早期脑缺血MR灌注成像的实验研究

目的 应用脑灌注ＭＲＩ技术研究早期脑缺血缺血血流动力学改变并探讨其临床应用价值。     

硬膜下血肿的MRI诊断(附30例报告)

目的：评价ＭＲＩ对硬膜下血肿的诊断价值。方法：回顾分析３０例各期硬膜下血肿的ＭＲＩ表现。结果：１０例（３３．３％）为双侧同时发生硬膜下血肿。血肿多呈“新月形”，呈“双凸形”者，在冠状位，横轴位及矢状位观察分别为１４，４和６例。血肿急性期（≤２ｄ）呈等Ｔ１长Ｔ２信号；亚急性（３～１４ｄ）及慢性期（＞１４ｄ）呈短Ｔ１长Ｔ２信号，部分中心可见少许等Ｔ１信号。结论：ＭＲＩ检查各期硬膜下血肿均有明显的阳性改变，且慢性期血肿在ＣＴ上呈等或低密度，故笔者认为硬膜下血肿应首选ＭＲＩ检查。     

脑梗塞的MR弥散加权成像

ＭＲ弥散加权成像是诊断早期脑梗塞最有前途的方法之一，并有可能区分可恢复脑组织与不可恢复脑的组织。本介绍这项技术的成像原理、动物实验结果和初步的临床应用。     

MR扫描序列优化组合诊断脑出血的实验研究

目的:初步探讨MR敏感扫描序列在诊断超急性期和急性期脑血肿中的应用价值.方法:32只健康家兔随机分为2组(实验组24只,对照组8只).实验组动物利用兔自身血注入形成脑血肿,分时间点(术后3、6、12、24和48 h)进行MR扫描,扫描序列包括T1WI、T2WI、T2*WI和扩散加权成像(DWI),并与各时段组织学表现进行对照分析.结果:血肿形成后每个时段T2*WI均可清晰显示脑内血肿,表现为低信号,边界清.利用容积测量软件测量实验组T2*WI上脑血肿体积,平均值为(310±19)μl,平均注血量为(250±20)μl,两者差异无显著性意义(t=0.003,P＜0.05).各时间点脑血肿在DWI上表现为中心低信号,周围有高信号环.脑血肿在T1WI、T2WI上信号无特征性,边界欠清.组织学检查显示6 h以后可见血肿周围有中性粒细胞和少量小胶质细胞浸润,12 h后可见血肿中心少量红细胞开始溶解.对照组各实验对象在组织学和MRI图像上均未见脑血肿形成.结论:T2*WI、DWI序列对诊断超急性期和急性期脑内出血的敏感性较高,结合常规扫描序列(T1WI和T2WI)对诊断超急性期及急性期脑血肿具有一定临床应用价值.     

慢性扩展性脑内血肿MRI诊断

目的探讨慢性扩展性脑内血肿(chronic expanding intracerebral hematoma,CEICH)的MRI表现。方法回顾性分析5例经手术及病理证实的CEICH患者的MRI资料。结果 5例中,3例为动静脉畸形,2例为小海绵状血管瘤,包膜内有不同时期的血肿;T2WI、磁敏感加权成像(SWI)、扩散加权成像(DWI)分别可见高低信号形成的液-液平面,完整光滑的囊壁,囊壁内外的流空血管影;增强扫描示邻近脑质点状异常强化影;周围脑实质轻度脑水肿。结论 CEICH的MRI表现具有一定特点,结合增强扫描、SWI、DWI,可以提高其诊断水平。     

超急性期脑内血肿的超低场MRI表现

目的　探讨超急性期脑内血肿的超低场MRIT1 WI表现特点。方法　 160例超急性期脑内血肿行 0 .0 4TWDLMW -4 0 0MR机扫描 ,选用PS3DT1 WI(TR =12 5ms,TE =2 5ms)。结果　基底节出血 14 0例 ,脑叶出血 5例 ,小脑出血 13例 ,脑干出血 2例。 160例在PS3DT1 WI上均呈明显短T1 信号 ,并可见血肿的占位效应及血肿周围的水肿。结论　超急性期脑内血肿在超低场MRI诊断优于中高场MRI。     

