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Objective To compare the test bolus technique with the bolus tracking technique for dual-energy CT pulmonary angiography in patients suspected of pulmonary embolism (PE).Methods A total of 60 patients were randomized into 2 groups:bolus tracking technique group (group B,n =30) and test bolus technique group (group T,n =30).A standard dual-energy CT pulmonary angiography (CTPA)was performed after injection of 60 ml contrast medium followed by 35ml saline chaser at a speed of 4 mL/s.Attenuation profiles of different vascular segments (the subclavian vein,superior vena cava,left atrium,pulmonary trunk,S1 and S10 pulmonary artery) and enhancement value of lung parenchyma were measured to evaluate the timing techniques.The overall image quality of CTPA and pulmonary perfusion were analyzed by two radiologists.SPSS 19.0,Student t test,ANOVA test,Chi-Square test,Mann-Whitney U test and Kappa test were used for the statistic analysis.Results The attenuation of the subclavian vein [(1042 ± 639),(2200 ± 724) HU,F =43.196,P =0.001],superior vena cava [(529 ± 237),(904 ± 329)HU,F=25.654,P=0.001],pulmonary trunk [(325 ±112),(383±69)HU,F=5.94,P=0.018],S1 pulmonary artery [(320 ± 118),(385 ±73) HU,F =6.549,P =0.013],S10 pulmonary artery [(307 ± 78),(360 ± 82) HU,F =6.658,P =0.012] in group B were lower than those in group T,while the attenuation of the left atrium in group B was higher than that in group T [(270 ± 53),(219 ± 57)HU,F=12.823,P =0.001].The percentage of pulmonary arteries exceeding optimal attenuation (＞ 250 HU) in groups B was lower than that in group T [n =21 (70.0％),n =29 (96.7％),x2 =5.88,P ＜ 0.05].The enhancement value of pulmonary parenchyma in group B was lower than that in group T (the right lung (29±8)vs(34±8) HU,t=-2.401,P=0.020; the left lung (30±7)vs(36±9)HU,t=-2.493,P=0.016; total (30 ±7)vs(35 ±8) HU,t =-2.495,P =0.016).The image quality of CTPA in group B was poorer than that in group T (U =619.5,P ＜ 0.05,Kappa =0.708),while the artifacts of lung perfusion image in group B was less than that in group T (U =162.5,P ＜ 0.05,Kappa =0.796).Conclusion The test bolus technique has a better image quality of CT pulmonary angiography and a higher lung perfusion blood volume compared with the bolus tracking technique by using 60 ml contrast medium and 35ml saline.
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Objective To study the clinical significance of 3 dimensional time of flight magnetic resonance angiography(3D-TOF-MRA) for the pathogenesis of hemifacial spasm (HFS) and trigeminal neuralgia(TN).Methods 48 patients with HFS and 46 patients without HFS and 42 patients with TN and 40 patients without TN were examined by MRI and 3D-TOF-MRA by the enhancement of DTPA. Diagnosis of the presence of compressions in the root exit zone(REZ) of facial nerves and trigeminal nerves were done by two radiologists on an independent console. Results (1)In the patients, compression of the REZ of the facial nerves and trigeminal nerves were detected on 45 spastic sides (93.8%,neurovascular on 44 sides and tumor on 1 side) and 36 spastic sides ( 85.7%,neurovascular on 32 sides and tumor on 4 sides ), 8 and 4 on the asymptomatic sides (16.7% and 9.5%, all neurovascular ). In the controls, 4 and 5 sides ( 4.4% and 6.3% ) were found in the compression of the REZ of the facial nerves and trigeminal nerves. ( 2 ) The offending vessels of compression of the REZ of the facial nerves were the anterior inferior cerebellar artery (AICA) in 17 cases ( 38.6% ), the posterior inferior cerebellar artery (PICA) in 12 cases (27.3%), the vertebral artery (VA) in 6 cases (13.6%). The offending vessels of compression of the REZ of the trigeminal nerves were the superior cerebellar artery ( SCA ) in 18 cases ( 56.3% ), the anterior inferior cerebellar artery in 5 cases (15.6%), the difficult identified vessels (DIV) in 4 cases (12.5%). (3)The relative risks of microvascular compressions which cause HFS and TN were 26.6 and 9.84. (4) The compressions of the REZ of the facial nerves and trigeminal nerves were proved in 4 cases (neurovascular 3 cases and tumor 1 case) and 10 cases (neurovascular 6 cases and tumor 4 casee) in the operation.Conclusion MRI and enhanced 3D-TOF-MRA appeare to be the best imaging technology for the pathogenesis of HFS and TN now. The major causes of HFS and TN may be different neurovascular compressions in the REZ of the facial nerves and trigeminal nerves, some cases are caused by tumor compression.
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Objective To study the contribution of enhanced 3D time-of-flight MRA in the diagnosis of neurovascular compression in the patients with trigeminal neuralgia.Methods Enhanced 3D time-of-flight MRA and MRI in 37 patients clinical suspected trigeminal neuralgia were analyzed retrospectively.Results We found 27 sides trigeminal nerve in 24 patients were compressed by vascular in the enhanced 3D time-of flight MRA.In 24 patients neurovascular compression was ipsilateral with trigeminal neuralgia,and the side without trigeminal neuralgia, vascular compression in 3 cases were found.There was statistics correlation between neurovascular compression and trigeminal neuralgia.The other 13 patients with trigeminal neuralgia were non-neurovascular compression.The trigeminal nerve was compressed by superior cerebellar artery in 14 patients,anterior inferior cerebellar artery in 5 patients,tortuous vertebral artery in 1 patient,malformation of vascular in 1 patient,other microvascular in 5 patients.Conclusion Enhanced 3D time-of-flight MRA,which is super than MRI,can clearly display trigeminal nerve and neighboring vascular.Int is the optimum technology of radiology to diagnose the neuroveascular trigeminal neuralgia and helpful for diagnosis and treatment.
