Search

International audience; Cerebrospinal fluid (CSF) leaks involving the skull base are associated with considerable morbidity and mortality, and often present a diagnostic challenge. Current diagnostic methods are invasive and cumbersome and involve substantial radiation exposure of the patient. The authors identified seven patients with clinically suspected CSF leaks and evaluated them with a flow-sensitive magnetic resonance imaging (MRI) sequence in addition to more conventional studies. In cases with active CSF leakage, flow characteristics were documented with slow-flow and diffusion-weighted MRI. Unlike current approaches, MRI offers the advantages of rapidity, non-invasiveness, and absence of ionizing radiation. Preliminary results suggest that flow-sensitive MRI may have a role in the evaluation of CSF leaks involving the skull base and temporal bone.

PURPOSE: To evaluate the safety and efficacy of silk suture as an agent for preoperative embolization of cerebral arteriovenous malformations. METHODS: Clinical and histopathologic results were analyzed in six patients who underwent embolization of cerebral arteriovenous malformations using silk suture in combination with other agents. RESULTS: Three of the patients treated with silk hemorrhaged after embolization, and two of these patients died. Neuropathologic analysis of four patients showed acute perivascular inflammation, sometimes quite severe. CONCLUSIONS: The inflammatory response to silk may explain its effectiveness in producing vascular occlusion. However, a fulminate vasculitis theoretically can predispose to delayed hemorrhage. Other problems with silk include the pressure required to inject the agent and the inability to determine the final site of deposition of the silk. Although other embolic agents may share some of these potential difficulties, we feel that the disadvantages outweigh the advantages of silk as an embolic agent.

International audience; PURPOSE: To evaluate a slow-flow MR sequence in normal CSF flow and in CSF flow disturbance in cases of spinal stenosis. METHOD: The method was tested for flow sensitivity and applied to 67 sites of spinal canal compromise. RESULTS: Phantom studies show that flow can be depicted at a velocity of 0.5-1 mm/sec. On clinical images, stagnant CSF is black, flowing CSF is bright. Typically, in high-grade (90%-100%) stenosis, CSF above and below the site of spinal canal compromise (SCC) is black. With intermediate stenosis (50%-89%), CSF above the SCC remains white but becomes black distal to the SCC. Low-grade stenosis shows only localized flow disturbances. CONCLUSION: This easy-to-use sequence can solidify the MR diagnosis of high-grade stenosis when a distinct flow pattern is recognized. Flow patterns for intermediate and low-grade stenosis are less reliable.

The ACTA-scanner, a device for computerized axial tomography, permits cross-sectional radiographic study of the entire human body, including the spine. In the ACTA-scan, the spinal cord appears as a roundish formation surrounded by the less dense subarachnoidal cerebrospinal fluid. The spines of 18 patients with verified (nine cases) or suspected (nine cases) syringomyelia were studied by ACTA-scanning. In seven of the verified and in four of the nonverified cases, some evidence of cord cavitation was shown. The cystic part of a cervical-cord ependymoma was also demonstrated. ACTA-scanning is an easily performed, noninvasive, innocuous procedure. This technic, which complements other radiographic methods of evaluating the spinal cord, is particularly suitable for screening and follow-up study of patients with syringomyelia. The easily accomplished recognition of a possible associated hydrocephalus is an added advantage of ACTA-scanning.

Thirty-one patients with solitary pulmonary nodules--18 benign and 13 malignant--proven by either tissue diagnosis or prolonged follow-up were evaluated by computed tomography (CT). A device (ACTA scanner 0100) with scanning times greater than breath-holding was used with full understanding of its related limitations. A retrospective study of the CT features of these nodules led us to establish several criteria for benign nodules. CT evidence of calcium is felt to be the most important feature of benignancy. In the absence of calcium, irregular nodule margins, perinodular fibrosis, satellite nodules, and pleural thickening opposite a peripherally situated nodule are helpful to suggest its benign nature.

