Clinical frontiers of interactive image-guided neurosurgery. Introduction.
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Computer Graphics↗
Biomedical subjects
M P Heilbrun
Publications and source records attributed to M P Heilbrun.
BSH distributions in the canine head and a human patient using 11B MRI.
A 3D projection reconstruction (3DPR) method was used to obtain in vivo 11B images in a large canine brain tumor model and in a human infused with borocaptate sodium (BSH). Studies were performed in dogs with and without gliosarcomas implanted and grown to a size of 2-3 cm. The 3DPR method demonstrates a signal-to-noise ratio (SNR) that allows qualitative kinetic studies of the boron compound in normal and tumor tissue of the head. The measurements indicate initial uptake of the BSH compound in tumor to be less than that in muscle with no uptake in normal brain tissue. Moreover, uptake of BSH in tissue was found to lag the boron concentration in blood with delays that depend on tissue type. In addition, the first human boron images were obtained on a patient who underwent surgical resection and volumetric debulking of a large (7 cm) glioblastoma multiforme. BSH was readily taken up in residual tumor tissue, while diffusion into the resection volume was slower.
Animals↗
Three-point transformation for integration of multiple coordinate systems: applications to tumor, functional, and fractionated radiosurgery stereotactic planning.
The accuracy of an optimized three-point transformation method and its usefulness for integrating multiple independent coordinate systems has been described. Such integration can be implemented to accomplish complex stereotactic procedures which may require the use of multiple image data sets and combinations of frame-based and frameless stereotactic systems. This report details the application of an optimized transformation for intracranial lesion biopsy and/or resection, radiofrequency pallidotomy for treatment of Parkinson's disease, and fractionated stereotactic radiosurgery in a total of 68 patients. For approach to intracranial lesions, a noninvasive definition of image coordinate systems with multiple radiodense scalp markers was cross-registered with a standard stereotactic guidance system. This method allowed for elective acquisition of stereotactic image sets without requiring head frame fixation until the time of the operative procedure. In planning pallidotomy procedures, spatial cross-registration of CT and MR image coordinates were performed to target the posteroventral pallidum. CT coordinates were defined by the standard picket fence algorithm while MR images were referenced with multiple scalp markers. The addition of MR data sets improved anatomic resolution in the regions of the basal ganglia and commissures. Fractionated radiosurgery was accomplished by cross-registration of CT, MR, and plain radiographs using BRW localizers coupled with multiple scalp markers. A daily check of target positioning was performed with the BRW angiograph localizer. The average calculated error was 2.83 mm with a standard deviation of 1.66 mm which remained within the average scan slice thickness of 3.63 mm. In all cases surgical targets were reached without complication.(ABSTRACT TRUNCATED AT 250 WORDS)
Adult↗
Preliminary experience using an optimized three-point transformation algorithm for spatial registration of coordinate systems: a method of noninvasive localization using frame-based stereotactic guidance systems.
This study describes the use of an optimized three-point transformation algorithm to spatially cross-register a volumetric computerized tomographic scan or magnetic resonance image data set with the coordinate system of a stereotactic frame. This algorithm was tested for accuracy using a scanned phantom in which calculated targets, using the Brown-Roberts-Wells (BRW) frame picket-fence algorithm as a standard, could be compared to physical targets measured using a BRW arc and phantom. These target values were then compared to target values calculated with the optimized three-point algorithm. This method was used for target localization in 21 patients. Following this noninvasive localization method, the standard BRW stereotactic system was used for guidance. The application accuracy of this frameless localization technique was within the limits of the scan slice thickness in 16 of 21 cases, with an average error of 2.11 mm in an average scan slice thickness of 3.1 mm. Intracranial targets were successfully reached in all cases without morbidity or mortality. The algorithm can be customized to cross-register image data sets with the coordinate systems of a wide variety of stereotactic guidance systems. The method increases the convenience and flexibility of frame-based stereotactic guidance by providing a means of noninvasive localization that can be accomplished electively at a separate time from the guidance part of a stereotactic operative procedure.
