Objective To study the technical details, clinical results and complication of microendoscopic discectomy (MED) for the treatment of lumbar disc herniation. Methods Ninety cases of lumbar disc herniation were operated upon with MED, and followed up for 24-32 months. Under direct endoscopic manipulation, semi circular excision of the inferior part of lamina, removal of the lateral part of the ligamentum flavum and the medial part of the facet were performed. The annulus fibrosus was circularly excised and the nucleus pulposus was removed. Results After operation, the patients could walk in 1.9 days, resumed their daily activities in (2.4?1.9) weeks and went back to work in (4.3?3.8) weeks. The rate of improvement was 83.1%. Several technical problems could happen in the beginning of using MED, including wrong identification of the vertebral level, difficulty to enter into the spinal canal and to control the bleeding, as well as injury of nerve root, dura mater and facet joint. Conclusion The advantages of MED are removal of the annulus fibrosus, the calcified ligamentum flavum and osteophyte under direct vision. However, sometimes it is difficult to fix the tip of microendoscopic tube on the surface of the lamina. Improvement is needed for the instrument design in order to increase the safety and easier manipulation.

Purpose To explore the diagnostic value of dynamic contrast-enhanced CT (DCE-CT) in the differential diagnosis of chromophobic renal cell carcinoma (CRCC) and renal oncocytoma (RO). Materials and Methods A retrospective study was carried out on the DCE-CT findings of 24 patients with pathologically-proved CRCCs and 17 patients with pathologically-confirmed ROs. The enhancement percentage (EP) and the enhancement index (EI) of both types of lesions were compared on corticomedullary phase and nephrographic phase. Results CRCCs on corticomedullary phase and nephrographic phase:EP (132.8±39.8)%and (99.2±32.5)%, respectively;EI 0.31±0.11 and 0.30±0.12, respectively. ROs on corticomedullary phase and nephrographic phase:EP (234.1±129.1)%and (195.4±87.1)%, respectively;EI 0.66±0.33 and 0.68±0.28, respectively. Both EP and EI of CRCCs and ROs showed statistical difference (P<0.05). As the threshold value of EI on nephrograhic phase was 0.44, the sensitivity was 82.4%, specificity was 91.7% and Youden index was 0.74. Conclusion Imaging features of DCE-CT, especially EI on nephrographic phase, are helpful in the differential diagnosis of CRCC and RO.

Objective To assess the prognostic values of the immunohistochemical expression of vascular endothelial growth factor (VEGF) and vascular endothelial growth factor receptor-2 (VEGFR-2) in a cohort of patients with operable advanced laryngeal cancer who have been treated with induction chemotherapy. Methods VEGF and VEGFR-2 expression in the Forty-nine patients was quantified by an enzyme immunosorbent assay in a retrospective series.Results The moderate to high VEGF expression in 34 patients were found and low expression in 15 patients. VEGFR-2 expression was moderate to high in 31 patients and was low expression in 18. The probability of a complete response to induction chemotherapy was significantly higher in patients with none to low VEGF expression.Conclusion VEGF expression seems to be a significant predictor of complete response to induction chemotherapy.

Objective To investigate the operational timing and manner for the digestive tract reconstruction after Hartmann procedure and the prevention for the postoperative complications in the patients with left colorectal cancer.Methods The data of twenty-four cases with digestive tract reconstruction were analysed retrospectively containing the cause of Hartmann procedure for left colorectal cancer,preoperative evaluation of the digestive tract reconstruction,operation timing,operation manner,postoperative complications and length of hospital stay and so on.Results Three of 24 patients gave up the digestive tract reconstruction due to the results of their distant metastasis detection in the preoperative evaluation.As a commonly manner of digestive tract reconstruction,rectum-sigmoid colon or sigmoid-descending colon end-end anastomosis was used for 17 patients.Meanwhile,ascending colon-sigmoid colon end-side anastomosis was used for 4 patients.The incidence of postoperative complications was 14.29 ％ (3/21),and the mean time of postoperative hospital stay was 10.5 days.Conclusions In patients undergoing Hartmann procedure for left colorectal cancer,adequate assessment of the tumor recurrence and metastasis is necessary.In addition,the optimal timing of surgery should be selected after completion of chemotherapy,and operational manner should be determined by the situation of intraoperative exploration.

