Objective To evaluate the value of dual energy CT with Lung Vessels application in diagnosing pulmonary embolism (PE) of children.Methods Forty-seven patients with nephrotic syndrome and aged ≤ 18 years old (32 male,15 female,mean age 15 years) underwent dual-energy CT pulmonary angiography (CTPA).Two radiologists recorded the presence or absence of emboli and counted the clots on a per-patient and per-lobe basis with Lung Vessels,respectively.With conventional CTPA as reference standard,sensitivity,specificity,positive predictive value (PPV),negative predictive value (NPV) of Lung Vessels application to detect PE were computed for two readers.Inter-reader agreement was also calculated.Results Conventional CTPA detected 51 clots in 35 lung lobes in 13 patients,giving PE incidence was 27.6％ (13/47) for this cohort.On a per-patient basis,readers 1 and 2 detected 25 and 21 patients with PE with Lung Vessels,corresponding to sensitivities,specificities,PPVs,and NPVs of 100.0％ (13/13),58.6％ (17/29),43.3％ (13/30),100.0％ (17/17) and 100.0％ (13/13),76.5％ (21/29),50.0％ (13/26),100.0％ (21/21),respectively.On a per-lung lobe basis,readers 1 and 2 detected 74 and 63 clots with Lung Vessels,respectively,corresponding to sensitivities,specificities,PPVs,and NPVs of 94.3％ (33/35),79.5％ (159/200),44.6％ (33/74),98.7％ (159/161) and 97.1％ (34/36),85.5％ (171/200),54.0％ (34/63),98.8％ (171/173),respectively.On a per-clot basis,134 and 105 clots were detected with Lung Vessels application,corresponding to sensitivities,specificities,PPVs,and NPVs for DECT of 96.1％ (49/51),64.9％ (159/245),36.3％ (49/135),98.7％ (159/161) and94.1％ (48/51),75.0％ (171/228),45.7％ (48/105),98.3％ (171/174)for readers 1 and 2,respectively.Excellent or good inter-reader agreement was observed on a per-patient,per-lobe and per-clot basis (Kappa =0.828,0.859,0.695 ; all P ＜ 0.01).Conclusions Dual-energyCT with Lung Vessels application has a high sensitivity and negative predictive value for PE detection in children.More clots are detected with Lung Vessels application than conventional CTPA,which deserve further investigation.

Objective To study the potential of functional MRI (fMRI) during passive finger extension (FE) for predicting the motor function recovery of hemiplegic stroke survivors.Methods Nineteen survivors of a 1st cerebral infarction in the non-M1 cortex with complete paralysis on one side were selected for study.Within 1 week after the stroke,fMRI was performed while one of the patient's paralyzed fingers was passively flexed and extended.fMRI signals were acquired from the sensorimotor cortex (SMC),the supplementary motor area (SMA) and the premotor area (PM).Fugl-Meyer (FM) scores of arm motor function were recorded one week,one month and three months after the stroke.Results The early fMRI results were used to classify cortex activation performances as type Ⅰ (activation mainly on the affected side,but SMC and SMA activated bilaterally),type Ⅱ (activation of the SMC and SMA only on the affected side) or type Ⅲ (only activation of the SMC on the affected side).At one week after stroke the average FM scores of the three groups were not significantly different.At one month the three average FM scores were 47.1 ± 5.5 points,36 ±6.7 points and 11.2 ± 3.1 points,for groups Ⅰ,Ⅱ and Ⅲ respectively,each significantly different from the others.At three months the average FM ratings of groups Ⅰ (61.1 ± 3.8 points) and Ⅱ (59 ± 5.2 points) were not significantly different,but both were significantly higher than the average score of group Ⅲ (10.8 ± 5.6 points).Conclusion The early stage fMRI characteristics of hemiplegic patients can be used for predicting motor outcomes.