Aged↗
Stereotactic localization and guidance using a machine vision technique.
Machine vision techniques (video cameras) can be used to determine the three-dimensional position of objects. This transformation can be accomplished with standard mathematical algorithms. Initial accuracy tests of stereotactic localization with video cameras were performed using a standard Brown-Roberts-Wells (BRW) phantom simulator coupled with the BRW angiographic localizer. Localization accuracy was within 1.5 mm. Potential applications of machine vision techniques include freehand stereotactic localization of the position and orientation of surgical instruments. With sufficient computer speed these techniques can be used for continuous monitoring of the position of instruments within the cranial vault.
Brain↗
Estimating energy expenditure in traumatic brain injury: comparison of indirect calorimetry with predictive formulas.
A high degree of variability in energy expenditure has characterized the metabolic response to traumatic brain injury. A goal of parenteral or enteral repletion in this population is the precise estimation of caloric requirement to avoid complications associated with overfeeding and underfeeding. The first aim of this study was to evaluate three predictive formulas for comparison to measured energy expenditure (MEE) derived from indirect calorimetry in patients with traumatic brain injury. A total of 385 measurements were obtained in 102 patients and were compared concurrently with these predictive formulas. The best predictive method in this phase (bivariate regression) yielded r = 0.39 and P less than 0.001 (231 repeated measures). This best prediction, when compared with MEE, however, was able to capture values within 75 to 125% of MEE in only 56% of measurements. The two remaining formulas yielded r = 0.38 (P less than 0.001) and r = 0.23 (P less than 0.001) in 386 and 267 repeated measures, respectively. The second aim of this study was to evaluate the ability of additional nutritional markers to improve predictive ability. Regression analyses were performed on nutritional markers including indices of severity of injury, concurrent drug therapy, vital signs, neurological status, gluconeogenesis, protein synthesis/excretion, and immune response. The statistical results of the analysis on these multiple nutritional markers showed only heart rate, temperature, and number of days elapsed after injury to be significant predictors of MEE by indirect calorimetry in multiple regression analyses (R = 0.32; P less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)
Adult↗
Cerebral granular cell tumor occurring with glioblastoma multiforme: case report.
A 65-year-old man presented with 4 weeks of partial right visual field loss. A left occipital granular cell tumor was diagnosed via open biopsy. No specific tumoricidal therapy was given, and the patient returned 2 weeks later with fluent dysphasia and mild right hemiparesis, and formed visual hallucinations. A large left parietotemporal mass, separate from the granular cell tumor, was diagnosed as a glioblastoma multiforme by stereotactic biopsy. The histogenesis of cerebral granular cell tumors is controversial; this case supports recent speculation of their possible glial origin.
Aged↗
Dynamic field shaping to optimize stereotactic radiosurgery.
A dynamic field shaping collimation system is evaluated for use in stereotactic radiosurgery of non-spherical lesions. The concept is as follows: (a) use the existing circular collimators to define a cone which encompasses the maximum dimensions of the target volume; (b) position two sets of independent rectangular photon collimators immediately upstream from the circular aperture and allow each collimator to have independent translational and rotational motion in order to define, for each increment of arc, a polygonal field shape having up to four straight and four curved edges which enscribe the beam's eye projection of the target; (c) modify the translational and rotational position of each independent collimator with each change in arc angle to continuously shape the instantaneous field to the target shape. A prototype device has been constructed and uses vane control technology developed in a related research project in electron arc therapy. The efficacy of this device is illustrated by dose calculations and measurement based on actual clinical data. Dose volume histograms are used to compare the dose received by three techniques: single isocenter treatment using a single circular aperture, dual isocenter treatment, and single isocenter treatment using dynamically shaped fields. Doses were calculated throughout the brain using a volume grid of 3 mm spacing. Dose volume histograms comparing dose within the target volume and brain volume excluding target volume, as well as computed isodose distributions, demonstrate the possible reduction in normal tissue dose burden while simultaneously preserving dose uniformity throughout the prescribed target volume. This simple four-vane collimation system may provide a viable alternate treatment technique for non-spherical lesions.
