Uhlenbrock MR Imaging of the Spine and Spinal Cord

1. Auflage 2003
ISBN: 978-3-13-257816-6
Verlag: Thieme
Format: EPUB
Kopierschutz: 6 - ePub Watermark

E-Book, Englisch, 528 Seiten, ePub

Magnetic resonance imaging has become an increasingly beneficial tool for the radiologic evaluation of complex spine diseases. However, due to the many variables implicit in MR imaging technique, considerable experience and expertise are necessary to diagnose with confidence.

This book provides a comprehensive and practical overview of the field, and gives you the information to competently utilize MRI for the diagnosis of diseases of the spine and spinal cord.
- More than 1,300 high-quality images help you recognize and distinguish normal findings from pathologic spinal disorders and common MR artifacts - Systematic tables of indications and differential diagnoses summarize each disorder and help you in planning treatment strategies - Problem-solving tips and tricks provide details on various imaging techniques, as well as the advantages and disadvantages of different MRI sequences - Concise chapter summaries provide quick and easy access to the most current MR imaging information

Of great interest to radiologists, neuroradiologists, trauma surgeons, orthopedic surgeons, and neurosurgeons, this extensively illustrated work is an essential diagnostic reference for evaluating spinal disorders.

Zielgruppe

Ärzte

Autoren/Hrsg.

Uhlenbrock, Detlev

Fachgebiete

• Medizin | Veterinärmedizin Medizin | Public Health | Pharmazie | Zahnmedizin Medizinische Fachgebiete Bildgebende Verfahren, Nuklearmedizin, Strahlentherapie Magnetresonanztomographie, Computertomographie (MRT, CT)
• Medizin | Veterinärmedizin Medizin | Public Health | Pharmazie | Zahnmedizin Chirurgie Orthopädie- und Unfallchirurgie

Inhaltsverzeichnis

1 Physics and its Application
2 MRI and Spinal Surgery—Indications Based on the Spectrum of Surgical Therapeutic Options
3 Malformations of the Spinal Canal
4 Degenerative Disorders of the Spine
5 Tumours of the Spine and Spinal Canal
6 Inflammatory Disorders of the Spine and Spinal Canal
7 Use of MRI in Acute Spinal Trauma
8 Vascular Disorders of the Spinal Canal
9 Functional Analysis and Surgery of the Spine in an Open MR System

