Volume 9, Number 3, Summer (special issue): Neuroradiology: Applications in Neurology and Neurosurgery
Imaging for Neurological Disease: Current Status and New Developments
Stanley van den Noort, Elliot Frohman, and Teresa Frohman, University of California, Irvine
The Journal of Mind and Behavior , Summer 1988, Vol. 9, No. 3, Pages 221 -226 , ISSN 0271-0137, ISBN 0-930195-03-5
Approximately a century ago we were in the process of discrediting phrenology which attempted to predict behavior on the basis of the shape of the skull. With the advent of x-ray it was possible to detect fractures, tumors and infections which altered the structure of bone, and to use the frequently calcified pineal gland as a marker of shifts in the intracranial structures. In the years surrounding World War I we learned to use the introduction of air in the cerebrospinal fluid to achieve x-ray contrast for the definition of intracranial contents. Just prior to World War II came the ability to visualize the arteries and veins of the head by arterial injection of x-ray opaque substances; similar agents were injected into the cerebrospinal fluid. Over time these techniques gained in sophistication and safety but were associated with substantial limitations of accuracy, risk, and discomfort. The advent of computerized tomographic (CT) radiography of the skull and spine in the 1970s provoked a real revolution in the speed, accuracy, and safety of neurological diagnosis. Now magnetic resonance imaging (MRI) provides better accuracy and safety without an improvement in speed. Other technologies beckon and it is hard for any of us to confidently predict the future.
Requests for reprints should be sent to Stanley van den Noort, M.D., Department of Neurology, California College of Medicine, University, of California, Irvine, California 92717.
The Radiological Diagnosis of Primary Brain Tumours
Henry F.W. Pribram, University of California, Irvine Medical Center
The Journal of Mind and Behavior , Summer 1988, Vol. 9, No. 3, Pages 227 -240 , ISSN 0271-0137, ISBN 0-930195-03-5
The investigation of primary brain tumours has changed dramatically as a result of the development of Computed Tomography and Magnetic Resonance Imaging. Computed Tomography can be performed rapidly with little patient discomfort but artifacts degrade images of the posterior fossa. Magnetic Resonance Imaging of the brain is a more sensitive procedure but it is time consuming. In addition not all patients are cooperative enough and some become claustrophobic in the scanner. Patients with cardiac pacemakers, aneurysm clips or intraocular foreign bodies cannot be examined by MRI. These new modalities allow earlier diagnosis with less risk to the patient. The impact of early diagnosis in the treatment of malignant tumours is not clear, but in the case of benign tumours it will reduce the morbidity from operation.
Requests for reprints should be sent to Henry F.W. Pribram, M.D., Professor of Radiology and Neurology, University of California, Irvine Medical Center, 101 City South Drive, Orange, California 92668.
Principles and Applications of Magnetic Resonance Imaging (MRI) in Neurology and Neurosurgery
T.M. Peters, McConnell Brain Imaging Cantre and Montreal Neurological Institute
The Journal of Mind and Behavior , Summer 1988, Vol. 9, No. 3, Pages 241 -262 , ISSN 0271-0137, ISBN 0-930195-03-5
Magnetic Resonance Imaging has evolved from NMR Spectroscopy, a chemical analysis technique developed 40 years ago, into a sophisticated imaging modality which is rapidly becoming a major factor in the diagnosis of brain disease. The technique uses the properties of the interaction of certain spinning nuclei with applied magnetic fields to observe the behavior of these nuclei after being stimulated by radio-frequency radiation. Application of secondary (gradient) magnetic fields allows the spins to be frequency encoded with respect to their position in an object. The radio frequency signals produced by the spinning nuclei are detected and analysed by a computer to form images. The sophisticated high field-strength magnets used in these systems dictate that special provisions must be made for their installation in a hospital environment. Specific examples of MR images are presented with respect to stereotactic surgery planning, diagnosis of Multiple Sclerosis and spinal cord lesions, correlation with other imaging modalities, and in-vivo phosphorous spectroscopy.
Requests for reprints should be sent to T.M. Peters, Ph.D., Room WB-316, Montreal Neurological Institute, 3801 University Street, Montreal, Quebec H3A 2B4, Canada.
