Objective To study the clinical significance of routine MRI and 3 dimensional time of flight magnetic resonance angiography (3D-TOF-MRA) for the pathogenesis of Trigeminal neuralgia (TN) Methods 32 patients with TN and 32 controls were observed by MRI and 3D-TOF-MRA by the enhancement of DTPA Diagnosis of the presence of compressions in the root exit zone (REZ) of the Trigeminal nerves were carried out by two radiologist on an independent console Results (1) In patients studied, compressions of the REZ of the nerves were detected with 29 on symptomatic sides (90 63%), neurovascular on 25 sides and tumor on 4 sides, and 2 on the asymptomatic sides(6 25%, all neurovascular) In the controls, 3 sides (4 26%, all neurovascular) were involved in the compressions of the REZ of the Trigeminal nerves (2) In 25 cases with TN of neurovascular etiology, the offending vessels were the superior cerebellar arteries in 17 cases (68%), anterior inferior cerebellar arteries in 2 cases, vertebral artery (VA) in 1 cases, difficultly identified vessels in 2 cases, vein in 2 cases, vascular malformation in 1 case (3) The RR of microvascular and tumor compressions which cause TN were 36 74 (4) The real microvascular compression and entrapping were only detected on the symptomatic sides of TN in 13 patients (52%) Conclusion MRI and 3D-TOF-MRA appeared to be the best imaging test for the pathogenesis of TN now The major causes of TN might be different neurovascular and tumor compressions in the REZ of the fifth cranial nerve, with real compression, entrapping or tight contact

Objective To evaluate the application of CT myelography (CTM) in detecting the site of spontaneous cerebrospinal fluid (CSF) leaks and analyze it's imaging features.Methods Six patients (3 women and 3 men) with spontaneous intracranial hypotension (SIH) were included, who met the criteria of the International Headache Classification (2nd edition, 2004). Five patients subsequently underwent whole spine MRI and all 6 patients underwent CTM. Autologous blood mixed with omnipaque (300 mg/ml) was injected followed by selective puncture at the leak site indicated by CTM. Results MRI was failed to find leak site in the 5 patients, whereas CTM successfully found leak sites in all 6 patients. There were 1 to 7 leak sites respectively with an average of 4.2 sites (totally 25 points). Leak sites at cervical (12 sites) and thoracic (12 sites) were more frequent than at lumbar (1 site). CTM was featured by linear leakage of the contrast medium along the spinal nerve roots, paraspinal collections of hyper-density contrast medium and beak-like enlargement of the nerve sleeves. All patients responded well to the treatment, with complete resolution of symptoms. Conclusion CTM has been shown to be a study of choice to accurately define the location and extent of a CSF leak.

Objective The influence of antiplatelet medications on prognosis after non -aneurysmal subarachnoid hemorrhage(SAH)is unknown.This study aimed to evaluate the risk of antiplatelet mdications in devel-oping SAH.Methods 420 patients who underwent catheter cerebral angiography after presenting with nontraumatic SAH were included.Outcomes were assessed by using the modified Rankin scale.Results A total of 420 patients underwent catheter angiography for evaluation of SAH.Of these,63 cases (15%)were angiogram -negative.The fraction of patients presenting with angiogram -negative SAH as well as the frequency of antiplatelet use among these patients significantly increased during the study period.Antiplatelet use was more commonly associated with angiogram-negative SAH(18 /63,28.6%)than with angiogram -positive SAH(39 /357,11%;P =0.001).At 14 days after presentation,poor outcome was significantly more frequent among patients who took antiplatelet agents (20 /63, 31.7%)than among those who did not(12 /63,20%;P =0.017).Conclusion Antiplatelet medication use is asso-ciated with poor early,but not late,outcomes after angiogram -negative SAH.More studies are needed to confirm this association.

Objective To evaluate the effect of non-linear blending function for dual-energy CT on image of pulmonary angiogra-phy.Methods 27 patients underwent dual energy CT pulmonary angiography(CTPA).Data obtained with 100 kVp,140kVp,and non-linear blending were divided into group A,B,and C respectively.CT value of emboli 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 ana-lyze statistical significance among these values.Results On quantitative analysis of 27 patients,there was no statistical difference for CT value of CTPA among the three groups(P >0.05).For the noise,CNR and SNR,there were statistically significant among the three groups(P <0.05).Conclusion The non-linear blending function has certain advantages in improved image signal-to-noise ratio and it can be used in CT pulmonary angiography examination for patients suspected pulmonary embolism clinically .

