Cardiac MR imaging

There has been tremendous progress for MR imaging depiction of cardiac morphology and function. Further advances toward achieving faster acquisition with real-time imaging, higher resolution for plaque imaging, and quantitative analysis are taking place at a rapid pace.     

胼胝体梗死的MRI表现及其诊断价值

目的：探讨胼胝体梗死的MRI表现特征及其诊断价值。方法：在连续2年颅脑MRI检查中搜集569例脑梗死病例．对其中有胼胝体梗死的36例进行回顾性分析。全部病例均行sE与TSE序列T1WI、T2wI扫描，15例加FLAIR序列扫描，l3例行钆喷替酸葡甲胺(GdDTPA)增强扫描。结果：569例脑梗死中36例(6．3％)MRI确诊为胼胝体梗死。其中3例为单纯胼胝体梗死，33例同时伴其它部位脑梗死。36例共45个梗死灶，位于胼胝体膝部19个，体部15个，压部10个，膝体部1个。T1WI呈略低信号26个，低信号19个，T2wI均呈高信号；15例FLAIR序列11例呈高信号，4例呈低信号；13例增强扫描9例强化。结论：胼胝体梗死少见。MRI可清楚显示胼胝体梗死的存在、部位与范围，但缺乏特征性，结合临床及脑内其它部位梗死灶并存可确定诊断。     

颅内髓母细胞瘤术后播散MRI表现

目的 分析颅内髓母细胞瘤(medulloblastoma,MB)术后复发播散的MRI特征,为临床治疗及估计预后提供参考.方法 回顾性分析48例颅内MB术后复发播散患者的临床及影像资料.结果 颅内MB术后播散,MRI表现为线状增厚型35例(72.9%),结节型40例(83.3%),呈单发或多发结节,肿块型14例(29%),弥漫性柔脑膜强化型4例(8.3%).增强扫描所有病例均发现线状增厚、结节状或团块状强化.21例(43.7%)出现不同程度的脑积水征象.结论 颅内MB术后易发生复发播散,MRI增强扫描对诊断、治疗、术后随访及估计预后提供有价值的信息.     

Tuberculous arthritis of the appendicular skeleton: MR imaging appearances

Tuberculosis [TB] of the appendicular skeleton is an uncommon infection caused by the tuberculous bacilli and constitutes only 1-3% of all tuberculosis infections. MR imaging features of tuberculous arthritis include bone marrow oedema, cortical erosions, synovitis, joint effusion, tenosynovitis, soft tissue collections, and myositis. These imaging features are at times non-specific, but in the correct clinical context help in diagnosis of tuberculosis. We present the various pathological manifestations of TB arthritis involving the different joints of appendicular skeleton and discuss their MR imaging appearances.     

胰腺MRI、MRS和MRCP检查与正常表现

MR检查已成为临床上评价胰腺疾病的常用手段.了解不同MR脉冲序列上正常胰腺的影像表现是合理应用扫描序列和识别病变的前提.介绍了胰腺MRI、磁共振波谱和磁共振胆胰管成像检查技术,描述了正常胰腺影像解剖以及不同脉冲序列上胰腺MRI信号变化情况.     

正常胃的MRI表现与扫描技术

目的：研究正常胃的MRI表现和扫描技术。方法：在胃不同充盈状态下，采用单次屏气快速扫描序列，共进行72人次MRI平扫和7次增强检查，分析正常胃的MRI表现和图像质量。结果：按充盈程度不同，胃壁形态可分为扩张不良，适度扩张、充分扩张3型表现。MRI能较好显示胃及其与邻近器官的关系。胃壁厚度平均值在适度扩张下为2．7mm，在充分扩张下为2.4.T2WI图像均无运动伪影，79％的T1WI图像在使用解痉剂后无运动伪影。结论：采用单次屏气快速扫描序列，MRI能获得满意的胃部图像，较好显示胃及其与邻近解剖关系。     

External jugular vein vascular malformation: sonographic and MR imaging appearances

Vascular malformations arising from the wall of the external jugular vein are rare. This case series discusses the sonographic and MR imaging appearances of four such cases and reviews the literature. The diagnosis should be suggested preoperatively particularly because of the close relationship such malformations to the external jugular vein, as this helps surgeons to plan the operative procedure. The imaging appearances are similar to those of other vascular malformations elsewhere in the head and neck.     

