Objective To evaluate the clinical value of myocardial perfusion imaging with dual-source dual-energy CT and a contrast agent at a low concen.tration in the diagnosis of myocardial infarction in the elderly Methods One-stop cardiac imaging with dual-source CT was conducted in 138 elderly patients diagnosed with myocardial infarction between October 2015 and May 2016.The patients were randomly divided into two groups,Group A and Group B,each with 69 patients.Myocardial perfusion was performed for coronary imaging,using 70 ml Visipaque(270 g/L)and 50 ml saline for Group A and 70 ml iopromide(370 g/L)and 50 ml saline for Group B.Myocardial transmural perfusion gradients(TPG)were calculated,and the total iodine dose and the rate of iodine infusion were compared between the two groups.Results The procedure was successfully carried out in all 138 patients.There was no statistically significant difference in TPG between the two groups in the right coronary artery,the anterior descending artery and the circumflex artery(P＞0.05).The total iodine dose for Group A was 18.5 g,27％ less than that for Group B(25.9 g).The rate of iodine infusion for Group A was 3.5 g/s,also 27％ less than that for GroupB(18.5 g/s).Conclusions Myocardial perfusion imaging with dual-source dual-energy CT and contrast agents at low concentrations is a promising approach,which is capable of achieving quality imaging for the assessment of myocardial infarction with reduced use of iodine and represents a clinically valuable option.

Objective To investigate the application value of low kilovolt technique combined with lower contrast in the head and neck angiography by the second-generation dual source CT.Methods From October 2013 to January 2015,120 patients undergoing head and neck computed tomography angiography (CTA) were randomly divided into groups A,B,C,D.Each group was given a different tube current and different dose of contrast agent and saline solution 50 ml.Group A received current 100 mA and contrast agent 50 ml,group B received current 100 mA and contrast agent 40 ml,group C received current 80 mA and contrast agent 50 ml,and group D received current 80 mA and contrast agent 40 ml.CT values of aortic arch,bilateral common carotid artery bifurcation,double sided M1 segment of middle cerebral artery,basilar artery enhanced degree of the straight sinus were measured in each group.Residual artifacts caused by contrast agent in brachiocephalic vein and subclavian vein were observed.5-score method was used to assess the quality of reconstructed image,and the radiation exposure dose was calculated.Results The mean effective dose was reduced by 29％ in group C as compared with group A [(0.53±0.17) mGy vs.(0.74±0.04) mGy].There was no significant difference in developing strength in cerebral arteries angiography between group C and group A (P=0.247),but the inage noise was slightly larger in group C than group A,without significant differences (P=0.203).The average effective dose in group A was almost the same as that in group B [(0.74 ± 0.04) mGy vs.(0.73 ± 0.05) mGy].Structure display of cerebral arteries on CT volume rendering (VR) and multiplane reformation (MPR) images had no significant differences between group A and group B (P=0.114).The average effective dose in group C was almost the same as that in group D[(0.53 ± 0.17) mGy vs.(0.53 ±0.01) mGy].Structure display of cerebral arteries on CT volume rendering (VR) and muhiplane reformation (MPR) images had no significant differences between group C and group D (P=0.109).The mean effective dose was reduced by 28％ in group D as compared with group B[(0.53±0.01)mGy vs.(0.73±0.05) mGy].There was no significant difference in developing strength in cerebral arteries angiography between group C and group A (P=0.236),but the image noise was sligbtly larger in group C than group A (P =0.212).Conclusions Application of low tube current combined with low concentration of contrast agent in the head and neck dual-source CT angiography is feasible in clinical diagnosis,with good clinical value.It can not only get better image quality,but also meet the needs of clinical diagnosis.

11 mm) and presence of central necrosis are the suggestive morphologic features of metastatic paraaortic nodes.

Objective To study the therapeutic efficacy of the chondroplasty with radiofrequency technique under arthroscope for osteoarthritic knees in the senile patients.Methods Thirty-six patients were divided randomly into control and test groups(in each with 18 patients).The patients suffered from osteoarthritis of knees.The control group confirmed and treated by knee arthroscope,which was subjected to debridement with routine technique.The test group was treated by chondroplasty with radiofrequency technique under arthroscope.Results The patients developed no infection or other complications.Better therapeutic results were obtained after follow up of 6 to 18 months.Conclusions Chondroplasty with radiofrequency technique under arthroscope for the osteoarthritic knees has the advantages of less injury,less bleeding,less complication and quick recovery.