Humans↗
Neurosurgery image manager.
Computer technology has become standard in many areas of medical practice, but computer-assisted instruction has not replaced standard textbooks and didactic lectures. This paper describes the development of a computer image-based educational system designed for neurosurgical instruction. The advantages and applications of this system for both clinical and academic use and the required software and hardware requirements are delineated. This computerized tutorial can organize and manipulate large amounts of data. The Neurosurgery Image Manager system contains an introductory help section, a self-assessment test in neurosurgery, and a data base of images from the video disc "The Slice of Life," produced at the University of Utah. Questions are taken from the Self-Assessment in Neurological Surgery series. Additionally, the system contains a reference index for all material in the tutorial, a scored clinical problems section, and a several hundred word glossary. The system is programmed using the Macintosh Hypercard authoring system. Large data bases can be manipulated and linked with graphics, text, and peripherals. Images are stored using the MacVision II digitizing system. The hardware necessary to operate the system and the method of implementation of Neurosurgery Image Manager are described. The prototype Neurosurgery Image Manager has been accepted by the Joint Committee on Education of the American Association of Neurological Surgeons and Congress of Neurological Surgeons as one of the computer formats for the next self-assessment tests.
Computer Graphics↗
Loss of heterozygosity on chromosome 10 in human glioblastoma multiforme.
Recessive mutations, revealed by loss of the wild-type allele, have been associated with the development of a variety of cancers in children and adults. Polymorphic chromosome 10 markers were used to screen paired tumor and lymphocyte DNA samples in 13 patients with glioblastoma multiforme. Ten patients showed loss of constitutional heterozygosity in the tumor samples. This finding suggests that a recessive gene involved in the development of glioblastoma multiforme is present on chromosome 10.
Alleles↗
Stereotactic surgery in children.
Stereotactic biopsy has been popularized over the last decade since the advent of newer, more sophisticated instrumentation and technology. However, less than 300 cases of pediatric stereotaxy are recorded in the literature and few reports emphasize the necessary modifications required in children. Sixty-six stereotaxic procedures were performed on 62 children using the Brown-Roberts-Well (BRW) apparatus at our institutions. The mean age was 9.0 years (range 5 months to 18 years). The indication for the technique was diagnostic in 36 cases and therapeutic in 9 cases; location was a factor in 21 children with the lesion involving a 'deficit-prone' area of the brain. The BRW technique was applicable in 61 procedures (93%). Inability to enter cysts or biopsy of necrotic tissue and tumor capsule occurred in 5 cases. One patient had a transient increase in cerebral edema, for an overall complication rate of 2%. It appears that the BRW stereotactic technique is equally effective in children and adults and will no doubt play an ever increasing role in the future of pediatric neurosurgery.
Adolescent↗
Stereotactic interstitial brachytherapy of malignant astrocytomas with remarks on postimplantation computed tomographic appearance.
Seventeen patients were treated with stereotactically implanted high activity iodine-125 seeds, 12 patients for recurrent malignant astrocytomas (Protocol I) and 5 patients for newly diagnosed glioblastomas (Protocol II). Total radiation dosage to the recurrent tumors in Protocol I, including prior external beam irradiation, averaged 13,500 cGy. In the follow-up period of 6 to 50 months, the survival rate was 93% at 6 months, 60% at 12 months, 50% at 18 months, and 38% at 24 months after implantation. In Protocol II, brachytherapy was used as an interstitial radiation boost to the conventional treatment of newly diagnosed glioblastomas. External beam therapy and interstitial brachytherapy provided 11,000 cGy to these tumors. In the follow-up period of 15 to 27 months, there was a 100% survival at 12 months, 75% at 18 months, and 25% at 24 months after implantation. Eight of our 17 patients required reoperation for persistent or recurrent mass lesions at 6 to 15 months postimplantation; 7 were found to harbor masses of radionecrosis containing nests of anaplastic astrocytes; 1 had frank tumor recurrence. Median survival in this group of patients requiring reoperation was 18.7 months postimplantation. In a review of postimplantation computed tomographic scans, significant mass effect and crossover of hypodensity or enhancement into the corpus callosum or opposite hemisphere were found to have prognostic significance; persistent areas of contrast enhancement and excessive peritumoral hypodensity did not.