Functional Stereotactic Neurosurgery With Magnetic Resonance Imaging Guidance
Ronald F. Young, University of California, Irvine
The Journal of Mind and Behavior , Summer 1988, Vol. 9, No. 3, Pages 263 -272 , ISSN 0271-0137, ISBN 0-930195-03-5
The development of stereotactic surgery has been dependent upon concomitant advances in brain imaging techniques. Human stereotactic surgery effectively began in 1950 with the advent of contrast ventriculography. The anatomy of the third ventricle outlined by ventriculography was used as a reference to determine the location of structures, within essentially normal brains, whose functions could be surgically altered to favorably affect the course of certain neurological diseases. Such functional neurosurgery has been employed most effectively in the treatment of movement disorders such as Parkinson’s disease and for surgery of intractable pain. Unfortunately, ventriculography does not allow direct visualization of the target in the brain to be treated, thus providing inaccuracies in target localization. Functional stereotactic guidance, by computerized tomographic scan data, provides a near direct view of the brain, but lack of resolution and radiation exposure limit its usefulness. Magnetic resonance imaging guidance for stereotactic surgery offers the possibility of improved target visualization and avoids radiation exposure. This report describes the author’s prelimanary experience using the Leksell stereotactic system and magnetic resonance imaging guidance for the performance of functional stereotactic neurosurgery.
Requests for reprints should be sent to Ronald F. Young, M.D., Division of Neurological Surgery, California College of Medicine, 101 City Drive South, University of California, Irvine, California 92668.
Magnetic Resonance Imaging in Neuro-ophthalmology
Edward K. Wong, Jr. and Bradly P. Gardner, University of California, Irvine
The Journal of Mind and Behavior , Summer 1988, Vol. 9, No. 3, Pages 273 -288 , ISSN 0271-0137, ISBN 0-930195-03-5
Magnetic Resonance Imaging (MRI) of the visual system is an important new diagnostic technique used in neuro-ophthalmology. MRI has been used to detect intraocular and orbital pathology complementary to computerized tomographic (CT) scanning and ultrasoundin the resolution of small anatomic structures. MRI has been able to demonstrate with exquisite detail the complete visual and oculomotor pathways, from the eye to the occipital lobe and brainstem. Laboratory studies involving MRI in both in vitro and in vivo designs have attempted to elucidate the underlying biochemical mechanism involved with specific disease processes. This may lead to earlier detection of disease, with the potential for differentiation between specific histopathologic tumor types through noninvasive means. Other studies are involved with high energy phosphate metabolism sodium imaging, and hydration. MRI holds great potential for the future as technology continues to advance with increasing magnetic field strength and better techniques of resolution.
Requests for reprints should be sent to Bradley P. Gardner, M.D., 5453 Lasher Road, Hidden Hills, California, 91302.
Use of Intraoperative Angiography in Neurosurgery
Leslie D. Cahan, California College of Medicine and Grant B. Hieshima, Randall T. Higashida, Van V. Halbach, San Francisco School of Medicine, University of California
The Journal of Mind and Behavior , Summer 1988, Vol. 9, No. 3, Pages 289 -298 , ISSN 0271-0137, ISBN 0-930195-03-5
Neurosurgeons have long recognized that interoperative angiography could be of significant help to guide surgery for aneurysms, vascular malformations and intercranial anastomoses. In recent years, the advent of portable digital subtraction angiography equipment has allowed neurosurgeons to obtain high quality, rapid sequence cerebral angiograms in the operating room. We have used this equipment to verify clip placement on aneurysms, assess the excision of vascular malformations, and to guide injection of liquid adhesive into arteriovenous malformations in the operating room. The expanded use of stereotaxic surgery for functional and tumor work has also been facilitated in recent years by CT and MR scanning. Stereotaxic neurosurgery can be modified to include angiography so that risk of injury to intracerebral vessels will be lessened. Angiographic landmarkscan also be used to define intracerebral structures. In this paper, we will outline the use of intraoperative angiography in open neurosurgical procedures as well as its application to stereotaxic procedures.
Requests for reprints should be sent to Leslie D. Cahan, M. D., Division of Neurosurgery, UCI Medical Center, 101 The City Drive South, Orange, California 92668.
