A retrospective clinical and radiographic analysis of 20 patients with orbital venous malformations was performed. The malformations were fed by other veins rather than arteries. They may nearly always be demonstrated by orbital or jugular phlebography, though occasionally they will fill only following direct puncture. There appeared to be varied etiologies. A few were related to trauma or to other causes of increased intraorbital pressure. There is an association with periorbital hemangiomas suggesting developmental or congenital origin.
✓ Interventional neurovascular techniques have advanced to a level where treatment of intracranial aneurysms by intravascular detachable balloon embolization therapy is now possible. A patient is presented who had a spontaneous subarachnoid hemorrhage from a large aneurysm of the distal basilar artery. The aneurysm arose at the bifurcation of the posterior cerebral arteries and measured 15 × 9 × 9 mm. With the patient fully awake, a detachable silicone balloon was passed into the basilar artery by a transfemoral arterial approach. Stenosis (> 60%) of the mid-section of the basilar artery, secondary to arterial vasospasm from the recent hemorrhage, was present. The stenosis was treated by transluminal angioplasty, after which the balloon was passed into the aneurysm and detached. A follow-up angiogram 3 months later demonstrated complete occlusion of the aneurysm and a widely patent basilar artery at the angioplasty site.
We recently encountered a case of intraventricular cysticercosis in which the cyst had an unusually high signal on T1-weighted MR imaging. Pathologic studies showed cyst degeneration. Since the surgical management of these patients partly depends on the physiologic state of the cyst, the radiologist should recognize MR's ability to depict those life-cycle stages
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.
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 position 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.
Over the past few years , major advances in the develop ment of new microcatheter systems have greatly improved the safety and efficacy of therapeutic endovascular tech niques (1 -4). The ideal embolization catheter should have the following characteristics: simplicity of use, ability to negotiate tortuous curves with a minimum of manipulations and without trauma to the artery or induction of spasm, outer diameter small enough that the physical presence of the catheter in the vessel is not occlusive, and inner diameter large enough to permit a choice of embolic agents of various types and sizes. We present our experience with the Progressive Suppleness Pursil Catheter,* which helps fulfill these criteria. With the 3-French/1 .8-French microcatheter, tortuous ves sels can be catheterized and good quality superselective angiograms can be obtained (Fig . 2). Bench experiments showed that attempting wire manipulation can result in sep aration of the Pursil catheter from the proximal 3-French shaft because of friction between wire and catheter; therefore, this maneuver should be attempted only with extreme caution or should not be attempted at all. Two or three separate injec tions per catheter may be performed providing the following steps are followed: a homogeneous mixture of tantalum pow der (1 g) and iophendylate (0 .3-1 ml , depending on the polymerization time desired) should be obtained by gentle swirling before addition of 1 ml of isobutyl 2-cyanoacrylate (bucrylate) (IBCA); a 25cgauge needle should be used to aspirate the supernatant portion of the IBCA-iophendylate tantalum mixture in order to prevent loading of clumps (which can block the microcatheter) into the embolization syringe (1- ml Luer lock); with the microcatheter loaded with 5% dextrose in water solution (D 5W) , no more than 0.3-ml IBCA-iophen dylate-tantalum mixture should be initially loaded via a three way stopcock; then the mixture should be pushed through using either a 1- or 3-ml syringe containing D5W; after remov ing the stopcock and syringes, at least 5 ml of DsW should be flushed through the catheter. Despite these precautions, deposition of small amounts of tantalum powder on the inner wall will cause progressive narrowing of the catheter lumen; this increases the force required for injection and can even tually result in occlusion or even rupture of the catheter near its junction with the 3-French segment. Hence, the total number of IBCA injections should not exceed three per cath eter if the descri bed steps for IBCA preparation are followed (if they are not followed, only one injection of IBCA should be performed per catheter).
Gas cisternography was combined with edge-enhanced computed tomography (CT) in 6 patients and demonstrated the seventh and eighth cranial nerves thorugh both the cerebellopontine angle cistern and the internal auditory canal in the normal patients. The normal nerve outline was lost when a tumor was contained within the canal. This technique is a more reliable means of identifying small tumors than relying on non-filling of the canal by positive contrast media or gas.