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.

Objective In this study,functional magnetic resonance imaging(fMRI)is performed to visualize what type of brain activity correlates with writer's cramp.Methods Ten patients with writer's cramp and ten age-and gender-matched control subjects participated in this study.fMRI block design is used.Subjects were scanned while performing three visually instructive tasks with MR Vision 2000:(1)suppositional writing;(2)writing with finger;(3)writing with a pencil.Data were analyzed with Analysis of Functional Neuroimaging(AFNI)software for groups of patients versus controls.Results Compared with controls,patients with writer's cramp showed greater activation of contralateral basal ganglion(especially the putamen,864 activated voxels in patients versus 54 in controls),ipsilateral cerebellar hemisphere,and contralateral sensorimotor,supplementary motor,premoter,primary sensory cortex in the task of writing with a pencil.There is no obvious difference in the task of writing compared with finger writing.Furthermore,these differences existed in the subtractive activated maps for “writing with pencil” minus “writing with finger”,while the activation of subcortical area and insula in controls disappeared.Conclusion These results indicate that the dysfunction of basal ganglion and subcortical-cortical loop might play a pathophysiologic role in the writer's cramp.

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.

Objective To evaluate the clinical value of susceptibility weighted imaging (SWI)in full-term neonatal hypoxic ische-mic encephalopathy (HIE).Methods Sixty-three neonates with HIE were collected and scanned by Siemens 3.0T superconducting MR scanner.Routine axial conventional MRI scan and axial SWI scan were conducted.Results In 63 neonates,a total of 29 cases with different degree of intracranial hemorrhage were scanned with SWI sequence.A total of 1 5 1 intracranial hemorrhages were found.Conventional MRI sequences were performed in 1 5 cases with different degree of intracranial hemorrhage.Only 78,43 and 88 hemorrhages were found by T1 WI,T2 WI and T2 Flair sequences,respectively.SWI were significantly superior to conventional MRI sequences in displaying the scope and boundary definition of hemorrhage.Conclusion SWI sequence is obviously better than the con-ventional MRI sequences in bleeding detection and displaying hemorrhage stove,and it provides a powerful imaging method for the clinical diagnosis and treatment.

Objective To investigate CT and MRI imaging of Warthin tumor of parotid gland.Methods CT and MRI character-istics of 5 1 patients confirmed as Warthin tumor by operation and pathology were analyzed retrospectively.Results Among 5 1 cases, 43 patients were males,and 8 patients were females.A total of 84 lesions were found in all cases,20 cases had at least 2 lesions.The margins of lesions were well-defined.68 lesions were round or elliptical.45 lesions located in the posterior and inferior quadrant of the parotid gland completely or premodinantly.The density and signal of most lesions were homogeneous.The parenchymal area of most lesions showed an early moderate-remarkable enhancement.Small blood vessels surrounded the lesions in 1 9 cases.Conclusion CT and MRI are important and valuable for the diagnosis of Warthin tumor.

Objective To evaluate the changes of diffusion kurtosis imaging (DKI) parameters with time in cerebral in farction patients,and contrast with diffusion tensor imaging (DWI).Methods DWI and DKI scans were performed in 95 patients of cerebral infarction.The patients were divided into five groups according to the time of cerebral infarction:Hyperacute phase (n=10),acute phase (n=12),early subacute phase (n =33),late subacute phase (n =20) and chronic phase (n =20).Parameters of DKI were obtained,and the parameters and percentage change of diffusion metrics from normal to ischemic tissue were compared.The evolution rule of parameter with time was analyzed.Results Mean kurtosis (MK),axial kurtosis (K//),radial kurtosis (K⊥) of DKI parameters increased after infarction,and reached the peak at acute phase,and decreased gradually with the prolonging of time.Mean diffusion (MD),axial diffusion (D//),radial diffusion (D⊥) of DTI parameters decreased after infarction,and reached the lowest at the acute phase,and increased gradually with the prolonging of time.The percentage change of MK,K//,K⊥ were higher than those of MD,D//,D⊥,and percent change along the axial direction were significantly larger than that along the radial direction.Conclusion DKI is superior to DTI in evaluating cerebral infarction,and can analyze the changes of microstructure of cerebral infarction comprehensively.