Anatomical Definition in PET Using Superimposed MR Images
Ranjan Duara, Anthony Apicella, David W. Smith, Jen Yueh Chang, William Barker, and Fumihito Yoshii, Mount Sinai Medical Center, Miami Beach
The Journal of Mind and Behavior , Summer 1988, Vol. 9, No. 3, Pages 299 -310 , ISSN 0271-0137, ISBN 0-930195-03-5
Techniques such as PET and SPECT provide tomographic images of function. These images may also represent underlying structure, but to a variable extent, depending on the type of physiological activity that is being imaged. MRI can provide images with exquisite anatomical detail, and can potentially be used to define underlying structure in PET and SPECT images of the brain. In the presence of anatomical distortion of the brain or focal or global atrophy, existing methods for anatomical localization (e.g., stereotactical localization) in functional images are deficient. We have developed a method of superimposing MR images onto PET images in an objective fashion. Using the outermost contour of the two images to derive, mathematically, the center of mass and the major and minor axes, we obtain the translational and rotational parameters to accomplish the superimposition of images. The aspect to this method that requires the most attention to detail is the positioning of the patient in the two tomographic devices and immobilization of the patient during the scans. We have obtained an estimate of error of the superimposition process by performing phantom studies which revealed an overall error of alignment for any poimt in the skull to be 1.54±0.8mm. We have found this method to be convenient and accurate by visual inspection in a variety of patients with dementia. The method also lends itself to such applications as correction of measured isotope concentration for the effects of atrophy and for attenuation correction of emmited photons.
Requests for reprints should be sent to Ranjan Duara, M.D., Section of Positron Emission Tomography, Division of Nuclear Medicine, Mount Sinai Medical Center, 4300 Alton Road, Miami Beach, Florida 33140.
Neuroimaging of Head Injury
Maria Luisa Pasut and Sergio Turazzi, University Hospital, Verona
The Journal of Mind and Behavior , Summer 1988, Vol. 9, No. 3, Pages 311 -350 , ISSN 0271-0137, ISBN 0-930195-03-5
Neuroimaging in head traumatology has received a decisive impulse with the advent of computed tomoography (CT). CT scanning is noninvasive and therefore repeatable as the need arises; it affords direct and accurate visualization of brain damage at all stages, and permits intelligent planning of surgery for expanding lesions, sometimes before such lesions produce neurological deterioration. Also, as a byproduct of more realistic definition of traumatic brain damage, CT scanning has revealed the obsolescence of classic neurotraumatological terminology as well as some reliable correlations between different lesions and final outcome. Cerebral angiography, however, retains its full value in vascular traumatic pathology and the rare cases of traumatic aneurysm, which cannot be detected with certainty by CT scanning. Even newer methods are positron-emission tomography (PET) and nuclear magnetic resonance (NMR), the former yielding valuable information on brain tissue metabolism, the latter being effective in differentiating gray matter from white and estimating their water contents.
Requests for reprints should be sent to Maria Luisa Pasut, M.D., Dipartimento di Neurochirurgia, Istituti Ospitalieri, 37126 Verona, Italy.
Alzheimer’s Disease, Dementia and Down Syndrome: An Evaluation Using Positron Emmissions Tomography (PET)
Neal R. Cutler, Center for Aging and Alzheimer’s and Prem K. Narang, Adria Labs, Columbus, Ohio
The Journal of Mind and Behavior , Summer 1988, Vol. 9, No. 3, Pages 351 -366 , ISSN 0271-0137, ISBN 0-930195-03-5
The assessment of brain metabolism using positron emission tomography (PET) and radioactive tracers holds promise in the differential diagnosis and early detection of various dementing disorders. Such research may also further our understanding of normal aging and of underlying disease mechanisms in pathologic conditions. For example, PET measurement of cerebral metabolic rates for glucose (CMRglc) appears to be a more sensitive indicator of brain changes in Alzheimer’s disease than cognitive and sensory tests. In Down’s syndrome patients, age-related decrements in CMRglc are seen that are consistent with the neuropathologic changes associated with the disease; by contrast, CMRglc appears to be age-invariant in normal subjects. Such assessments have also revealed differences from normal controls among individuals at genetic risk for Huntington’s disease. These findings and other data on brain metabolism rates in the dementing disorders are critically reviewed, and avenues for future research are suggested.