Adolescent↗
Improved precision of interstitial brain tumor irradiation using the BRW CT stereotaxic guidance system.
A technique is described which enables precise temporary interstitial volume implantation of brain tumors using a CT stereotaxic guidance system. This technique has the advantages of designing irregular isodose distributions during the preplanning stage. Although the preplanning stage can be time-consuming, this is performed while the patient is in the hospital room and CT scanner time, anesthesia time, and operating room time is minimized for individual patients.
Astrocytoma↗
Behavioural manifestations of third ventricular colloid cysts.
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Biopsy↗
Brown-Roberts-Wells stereotactic frame modifications to accomplish magnetic resonance imaging guidance in three planes.
The Brown-Roberts-Wells (BRW) computer tomography (CT) stereotactic guidance system has been modified to accommodate magnetic resonance imaging (MRI). A smaller head ring, which fits in standard MRI head coils, is constructed of a non-ferromagnetic aluminum ring that is split to prevent eddy currents and anodized to prevent MRI image distortion and resolution degradation. A new localizing device has been designed in a box configuration, which allows BRW stereotactic coordinates to be calculated from coronal and sagittal MRI images, in addition to axial images. The system was tested utilizing a phantom and T1- and T2-weighted images. Using 5-mm MRI scan slices, targets were localized accurately to a 5-mm cube in three combined planes. Optimized calibration of both low field strength (0.3 T) and high field strength (1.5 T) MRI systems is necessary to obtain thin slice (5 mm) images with acceptable image resolution. To date, 10 patients have had MRI stereotactic localization of brain lesions that were better defined by MRI than CT.
Equipment Design↗
Enchondroma of the cervical spine.
Enchondroma is a benign cartilaginous tumor rarely found in the vertebral column. The authors report a case of a 24-year-old woman with upper extremity paresthesias and weakness secondary to bony destruction of multiple vertebral bodies by an enchondroma. The tumor was treated by block excision of the involved vertebral bodies followed by placement of a bone graft.
Adult↗
Real-time three-dimensional graphic reconstructions using Brown-Roberts-Wells frame coordinates in a microcomputer environment.
A desktop microcomputer environment that utilizes Brown-Roberts-Wells (BRW) frame coordinates for creation of three-dimensional depiction of operator-defined intracranial structures has been developed. The system allows direct reading of Siemens CT scan images from a floppy disc, structural edge definition, and reconstruction of defined images. The system is used in the operating room to view scans, perform standard BRW stereotactic functions, and create three-dimensional graphics for such tasks as defining tumor margins, conceptualizing positional relationships of intracranial structures, and radiation planning.
Brain Diseases↗
Computed tomography-guided stereotactic systems.
CT stereotactic guidance systems of modern design provide the neurosurgeon with a precise methodology in approaching intracranial targets. These systems eliminate the potential inaccuracy of freehand approach, no matter how skilled the neurosurgeon. System software which requires no specialized computer expertise has been developed. To accommodate the many requirements of operative manipulation, a total operating system using both standard and innovative surgical instruments has been adapted to the BRW frame. Utilizing the imaging mode for localizing data alone, the system can be used with multiple imaging modes and in multiple locations. Thus, the system can be used for standard methods of functional neurosurgery utilizing ventriculography, new methods of functional neurosurgery using either combined ventriculography and CT or CT alone, and for newer modes of imaging including ultrasound for real-time monitoring of the target lesion during surgery, and target localization using positron emission tomography and nuclear magnetic resonance. It is our belief that CT-guided stereotactic systems could become a standard technique for approaching all intraparenchymal brain targets.
Biopsy↗