Objective To assess the value of dual-source computed tomography angiography (DSCTA)in detecting intracranial aneurysms by comparing with conventional and three-dimensional DSA.Methods In this study,95 patients with subarachnoid hemorrhage(SAH)underwent both DSCTA and DSA examination.The detection rate,size,and ratio of the neck to the dome(N/D ratio)of the aneurysrns were evaluated.Statistical analysis was performed using a paired sample Student's t-test for the comparisons of the value of N/D and 2 Related Samples test for long axis.Results A total of 67 aneurysms in 63 patients at DSA and 64 aneurysms in 60 patients at DSCTA were detected,respectively;whereas no aneurysm was detected in 32 patients at DSA.Compared with DSA,the overall sensitivity.specificity,positive predictive value,and negative predictive value of DSCTA on a per-aneurysm basis were 94.2%,100.0%,100.0%,and 91.4%,respectively.For the aneurysms larger than 3 mm,the sensitivity and specificity of DSCTA in detecting intracranial aneurysms were equal to those of DSA:For aneurysms smaller than 3 mm,however,the sensitivity and specificity of DSCTA is 80.0% and 100.0%.The N/D ratio for DSA and DSC:TA was 0.46±0.14 and 0.51±0.18.respectively,and the median of long axis was 4.9 mm and 4.8 mm.respectively.There was no significant difierence in the N/D ratio(t=3.20;P＞0.05)and the long axis(Z=-1.309;P＞0.05)between DSA and DSCT.Condusions Compared with conventional and three-dimensional digital subtraction angiography,DSCTA has high sensitivity and specificity in the detection of intracranial aneurysms,especially for detection of snlall aneurysnm(＜3 mm).It can be used as a routine screening technique.

Objective To assess the clinical value of dual-energy intracranial CT angiography (CTA).Methods Forty-one patients suspected of intracranial vascular diseases underwent dual-energy intracranial CT angiography, and 41 patients who underwent conventional subtraction CT were enrolled as the control group.Image quality of intracranial and skull base vessels and radiation dose between dual-energy CTA and conventional subtraction CTA were compared using two independent sample nonparametrie test and independent-samples t test, respectively.Prevalence and size of lesions detected by dual-energy CTA and digital subtraction CTA were compared using paired-samples t test and Spearman correlative analysis. Results The percentage of image quality scored 5 was 70.7% (29/41) for dual-energy CTA and 75.6% (31/41) for conventional subtraction CTA.There was no significant difference between the two groups(Z= -0.455, P=0.650).Image quality of vessels at the skull base in conventional subtraction CTA was superior to that in dual-energy CTA, especially for the petrosal and syphon segment (Z=-4.087, P= 0.000).Radiation exposure of dual energy CTA and conventional CTA were (396.54±17.43) and (1090.95±114.29) mGy · cm respectively.Radiation exposure was decreased by 64% (t=-38.52, P=0.000) by dual energy CTA compared with conventional subtraction CTA.Out of the 41 patients,19 patients were diagnosed as intracranial aneurysm, 2 patients as arteriovenous malformation (AVM), 3 patients with Moya-moya's disease, and the remaining 17 patients with negative results.Nine patients with intracranial aneurysm, 2 patients with AVM, 3 patients with Moya-moya's disease, and 2 patients with negative findings underwent DSA or operation, with concordant findings from both techniques.Diameter of aneurysm neck, long axis and minor axis by dual-energy CTA was (2.90±1.61), (5.23±1.68) and (3.83±1.69) nun, respectively; Diameter of aneurysm neck, long axis and minor axis by DSA was (2.95±1.71), (5.10±1.60) ,(3.83±1.65) nan,respectively.There was no significant difference for the diameters of aneurysm between dual energy CTA and DSA ((t=-0.734,1.936,0.12.5 respectively, P=0.482,0.085,0.903 respectively), and good correlation was found between diameter measurements using the two techniques(r=0.964,0.976,0.973, respectively, all P=0.000) Conclusions Compared with conventional subtraction CTA, dual energy CTA has good image quality for intracranial vessels; however, image quality of the skull base vessels is worse, especially for the petrosal and syphon segment.Dual energy CTA has decreased radiation dose and a high diagnostic accuracy, being a practical imaging madality for diagnosis of intracranial vascular lesions.

Objective To assess the feasibility, safety, and efficacy of balloon disruption of thrombus by using a deflated balloon catheter combined with intraarterial thrombolysis for the treatment of acute middle cerebral artery(MCA) occlusion. Methods Five consecutive patients with acute MCA occlusion underwent balloon disruption combined with intra-arterial thrombolysis. The microballoon was inflated in the distal carotid artery and then deflated and advanced just distal to the occlusion site in the MCA. Thereafter, intra-arterial thrombolysis of the MCA was applied and the maximum dosage of urokinase was 500,000 U. Results Complete recanalization was achieved in 3 patients and partial recanalization in 2. All patients got favourable clinical outcome. There was no major intracerebral hemorrhage. Conclusion The penetration of the MCA with a deflated balloon catheter combined with an intra-arterial thrombolysis may be a safe and effective treatment for acute ischemic stroke.

