Objective To determine the accuracy and radiation dose of dual-energy computed tomography (CT) in evaluating solitary pulmonary nodules (SPNs) by virtual non-enhanced images.MethodsSixty-one patients with SPNs including 39 malignant and 18 benign nodules proved by pathology underwent DECT scans. The CT values of SPNs on enhanced weighted average and virtual non-enhanced images were compared by using Liver VNC processing unit in terms of their diagnostic accuracy for distinguishing malignant and benign nodules with a 20 HU threshold. Diagnostic accuracy was compared. In 28 patients of all patients, image noise and quality score of the non-enhanced and virtual non-enhanced images were compared, and radiation doses of each patient were recorded. The paired t test was used to analyze the noise difference between the plain scan and virtual non-enhanced scan. The Mann-Whitney U test was used to analyze statistically significant differences of the image quality score and radiation dose between the non-enhanced scan and virtual non-enhanced scan. ResultsThe sensitivity, specificity and accuracy for distinguishing benign and malignant nodules by using the virtual non-enhanced image of were 89. 7％(35/39), 72.2％ (13/18), 84.2％ (48/57)respectively.The noise of common CT and virtual nonenhanced images were(8. 49 ± 1. 94) HU and( 10. 14 ± 2. 18 ) HU, and there were statistically difference (t＝9.45,P＜0. 01 ). The quality scores of common CT and virtual non-enhanced images were (4.71 ±0. 46 ) and ( 4.42 ± 0. 57 ), and there were no statistical difference ( U ＝ 290. 00, P ＞ 0. 05 ). The radiation doses of common CT and DECT were ( 3. 72 ± 0. 48 ) mSv and ( 3.78 ± 0. 45 ) mSv, and there were no statistical difference ( U ＝ 350. 50,P ＞ 0. 05 ). ConclusionDECT by using virtual non-enhanced images is useful tool to distinguish the benign and malignant SPN without additional radiation dose.

Objective To investigate the essential points of the diagnosis and the surgical treatment of malignant gastrointestinal tumors in children.Methods Clinical data involved the sites and pathological types of the tumors,clinical manifestation,effective treatment and prognosis were retrospectively analyzed in 29 consecutive patients reffered to Beijing Children's Hospital between January 1996 and May 2008.Results Of 29 patients,26 were males and 3 were females(aged from 1 year and 10 month to 14 years,mean age of 10 years).Gastric tumor was found in 5 cases (interstitialoma in 1,lymphoma in 2,endodermal sinus tumor in 1 and P-J syndrome canceration in 1),whereas intestinal tumor was found in 24 cases(malignant Iymphoma in 17,colon carcinoma in 4 and carcinoid of appendix in 3).The main clinical manifestations were abdominal pain,emesia,fever,alimentary tract hemorrhage and emaciation.Surgical complication involved perforation,internal fistula,obstruction,invaginate and hemorrhage.Twenty-four patients underwent(gaster)intestine resection and anastomosis.Biopsy was performed in 5 patients.Two patients with colonic carcinoma relapsed 6 months to 1 year after operation.Of 29 patients,17 patients survived,6 patients missed the follow-up and 6 patients died.Conclusions Pediatric malignant gastrointestinal tumor is rare.The unspecific presentation makes the diagnosis difficult.In diagnosis of acute abdomen and gastrointestinal tract diseases,the possibility of malignant tumor should be reminded.The imaging and endoscopic examination are very important to diagnosis.The surgical resection or combined with chemotherapy are mainly used in treatment of tumors.The prognosis is related to the pathological nature of the tumor.

Objective To discuss the clinical manifestations, diagnosis and treatment of solidpseudopapillary tumor of the pancreas (SPTP) in children. Methods Clinical data of 12 cases of SPTP admitted to Beijing Children's Hospital from Mar 2001 to Mar 2007 were collected and analyzed retrospectively. Result There were 7 females and 5 males among the patients. The mean age was 13.6 years. The main symptoms were abdominal pain and mass. Tumors located in the head in 4 cases, in the body and tail of the pancreas in 8 cases. Five cases underwent tumor enucleations, one case underwent body resection of the pancreas, two cases underwent Whippple's procedure including one recurrent case, five cases underwent body and tail resection of the pancreas plus splenectomy. All these 12 cases were followed up for 6 months to 6 years. One case lost follow-up 6 months after body and tail resection of the pancreas plus spleneetomy. Another one suffered from live tumor one year after operation and refused surgical exploration and lost follow-up. The other 10 cases were still alive. Conclusion SPTP are predominantly seen in adolescent females. For its benign clinical behavior and relatively good prognosis, surgical resection is the main choice of therapy.