Leseproben

2 MRI and Spinal Surgery – Indications Based on the Spectrum of Surgical Therapeutic Options R. Schultheiss   Contents   General Comments on Preoperative Diagnostics and Planning Strategy Surgical Management of Spinal Diseases with Reference to MRI Cervical Intervertebral Disk Prolapse Operative technique of anterior operations on the cervical spine Lumbar Intervertebral Disk Prolapse/Degenerative Diseases of the Lumbar Spine Microsurgical technique for lumbar intervertebral disk procedures Recess Stenosis and Spinal Canal Stenosis Technique of decompression for recess stenosis and undercutting decompression for lumbar spinal stenosis Failed Back Surgery Syndrome (Post Diskectomy Syndrome) Spondylolisthesis Spinal Tumors Intraspinal Tumors Extramedullary Tumors Intramedullary Tumors and Syringomyelia Changes at the Craniocervical Junction Technique of anterior odontoid screw fixation Technique of posterior C1/C2 screw fixation and cerclage wiring Technique of posterior craniocervical stabilization Inflammatory Changes Traumatic Changes Communication as a Problem of Diagnostics Summary      General Comments on Preoperative Diagnostics and Planning Strategy In almost all the cases of spinal lesions amenable to surgery, spinal MRI currently allows a very precise diagnosis and guidelines for preoperative planning to be established without direct contact between the patient or examiner and the prospective surgeon. The main indication for spinal MRI is usually to secure a diagnosis. Any question directed to the examiner regarding the possible level and nature of the lesion must be formulated as precisely as possible and include an exact neurological classification of the clinical findings. This is particularly helpful when no pathological finding has been noted on MRI despite unequivocal clinical symptoms. A disturbance of gait, for instance, can be caused by cervical myelopathy, lumbar spinal canal stenosis, normal pressure hydrocephalus, Parkinson's disease, disseminated encephalitis, polyneuropathy, an intramedullary tumor or a bone metastasis to the spine, or a spinal AV fistula—only an exact analysis of the patient's history and the clinical findings will in this case provide the examiner with the necessary data on which to focus the examination technique. It should be borne in mind that an exclusion diagnosis, in particular, can sometimes be technically very demanding. In addition, information from the surgeon's point of view regarding operative strategy, which may not necessarily have been offered for a routine examination, might nevertheless become important. In order to make optimal use of the imaging equipment, thoughts about preoperative planning or additional information on how the indication was reached should, if possible, be available for consideration at the initial diagnostic MRI scanning. The following aspects are of particular interest when a pathological finding amenable to surgery is noted on MRI:   • topographic assignment, • specific diagnostic classification.   Documentation of level and expansion of the lesion must be precise, i.e., it must be possible for the surgeon to take responsibility for counting off each vertebral segment from the spinal sections depicted on the MR image and to transfer the findings on to plain x-rays and intraoperative fluoroscopy. The neck and upper thoracic spine will therefore require depiction of the vertebral landmarks of the craniocervical junction, and inclusion of the sacrum is necessary for the lower thoracic and lumbar spine. For the mid-thoracic spinal region, it is always obligatory to provide a sagittal reference image that includes the sacrum or the craniocervical junction. Assigning and labeling the level of individual vertebrae on the image are only helpful when done electronically by the examiner, thus converting it into a permanent document and rendering it legally binding. Otherwise the image must be repeated in order to assure the necessary reliability of the assigned level. Labels on the film may be accurate, but they do not provide any legally binding basis for the site of the operation because it will never be certain with hindsight whether the labeling was done authentically by the examiner or later—and possibly incorrectly—by some other observer. The operative strategy of the much cited minimally invasive surgery requires, in the first instance, an exact localization—a lateralized spinal meningioma, for example, already demonstrated earlier during laminectomy, which had included the adjacent segments, can only be removed microsurgically by a stability-maintaining hemilaminectomy if it is possible during surgery to locate exactly which hemi-arch is to be removed. It is always compulsory to display spinal disorders in the sagittal and transverse plane, and often preferably in the frontal plane, even though the information value of this frontal slice orientation is limited because kyphosis or lordosis requires an adjustment of the scanning plane for depiction of the spinal canal. It can, however, facilitate orientation in paravertebral lesions of the thoracic and retroperitoneal cavities. Because the plethora of image sections will sometimes require limitation of the final amount of image documentation, it is important that a continuous image series is taken to provide the surgeon with some form of spatial orientation. Omitting seemingly irrelevant images can lead to confusion and faulty assignment of location. Anatomical considerations also play a decisive role when planning the operative approach so that the documented images should allow additional anatomical information to be gleaned as comprehensively as possible and recorded in three dimensions. The choice of slice thickness and of the interval between individual sections will depend on the dimensions of the lesion in question. For example, thin slices in the region of the tumor are decisive for preoperative planning, particularly with intramedullary tumors. With spinal metastases, on the other hand, it is important that virtually the entire spine is depicted to avoid overlooking tumor formations additional to the metastasis responsible for the symptoms. In case surgical stabilization is required, portrayal of the vertebrae adjacent to the lesion will provide enough assurance that these are not affected by the tumor and can be used for supporting the instrumentation. Since, in this case, priority lies more in including contiguous regions, it is advisable to use thicker slicing. It can be helpful if the relevant images of the various scanning planes are combined on one or a few films. However, this is no substitute for the information value provided by a complete series with regard to anatomical considerations relating to preoperative planning. With the increasing significance of neuronavigation in spinal surgery, it will presumably be wise in future, when a finding requiring surgery is noted, to electronically store image data sets for later use by the respective neuronavigation systems after consultation with the potential surgeon. Digital documentation of the image data would be ideal, allowing appropriate evaluation at any time. Paper radiographs would then probably suffice for an overview assessment in cases of more complex lesions, where they might otherwise be limited in their informative value. In view of the number of sections in different planes and sequences, it is helpful if the relevant images are marked with self-stick dots or the like. This can save a considerable amount of time during the overview assessment. The specific diagnostic classification of the observed findings by the examiner is considerably more relevant than with other imaging techniques. While with CT, for example, an interpretation of the images by others poses no problem as a rule, the appreciation of why a particular MR imaging sequence was selected obviously requires additional diagnostic information that is not always available to those foreign to the matter. It is therefore of utmost importance that the examiner specify the degree of differential-diagnostic certainty of a finding. MRI is becoming increasingly important for the emergency diagnostics of acute spinal cord paralysis so that attempts should be made whenever possible to widen the availability of this diagnostic procedure, at least on a regional basis, by allowing examinations to be also performed outside regular office hours. A spinal empyema, an epidural hematoma and a central cervical cord lesion are often difficult, or even impossible, to detect with other techniques; the density of information in a case of metastatic disease of the spine can be enlarged rapidly so as to allow well-founded indications to be defined and, perhaps, even considerations regarding an overall oncological concept to be taken into account. Routine diagnostics of spinal trauma using MRI is still certainly a problem because there are only very limited possibilities of monitoring vital signs during the diagnostic work-up. Nevertheless, it should be remembered that, e.g., the diagnostics of traumatic vascular dissection of the cervical spine, a problem area which up to now has been difficult to diagnose...

Über Autor(innen)

Detlev Uhlenbrock