Thin-section computed tomographic (CT) scans of 3 and 1.5 mm thickness were obtained using the Philips Tomoscan 310 and General Electric 8800 CT/T scanners in the study of 10 consecutive patients with progressive supranuclear palsy (PSP) and 31 patients with other diseases. Marked midbrain and moderate pontine atrophy, a dilated third ventricle, and enlarged quadrigeminal plate cisterns were observed in all PSP cases. The aqueduct was dilated in several. In six of the PSP cases, there was a striking midbrain abnormality in the form of a low-density area extending from the interpeduncular cistern toward the aqueduct. Thin-section metrizamide-enhanced cisternography of three of the six PSP cases showed that the low-density abnormality was the result of the interpeduncular cistern invaginating the atrophic midbrain.

Twenty-four patients with ventricular septa are discussed. Seventeen patients had septa acquired during the neonatal period and seven exhibited septations at birth (cogenital septa). Among the acquired septa, there were true intraventricular septa and septa that originated outside the ventricles but later became part of the ventricular system (pseudosepta). Pseudosepta originate in necrotic, cavitating periventricular white matter that, in temporal sequence, becomes ventricularized. Serial use of cranial sonography provided important information about the pathologic mechanisms that govern the development of septa. Intraventricular hemorrhage and infection are the major causes of true intraventricular septa, while periventricular leukomalacia serves as primary cause of pseudosepta. Sonography is the diagnostic method of choice. Septa are associated with a high incidence (62%) of shunt failure.

At present, the diagnosis of pseudohypertrophic muscular dystrophy (PHMD) rests on the clinical picture and the pattern of inheritance and is supported by electrodiagnostic, histologic, and histochemical techniques. In this report we describe the observed computed tomography (CT) changes in six patients with PHMD and compare these abnormal CT scans with scans of the same anatomic region in 16 normal individuals. Scans of patients with polymyositis and sarcoid myopathy are shown for comparison. Two CT patterns, frequently observed in our series, are described.

Computed tomography (CT) of the thoracic and cervical spine was carried out after lumbar intrathecal introduction of a water-soluble radiographic contrast medium (metrizamide). By choice, no head-down position of the patient was used to facilitate craniad movement of the contrast medium; rather, advantage was taken of the normal CSF flow. This technique, referred to as computer-assisted myelography (CAM), permits the demonstration of the metrizamide-containing subarachnoidal spaces surrounding the thoracic and cervical cord. Some examples of the diagnostic possibilities of the method are discussed.

Three hundred fifty-four patients with taste and/or smell disorders were evaluated with computed tomography (CT). The largest group was characterized by head trauma (27%), followed by idiopathic causes (26%), postinfluenza-like hyposmia and hypogeusia (15%), and congenital etiologies (14%). Hyposmia and hypogeusia occurred concomitantly in 21%-45%, the percentage varying according to etiologic subgroup. CT abnormalities were found in 108 (31%) of the 354 patients. The most frequent pathologies were frontal encephalomalacia, subfrontal atrophy in the region of the olfactory bulbs, and anterior temporal lobe atrophy. These changes were found alone or in tandem. Some CT findings suggest common cerebral taste and smell centers and common neural pathways and association centers.

Periventricular leukomalacia (PVL) is well recognized as a relatively uncommon yet particularly serious complication of prematurity. Although the sonographic features of PVL have been described, its association with intraventricular hemorrhage (IVH) has not been emphasized. Reviewing 26 consecutive cases of PVL in neonates of 34 weeks or less gestational age, significant associated hemorrhage was found in six (23%). Small quantities of blood were also noted in most of the other 20 infants. Of the six infants with both significant IVH and PVL, five required ventricular shunt and all had particularly poor clinical outcomes. In the neonates who required surgical intervention, rapid ventricular enlargement was accompanied by extensive periventricular cyst formation. Eventually, the septations within the cysts and frequently even the ependyma of superior/posterior lateral ventricles degenerated. Cysts merged imperceptibly with the ventricles giving an appearance that mimicked severe hydrocephalus. This was termed "pseudoventricle formation," as the large intracerebral cerebrospinal fluid spaces are primarily porencephaly and not enlarged ventricles. Response to shunting was minimal by sonography in all five cases and multiple shunt revisions were required in four. Clinical follow-up in children with significant IVH in combination with PVL has shown severe mental retardation and tetraplegia in all cases.