Objective To summarize the image features of primary retrograde type A aortic dissection by CTA examination, aiming to improve the precise diagnosis of this type of specific aortic dissection, and to provide imaging evidence for subsequent therapies.Methods The CTA data of 17 patients with primary retrograde type A aortic dissection treated in Cardiothoracic Surgery Department of Nanjing General Hospital of Nanjing Military Command from January 2010 to December 2014 were retrospectively reviewed.The image features including the dissection type, the location and quantity of intimal tear, the aorta involving area, and the origin of branch vessels were analyzed.Results Nine cases of the total 17 patients had pericardial/pleural effusion.Fourteen patients showed intramural hematoma in ascending aorta, while 3 patients showed active blood flow and thrombosis formation in false lumen of ascending aorta.Five patients showed aortic ulcers and intramural hematoma in descending aorta, and the other 12 patients showed typical dissection image with active blood flow in both true and false lumen,among the 12 patients, there were obvious intimal separations observed in 11 cases, while multiple aortic ulcers in 1 case.Abdominal aorta was involved in l0 cases of the above 11 patients.All of the abdominal branch vessels were originated from true lumen in 2 of the 10 patients,and the other 8 patients showed 1-2 vessels originated from false lumen.Conclusion Primary retrograde type A aortic dissection is relatively rare.However,specific imaging features different from typical aortic dissection can be observed in this type of aortic lesion.Careful viewing of CTA image is extremely necessary for accurate diagnosis.

Objective To investigate the significance of change of fluid-attenuated inversion recovery(FLAIR) hyperintense vessel sign(HVS) after endovascular recanalization in acute ischemic stroke. Methods The clinical and imaging data of the patients with acute middle cerebral artery(MCA) occlusion treated by mechanical thrombectomy with Solitaire AB from January 2013 to october 2014 were analyzed retrospectively. The inclusion criteria: (1) The preoperative MRI included conventional non-enhanced MR, diffusion-weighted imaging (DWI), magnetic resonance angiography(MRA) and perfusion-weighted imaging (PWI), and HVS was observed on preoperative FLAIR images; (2) acute MCA occlusion verified by conventional angiography;(3) postoperative similar MR images examination was performed within 48 hours. The relationships among postoperative changes in the HVS, DWI and Thrombolysis In Cerebral Ischemia (TICI) scale (1—3) were assessed. Results After endovascular therapy, HVS of the 11 cases were showed to be disappeared(n = 9) and decreased (n = 2). All the 9 patients with disappeared HVS achieved high grade flow (TICI 3), and minor decrease of ischemic area on DWI in 1 case, minor progression in 6, and significant progression in 2. However, of the 2 patients with decreased HVS, one achieved relatively low grade flow (TICI 2a) and the other was found to be relatively high grade flow (TICI 2b), but severe MCA stenosis. DWI demonstrated significant progression in both two cases. Conclusion Our data indicate that endovascular recanalization of acute MCA occlusion was effective for decreasing HVS. Postoperative decrease and disappear in HVS can be considered as a marker for hemodynamic improvement.

