Showing papers by "Peter C. Burger published in 1984"

Suprasellar papillary squamous epithelioma (papillary craniopharyngioma)

Abstract: Six cases of a distinctive suprasellar papillary neoplasm are presented and the features of this lesion are contrasted with those of the classical adamantinomatous craniopharyngioma. Characteristics distinguishing the former from the latter include a predominate, and perhaps exclusive, occur

Scanning electron microscopy of vascular casts

Abstract: Corrosion casts provide three dimensional replicas that can be examined readily by scanning electron microscopy (SEM). They are prepared by filling vascular networks with polymerizing plastic and then digesting away the tissue. As based on our studies of ocular vessels, this report describes the vascular anatomy, as well as the artifacts, that are encountered during SEM studies of such preparations.

CT-guided stereotactic biopsies using a modified frame and Gildenberg techniques.

Abstract: Eighteen patients underwent CT guided stereotactic biopsies using either a Riechert-Mundinger stereotactic frame modified for use in the CT scanner or the CT-based intracranial landmark technique of Gildenberg and a Todd-Wells frame. In seven patients undergoing biopsy with the modified frame technique, representative tissue samples were obtained in all cases. Eleven patients had biopsies using the Gildenberg technique and representative tissue samples were obtained in 10 of the 11. No major postoperative complications occurred in either group. Both techniques allowed samples of intracranial tissue to be obtained safely and efficiently. The modified frame technique provided a higher degree of accuracy while the Gildenberg technique required significantly less CT time and provided a satisfactory degree of accuracy. In seven patients with ring enhancing lesions, biopsies of the enhancing rim provided diagnostic tissue while biopsy of the central low density center of the lesion in three patients provided necrotic material which was useful in histologically grading the tumour.

Examination of the extracranial carotid bifurcation by thin-section dynamic CT: direct visualization of intimal atheroma in man (Part 1).

Abstract: Because carotid angiography has been shown to have limitations in the detection of intimal disease at the bifurcation, a new method of examination of the extracranial carotid artery has been developed using thin-section dynamic computed tomographic (CT) scanning. Carotid atheroma and thrombi can be imaged directly on these sections. The intimal lesions are uniformly hypodense with respect to the carotid arterial wall. Radiologic-pathologic correlation studies using human carotid arteries in a neck phantom confirm that these hypodense lesions are atheromas or thrombi. There is good correlation between CT cross-sectional images and cross-sectional postmortem artery sections. While a number of new computer-based methods of reformation of the carotid artery have been developed, consecutive thin slices through the carotid bifurcation display the pathologic lesions satisfactorily.

Preparation of biological tissue sections for correlative ion, electron, and light microscopy

Abstract: In order to correctly interpret the chemical images obtained using ion microscopy (IM), it is useful to correlate them with the information provided by conventional light microscopy (LM), secondary electron imaging (SEI), backscattered electron imaging (BEI), and electron probe microanalysis (EPMA). Accordingly, we have devised a technique of specimen preparation which allows for the application of several different microanalytical techniques to a single histologic section mounted on the same substrate. Sections are cut onto polyester plastic coverslips (devoid of peaks for any element with atomic number > 9 using EPMA) and studied by LM. After a light rotary coating with carbon (to prevent charging), the section can then be examined by SEI, BEI, and EPMA. Specific areas can be marked for IM study either with an objective-mounted pin tissue microlocater, or by placing small pieces of metal foil, cut in specific geometric shapes, over features of interest. After sputter-coating the sample with platinum, metal-free shadows are visible using a low-power reflected light microscope available on a typical IM sample chamber as a guide for ion beam placement. The conductive coatings also minimize specimen charging during IM. Post-IM light microscopy, SEI, and BEI are used to confirm the location of specific areas probed in the IM experiments and to provide information on differential ion-sputtering artifacts and tissue contaminants. This new correlative technique should permit better understanding of the images obtained with these diverse instruments.

The glioblastoma multiforme and the metastatic carcinoma: a morphometric study of nuclear size and shape.

Abstract: Thirty-one surgically excised glioblastomas multiforme (GBM) and 34 intracranial metastatic carcinomas were studied morphometrically to determine the confidence with which these two common lesions can be distinguished on the basis of their nuclear sizes and shapes. Planimetry was used to characterize the nuclei in these lesions and two primary variables were calculated: (1) the mean nuclear size and (2) a measure of roundness, the mean 'form PE'. The two neoplasms were then compared by logistic regression which calculated the coefficients of two equations expressing the probability that each of the 65 lesions was a GBM. There were significant differences between the two lesions (p = 0.001 or less) in both nuclear size and shape. The nuclei of the GBM were smaller and less round. The first logistic regression equation utilized mean nuclear size and mean form PE and 'correctly' classified 26 of the GBM and 30 of the carcinomas. The second equation utilized mean nuclear area and the coefficient of variation of nuclear area. Only 6 neoplasms, 3 metastatic carcinomas and 3 GBM, were 'incorrectly' classified. The results suggest that there are significant differences in nuclear size and shape in these two lesions and that these differences are amenable to morphometric and statistical study. Similar predictive equations should be tested as potential diagnostic aids.

Opacification of epidural venous plexus and dura in evaluation of cervical nerve roots: CT technique.

Abstract: Thin-section computed tomography (CT) after bolus high-volume, intravenous contrast enhancement of the cervical epidural and intervertebral foraminal venous plexus was undertaken in eight patients. Visualization of exiting cervical nerve root by opacification of the surrounding intervertebral plexus was evaluated in 38 foramina. Visualization was judged as excellent in 77% and good in 21%. Thus the nerves were seen satisfactorily in all but one foramen. As the CT scan parallels the long axis of the cervical roots as they pass through the intervertebral foramen, anatomic delineation of the root out to the level of the vertebral artery is excellent. A local widening of the root, which was thought to represent the dorsal root ganglion, was seen in most foramina examined. Excellent filling of the epidural plexus was seen in seven of eight subjects; good opacification was seen in the other subject. In no instance did the study fail to satisfactorily fill the epidural plexus in the cervical vertebral canal. This technique appears to be an excellent method for evaluating the cervical nerve roots and the epidural space.