失去肝动脉血液供应后大鼠肝门部胆管周围血管丛变化的三维构像研究

目的 探讨完全失去肝动脉血液供应后，大鼠肝门部胆管周围血管丛（PBP）的形态学变化。方法 将SD大鼠随机分为两组，对照组仅游离胆总管、门静脉、腔静脉和肝总动脉，不做切断；实验组结扎肝动脉，并切断肝十二指肠韧带除门静脉以外的其它组织，阻断其它侧支血管对肝门部胆管的血液供应。术后应用计算机对大鼠肝门部组织切片进行PBP三维可视化构建，并对PBP内层微血管进行定量分析，对胆管壁组织进行病理学检查。结果 实验组肝门部胆管分叉部位PBP平面结构显示胆管扩张，胆管壁明显增厚，壁内微血管尖细，排列紊乱，内层微血管密度减低；PBP立体构像显示空间结构紊乱，不规则，微血管细小，管壁不均匀增厚。与对照组相比，实验组肝门部PBP内层微血管总数明显减少（P〈0．01），肝门部PBP内层微动脉数也明显减少（P〈0．05）。实验组肝门部胆管壁呈慢性增生性炎症改变。结论 失去含氧量高的动脉血液供应时，PBP形态结构将会发生一系列改变，胆管壁组织也将发生相应的病理变化。     

高分辨MRI对颈动脉粥样硬化斑块成分显示的病理对照研究

目的分析和评价高分辨MRI对颈动脉粥样硬化斑块不同成分的显示效果,为颈动脉内膜切除术术前判断斑块稳定性提供参考。方法对26例行颈动脉内膜切除术的颈动脉粥样硬化性狭窄患者术前高分辨MRI 4种不同序列的影像(T1WI、T2WI、PDWI和3D TOF)与斑块标本病理进行逐层对照,分析斑块内不同成分的MRI影像特点。结果获得斑块28块,切为238段,主要分布于颈总动脉和颈内动脉,以复杂斑块为特征的Ⅳ～Ⅴ型58段(24.37%)和Ⅵ型79段(33.19%)为主;斑块内纤维帽主要表现为TOF序列的带状低信号,钙化和纤维化组织分别表现为在各序列影像上的不规则低信号和不特定信号,脂质池和坏死核呈T1WI、PDWI和3D TOF序列的等至稍高信号,近期出血表现为T1WI、T2WI和PDWI序列的明显高信号。结论高分辨MRI不仅可以清晰显示动脉粥样硬化斑块,进行动脉管腔狭窄程度的测定,通过多序列影像联合分析还可以分辨斑块内部不同成分,有助于术前对斑块稳定性的判断。     

Effect of Short-Term Ethanol Feeding on Rat Testes as Assessed by 31P NMR Spectroscopy, 1H NMR Imaging, and Biochemical Methods

31P Nuclear magnetic resonance (NMR) spectroscopy and 1H NMR imaging were used to examine the effect of short-term ethanol feeding on the rat testis. Weanling rats were pair-fed for 10 weeks either on ethanol containing liquid diet (36% ethanol of total calories) or a diet in which dextrimaltose was isocalorically substituted for the ethanol of the alcohol-containing diet. In vivo 31P NMR of the testes was used to determine the intratesticular pH and the relative concentrations of various phosphorus-containing metabolites. The integrity of the blood-testes barrier was evaluated using 1H NMR imaging following a gadolinium diethylene tetramine pentaacetic acid derivative (Gd-DTPA) administration as a vascular contrast agent. After the completion of NMR studies, the testis and the liver were freeze-clamped to allow for the assay of their adenosine-5'-triphosphate (ATP) contents. Serum was assayed for its content of aspartate aminotransferase (AST), alanine aminotransferase (ALT), alcohol and testosterone. Ethanol feeding resulted in the following: (a) a reduction in the body weight (p less than 0.05), (b) a reduction in the testicular phosphodiesters (PDE) PDE/ATP ratio (p less than 0.05), (c) an increased change in the testis image intensity difference between pre- and post-iv Gd-DTPA images, (c) a reduction in the testicular and hepatic content of ATP, and (d) increased serum levels of AST and ALT.(ABSTRACT TRUNCATED AT 250 WORDS)     

Practical selection criteria for unenhanced cranial CT in patients with acute headache

We studied clinical predictors of cranial computed tomography (CT) abnormalities in patients with acute or acutely worsened headache. Data were collected from chart review of 333 consecutive patients presenting to an emergency department and who were clinically selected for cranial CT. Patients with a positive neurologic examination were at 10.7 times greater risk for a positive CT than the rest of the sample (p<1.5 – 10⁻¹⁰). Using only neurologic examination to select patients for CT would have missed 30.3% of the positive scans. The amnesia, depressed sensorium, and hypertension variables had CT yields approximating 10% or greater even in the presence of a negative neurologic examination. Together with a positive neurologic examination, these variables detected 87.9% of the patients in this sample with positive scans; their absence had a negative predictive value of 98.0%. Of the four patients with positive scans who would have been missed using this strategy, one was discharged directly from the emergency department anyway and the other three developed positive neurologic examinations within 24 hours. One died of causes unrelated to the intracranial pathology. Positive neurologic examination, hypertension, history of amnesia, or a depressed sensorium provide reasonable initial guidelines to select for CT patients with an acute headache.     