Objective To investigate the clinical application of early postoperative enteral nutrition in patients undergoing colon cancer operation.Methods 90 patients suffering from colon cancer were randomly divided into the enteral nutrition group,indwelling stomach tube group and the control group.The control group was given conventional treatment and the indwelling gastric tube group was received postoperative intermittent clamping of stomach tube and enteral nutrition.Moreover,patients in the enteral nutrition group were pulled out the tube on the first postoperative day while giving enteral nutrition.All patients were observed for exhaust defecation time,length of hospital stay postoperative and nutrition indicators.Results Exhaust defecation time,length of hospital stay postoperative had significant difference among three groups.Indwelling stomach tube group set minimum length of stay and first passage of flatus and defecation in the three groups [the enteral nutrition group:(50.07±11.59) h,(76.75±27.37) h,(10.1 1±1.57) d,the control group:(62.03±12.31) h,(90.67±25.64) h,(11.80±1.83) d,indwelling stomach tube group:(43.53±11.94) h,(61.17± 22.67) h,(8.70±1.53) d (P ＜ 0.05)].The levels of hemoglobin and plasma albumin one week after operation were statistically lower than pre-operation,while that the level of these nutrition indicators were higher in indwelling stomach tube group compare to control group (all P ＜ 0.05).The same result was observed between enteral nutrition group and control group.Whereas,the change of nutrition indicators between the enteral nutrition group and the control group was not statistical significant (P ＞ 0.05).Conclusion Indwelling stomach tube combined with enteral nutrition is a reasonable choice for patients after colonic cancer surgery.

Purpose To investigate CT and MRI manifestations of renal cell carcinoma associated with Xp11.2 translocation/TFE3 gene fusions (abbreviation as Xp11.2 translocation renal cell carcinoma).Materials and Methods Eighteen cases of Xp11.2 translocation renal cell carcinoma confirmed by pathology were retrospectively analyzed.Ten patients underwent CT scans,2 of them had unenhanced CT and 8 of them had pre-and post-contrast CT scan.Fourteen cases underwent plain and multi-phase contrast MRI scan,including 2 cases with unenhanced CT and 4 cases with pre-and post-contrast CT scan.The location,size,shape,density/signal,blood supply and the enhancement of the Xpl 1.2 translocation renal cell carcinoma were analyzed.Results All of the 18 tumors located in the corticomedullary with 17 solid lesions and 1 cystic lesion.The mean maximum diameter of the tumor was (4.6±2.0) cm.Thirteen lesions were circular or oval and 5 were irregularly or lobulated lesions.Ten lesions showed slightly high or high density on unenhanced CT,and the average CT value was (50.6± 11.5) HU,in which 4 lesions showed calcification.Among 8 cases of enhanced CT,1 lesion showed abundant blood supply,while 7 lesions showed lack of blood supply.Fourteen cases of MRI scan exhibited various imaging features with short T1 and T2 signal,and the persistent enhancement in the medullary phase.The MRI findings were further divided into 3 types according to the signal intensity and blood supply except 1 cystic lesion:① 5 lesions predominantly with short T1 and T2 signal were lack of blood supply;② 4 lesions predominantly with slightly longer T1 and T2 signal were abundant blood supply;③ 4 lesions predominantly with equal T1 and T2 signal were relatively lack of blood supply.Conclusion The CT and MRI features of Xpl 1.2 translocation renal cell carcinoma had certain manifestations:slightly high or high density nodule or mass located in corticomedullary on pre-contrast CT scan,various signal intensity with short T1 and T2 signal on MRI,and the persistent enhancement in the medullary phase.These image features combined with clinical data are helpful for diagnosis.

Objective To investigate the value of diffusion-weighted magnetic resonance imaging in the differential diagnosis of primary gallbladder cancer with liver invasion and primary hepatocellular carcinoma (HCC) with gallbladder invasion. Methods From January 2009 to October 2010, 11 patients with primary gallbladder cancer and 19 patients with primary HCC were admitted to the PLA General Hospital. The clinical data of the 30 patients were retrospectively analyzed. All patients underwent diffusion-weighted magnetic resonance imaging with b value of 800 s/mm2, and the receiver operating curve (ROC) was drawn. The apparent diffusion coefficient (ADC) values of the patients with gallbladder cancer and HCC were compared by independent sample t test. Results Thirty tumors were detected in the 30 patients. All tumors showed high signal on DWI, slightly low signal on T1 WI and slightly high signal on T2 WI. The foci of 11 patients with primary gallbladder cancer were at the gallbladder fossa, and 10 of them had liver involvement. The mean ADC value of the 11 patients was (0.89 ±0. 14)mm2/s. Of the 19 patients with primary HCC, the foci of 15 patients were at the right lobe of liver, and 4were at the left lobe. The mean ADC value of the 19 patients was (1.04 ±0.18)mm2/s. There was a significant difference in the ADC value between patients with primary gallbladder cancer and those with primary HCC ( t =2.425, P＜0. 05). The area under the ROC was 0. 756 (95% confidence interval: 0.577-0. 935), and the sensitivity and specificity were 68.4% and 81.8%, respectively, when the threshold value was 0.96 mm2/s.Conclusion The ADC value of patients with primary gallbladder cancer is lower than those with primary HCC when the b value is 800 s/mm2, which is helpful in the differential diagnosis of primary gallbladder cancer and primary HCC.