Objective To establish the animal model of chronic thromboembolic pulmonary hypertension(CTEPH) and to compare the accuracy of dual-energy CT (DECT) pulmonary angiography and histopathology for detecting CTEPH. Methods Eighteen canines were included in the study. All canines underwent paracentesis, embolization, CT scanning, pressure measurement and tranexamic acid feeding. The procedures were repeated every two weeks, until systolic/diastolic pressure in canines was≥30/15 mmHg or mean pulmonary artery pressure ≥ 20 mmHg.And then canines were sacrificed for histopathology examination. For CT pulmonary angiography (CTPA)in DE mode and DECT lung perfused blood volume (Lung PBV) images, the presence or absence of PE or perfusion defects were recorded on a per-canineand aper-lobe basis. With histopathological results as reference standard, the sensitivity, specificity of CTPA and lung PBV to detect PE were computed for two readers. The pairedχ2 test (McNemar test) was used to analyze the difference in diagnostic accuracy between CTPA and Lung PBV. Inter-reader agreement was also calculated with kappa test. Results CTEPH was demonstrated in 13 canines. On a per-canine basis, both readers found uneven and peripheral perfusion defects with DECT in 11 canines (84.6%, 11/13); while 5 canines (38.5%, 5/13) had cutoff or sudden stenosis of pulmonary arteries with CTPA;on a per-lobe basis,
both readers had sensitivities of 14.3%(5/35), 83.3%(30/36), specificities of 100.0%(30/30), 100.0%(29/29), accuracies of 53.8%(35/65), 90.8%(59/65)for CTPA and DECT, respectively. DECT had a higher sensitivity(χ2=-4.690,P<0.01)and accuracy(χ2=8.284,P<0.01) in detecting CTEPH. Excellent and moderate inter-reader agreements were observed with CTPA and DECT (Kappa=0.938, 0.572, both P<0.001). Conclusions It is feasible to make a CTEPH animal model with autologous thrombus. DECT shows a higher accuracy than CTPA to detect CTEPH in this canine model study.

Objective To evaluate the diagnostic accuracy of digital subtraction bone removal CT angiography (DS-BR-CTA) and dual energy bone removal CTA (DE-CTA) compared with conventional and rotational DSA. Methods A total of 264 patients underwent 3D-DSA were enrolled, 190 of them underwent also DS-BR-CTA, while 74 underwent DE-CTA as well. Aneurysms detected with DS-BR-CTA and DE-CTA were analyzed compared with 3D-DSA on per-patient and per-aneurysm basis. The sensitivity, specificity, positive predictive value and negative predictive value of two methods for diagnosis of aneurysm were calculated. Results Taking DSA as the standard, the sensitivity and specificity of DS-BR-CTA to detect intracranial aneurysms was 96.90％ and 98.36％ on per-patient basis, while 97.37％ and 99.97％ on per-aneurysm basis, and the sensitivity and specificity for the detection of aneurysm ≤3 mm was 88.89% and 98.36%. The sensitivity and specificity of DS-BR-CTA to detect intracranial aneurysms was 98.25% and 100% on per-patient basis, 95.52% and 100% on per-aneurysm basis, and the sensitivity and specificity for the detection of aneurysm ≤3 mm was 90.91% and 100%. Conclusion DE-CTA has a comparable diagnostic accuracy with DS-BR-CTA to diagnose intracranial aneurysms, and can be used in the routine workflow for detection of intracranial aneurysms.

Objective To determine the expression of brain-derived neurotrophic factor (BDNF) in pancreatic ductal adenocarcinoma and its clinical significance.Methods SP immunohistochemical staining method was used to detect the expression of BDNF in 46 cases of pancreatic ductal adenocarcinoma,38 cases of benign pancreatic diseases and 20 cases of normal pancreatic tissue.Real time PCR and Western blot was used to detect the protein and mRNA expression levels.The relationship between BDNF expression and clinicopathological parameters of pancreatic cancer was determined.Results The positive expression rate of BDNF was 52.2％ (24/46) in pancreatic ductal adenocarcinoma pancreatic ductal adenocarcinoma,7.8％ (3/38) in benign pancreatic diseases,and none of the normal pancreatic tissue was BDNF positive.The BDNF protein expression levels in pancreatic ductal adenocarcinoma,benign pancreatic diseases and normal pancreatic tissue were 0.38± 0.01,0.56± 0.01,0.97± 0.01,respectively,and the BDNF mRNA expression levels were 0.85 ± 0.14,1.67 ± 0.21,3.45 ± 0.67,respectively,and the expression levels in pancreatic ductal adenocarcinoma and benign pancreatic diseases were significantly higher than that in normal pancreatic tissue,while the expression level in pancreatic ductal adenocarcinoma was significantly higher than that in benign pancreatic diseases (P ＜0.05).Positive BDNF expression was correlated with nerve infiltration and lymph node metastasis of pancreatic ductal adenocarcinoma,but it was not related to age,sex,tumor size,location and differentiated degree (P ＞ 0.05).Conclusions BDNF is involved in the development and growth of pancreatic cancer,and it may be related with patient's prognosis.