John R. Bentson

Steroids and apparent cerebral atrophy on computed tomography scans.

Computed tomography scans of 15 long-term steroid users showed varying degrees of apparent cerebral atrophy, not expected at their ages (8 to 40 years). Most were suffering from autoimmune diseases. There appeared to be some correlation between dosage and degree of apparent atrophy. There was surprisingly little clinical evidence of cerebral dysfunction associated with this apparent atrophy. In two of the cases, the appearance of the brain improved following decrease or cessation of steroid use. Speculations are made on possible causes.

Cerebral venous drainage pattern of the Sturge-Weber syndrome.

Carotid angiographies of 11 patients with Sturge-Weber syndrome revealed cerebral venous abnormalities in each. An abnormal cerebral venous drainage pattern was found, consisting of lack of superficial cortical veins and associated nonfilling of the superior sagittal sinus, enlargement and tortuosity of the deep subependymal and deep medullary veins, and occasionally bizarre courses of cerebral veins. The basis of the pattern appears to be nonfunction or absence of cortical veins beneath the Sturge-Weber leptomeningeal angiomatosis, with collateral flow centrally to the subependymal veins.

Blunt trauma to the high cervical carotid artery

Closed injuries to the neck, occasionally associated with mandibular fractures, can result in trauma to the internal carotid artery at the high cervical level opposite the uppermost cervical vertebrae. Such arterial injuries range from spasm to intimal tear with thrombus formation, medial tear, and aneurysm formation. These types of lesions may overlap. Ten patients are presented, five with traumatic carotid occlusions and five with traumatic aneurysms. The clinical diagnosis of traumatic cervical carotid occlusion may be difficult because of the absence of physical trauma to the neck. The diagnosis of aneurysm poses fewer problems. Oculopneumoplethysmography, computerized tomographic head scanning, and carotid arteriography with cross compression are the most useful diagnostic techniques. Thrombectomy should be carried out early, particularly in the presence of fluctuating neurological signs. Aneurysms that cannot be approached directly may necessitate carotid ligation.

Anatomical Localization Schemes for Use in Positron Computed Tomography Using a Specially Designed Headholder

A headholder system is described for use in the correlation of images obtained with positron computed tomography (PCT) and other neuroradiological imaging modalities. Methods are described for defining brain anatomy from PCT images by the use of projection schemes from tomographic data. Cross-correlation of images between positron CT and standard lateral skull films, X-ray computed tomography (XCT), and two-dimensional rectilinear positron images are discussed. Such methods allow for improved reproducibility of head positioning and more precise cortical localization necessary in studies of normal brain function as well as in neuropathological conditions.

Embolization: an adjunctive measure for removal of carotid body tumors.

Small carotid body tumors that do not encircle the internal carotid artery are excised with relative ease and minimal risk by the conventional subadventicial approach. Large carotid body tumors frequently encircle the internal and external cartoid arteries, and extensive bleeding often complicates the resection, increasing the risk of carotid artery rupture and damage to major cranial nerves. Recent improvements in surgical techniques and selective embolization have lessened the risks of surgical excision, decreased the blood loss, and diminished the time required for resection. Experiences in the resection of carotid tumors with and without embolization are compared. Early resection of carotid body tumors, before involvement of the internal carotid artery and carotid bulb, is advocated.

Ferromagnetic Silicone Necrosis of Hypernephromas by Selective Vascular Occlusion to the Tumor: A New Technique

Arterial vascular occlusion of hypernephromas may be performed by obstructiing the tumor vascular tree with the injection of ferromagnetic silicone microspheres. The powerful superconducting electromagnet confines the embolized iron-silicone compound to the neoplastic target organ. Radioactive material may or may not be added to the iron-silicone compound to give local direct radioactive radiation therapy to the tumor area. In experimental dogs up to 70,000 rad of beta radiation from the P32 source had been delivered homogeneously within the kidney when mixed with the ferrosilicone. This technique may well be used in cases in which a major operation is contraindicated or when preoperative necrosis of the tumor is advisable. Since the entire procedure can be done with the patient under local anesthesia in a radiology department it may be a valuable new technique in the future management of urological tumors, unilateral renal hypertension, solitary kidney pathology and so forth. Ferrosilicone material has not been found to be toxic. The application of a powerful superconducting electromagnet to the technique provides a means of confining the embolized iron-silicone compound to the target organ.