Objective To investigate the relationship between apolipoprotein E (ApoE) ε4,ε2 alleles and intrauterine growth.Methods ApoE genotypes of 1418 people born in Peking Union Medical College Hospital were analyzed,allele frequencies were calculated and their parameters at birth were collected.To compare ApoE ε4,ε2 alleles with parameters at birth through single factor analysis and Logistic regression analysis.Results The alleLic frequencies of e2,83 and 84 were 8.11%,83.39% and 8.50% in the group.The results of single factor analysis showed that there was significant difference between the distribution of ponderal index (PI) in the ApoE ε2 allele group(χ2=4.87 ,P=0.027).While there was no significant difference between the distribution of head circumference at birth,placental weight and gestational age in the ApoE ε2 allele group.ApoE ε2 allele showed negative correlation with small PI in the logistic regression analysis(χ2=5.077 ,P=0.024),after adjusted for gender,age,head circumference at birth,placental weight,gestational age,parity and maternal age at delivery.No association between ApoE ε4 allele and parameters at birth was found.Conclusions ApoE ε2 allele may have protective effect on PI.No association was found between ApoE ε4 allele and intrauterine growth.

Objective To introduce the methods and key points for the external fixation combinel with limited percutaneous internal fixation plus colostomy in the treatment of open pelvic fracture concomitant with perineal laceration.Methods Nine patients with open pelvic fractures concomitant with perineallaceration were treated by external fixator combined with limited percutaneous internal fixer plus colostomy. Data including injury details, management and outcomes were collected for comparison.Results All the patients survived and attained bony union except for two patients with local infection that was healed several days after repeated wound debridement and use of wide spectrum antibiotics. All the patients had good extremity function at the latest follow-up. Conclusion External fixation combined with limited percutaneous internal fixation plus colostomy is a reliable, safe and less invasive procedure for the treatment of open pelvic fractures concomitant with perineal open wound.

Objective To evaluate the clinical outcome in the treatment of humerus shaft comminuted fractures using limited open reduction and internal fixation combined with an external fixator.Methods Data of 80 patients with comminuted humerus shaft fractures treated from January 2005 to January 2013 were analysed retrospectively.All the patients underwent limited open reduction and internal fixation combined with an external fixator (treatment group) and open reduction and plate fixation (control group) according to the random number table.In the treatment group,there were 40 patients (28 males,12 females),at mean age of 33.5 years (range,21-54 years),with causes of injury including traffic accidents in five patients,falls in nine,crashes in seven and others in six.There were seven patients with open fractures and 33 with closed fractures.In the control group,there were 40 patients (25 males,15 females),at mean age of 32.9 years (range,19-55 years),with causes of injury including traffic accidents in 16 patients,tumbling in seven,crush in seven and others in ten.There were eight patients with open fractures and 32 with closed fractures.The operation time,intraoperative blood loss,bone union time and complications in both groups were recorded.Clinical efficacy was evaluated using the Stewart and Hundley standard.Results Mean follow-up was 19 months (range,15-24 months).Treatment and control groups showed significant differences in operation time [(55.5 ± 10.3) minutes vs.(120.5 ± 15.3) minutes],intraoperative blood loss [(120.4 ± 20.7) ml vs.(245.4 ± 26.7) ml] and bone union time [(11.6 ± 1.3) weeks vs.(14.9 ± 2.3) weeks] (P ＜ 0.05).Rate of incision infection was 8％ (3/40) in treatment group and 10％ (4/40) in control group (P ＞ 0.05).In treatment group the results were excellent in 31 patients and good in nine.In control group the results were excellent in 27 patients,good in nine,fair in one and poor in three.One patient with radial nerve injury after a second surgery for implant removal and two patients with osteomyelitis or bone nonunion were noted in control group.Conclusion Limited open reduction and internal fixation in combination with an external fixator is associated with small trauma,easy operation,short operation time,few bleeding,rigid fixation,early functional exercises and reduced bone nonunion for treatment of comminuted humerus shaft fractures,which exhibits great clinical value.

