长信号

objective to study mri diagnostic value on multiple sclerosis.methods mri examination data of 31 patients with multiple sclerosis were analysised retrospectively.results total 184 lesions were detectived in 31 patients.most lesions were located on white watter area beside the lateral ventricle,and a few lesions were located on the spinal cord,cerebellum,brain stem and corpus callosum.the shape of lesion can be circle or ellipse.the lesion showed as slightly long t1 and long t2 signal.the acute stage lesions can have enhancement.conclusions ms have characteristic findings on mri image.mri can show the patholoic changes,and provide strong evidence for clinic diagnosis of multiple sclerosis.

摘 要］目的：探讨多发性硬化（muliplle sclerosis，ms）的mri特征表现及其诊断价值。方法：回顾分析31例临床诊断为ms患者的mri检查资料。结果：31例共发现病灶184个，病灶于侧脑室旁白质区、半卵圆中心及皮层下区最多见，其次见于脊髓小脑、脑干及胼胝体，部分可见视神经受累，病灶呈卵圆形或圆形稍长t1、长t2信号，矢状位像见病灶与侧脑室垂直，急性病灶增强扫描有的可呈结节状、环状或斑点状强化。结论：在mri图像上ms有特征性表现，mri能反应ms病理变化，为临床诊断ms提供可靠依据。

The age of onset were 7 to 11 years old.Three patients revealed mental impairment and limbs weakness.Other symptoms included alalia,ataxia in three cases and visual and auditive disturbances in 2 case,One case had visual nerve atrophy and seizures.Testost in one case and 17-hydroxide steroid in another case were degressive.Cerebral biopsy in one case suggest lipide sediment.Testicle impairment in one case was found by ultrasonography.The cerebral magnetic resonance imaging of all the 4 patients showed the characteristic pattern of symmetrical long T1 and long T2 signal in the parieto-occipital region.

结果发病年龄7~11岁，均有智能下降、肢体无力，3例伴言语不清、共济失调，2例伴视听力下降，1例伴视神经萎缩、癫发作，血睾酮降低及血17-羟类固醇降低各1例，B超示双侧睾丸弥漫性病变、脑活检示类脂质沉积病各1例，4例磁共振均见双侧枕顶叶对称性蝶翼状长T1、长T2信号灶，可累及颞叶、内囊和脑干白质。

The image of MR showed mixedlong T1 and long T2 signals, and circular reinforcement of even thickness could be found after enhancement, mostly with chambered reinforcement.

MR表现为混杂的长T1长T2信号，增强后可见厚薄较均匀一致的环形强化壁，多有分房状强化。

Results:MRI demonstrated that cerebral metastases were mainly from extracerebral organs(91.8%); multifocal metastasis occurred more frequently(57.1%);the cerebral parenchyma was the most common site of cerebral metastasis(87.8%),the following was the sk...

结果 ：MRI显示脑转移瘤主要为外源性，占 91.8%；多发性较常见，占 5 7.1%；转移部位多为脑实质( 87.8%)，其次为颅骨( 6 。1%)、软脑膜( 4 。1%)、幕下( 2 。0 %)转移；大多数转移瘤的MRI表现为类圆形长T1 长T2 信号肿块，实性部分多数均匀增强。

Eases extracerebral CAs located in parasellar region, which presented as isointensity or slightly-hyperintensity on plain CT and isointense signal or slightly hypointense signal on T1WI, but markedly hypointense en T2W1. All extracerebral CA lesions demonstrated intensive enhancement on enhanced CT or Gd-DTPA enhanced MRI, which appeared as a "knead dough".

脑外型CA位于鞍旁区，CT平扫为等密度或稍高密度；MRI平扫为等T1或稍长T1，明显长T2信号，增强后均明显强化，呈&揉面团&样；DSA检查可见肿瘤染色。

Hepatic angiography showed the tumors were hypervascular and the hepatic artery was the main feeding vessel.

MRI平扫呈长T1，稍长T2信号。肝动脉造影示肿瘤富血供，由肝动脉供血。

For signals that exhibit a weak or moderate long-term persistence,an OIVPM-MDL structure identification method is proposed based on overdetermined instrumental variable product moment and minimum description length criteria,and for signals with a strong long-term correlation between samples a combinative approach of inverse fractional filtering and the OIVPM-MDL method is also described.

本文研究了滤波分形差分高斯噪声过程的结构辨识问题，针对存在较弱和适中的长期间相关的信号，提出了一种基于超定辅助变量乘积矩和最小描述长度准则的OIVPM－MDL结构辨识方法；针对存在强长期间相关的过程，提出了分形反滤波与OIVPM－MDL的组合定阶方法。

Results Abnormal signal lesions were found in 47 patients with viral encephalitis, including multiple or single, symmetrical or asymmetrical large patch shape lesions, the located mainly in cortices, subcortical and basal ganglia and thalami. The lesions carried long T 1 and long T 2 on MRI. Enhanced MRI was performed in 22 cases, and demonstrated abnormal enhancement in 11 cases, including large patch or gyrus shape enhancement in 7 cases.

结果 病毒性脑炎脑内有多发或单发的对称或不对称大片状病灶，主要位于皮层、皮层下及基底节丘脑区，MRI呈长T1 长T2 信号，增强扫描22例，显示病灶强化者11例，其中呈大片状或脑回状强化者7例。

Vein of Galen thrombosis have a special CT and MR appearance,that is symmetric hypodense areas or long-T1 and long-T2 signal of bilaleral thalami,internal capsules and basal ganglias.Thrombus and its changing maybe directly observed on CT and MRI.

Galen静脉血栓有特征性的CT及MR表现，即双丘脑、双内囊及双基底节区对称性低密度影和长T1、长T2异常信号，CT和MR可直接观察栓子及其变化。

Results: This BVTS was caused by bilateral ventromedial thalamic infarctions, the brain MRI showed symmeteic bilateral ventromedial thalamic long Ti and T2 signals.

结果：本病为双侧腹内侧丘脑梗塞引起，MRI上为双侧中线旁丘脑对称性分布的蝶形长T1、长T2信号。

Breath, muscle contraction of the buttocks; arch body, as far as possible to hold his head, right leg straight towards the ceiling (peg-leg knee in order to avoid muscle tension).

呼气，收缩臀部肌肉；拱起身体，尽量抬起头来，右腿伸直朝向天花板（膝微屈，以避免肌肉紧张）。

The cost of moving grain food products was unchanged from May, but year over year are up 8%.

粮食产品的运输费用与5月份相比没有变化，但却比去年同期高8％。