Objective To document the MRI features of renal angiomyolipoma (RAML) containing minimal fat and to explore whether the MR features vary depending on the tumor size. Methods The MR findings of 15 cases of pathologically-proved RAML containing minimal fat were reviewed retrospectively from January 2008 to March 2010. All patients underwent MR in a 1.5 T or 3.0 T scanners. The MR features of the lesions were analyzed, with emphasis on the signal intensity and homogeneity on T2WI, in regards to pseudocapsule, lipid component, hemorrhage, cystic degeneration or necrosis, blood vessels, interface with renal parenchyma and enhancement pattern. All lesions were categorized into 2 groups; those with diameter ＞4 cm and those with diameter ≤4 cm. The difference of imaging characteristics between these two groups was analyzed using Fisher exact test. Results All 15 lesions demonstrated hypointensity on T2WI compared to the renal parenchyma. Homogeneous signal intensity on T2WI was seen in 6 lesions (6/15); peritumoral pseudocapsule in 3 lesions (3/15); cystic degeneration or necrosis, hemorrhage in 5 lesions (5/15); flow void of blood vessels in 2 lesions (2/15); lipid component in 4 lesions (4/15); angular interface with renal parenchyma in 10 lesions (10/15); homogeneous enhancement in 8 lesions (8/15). Fifteen lesions were divided into two groups; 9 categorized into group 1 (the maximum diameter ≤ 4 cm) and 6 into group 2 ( the maximum diameter ＞ 4 cm). Cystic degeneration or necrosis was seen in 0 of 9 in group one and 5 of 6 in group two respectively, hemorrhage(0 of 9 and 5 of 6 respectively) and pseudocapsule(0 of 9 and 3 of 6 respectively. The difference between these findings in the two groups demonstrated statistical significance (P ＜ 0. 05). Conclusion The MR features of RAML containing miminal fat were hypointensity on T2 WI,angular interface with renal parenchyma and homogeneous contrast enhancement, however, these findings can vary depending on the tumor size.

Objective To assess the diagnostic value of MRI on multiple focal nodular hyperplasia (FNH) of the liver. Methods MR images of 9 cases with pathological-confirmed multiple FNH were retrospectively analyzed. MRI features of the lesions were correlated with pathological findings. Results Multiple FNH was considered in all these 9 cases. Among them, the primary diagnosis was FNH in 5,hepatic adenoma in 3 and fibrolamellar hepatocellular carcinoma in 1 case. A total of 31 lesions were detected in the 9 cases. On T2WI, 19 lesions presented slightly high-signal intensity, and the other 12 presented iso-signal intensity. On T1WI, 12 lesions presented slightly low-signal intensity, 7 presented iso-signal intensity, and the other 12 presented high-signal intensity. On opposed-phase, the signal intensity of 1 lesion dropped unevenly. After bolus injection of contrast agent Gd-DTPA, in hepatic arterial phase 18 lesions showed mild to marked heterogeneous enhancement, 11 showed marked homogeneous enhancement, 1 showed moderate ring-like enhancement, and the last one did not have obvious enhancement In portal venous and delayed phase, all the lesions turned to iso- or slightly high-signal intensity gradually. Sixteen of 31 lesions presented central scar, which demonstrated mild star-like enhancement in delayed phase. Conclusion Multiple FNH presented certain MRI features, which contributed to the preoperative diagnosis.

Objective To identify the imaging characteristics of calcifying pseudoneoplasms of the neuraxis (CAPNON) and do literature review.Methods Five patients of pathologically-proved CAPNON underwent preoperative MR examination,among which 4 underwent CT scan,2 underwent DSA examination and 1 underwent SPECT. All imaging data were retrospectively analyzed with the emphasis on imaging characteristics.Results Five patients of CAPNON with the diameter of 1.5 to 5.0 cm were found in five patients ( Male 4 ; Female 1 ; age 25 to 60 years old ).Three lesions were located in the skull base,one was located in the cervical spine and one in the foramen magnum and upper cervical segment. All patients underwent MRI examination and 4 of them also took CT scanning.On plain CT,all lesions showed obvious calcification.On T1WI all masses showed hypointensity,and on T2WI 4 of the lesions showed iso- or hypointensity and 1 heterogeneous signal intensity. On contrast-enhanced MR images, peripheral enhancement was demonstrated in 3 lesions,homogeneous enhancement was found in case and one lesion showed no enhancement. The pathologic analysis indicated that inside the lesions were abundant calcification,fibroepithelial tissue and mucoid matrix and no edema was detected around the lesions.Conclusions CAPNON displayed the predilection to male adults and the neuraxis was the predilection site.Calcification on CT images,hypointensity on MR images and peripheral enhancement will be helpful for the diagnosis of CAPNON,but the final confirmation still needs the pathologic results.