Background and purpose: Magnetic resonance spectroscopy is currently the only non-invasive magnetic resonance imaging technique which can detect metabolite composition of live organ and tissue and also conduct semi-quantitative or quantitative analysis. We analyzed the characteristics of metabolic changes among normal liver, cirrhosis regenerative nodule and liver cancer on the background of cirrhosis by voxel proton MR spectroscopy at 1.5 Tesla. Methods: 20 healthy volunteers (control group), 25 cirrhosis (cirrhosis group) and 23 hepatocellular carcinoma after cirrhosis (HCC group) patients were our candidates. The characteristics of spectra of ~1H-MRS were observed. The height and ratio of choline complex (Cbo) and lipid methylene (Lip2) were recorded and the results were compared among the groups. Results: The success rate of ~1H-MRS was about 88.2% (60/68). There were statistically significant differences among the heights of Lip2 peak of the three groups, and also between that of the control group and the group of liver cancer. But there were no significant differences between that of control group and cirrhosis group, cirrhosis group and liver cancer group. The comparison of the height of Cho peak and the ratio of Cho/Lip2 showed statistically significances both among the three groups and between each other. Conclusion: The metabolic changes of the liver could be shown non-invasively by ~1H-MRS, which could be useful for differential diagnosis or diagnosis of cirrhosis regenerative nodule and HCC.

Objective Analyze the amino acids and acylcarnitines in the blood of patients first diagnosed with uremia using tandem mass spectrometry in order to provide a basis for clinical diagnosis and treatment. Methods 30 patients with uremia were selected as the research objects,while 15 cases of healthy person were served as the control. The values of 11 kinds of amino acids and 2 kinds of acylcarnitines in the two groups were detected using tandem mass spectrometry,and the data were analyzed and compared. Results The levels of alanine(Ala)and tyrosine(Tyr)in uremia group were significantly lower than those in control group(P < 0.05),while the levels of citrulline(Cit),glycine(Gly)and proline(Pro)were significantly higher in uremia group than in control group (P < 0.05). The differences were mainly in non-essential amino acids between the two groups. The levels of free carnitines and total carnitines in uremia group were significantly higher than those in normal group(P < 0.05). Conclusion For the patients first diagnosed with uremia(not treated with replacement therapy),the disturbance of amino acid metabolism mainly in non-essential amino acids were found in their blood,and the carnitine levels were higher than normal levels. The results could provide the basis for clinical nutrition therapy for patients with uremia.

Objective To retrospectively analyze CT and MR appearances of hepatic adenoma,and to study the causes of misdiagnosis with review of relative literatures.Methods CT and MRI data of 8 patients with pathologically confirmed hepatic adenoma were retrospectively analyzed.Pre-and post-contrast tri-phase (arterial,portal venous and delayed) CT scans and routine MR .scan were performed in all 8 patients,and proton magnetic resonance spectroscopy (~1H-MRS) was performed in 2 patients.Results Typical demonstrations were found in 4 patients who were correctly diagnosed.Among the others with atypical findings,3 patients were misdiagnosed as liver cancer and 1 as focal nodular hyperplasia (FNH) .The ~1H-MRS curves of 2 adenoma tumor showed that the peak of choline of tumor tissue had no significant difference comparing with that of normal liver tissue around the tumor tissue.Conclusion CT and MRI findings of hepatic adenomas have some characteristics,but atypical manifestations lead to misdiagnose.~1H-MRS may be helpful for the differential diagnosis of hepatic adenoma.

Objective To investigate the effective regimen to treat the hepatitis C virus (HCV) recurrence after orthotopic liver transplantation (OLT). Methods The clinical data of 4 cases of HCV recurrence after OLT were retrospectively analyzed. Of the 4 cases, there were 3 cases of HCV related liver cirrhosis and 1 case of HCV related liver cirrhosis in combination with hepatocellular carcinoma. The immunosuppression regimen as FK506, MMF and corticosteroids was used after OLT. As soon as HCV recurrence was confirmed by liver biopsy during 8 to 12 weeks after OLT, pegylated interferonα-2a (PEG-IFNα-2a) and ribavirin (RIB) were used for 48 weeks. PEG-IFNα-2a was started at a dose of 180 μg per week subcutaneously and RIB at a dose of 1000 mg per day orally, respective-ly. Blood routine, liver and kidney function test, HCV-RNA and transplanted liver biopsy were per-formed when necessary and biochemical response, sustained virologic response and histological re-sponse were tested in due time. Remits All of the 4 cases except for 1 achieved sustained virologic re-sponse and the liver function was as normal as before. The histological activity index was improved significantly for both inflammatory activity and fibrosis according to liver biopsy in 0, 48, 72 week srespectively. Case 4 was given corticosteroids for consecutively 3 days when acute rejection was veri-fied by liver biopsy and the condition improved. None of them stopped treatment or withdrew from them directly. Conclusion The combination of PEG-IFNα-2a and RIB was an effective regimen to treat the HCV recurrence after OLT and the side effects could be overcame easily.