Objective To explore the clinical application of 80 kVp tube voltage combined with low dose and low concentration contrast agent in CT imaging of renal artery (CTA) in elderly patients.Methods 160 elderly patients undergoing CT angiography of renal artery or abdominal aorta in our hospital from August 2016 to June 2017 were randomized to control group (routine-dose CT with 120 kVp at 120 mAs,contrast agent of 70 ml,n=40) and double low group (X ray tube voltage at 80 kVp and contrast agent of 50 ml),which was re-divided to double low-150 mAs group,double low-180 mAs group,and double low-210 mAs group (n=40,each).The CT value of bilateral renal arteries,their branches,and abdominal aorta at the same height of renal artery,signal to noise ratio (SNR),contrast to noise ratio (CNR),the effective radiation dose,and the incidence of adverse reaction were measured after sinogram-affirmed iterative reconstruction (SAFIRE).And the image quality was evaluated and rated on a scale from 1 to 5 by two independent qualified radiologists.Results The vascular enhancement was significantly higher in the three double low groups than in the control group (all P＜0.05).Noise level was higher in the three double low groups than in the control group (all P＜0.05).SNR and CNR showed no significant difference between the double low-210 mAs group and the control group (P＞0.05),while statistical differences were found in SNR and CNR in the control group versus double low-150 mAs and double low-180 mAs groups (all P＜0.05).As compared with the control group,effective radiation dose was decreased in the three double low groups by 63.3％ (150 mAs),56.2％ (180 mAs),48.8％ (210 mAs),respectively.All image scores in four groups were over 3 points.Mild adverse effects were observed in four cases from the control group,and no adverse effect occurred in the other three groups.Conclusions 80 kVp tube voltage combined with low dose and low concentration contrast agent can appropriately increase tube current.Combined with SAFIRE,it can not only help maintain image quality,but also decrease the damage of organs by reducing the doses of radiation and contrast agent.

Objective:To evaluate the clinical value of lymph node dissection (LND) for intrahepatic cholangiocarcinoma (ICC) after surgical resection.Methods:A retrospective study was conducted on the clinical data of 156 patients who underwent surgery for ICC in Eastern Hepatobiliary Surgery Hospital of Naval Military Medical University from November 2010 to December 2017, including 94 males and 62 females, aged (60.0±9.5) years. Curative surgery was performed in 114 cases. Of 64 cases were in stage Ⅰ according to American Joint Committee on Cancer (AJCC), including 38 cases of non-lymph node dissection (NLND) and 26 cases of LND; 21 cases were in AJCC stage Ⅱ, including 11 cases of NLND and 10 cases of LND; 22 cases were in AJCC stage Ⅲb, including 14 cases of LND and 8 cases of lymph node resection (LNR); 5 cases were in AJCC stage Ⅲa, 2 cases were in AJCC stage Ⅳ. Univariate and multivariate Cox regression analysis were used for the risk factors of ICC prognosis. The log-rank test compared the survival rates of the two groups.Results:Cox multivariate analysis indicated that lymph node metastasis was independent risk factors for prognosis in patients with ICC ( HR=1.96, 95% CI: 1.09-3.55, P=0.026). A total of 114 patients were included in the curative surgery group. The 1-, 3-, and 5-year overall survival (OS) rates of the negative lymph node group ( n=91) were 65.9%, 47.3% and 35.6%, respectively, which were significantly better than those of the positive lymph node group ( n=23) who had 1-, 3-, 5-year OS rates of 56.5%, 17.7% and 0, respectively (χ 2=8.11, P=0.004 ). In stage Ⅰ and Ⅱ patients, there were no significant differences in 1-, 3-, 5-year OS rates between the NLND group and the LND group (both P>0.05 ). In stage Ⅲb patients, the LND group had 1-, 3-, 5-year OS rates of 71.4%, 29.8% and 0, respectively, significantly better than those of the LNR group who had 1-, 3-, 5-year OS rates of 37.5%, 0 and 0, respectively (χ 2=6.45, P=0.011). Conclusions:Lymph node metastasis is an independent risk factor affecting the prognosis of ICC. Lymph node dissection should be performed cautiously in ICC with AJCC stage Ⅰ and Ⅱ, while routine lymph node dissection is recommended in ICC with AJCC stage Ⅲb.