串联线圈大鼠MR成像的初步应用研究

目的 探讨串联线圈进行大鼠3.0 T MR扫描的效果.方法 应用研制的串联线圈与随机所配的3个线圈,分别对自制的水溶液模型运用相同的快速恢复快速自旋回波序列(FRFSE-XL)进行扫描,选择4组图像中同一位置的层面,采用单幅图像测量信噪比(SNR).12只SD大鼠平均分为3个模型组和1个正常组.运用FRFSE-XL序列、快速扰相梯度回波(FSPGR)和多体素波谱(Probe-SI)序列,分别对大鼠脑损伤、脑氢质子MR波谱(1H-MRS)、脊髓损伤(SCI)和大鼠腹部进行了初步应用研究.结果 串联线圈的SNR(39.7)比随机所配的3个线圈中SNR(6.41)最好的膝关节线圈高出6倍以上.大鼠颅脑损伤的T2WI和T1WI能清楚分辨灰质和白质,很好地显示脑室的结构和血肿的位置及大小.注射6-羟基多巴胺(6-OHDA)2周后,大鼠脑部1H-MRS能显示氮-乙酰天冬氨酸/肌酸(NAA/Cr)的比值减小(注射6-OHDA前为1.240,注射2周后为0.781).大鼠胸髓T2WI可清楚显示卵圆形的脊髓,显示"H"形脊髓白质;大鼠SCI模型T2WI清楚显示大鼠胸部脊髓损伤的部位和程度.大鼠腹部扫描,FSPGR序列T1WI时间为8 s,有利于克服呼吸等运动的影响,清楚显示大鼠腹部的结构.结论 应用3.0 T MR结合串联线圈为活体大鼠模型的MR检查提供了很好的方法.     

脑血肿在低场MR中影像演变规律的研究──动物脑血肿模型观察结果

目的：了解脑血肿在低场ＭＲ中的影像演变规律。材料与方法：制作动物（狗）脑血肿模型共５个，３个为小模型，２个为大模型，按计划扫描。ＭＲ仪场强为０．０６４Ｔ。结果：与中高场ＭＲ仪结果相比较，急性期血肿于所有序列信号均较高，Ｔ２ＷＩ未见到低信号征象。慢性期末见低信号环。残腔期呈Ｔ１长Ｔ２信号，未见＂黑腔＂。此两期出现时间提前。超急性期表现与中高场机所见基本相同。仅１个大模型的亚急性期表现为＂周高中低＂信号，且存在时间较短。结论：脑血肿在低场强ＭＲ中的演变规律与中高场强机大体一致，不同之处主要在急性期、慢性期和残腔期的信号表现。造成的原因主要是Ｔ２ＰＲＥ效应与磁场强度有关。动物脑血肿模型更适用于早期血肿的研究。     

大鼠骨髓间充质干细胞磁标记及MR成像研究

目的应用菲立磁．多聚左旋赖氨酸复合物标记大鼠骨髓间充质干细胞，探讨MR成像显示磁标记干细胞的可行性。方法制备菲立磁-多聚左旋赖氨酸复合物。分离培养Wistar大鼠骨髓间充质干细胞，以菲立磁-多聚左旋赖氨酸复合物标记干细胞。分别于标记后24h及1、2、3周行普鲁士蓝染色观察细胞内铁，台盼蓝排除试验检测细胞活力。应用1．5TMR仪，以SE序列T1WI、T2WI和梯度回波（GRE）序列T2＊WI行磁标记干细胞成像。结果普鲁士蓝染色显示细胞质内大量铁颗粒存在，标记率100％；随细胞分裂增殖，细胞内铁颗粒逐渐减少。干细胞磁标记后24h及1、2、3周的台盼蓝拒染率分别为91．00％、93．00％、91．75％和92．50％，与未标记细胞相比较差异无统计学意义（P〉0．05）。10^3、10^4、10^5个磁标记干细胞T2WI信号降低分别为63．75％、82．31％、91．92％，T2＊WI信号降低分别为68．24％、83．01％、93．94％。10^5个干细胞磁标记后24h及1、2、3周T2＊WI信号降低分别为93．75％、75．92％、41．75％、8．83％。结论应用菲立磁-多聚左旋赖氨酸复合物标记大鼠间充质干细胞安全、有效；T2＊WI对磁标记干细胞的显示最敏感；MR信号改变与干细胞数目及分裂增殖状态相关。     