SARS胸部影像表现与评价(附75例分析)

目的：回顾分析75例严重急性呼吸综合症(SARS)病例，探讨该病影像学表现及其与临床治疗有关的问题。方法：全部75例患者均行胸片检查，一般隔日行影像追踪复查。结果：胸部X线表现为肺实质渗出病灶为主，肺内网状改变及肺门片块影较少。影像表现与临床病程有一定关系。结论：胸部影像表现以肺实质渗出病灶较常见。胸片检查是进行本病诊断和评估病程及疗效的重要方法。     

In vivo fluorescence spectroscopy and imaging of human skin tumours

The feasibility of using in vivo autofluorescence for the diagnosis of skin cancer was evaluated. In vivo fluorescence measurements were performed on healthy human volunteers, and patients with different types of benign and malignant skin tumours. Fluorescence spectra as well as fluorescence images were acquired. The excitation-emission matrix of normal skin (n=3) showed a broad peak at the shortest excitation wavelength (365 nm) and at 440 nm fluorescence wavelength, smoothly decreasing towards longer excitation and fluorescence wavelengths. Non-melanoma skin tumours (n=31) and control skin excited with 375 nm showed a broad fluorescence band from 400 to 700 nm, peaking around 436 nm. No significant differences in measurements between tumours and the corresponding control sites were found. A large spatial variation in the fluorescence intensity was observed both in the tumours and in the control sites. Standard deviations found ranged from 0.15 to 1.5 times the mean fluorescence. Fluorescence images, excited with 375 nm and taken with an image intensified CCD camera, on eight malignant melanomas and eight benign pigmented lesions did not indicate any fluorescence intensity distribution specific to the malignancy of the lesion. Neither the shape of the fluorescence spectra, nor the spatial distribution of the fluorescence intensity showed any signature specific to the histopathological nature of the lesions investigated. Optical diagnostics of skin tumours using the autofluorescence does not seem to be feasible at the present time.     

八例巨大型颈静脉球瘤的影像学研究

目的提高对颈静脉球瘤的影像学认识和诊断。方法对8例经病理明确诊断的颈静脉球瘤的影像学资料进行回顾性分析。结果6例巨大型颈静脉球瘤MRI出现特异型表现,即典型的“盐和胡椒”征;DSA检查不仅能够术前明确肿瘤供血血管,而且同时进行栓塞治疗可减少随后术中出血。结论MRI DSA是巨大型颈静脉球瘤术前最有价值的影像学检查工具。     

弥散张量磁共振成像方法概述

弥散张量成像(diffusion tensor imaging,DTI)是一种根据组织内水分子的弥散特性来探测有机体的微观结构和病理改变的核磁共振成像方法,目前已经成为临床评估和生命科学研究重要的工具。本文结合近年来的文献综述了弥散张量成像的基本原理,列举了目前常用的成像方法,分析了它们的优缺点以及用途,并对弥散张量成像的发展方向作了一些展望。     

女性控尿解剖学机制的MRI研究

目的探讨女性控尿的解剖学机制在MRI（磁共振成像）的表现和观察方法。方法对20例正常控尿的成年女性进行MRI扫描，采用八通道体部线圈、快束自旋回波（FSE）扫描序列进行扫描，采集静息时盆腔横断面、矢状面和冠状面影像。结果MRI显示，女性的尿道分三层结构，与病理学对照，由内向外依次为黏膜及黏膜下组织、肌肉、外膜组织，但无法区分平滑肌与括约肌；与控尿有关的盆底肌肉也能够清楚显示。结论MRI能够清楚观察到女性控尿的有关解剖结构，是观察女性控尿解剖结构的较理想影像方法。     

腮腺间隙良性肿瘤的MRI诊断

目的探讨腮腺间隙常见良性肿瘤的影像特征及其诊断与鉴别诊断。方法良性肿瘤20例，包括多形性腺瘤13例、乳头状淋巴囊腺瘤3例、淋巴管瘤2例、血管瘤1例、脂肪瘤1例。经手术病理证实15例，穿刺活检证实4例，典型MR特征结合病史确诊1例。结果13例多形性腺瘤中有11例位于腮腺浅叶，2例位于深叶；9例表现为均匀等T1长T2信号．4例在T2WI上信号明显不均匀；静脉注射Gd—UIPA后3例瘤实质均匀强化，4例增强后明显不均匀强化。3例Warthin瘤中2例发生于一侧，1例累及双侧腮腺，在T1WI上呈低信号，T2WI上信号等于或低于正常腺实质，增强后无明显强化。2例淋巴管瘤呈明显长T1长T2信号，并有多房现象。1例血管瘤信号不均质，呈明显长T1长T2信号，静1脉注射Gd—DTPA后病变往往显著异常强化。1例脂肪瘤在T1WI及T2WI上均表现为明显高信号强度。结论运用MR成像研究腮腺间隙的良性肿瘤，有利于疾病的定位，有助于病变的诊断与鉴别诊断。