Evaluation of nonischemic cardiomyopathies using cardiovascular magnetic resonance

Conclusion  A single CMR examination provides unparalleled information regarding various forms of cardiomyopathy and specifically allows for accurate assessment with regard to etiology and prognosis and helps guide decisions regarding therapy and risk stratification. Given its increasing availability, CMR is likely to play a bigger role in the investigation and risk stratification of patients in the future. Scan times are also shortening, and 3-T scanners now offer better spatial and temporal resolution than ever before.     

Hepatobiliary and pancreatic manifestations of cystic fibrosis: MR imaging appearances.

Magnetic resonance (MR) imaging and MR cholangiopancreatography are useful, noninvasive techniques for the assessment of pancreatic and hepatobiliary complications in cystic fibrosis. Abnormalities of the pancreas in cystic fibrosis are typically characterized by fat deposition, which has increased signal intensity on T1-weighted MR images, and pancreatic fibrosis, which has low signal intensity on both T1- and T2-weighted images. Pancreatic cysts are a relatively common finding; these cysts are typically quite small but are well demonstrated at MR imaging and MR cholangiopancreatography. Pancreatic duct abnormalities are also occasionally seen. Hepatic manifestations range from hepatomegaly and diffuse fatty infiltration to severe cirrhosis with fibrotic change, regenerative nodules, and portal hypertension. Splenomegaly is often characterized by siderotic nodules that manifest as multiple focal areas of abnormal low signal intensity within the spleen. Biliary manifestations include cholelithiasis, stricturization, and narrowing or dilatation of intra- and extrahepatic bile ducts. Gallbladder abnormalities including microgallbladder are also readily demonstrated. MR cholangiopancreatography can be used to help determine the presence and severity of biliary complications without resorting to more invasive procedures and, in conjunction with MR imaging, may prove useful in the assessment of patients with cystic fibrosis who present with abdominal symptoms that suggest hepatobiliary involvement.     

Cardiac rhabdomyosarcoma: diagnosis by MR imaging

We report a case of cardiac rhabdomyosarcoma the initial clinical features of which were pericardial effusion, clinical symptoms of congestive heart failure and probable pulmonary thromboembolism, in which echocardiography constituted the first approach to the diagnosis of cardiac tumor and MRI confirmed it, precisely delimiting the tumoral extension and possible infiltration of pericardiac structures. A brief literature review of this entity is given, the MRI findings obtained in our case are described, and we discuss the advantages and limitations of this technique as compared with other alternatives of image diagnosis. Received: 5 November 1997; Revision received: 6 April 1998; Accepted: 7 July 1998     

Cardiac masses: assessment by MR imaging

The purpose of this study was to assess the role of MR imaging for evaluating suspected cardiac tumors or paracardiac masses involving the heart. Sixty-one patients with clinical or radiologic evidence of cardiac masses were imaged with ECG-gated MR at 1.5 T (22 patients) or 0.15 T (39 patients). Fifty-one patients had echocardiography previously. Among the tissue diagnoses were myxoma (six); fibroma, rhabdomyoma, plasma cell granuloma, lipomatous hypertrophy of the atrial septum, mesothelioma, and thymoma (two each); and leiomyosarcoma, lymphoma, metastatic carcinoid, melanoma, malignant fibrous histiocytoma, hemangiopericytoma, and lung spindle cell sarcoma (one each). MR imaging demonstrated masses in 50 patients (82%); they were centered in the heart in 32, pericardial in nine, and juxtacardiac in nine. MR imaging provided diagnostic information that affected clinical management or surgical planning in 53 patients (87%), including 11 (18%) in whom cardiac mass was excluded by MR. The ability to provide a global view of cardiac anatomy and other unique capabilities of MR imaging give the procedure an important role in the diagnosis and preoperative assessment of cardiac masses.     

Sports-related muscle injuries of the lower extremity: MR imaging appearances

Sports-related injuries of the lower extremity are frequent. Before magnetic resonance (MR) imaging was available, ultrasound, radionuclide scintigraphy and computed tomography were used to evaluate muscle trauma. Although relatively inexpensive, these imaging modalities are limited by their low specificity. The high degree of soft tissue contrast and multiplanar capability of MR imaging, allow direct visualization as well as characterization of traumatic muscle lesions. This pictorial review highlights the spectrum of traumatic muscle lesions on MRI, with emphasis on its typical appearances. Received: 8 May 1998; Revision received: 31 August 1998; Accepted: 23 September 1998