大鼠肝癌模型LAC-BSA-SPIO增强MR成像研究

目的：探讨LAC-BSA-SPIO对检出肝脏病灶,尤其是微小病灶的潜在价值及其对病灶良恶性鉴别诊断的价值。方法：建立大鼠肝硬化肝癌模型,分别测试LAC-BSA-SPIO最佳注射剂量和最佳扫描时间。28只大鼠MRI平扫序列为SET2map、FSET2WI、SET1WI、FRFSET2WI、GRE、3DFIESTA、SWI,注射LAC-BSA-SPIO（50μmolFe/kg）后30min行增强扫描。结果：成功建立大鼠肝硬化肝癌模型28只,共检出≥2mm的病灶63个,包括36个为肝细胞癌（HCC）,19个腺瘤性增生结节（AHN）,8个炎症性肌纤维母细胞瘤（IMT）。CNR最高的是50μmolFe/kgLAC-BSA-SPIO组;CNR最高的是30min组。增强扫描后AHN、IMT和HCC之间的T2值差异有显著性意义（P〈0.05）。SNR下降最明显的依次是GRE、3DFIESTA、FSET2WI、FRFSET2WI。在所有的序列上,HCC、AHN、IMT增强扫描前后的CNR差异均有显著性意义,所有序列增强扫描前后的差值在HCC、AHN、IMT之间差异有显著性意义（P〈0.05）。结论：LAC-BSA-SPIO有助于提高肿瘤-肝脏的CNR,对于肝硬化性肝癌的病灶有较高的鉴别诊断价值;最佳剂量为50μmolFe/kg,最佳扫描时间为静脉注射后30min。     

Meniscal hematoma of the knee joint: a case report

We report here an unusual case of medial meniscal hematoma of the knee joint. A review of the literature has revealed only one case that was previously reported. The authors present the successful decompression of the posterior horn of a medial meniscal hematoma through the direct posterior–posterior triangulation arthroscopic visualization method. We present here the case report.     

小儿急性颅内血肿(附105例分析)

1958～1985年我院收治小儿急性颅内血肿105例。男78例,女27例。年龄自5个月至5岁。头部外伤占93.3％,脑血管畸形及肿瘤卒中占3.8％。硬膜外或硬膜下血肿85例(80.9％),余20例(19.1％)系多发或脑内血肿。多有颅压增高与脑受压征象,癫痫的发生率占25.7％。103例采取钻孔或骨瓣开颅清除血肿,2例经前囟穿刺抽出积血。手术结果,痊愈90例(85.7％),死亡11例(10.5％)。作者认为,对本病应早期诊治,并预防手术中发生休克与衰竭。     

主动脉壁内血肿的影像学诊断

目的 分析总结主动脉壁内血肿(AIH)的影像学特点。资料与方法 回顾8例影像学资料完整的AIH病例，分析其胸部X线平片、CT、MRI及血管造影特点。结果 8例AIH，1例累及升主动脉根部至腹主动脉远端，1例累及主动脉弓及降主动脉，6例累及降主动脉和／或腹主动脉，其中2例为降主动脉近中段动脉粥样硬化斑块穿通溃疡(PAU)形成局部AIH。胸部X线平片、增强CT、MRI及血管造影均可见阳性征象，CT、MRI直接观察到病变程度及累及的范围。结论 CT和MRI是确诊AIH的最主要检查手段。     

Intrathecal injection of epidural blood patch: a case report and review of the literature

Epidural blood patch (EBP) is a commonly performed procedure for the treatment of persistent severe post- dural-puncture headache (PDPH). It has a high success rate with a low incidence of complications. We report the case of a 27-year-old woman who developed progressive back pain and radicular symptoms after an EBP was performed for PDPH. An emergency MRI showed a subarachnoid hematoma. Gradual recovery occurred without the need for intervention. To our knowledge, this is the only case demonstrating the MRI findings of a rare complication of a common procedure. Radiologists may benefit from familiarity with epidural blood patching, including the technique, risks, benefits, and potential complications     

Intracranial hemorrhage: principles of CT and MRI interpretation

Accurate diagnosis of intracranial hemorrhage represents a frequent challenge for the practicing radiologist. The purpose of this article is to provide the reader with a synoptic overview of the imaging characteristics of intracranial hemorrhage, using text, tables, and figures to illustrate time-dependent changes. We examine the underlying physical, biological, and biochemical factors of evolving hematoma and correlate them with the aspect on cross-sectional imaging techniques. On CT scanning, the appearance of intracranial blood is determined by density changes which occur over time, reflecting clot formation, clot retraction, clot lysis and, eventually, tissue loss. However, MRI has become the technique of choice for assessing the age of an intracranial hemorrhage. On MRI the signal intensity of intracranial hemorrhage is much more complex and is influenced by multiple variables including: (a) age, location, and size of the lesion; (b) technical factors (e.g., sequence type and parameters, field strength); and (c) biological factors (e.g., pO2, arterial vs. venous origin, tissue pH, protein concentration, presence of a blood-brain barrier, condition of the patient). We discuss the intrinsic magnetic properties of sequential hemoglobin degradation products. The differences in evolution between extra- and intracerebral hemorrhages are addressed and illustrated.     

