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 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 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.

clues for interpretation of myocardial ischemia.

ObjectiveTo investigate the feasibility and accuracy of dual energy CT (DECT) in detecting acute myocardial ischemic reperfusion injury in a swine model.Methods Acute myocardial ischemic reperfusion injury model was made by ligaturing the left anterior descending coronary artery (LAD)or the first diagonal artery ( D1 ) of swine heart,the first-pass contrast enhanced DECT was performed.And then pigs were sacrificed,and the hearts were removed,triphenyhetrazolium chloride staining was performed.The CT numbers of non-ischemic and ischemic regions were measured.In the short axis of the left ventricle,the ventricular wall was divided into 17 segments for analysis,segments with myocardial perfusion defect in DECT myocardial iodine maps,DECT ( 140,100 kV,weighted average 120 kV) were determined and compared with histopathology.The sensitivity,specificity and inter-modality agreement of DECT in detecting myocardial injury were calculated.One-way ANOVA test was used to analyze the differences between the CT number and weight of infracted myocardium measured on DECT at 140,100 kV,weighted average 120 kV in ischemic and normal regions.ResultsPartial sparse or defective perfusion in the apical anterior and septal wall were demonstrated in DECT myocardial iodine maps.The CT number of injured myocardium was significantly lower than that of normal myocardium at 140,100 kV,weighted average 120 kV.The sensitivity,specificity of DECT myocardial iodine maps were 85.2％ (23/27),86.2％ (94/109),and Kappa value was 0.62,the sensitivity,specificity at 140 kV were 88.9％ (24/27),92.7％ (101/109),and Kappa value was 0.76,the sensitivity,specificity at 100 kV were 85.2％(23/27),89.0％ (97/109),and Kappa value was 0.67,the sensitivity,specificity at weighted average 120 kV were 88.9％ (24/27),91.7％ ( 100/109),and Kappa value was 0.74.There were no significant differences between the weight of infracted myocardium measured on DECT at 140,100 kV,weighted average 120 kV and histopathological results ( F =0.419,P =0.741 ).ConclusionDECT myocardial iodine maps can detect acute myocardial ischemic reperfusion injury in a swine model and have a good correlation with histopathology.

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.

Objective To evaluate monoenergetic imaging of dual energy CT in the visualization of metal fixation of factures. Methods In total, 29 patients with factures underwent 36 metal fixations,including 11 external fixations implanting in tibiofibula (n = 11 ) and 25 internal fixations (cervical spine,n=10; lumbar spine, n=4; tibiofibula, n=8; radial bone, n=3). They were recruited into this study.After dual energy CT scan, monoenergetic software was used to post-process with the following 6 photon energies: 40, 70, 100, 130, 160, 190 keV. Two radiologists evaluated and rated the reformatted images with 6 different photon energies and average weighted 120 kV images according to the following 4-score scale. Score 1: nonassessable, with marked artifact; score 2: assessable, moderate artifact; score 3: good,mild artifact, good visualization of bony structures; score 4: excellent, no artifact. Kruskal-Wallis was used to perform statistical analysis of image quality for total fixations, external and internal fixations with various selective kev settings and average weighted 120 kV. Results For total fixations, monoenergetic imaging of dual energy CT has 25 fixations with score 3 and 4, but 120 kV has only 4 fixations with score 3 and 4.Monoenergetic imaging of dual energy CT improved image quality of fractures with metal fixation compared to average weighted 120 kV images ( F = 116. 487, P ＜0. 01 ). Images of 130 kev had the best image quality for external metal fixation (9 fixations with score 3 and 4, F = 60. 902, P ＜ 0. 01), while 70 kev was best for internal metal fixation ( F = 122. 149, P ＜ 0. 01). Conclusions Monoenergetic imaging of dual energy CT improves image quality of fractures with metal fixation. Reformatted images at 70 keV and 130 keV havethe optimal image quality for internal and external metal fixation, respectively.

Objective To observe the cortical functioning of healthy volunteers during acupuncture as a way of exploring acupuncture's neural mechanisms.Methods Twenty healthy volunteers received acupuncture applied to the left hegu and waiguan acupoints while their cortical activity was examined using blood oxygenation level-dependent functional magnetic resonance imaging (BOLD-fMRI).Brain activation,especially of the regions related to motor function,were observed and analyzed.Results Acupuncture applied to the left hegu and waiguan acupoints was observed to significantly activate the left middle frontal gyrus and the inferior frontal gyrus,with many activated regions in the left insula and a few in the left cerebellum,the left precentral gyrus,the left postcentral gyrus,the left inferior parietal lobule,the left medial frontal gyrus,the left precuneus,the left anterior cingulate gyrus and the left claustrum.The right side of the brain was excited mainly in the right middle frontal gyrus and the right medial frontal gyrus.The right inferior parietal lobule and the right precentral gyrus were also activated to some extent.There was slight activation of the right middle temporal gyrus,the right superior temporal gyrus,the right insula,the right inferior frontal gyrus and the right postcentral gyrus.The negatively activated regions were mainly located on both sides of the limbic lobe,including the hippocampus,the parahippocampal gyrus and the cingulate gyrus.The left superior temporal gyrus,the left middle temporal gyrus and the right middle frontal gyrus also had small negative activation zones.Conclusions In brain regions associated with motor function,in addition to partial activation of the contralateral primary sensorimotor area,acupuncture at these two points clearly generates bilateral activation of secondary motor areas with some activation in the ipsilateral cerebellum.This may serve as a neuropathological basis for acupuncture treatment of motor dysfunction.BOLD-fMRI imaging displays the neural effects of acupuncture in an intuitive way.It can be a useful technique for further study of the neural effects of acupuncture on pathological conditions.