Requests for reprints should be sent to Neal R. Cutler, M.D., 8500 Wilshire Blvd., Lobby Suite, Beverly Hills, California 90211.
Neurotransmitter Receptor Imaging in Living Human Brain with Positron Emmision Tomography
Stephen M. Stahl, Rosario Moratalla and Norman G. Bowery, Merck Sharp and Dohme Research Laboratories
The Journal of Mind and Behavior , Summer 1988, Vol. 9, No. 3, Pages 367 -384 , ISSN 0271-0137, ISBN 0-930195-03-5
New neuroimaging technology can label specific receptors in living human brain with ligands tagged with radio-isotopes, and then anatomically localized and quantitate them with positron emission tomography (PET). This approach requires a multidisciplinary team, including radiochemists who prepare tagged ligands, pharmacologists who develop in vitro and ex vivo techniques for quantitating receptors in experimental animals, and PET experts who adapt these techniques for in vivo study of human subjects. This article outlines the principles of quantitative PET anaylsis by examining the numerous biochemical, kinetic and anatomical methods available for neurotransmitter receptor quantitation in experimental animals, as well as their applications to the study of neurotransmitter receptors in living human brain with PET.
Requests for reprints should be sent to Stephen M. Stahl, M.D., Ph.D., Merck Sharp and Dohme Research Laboratories, Neuroscience Research Centre, Terlings Park, Eastwick Road, Harlow, Essex, CM20 2QR, United Kingdom.
SPECT Imaging in Alzheimer’s Disease
B. Leanard Holman, Brigham and Women’s Hospital, Keith A. Johnson, Massachusetts General Hospital and Thomas C. Hill, New England Deaconness Hospital
The Journal of Mind and Behavior , Summer 1988, Vol. 9, No. 3, Pages 385 -398 , ISSN 0271-0137, ISBN 0-930195-03-5
A number of radiotracers have recently been developed that accumulate in the brain proportional to cerebral blood flow. These compounds are lipophilic, moving across the blood-brain barrier with nearly complete extraction during a single passage through the cerebral circulation. Once inside the brain, they are either bound to nonspecific receptors or metabolized to nonlipophilic compounds. As a result, they maintain this distribution within the brain for some time after injection. The development of these commercially available tracers promises to bring into general medical practice the remarkable diagnostic advances that have been limited to the small number of centers that can afford the costly on-site cyclotrons and technical support required for positron emission tomography. This review will describe the radiopharmaceuticals and instrumentation which may be expected to provide useful clinical information about cerebral perfusion, and will describe the authors’ initial experience with these techniques in memory disorder.
Requests for reprints should be sent to Leonard Halman, M.D., Department of Radiology, Brigham and Women’s Hospital, 75 Francis Street, Boston, Massachusettes 02115.
Ditigal Subtraction Angiography
John R. Hesselink and Steven M. Weindling, University of California Medical Center, San Diego
The Journal of Mind and Behavior , Summer 1988, Vol. 9, No. 3, Pages 399 -414 , ISSN 0271-0137, ISBN 0-930195-03-5
Digital subtraction angiography (DSA) brought the computer into the angiography suite. With it came the capability of rapid subtraction angiography and post processing of the images to optimize image contrast and brightness. DSA is a valuable adjunct to conventional angiography and has added considerable flexibility to the angiographic procedure. Using intravenous techniques, the extracranial carotid and vertebral arteries can be imaged to assess the degree of atheromatous disease with reasonable consistency and accuracy. Arterial DSA can image the intracranial circulation rapidly using smaller doses of contrast material to reduce procedure time and the risk of a complication. DSA is particularly helpful in those patients where severe atheromatous disease or vessel tortuosity preclude selective catheterization. Conventional film angiography remains the gold standard for cerebrovascular imaging.
Requests for reprints should be sent to John R. Hesselink, M.D., Department of Radiology, UCSD Medical Center, 225 Dickinson Street, San Diego, California 92103.