Objective To evaluate the value of dual energy computed tomography (DECT) for the diagnosis of gout.Methods Twenty-fivc consccutive patients with gout were selected as the experimental group and 20 patients with rheumatoid arthritis (RA) were selected as the control group.DECT scans were performed for every patient (all peripheral joints for the experimental group and affected joints for the control group).And every patient with gout had X-ray examination of the involved joints.x2 test and t-test were used for statistical analysis.Results All 25 patients with gout showed urate deposits on their DECT scans,whereas none of 20 controls showed urate deposits (P＜0.01).DECT scans revealed a total of 184 areas of urate deposition in 25 patients,in which 107 (58.2％) were at feet and ankle,72 (39.1％) were at knees,4 (2.2％) were at hands and wrists,1 (0.5％) was at elbows,whereas physical examination only showed 64 areas of urate deposition,in which 38(59.4％) were at feet and ankle,24(37.5％) were at knees,2(3.1％) at hands and wrists,0 was at elbows(P＜0.01 ).Only 6 patients with gout showed nonspecific manifestations on X-ray.Conclusion DECT scans may have potential value for the diagnosis of gout since it could produce evident colour displays for urate deposits and help to identify subclinical tophus deposits.

Objective To study the distribution of surfactant protein A2 (SP-A2) haplotype and its association with preterm respiratory distress syndrome (RDS) susceptibility in a local Chinese cohort.Methods Using population base and case-control study cohorts,genotyping for four single nucleotide polymorphism (SNP) was performed,rs1059046,rs17886395,rs1965707,rs1965708,in 80 term infants,50 preterm infants with RDS (RDS group) and 50 preterm infants without RDS(control group) by using TaqMan (R) real-time polymerase chain reaction.Infants in RDS group and control group were matched according to gender and gestational age.Frequency of each haplotype was compared between preterm infants with RDS and without RDS,term infants and preterm infants without RDS.Results Most common haplotypes in term infants were 1A0,1A5,1A1.In each preterm infants groups with RDS and without RDS,1A0,1 A5,1 A1 were also the most common haplotypes.Among these three common haplotypes,frequency of 1A0 was lower in preterm infants,including RDS group and control group,than that in term infants.No significant difference was found between preterm groups with RDS and without RDS (P ＞ 0.05),neither in preterm infants with gestational age ≥32 or ＜ 32 weeks.Haplotype 1A0 frequency(0.542) in term infants was significantly higher than that in preterm infants ＜ 32 weeks without RDS (0.329) (x2 =6.06,P =0.01).Conclusions SP-A2 haplotype distribution in a local Chinese population shows ethnic characteristics to some extent.Only SP-A2 does not contribute to the susceptibility for preterm RDS.

Objective To investigate ABCA3 gene polymorphism and its relationship with neonatal respiratory distress syndrome (NRDS) in the Guangxi Zhuang Autonomous Region of China by genotyping and haplotype analysis.Methods Using a tagging single nucleotide polymorphism (tSNP) strategy and TaqMan (r) real-time PCR,we genotyped 4 tSNPs (rs4787273,rs 1 50929,rs 11867129,and rs 17135889) and one additional coding SNP(rs13332514) of the ABCA3 gene in preterm infants with NRDS(NRDS group,n =45) and without NRDS (non-NRDS group,n =45) and subsequently predicted the haplotypes.The minor allele frequency and the haplotype 'distribution were compared between the two groups.Results The minor allele A(0.14 vs.0.05,P =0.046) and genotype AG (0.289 vs.0.111,P =0.035) frequency of SNP rs17135889 in NRDS group were significantly higher than those in non-NRDS group.Totally 6 haplotypes occurred at a frequency ≥0.01,among which,the haplotype TGGAG,depended on rs17135889,was significantly higher in NRDS group than that in non-NRDS group (0.061 vs.0.000,P =0.014).Conclusion The results suggested that SNP rs17135889 of ABCA3 gene might be related to NRDS in preterm population of the Guangxi Zhuang Autonomous Region.Allele A contributes to NRDS susceptibility in preterm infants.