摘要:

Standard anatomy of the spine may be found in anatomy and radiology textbooks. However, there are aspects of spinal anatomy that are of particular importance to magnetic resonance imaging (MRI). The structure and orientation of the facet points and their relationship to the neural foramina receive relatively little attention in standard anatomic works, but they are of great importance in evaluating nerve root compression syndromes. Similarly, the relationships between the cross-sectional diameters of the spinal canal, the subarachnoid space, and the spinal cord assume a great deal of significance when evaluating patients with signs or symptoms of spinal stenosis. Changes in the configurations and composition of the spinal cord will become increasingly important to the radiologists as it becomes possible to identify and distinguish spinal cord grey and white matter. Degenerative syndromes of the spinal cord may be more thoroughly evaluated once MRI permits identification of the specific regions or structures of the cord in which the tissue loss has been most severe.

ISSN:0899-3459    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

Perhaps in no other area of radiology is the appearance of the images as dependent on the technique used to obtain them as is the case in magnetic resonance imaging (MRI). In some instances, such as decreasing signal-to-noise ratios at the periphery of surface coils or obvious difficulties in localizing the level of an abnormality detected in spinal images, the technical dependence is obvious. There are many instances, however, in which the influence of technology may be more subtle, although no less important. It is far less of a problem to have difficulty localizing a level when this difficulty is recognized than it is when ambiguity concerning the level of an abnormality goes undetected. Obsessive attention to accurate localization of levels is necessary to avoid potentially dangerous mistakes. Terms such as “TI weighted” rarely provide an accurate description of the contrast characteristics of an MRI image. Careful use of terminology, or at a minimum clear thinking concerning the determinants of image contrast will avoid confusion in image interpretation. The “weighting” of an image usually cannot be defined in terms of a single parameter, and attempts to do so often obfuscate more than they clarify. As technology evolves, a variety of different “TI-weighted” pulse sequences may be introduced. Each of these may display different contrast characteristics. It will be important to identify the specific pulse sequence, rather than “weighting” to understand the signal intensities observed on images.

ISSN:0899-3459    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

Evaluation of degenerative disk disease is, by far, the most common indication for spinal magnetic resonance imaging (MRI). It is rare to identify a patient over the age of 40 whose spine does not demonstrate at least some of the imaging features of degenerative disease. In spite of the ubiquitous nature of degenerative changes in the spine and decades of intensive study of degenerative processes, many questions concerning degenerative disease, including its immediate etiology, remain unanswered. Radiologic evaluation of degenerative spine disease focuses on the anatomic relationship between the disk, vertebral endplates and facet joints with the subarachnoid space, nerve roots, and spinal cord. Although MRI lacks the detail of high resolution computed tomography for defining the anatomy of osteophytes. MRI appears to be the primary modality for evaluating degenerative spine disease, and in most cases, MRI may be definitive.

ISSN:0899-3459    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

Spinal neoplasms may be primary or metastatic, benign or malignant. In adults, metastatic involvement of the spine will represent the most important neoplastic disease of this region. However, hemangiomas are the most common spinal neoplasms. The vast majority of intradural, extramedullary neoplasms that will be identified in the spine are meningiomas and neurobromas. Both lesions may be sporadic or associated with phakomatoses. Intramedullary spinal cord and filum terminale tumors are relatively rare and are far less common than intramedullary brain tumors. As is the case in the brain, these are overwhelmingly glial neoplasms, with ependymomas and low-grade astrocytomas representing the majority of the lesions. Hemangioblastoma deserves mention because of its often characteristic imaging findings and its association with von Hippel-Lindau disease.

ISSN:0899-3459    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

Demyclinating lesions of the spinal cord, including multiple sclerosis, as well as other less common diseases, probably represent the etiology of a substantial proportion of all idiopathic myelopathies. Magnetic resonance imaging (MRI) has made major advances in the diagnosis and characterization of demyclinating disease. Infections of the spine may have severe consequences and, if detected early, are usually treatable processes. Osteomyelitis and epidural abscesses have characteristic imaging findings. Poor outcomes are more often due to delays in clinical presentation or the debilitated condition of the patients than to limitations in the accuracy of MRI diagnosis. Cavitary lesions of the spinal cord were among the first applications in which MRI proved its superiority to previously available techniques. Accurate diagnosis of these lesions involves detecting characteristics findings and relating these observations to the clinical history. Spinal cord infarction is relatively rare due to the extensively collateralized blood supply to the spinal canal. However, aortic aneuryms and the surgery for these lesions places the blood supply of the distal spinal cord and conus at risk. The syndrome of postoperative spinal cord infarction has characteristic clinical findings. However, MRI may contribute to distinguishing transient ischemia from true infarction and to predicting the severity of the final deficit.

ISSN:0899-3459    

出版商:OVID    

年代:1992

数据来源: OVID

ISSN:0899-3459    

出版商:OVID    

年代:1992

数据来源: OVID

ISSN:0899-3459    

出版商:OVID    

年代:1992

数据来源: OVID