The role of aortic wall CT attenuation measurements for the diagnosis of acute aortic syndromes

Objectives

To determine if measurements of aortic wall attenuation can improve the CT diagnosis of acute aortic syndromes.

Methods

CT reports from a ten year period were searched for acute aortic syndromes (AAS). Studies with both an unenhanced and a contrast enhanced (CTA) series that had resulted in the diagnosis of intramural hematoma (IMH) were reviewed. Diagnoses were confirmed by medical records. The attenuation of aortic wall abnormalities was measured. The observed attenuation threshold was validated using studies from 39 new subjects with a variety of aortic conditions.

Results

The term “aortic dissection” was identified in 1206, and IMH in 124 patients’ reports. IMH was confirmed in 31 patients, 21 of whom had both unenhanced and contrast enhanced images. All 21 had pathologic CTA findings, and no CTA with IMH was normal. Attenuation of the aortic wall was greater than 45 HUs on the CTA images in all patients with IMH. When this threshold was applied to the new group, sensitivity for diagnosing AAS was 100% (19/19), and specificity 94% (16/17). Addition of unenhanced images did not improve accuracy.

Conclusions

Measurements of aortic wall attenuation in CTA have a high negative predictive value for the diagnosis of acute aortic syndromes.     

A hematoma of the esophagus causing the trachea to stenose

We report a case of spontaneous intramural hematoma of the esophagus (SIHE) with severe dyspnea due to compression of the trachea. SIHE is a rare hematoma that commonly presents with chest pain, epigastralgia, hematemesis, and dysphagia. Dyspnea is not a common symptom; it has been reported in only one patient, who underwent surgery. In our case, intubation of the compressed trachea prevented it from becoming more stenosed, and an operation was not needed. Another unusual feature of this case is the endoscopic findings. Endoscopic examination in SIHE has often revealed the presence of a dark red, bluish, or purplish bulge, suggesting the presence of a clot or blood in the esophageal wall. In our case, the bulge revealed by endoscopy in the esophageal lumen was white at first, before later turning dark red. Electronic Publication     

FDG-PET imaging for chronic expanding hematoma in pelvis with massive bone destruction

Chronic expanding hematoma is a rare presentation of a hematoma characterized by a persistent increase in size for more than a month after the initial hemorrhage. We present a 65-year-old man with a chronic expanding hematoma in his ilium who was receiving anticoagulant treatment. The patient had a delayed manifestation of a femoral neuropathy with massive bone destruction. 2-Deoxy-[¹⁸F]fluoro-d-glucose (FDG) positron emission tomography (PET) imaging revealed an increased uptake in the rim of the mass in images acquired 1 h after FDG injection. FDG-PET scans were performed using a dedicated PET scanner (HeadtomeV/SET2400 W, Shimadzu, Kyoto, Japan), and the PET data for the most metabolically active region of interest (ROI) were analyzed. The maximum standardized uptake value (SUVmax) was set to a cut-off point of 3.0 to distinguish between benign and malignant lesions. The SUVmax of the patient’s lesion was 3.10, suggesting a malignant lesion. The characteristics of FDG-PET images of chronic expanding hematomas, including the uptake of FDG in the peripheral rim of the mass as a result of inflammation, should be recognized as a potential interpretive pitfall in mimicking a sarcoma.     

纵隔血肿的 CT诊断

目的 分析纵隔血肿的CT表现,以提高其诊断水平。资料与方法 回顾性分析19例经临床、手术证实的纵隔血肿资料。结果 前纵隔血肿8例,其中片状血肿6例,结节状血肿1例,团块状血肿1例;中纵隔血肿2例,均呈结节状;后纵隔血肿4例,其中片状血肿2例,团块状血肿2例;弥漫性纵隔血肿5例,均呈片状。结论 心脏大血管的损伤往往导致弥漫性纵隔血肿,小血管损伤导致的纵隔血肿大多比较局限。CT扫描对于纵隔血肿的诊断具有重要价值。     

急性创伤性胸壁血肿（附50例报告）

本文报告了急性创伤性胸壁血肿５０例。右侧２２例，左侧２７例，胸骨体内壁血肿１例。共有血肿５９个，（其中９例出现２个血肿）。血肿出现多在骨折处。４７例为两根以上多发性肋骨骨折，但亦有２例无肋骨骨折。对胸壁解剖特点及血肿形成机制、ｘ线表现及其临床意义进行了讨论。并将血肿分为三种类型：（１）胸壁内型；（２）胸壁外型；（３）双向型。