Objective To investigate the differences of carotid plaque burden,composition characteristics between index side and non-index side in patients with ischemic stroke by multi-contrast 3.0T MRI,and analyze their relationships with cerebral ischemic events.Methods Sixty-two ischemic stroke patients,admitted to our hospital from 2012 August to 2013 December,were chosen in our study;they all underwent brain routine 3.0T MR imaging examinations within 2 weeks of stoke onset; according to the ischemic signs,the index side and non-index side of the patients were recognized and noted; carotid artery multi-contrast MR imaging was,then,employed to distinguish the discriminant carotid artery plaque components (such as calcification,lipid rich necrotic core [LRNC],intraplaque hemorrhage [IPH])and measure the corresponding volume,to judge the carotid artery plaque fibrous cap surface state (complete or broken) measure the total vessel area,lumen area,wall thickness and calculation wall area and normalized wall index.Results A total of 120 carotid arteries met the inclusion criteria,including 85 in the index side and 35 in the non-index side.LRNC and IPH incidence rates between the index side and non-index side (71.7％ vs.22.8％; 12.9％ vs.0％) and volume (19.96 mm3 [0 mm3,61.91 mm3] vs.0mm3 [0 mm3,0 mm3]; [0 mm3,58.73 mm3] vs.[0 mm3,0 mm3]) were statistically different (P＜0.05).FCR incidence rate showed no significant difference between the index side and non-index side (P＞0.05).The carotid artery average and maximum wall area ([28.06±10.06] mm2 and [47.61±16.82] mm2),average and maximum wall thickness ([1.07±0.37] mm and [2.88±1.72] mm),and average and maximum wall standard index ([0.41 ±,0.09] and [0.54±0.16]) of index side had significant difference as compared with the non-index side([22.50±5.04] mm2 and [36.22±10.53] ram2; [0.88±0.18] mm and [1.91±1.00] mm;[0.36±0.05] and [0.45±0.10],P＜0.05).Conclusion The 3.0T multi-contrast high resolution MRI of the carotid artery can quantitatively measure the carotid plaque burden and evaluate the plaque characteristics; the heavier the plaque burden,the more complex the components,the higher the cerebral ischemic events.

Objective To analyze the CT and MR imaging features of intracranial teratomas to improve the diagnostic accuracy.Methods Twenty patients with intracranial teratomas,admitted to and performed surgery in our hospital from January 2010 and January 2014,were chosen;the teratoma was confirmed by histopathology.The CT and MR imaging features,clinical and pathology materials of these patients were retrospectively analyzed.Results Twelve immature teratomas,7 mature teratomas and one teratoma with malignant transformation were noted;18 patients were in the central line area and 2 were not.In the 9 patients performed CT scan,7 showed heterogeneous mass;peritumoral calcification was more common than intratumoral calcification,and it turned out to be round with diameter less than 1 cm,while intratumoral calcification was multifocally strip and patchy.In the 17 patients performed MR imaging,14 showed heterogeneous signal and fatty signal was detected in 3;enhanced MR imaging showed that 6 presented nodular enhancement,3 presented multilocular enhancement markedly,patchy enhancement showed in 2,and one showed marked enhancement in mural nodule and cystic wall.In 8 patients performed diffusion-weighted imaging,7 displayed hypointense to isointense and one demonstrated isointense to hyperintense.Conclusions Intracranial teratoma has some characteristic imaging features,so by combining clinical materials,it should be considered when fatty component is detected in a heterogeneous intensity tumor with multiple cystic change,calcification and a hypointense to isointense signal on DWI;however,pathology is needed to make a definite diagnosis.

Objective To explore the MR imaging characteristics of brain tumors in infants to improve the diagnosis and early treatment.Methods Twelve infants with brain tumors (less than 1 year old),performed surgery in our hospital from April 2008 to August 2014 and proved by pathology,were collected in our study; the clinical data and MR imaging features were reviewed retrospectively.Results Among the 12 infants,4 (33％) had tumors located at the lateral ventricle,3 (25％) at the cerebral hemisphere,one (8.3％) at the pineal region,one (8.3％) at the suprasellar region,one (8.3％) at the cerebral convexity,one (8.3％) at the cerebellar hemisphere and one (8.3％) at the fourth ventricle.These tumors included immature teratoma (n=3),choroid plexus tumor (n=3),atypical teratoid/rhabdoid tumor (n=2),medulloblastoma (n=1),anaplastic ependymoma (n=1),pilomyxoidastrocytomas (n=1) and infantile fibrosarcoma (n=1).Diversity of MR imaging features was found in different types of brain tumors; tumors as immature teratoma,atypical teratoid/rhabdoid tumor and infantile fibrosarcoma showed mainly mixed signal intensity on T1-weighted images and T2-weighted images,and these tumors displayed heterogeneously enhancement at MR imaging; choroid plexus tumors and medulloblastoma showed isointenseon T1-weighted images and T2-weighted images mostly,and both had obvious enhancement; anaplastic ependymoma showed isointensity signal on T1-weighted images,slightly hyperintenseon T2-weighted images and heterogeneously enhancement; pilomyxoidastrocytomas were hypointenseon Tl-weighted images,hyperintenseon T2-weighted images and homogeneous enhancement.Conclusions Immature teratomas,choroid plexus tumors and embryonal tumors are common in infants.Supratentorial tumors are mostly found.Typical features are showed in some brian tumors,but part of atypical tumors remain challenging in diagnosis.To improve diagnostic accuracy,imaging data should be accumulated in the future.