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 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 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 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 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.

clues for interpretation of myocardial ischemia.

Objective To evaluate the clinical values of dual energy lung perfusion using dual-source CT. Methods Fifty-four patients who underwent chest contrast-enhanced CT were included in this study from May to August in 2007. Dual energy CT scanning was performed in all patients. The patients were divided into four groups: normal group, exudation lesion group, mass lesion group, and pulmonary embolism group. Imaging appearances of dual energy CT perfusion in four groups were analyzed. Results Dual energy CT showed symmetrical homogeneous perfusion in healthy subjects (n = 14), exudation lesions (n =10) appeared as low perfusion, In mass lesions (n =27), peripheral masses presented as local perfusion defect, central masses appeared as segmental perfusion defect because of the involvement of hilar vessels,and pulmonary embolism (n = 3) appeared as perfusion defect in corresponding pulmonary segment.Conclusion Dual energy CT scanning can be used to show the pulmonary perfusion status and assess the pulmonary perfusion abnormalities in central lung cancer and pulmonary embolism.

Objective To assess the feasibility of arterial blood bypass using microcatheter in intraarterial thrombolysis for acute cerebral ischemic stroke.Methods Six patients with acute cerebral infarction within 6 hours underwent intraarterial thrombolysis,in which arterial blood bypass was used.A 2.3 F microcatheter was advanced through the clot and two milliliters of contrast was injected beyond the clot that remained stagnant in the major branches.At this point,20 ml of oxygenated blood from femoral artery was injected for 2 minutes through the microcatheter past the occluding clot Then,conventional intraarterial thrombolysis,including fibrinolytic agents infusion and mechanical disruption,was performed.Intraarterial thrombolysis and oxygenated blood infusion alternated every 30 minutes.Results Every patient received arterial blood bypass with average three times(from 1 to 5 times)in the process of the intraarterial thrombolysis,which cost(8.0±3.2)min.Recanalization was achieved in all 6 patients,but minor subarachnoid hemorrhage developed in one patient All the patients got favorable clinical outcome.The life conditions is excellent in 4 cases and good in 2 cases.Conclusions Arterial blood bypass using microcatheter in intraarterial thrombolysis for acute cerebral ischemic stroke might be feasible,which did not interfere with conventional intraarterial thrombolysis and prolong the operation time significantly but could protect ischemic penumbra.

Objective To investigate the clinicopathological features of patients with serous cystadenomas of the pancreas (SCAP).Methods The clinical and pathological features of 21 cases of SCAP were retrospectively analyzed.Results The mean age of the 21 cases was 61 years old,male:female ratio was 1∶ 1.33,18 (85.7％) patients presented with abdominal pain,bloating,abdominal mass,weight loss,and 3 (14.3％) patients were found during check-up.The tumors were located in pancreatic head in 9 patients,in pancreatic body and tail in 12 patients.The clinical manifestations were pancreatic cystic lesions.All patients underwent surgery.Histologically,the cyst wall was complete and lined with flat or cuboidal epithelium,cytoplasm was translucent,nucleus were round or oval with similar size,no significant nuclear atypia and mitotic activity was found.The pathologic diagnosis was micro-cyst type in 15 cases,single-cyst type in 6 cases.Immunohistochemistry method showed EMA,CK7,CK19 positive and PAS staining positive.The positive expression rate of Ki 67 was between 1％ and 3％.After follow-up of 19 cases ranging from 3 months to 7 years,no recurrence and metastasis was detected.Conclusions SCAP is seen predominantly in elderly female patients with significant symptoms.A majority of tumors are located in the pancreatic body and tail.SCAP presents with characteristics of pancreatic ductal epithelial,and the prognosis is excellent.

ObjectiveTo evaluate the image quality of displaying the pulmonary artery and pulmonary emboli at different tube voltages and find the optimal tube voltage.MethodsSixty-six patients underwent contrast-enhanced dual energy CT pulmonary angiography (CTPA) from August 2007 to February 2010.Data obtained with 80 kVp,weighted average 120 kVp,and 140 kVp were divided into group Ⅰ,Ⅱ,and Ⅲ respectively.CT value of pulmonary artery ( grade 1—4),emboli,and muscles were measured.Corresponding signal to noise ratio (SNR) and contrast to noise ratio (CNR) were calculated.One-way ANOVA analysis and Friedman test were used to analyze statistical significance among these values.Image quality of CTPA from these three groups was assessed.The inter-reader agreement of image quality was performed by kappa test.ResultsCT value of branch 1 to 4 of ptlmonary artery was (446 ± 140) HU,(433±130) HU,(411 ±138) HU,and (392±127) HU in group Ⅰ,(303±91) HU,(290±85) HU,(276±86) HU,and (263 ±85) HU in group Ⅱ,and (244 ±70) HU,(230 ±63) HU,(216 ±72) HU,and (205 ±68) HU in group Ⅲ.There was significant difference for CT values (P ＜0.01) among three groups.CT value of pulmonary artery in 80 kVp images was higher than 140 kyp and 120 Kvp.On quantitative analysis of 37 patients,CNR value of pulmonary clots was 8.3 ± 3.3,8.0 ± 2.9,and 5.6 ± 2.2 in group Ⅰ,Ⅱ,and ⅢⅢ,respectively.CNR values of pulmonary clots in 80 kVp images and 120 kVp images were higher than that in 140 kVp (P ＜0.01 ).There was no statistical difference for image quality of CTPA among the three groups ( P ＞ 0.05 ).Agreement of image quality of CTPA derived from 80 kVp (kappa value =0.789,P ＜0.01 ) was superior to that of 120 kVp (kappa value =0.652,P ＜0.01 ) and 140 kVp ( kappa value = 0.509,P ＜ 0.01 ).Conclusions CT value of pulmonary artery in 80 kVp images was higher than that of weighted average 120 kVp and 140 kVp,and the image quality and CNR was comparable with that of weighted average 120 kVp images.This tube voltage ( 80 kVp) is optimal for CT pulmonary angiography in the evaluation of patients with suspected pulmonary embolism.