Use of a new mixture for embolization of intracranial vascular malformations

SummaryThe internal carotid artery system in swine has a special anatomic configuration similar to a brain “arterial-arterial malformation”. The internal carotid artery breaks up into a multitude of fine channels (rete mirabile) situated at the base of the skull on the side of the hypophysis. This anatomic arterial model was used to analyze acute and chronic angiographic and histological changes after occlusion of the rete mirabile with I) avitene, II) avitene, and 50% ethanol, III) avitene, 30% ethanol and Polyvinyl alcohol, IV) avitene 50% ethanol and Polyvinyl alcohol, V) IBCA and VI) silk. Histopathological changes observed in the rete mirabile six weeks following occlusion demonstrated that a mixture of avitene, 30% ethanol and Polyvinyl alcohol and IBCA produced the best anatomic results. Embolization with avitene, PVA and ethanol induced a more bland histological reaction than the one observed with IBCA. Preliminary clinical experience with this mixture is reassuring in those cases in which the AVM was surgically resected. The partially thrombosed AVM was easily depressed and compressed by the neurosurgeon allowing for satisfactory hemostasis in and around the nidus of the AVM.

Implementation of a large-scale picture archiving and communication system

This paper describes the implementation of a large-scale picture archiving and communication system (PACS) in a clinical environment. The system consists of a PACS infrastructure, composed of a PACS controller, a database management system, communication networks, and optical disk archive. It connects to three MR units, four CT scanners, three computed radiography systems, and two laser film digitizers. Seven display stations are on line 24 h/day, 7 days/wk in genitourinary radiology (2K), pediatric radiology in-patient (1K and 2K) and outpatient (2K), neuroradiology (2K), pediatric ICU (1K), coronary care unit (1K), and one laser film printing station. The PACS is integrated with the hospital information system and the radiology information system. The system has been in operation since February 1992. We have integrated this PACS as a clinical component in daily radiology practice. It archives an average of 2.0-gigabyte image data per workday. A 3-mo system performance of various components are tabulated. The deployment of this large-scale PACS signifies a milestone in our PACS research and development effort. Radiologists, fellows, residents, and clinicians use it for case review, conferences, and occasionally for primary diagnosis. With this large-scale PACS in place, it will allow us to investigate the two critical issues raised when PACS research first started 10 yrs ago: system performance and cost effectiveness between a digital-based and a film-based system.

Ischemic paralysis of the facial nerve: A possible etiologic factor in Bell's palsy

Numerous causes of peripheral facial nerve paralyses have been described; however, none has satisfactorily explained the genesis of the most common type of paralysis, Bells palsy. Two patients undergoing an experimental embolization of vascular intracranial tumors suffered a total peripheral facial nerve paralysis when occlusion of the middle meningeal artery had been accomplished. It is speculated that this paralysis resulted from ischemia of the horizontal portion of the facial nerve, an observation that has not previously been described and that might be applicable as well to the etiology of Bells palsy.

Pre-operative micro-angioplasty of refractory vasospasm secondary to subarachnoid hemorrhage

SummaryA patient with subarachnoid hermorrhage secondary to a basilar artery aneurysm developed severe bilateral middle and anterior cerebral artery vasospasm with extensive neurologic deficits. Microangioplasty of the middle cerebral artery segments bilaterally led to reversal of the neurologic deficits, allowing early operative treatment of the aneurysm in a previously inoperable patient.