods CT and MR imaging manifestations in 25 cases of testicular germ cell tumors proved by pathological examinations were analyzed retrospectively. All tumors were divided into seminomas group (12 cases) and NSGCT group (13 cases). In the seminomas group, 5 cases were examined by CT and 4 of those also had contrast enhanced CT. Seven cases had MRI and 4 of those had dynamic enhanced MRI. In the NSGCT group, 5 were examined by plain CT in which two were by contrast enhanced CT, eight were by MRI in which 4 were by dynamic enhanced MRI. CT or MRI characteristics (morphology, density or intensity, enhancement) in both groups were analyzed by Fisher test. Results Histological examination revealed 25 intratesticular lesions. In 12 seminomas, 10 showed a nodular/lobulated shape, 5 showed a mixed density or intensity. In 13 NSGCT, only one lesion showed a lobular shape, 11 showed a mixed density or intensity. Seven seminomas showed a low signal on T2WI on MRI while only two NSGCT showed this sign. In four lesions underwent dynamic MRI scanning, 3 showed fibrous septum enhancement while no lesions in NSGCT showed this sign. The occurrence rate of the above imaging characteristics in both group was significantly different (P<0.05). Conclusion Seminomas and NSGCT may have their own CT and MRI characteristics, which may be of great value for differential diagnosis .

Objective To explore the imaging characteristics of testicular germ cell tumors and to improve the MRI diagnostic level. Methods MRI and clinical data of 25 cases confirmed testicular germ cell tumor by pathological examination were retrospectively analyzed. All the 25 cases were performed plain scan of MRI,and 16 patients underwent MRI enhanced scan.The size,morphology,signal intensity, adjacent structures,enhancement figure and tumor supplying artery were assessed and the histopathological findings were servered as the standard of reference.Results In the all 25 testicular germ cell tumors,10 cases were seminoma,8 cases showed homogeneous low signal intensity,2 cases of seminoma were low signal intensity on T2 WI,furthermore 5 cases performed poor nodular enhance-ment,2 cases performed homogeneous enhancement,4 cases performed fibrous septa enhancement.4 cases were yolk sac tumor ap-peared equal-low signal on T1 WI,slightly high signal intensity on T2 WI and progressive enhancement.Mature teratoma,pidermoid cyst and mixed germ cell tumor were 3 cases respectively,the MRI demonstrated mixed low signal intensity on T1 WI and mixed high signal on T2 WI.2 cases were embryonal carcinoma demonstrated middle-low signal intensity on T1 WI,and mixed low signal intensity on T2 WI.The two cases revealed bleeding signal intensity and septa enhancement.Conclusion MRI can be used to diagnose germ cell tumors with high accuracy,and provides essential information for pathological type,stage and differential diagnosis.

Objective To investigate the effect of special CT monochromatic images on improving imaging quality in Budd-Chiari Syndrome.Methods 40 patients with Budd-Chiari Syndrome underwent CT venography (CTV)with gemstone spectral imaging (GSI).Using the optimal contrast to noise ratio (CNR)curve of GSI software,the optimal CNR monochromatic images of the infe-rior vena cava and hepatic vein were chosen.The CT value of the intrahepatic segment of inferior vena cava,hepatic vein and the same level liver tissue were measured,and the CT value of the same region were measured on 140 kVp mixed energy images and 70 keV images.CNR on the optimal monochromatic images,the 140 kVp mixed energy images and 70 keV images were calculated respectively,and the image quality of the optimal monochromatic image,the 140 kVp mixed energy images and 70 keV images were subjective scoring.One-way ANOVA was used for statistical analysis using SPSS1 7.0 software.Results The optimal keVs from monochromatic images were distributed at 40 keV (50%)and (5 1 ± 1 )keV (50%)for IVC and 40keV (25%)and (53 ± 3)keV (75%)for HV.The CNR and CT value and subjective score of IVC/HV got from the optimal monochromatic images were signifi-cantly higher than those from 140 kVp mixed energy images and 70 keV images respectively(P <0.01 ).Conclusion The optimal monochromatic images provide higher image quality of IVC and HV in patientswithBudd-Chiari syndrome.

Objective To evaluate the clinical effect of hybrid operation in treating Stanford type B aortic dissection. Methods During the period from January 2011 to December 2013, hybrid operation was performed in 33 patients with complex Stanford type B aortic arch dissection. The patients included 28 males and 5 females with a average age of (50±12) years. The clinical effect and the complications, occurring in perioperative period and in 24-month follow-up period, were analyzed. Results The operation was successfully accomplished in all 33 patients, with a technical success rate of 100%. The average hospitali-zation time was 20 days. After the operation, 29 cases were followed up for 3-34 months and 4 cases were lost to follow up, the following-up rate was 87.9%. In 21 cases, the following-up time was over 12 months. Postoperative angiography showed that there was no typeⅠendoleak; complications included pulmonary infection (n=1), strokes (n=1), reversible abnormal renal function (n=6) and retrograde aortic arch dissection (n=1). No paraplegia occurred. During hospitalization time, two cases died, the mortality was 6.06%. During the following-up time, graft infection occurred in one case and continued presence of retrograde aortic arch dissection was observed in one case. Conclusion The complication occurrence after hybrid operation for Stanford type B aortic dissections is low. The hybrid technique is very safe and feasible, but several serious postoperative complications should not be ignored. The long-term effectiveness needs to be further clarified by systemic and large sample studies.