Spinal vascular malformations: MR angiography after treatment.

PURPOSE: To evaluate the role of magnetic resonance (MR) angiography in the assessment of spinal vascular malformation therapy. MATERIALS AND METHODS: Thirty-four patients with spinal vascular malformations (30 dural arteriovenous fistulas, two perimedullary arteriovenous fistulas, and two intramedullary arteriovenous malformations) underwent MR angiography and MR imaging before and after endovascular or surgical treatment. RESULTS: MR angiography showed residual flow in perimedullary vessels in seven patients with dural fistula after embolization with liquid adhesive. In all seven, treatment failure was confirmed with arteriography. Long-lasting disappearance of flow in perimedullary vessels was demonstrated at MR angiography in 22 patients with dural fistula. MR imaging demonstrated normalization of spinal cord volume in 16 of 22 patients and signal intensity on T2-weighted images in three patients. Disappearance of cord enhancement was observed in five of 21 patients and of perimedullary enhanced vessels in six of 13 patients. In one additional patient with dural fistula treated with embolization, early posttreatment MR angiography showed disappearance of flow in perimedullary vessels, which reappeared at follow-up and was consistent with reopening of a small residual fistula. Posttreatment MR angiography demonstrated transient reduction of flow in the nidus in two patients with intramedullary malformations treated with embolization. Permanent disappearance of flow in the perimedullary vessel was seen after endovascular treatment in two patients with perimedullary fistula. CONCLUSION: MR angiography is more sensitive than MR imaging in depicting residual or recurrent flow in peri- or intramedullary vessels, which indicates patency of the vascular malformation.

Phase-contrast MR angiography of intracranial dural arteriovenous fistulae.

MRI and phase-contrast MR angiography (PC MRA) were obtained in 13 patients with angiographically confirmed intracranial dural arteriovenous fistulae (DAVF). Three- and two-dimensional PC MRA was obtained with low (6-20 cm/s) and high (> 40 cm/s) velocity encoding along the three main body axes. MRI showed focal or diffuse signal abnormalities in the brain parenchyma in six patients, dilated cortical veins in seven, venous pouches in four with type IV DAVF and enlargement of the superior ophthalmic vein in three patients with DAVF of the cavernous sinus. However, it showed none of the fistula sites and did not allow reliable identification of feeding arteries. 3D PC MRA enabled identification of the fistula and enlarged feeding arteries in six cases each. Stenosis or occlusion of the dural sinuses was detected in six of eight cases on 3D PC MRA with low velocity encoding. In six patients with type II DAVF phase reconstruction of 2D PC MRA demonstrated flow reversal in the dural sinuses or superior ophthalmic vein.

Contrast-enhanced time-resolved MR angiography of spinal vascular malformations.

PURPOSE: The purpose of this work was to assess the potential and limitations of a contrast-enhanced time-resolved MR angiography technique for evaluation of spinal vascular malformations. METHOD: Two patients with intramedullary arteriovenous (AV) malformations and three patients with dural AV fistula underwent four serial acquisitions, every 17-20 s, of 20-32 coronal 1.5- to 2-mm-thick partitions with a fast 3D SPGR sequence after injection of 0.2-0.3 mmol/kg paramagnetic contrast agent. This was followed by coronal 3D and sagittal or coronal 2D phase contrast (PC) MR angiography. RESULTS: No spinal vessels were visualized in the first (baseline) series. In patients with intramedullary AV malformations, the arterial feeders, nidus, and perimedullary draining veins were visualized in the second (early) series. In the third (intermediate) series, the arterial feeder vanished, whereas the intercostal and lumbar veins appeared. In patients with dural AV fistula, abnormal intraspinal vessel appeared in the third series and persisted, although less conspicuous, in the fourth (late) series. Contrast-enhanced time-resolved MR angiography demonstrated the venous components of the lesion with better conspicuity than 3D PC MR angiography, whereas it was inferior for visualization of arterial feeders. Moreover, indirect identification of the level of the dural AV fistula was possible only on the phase display of the 2D PC MR angiography. CONCLUSION: Contrast-enhanced time-resolved MR angiography is a useful complement to PC MR angiography for the evaluation of spinal vascular malformation.

Syringomyelia in myotonic dystrophy due to spinal hemangioblastoma.

BACKGROUND: Syringomyelia is an uncommon, poorly understood finding in patients with myotonic dystrophy. METHODS: We describe a patient with myotonic dystrophy and neck pain in whom an extensive neuroradiologic diagnostic work-up was carried out. RESULTS: Magnetic resonance imaging revealed a large intramedullary cavity extending from the bulbo-medullary junction to the conus medullaris. After intravenous Gadolinium-DTPA administration, an enhanced nodule was seen at T6. Spinal arteriography showed a single hypervascular nodule and slow flow perimedullary draining veins consistent with hemangioblastoma. After removal of the nodule, a partial collapse of the intramedullary cyst was observed. CONCLUSIONS: Intramedullary tumors can underlie syringomyelia in patients with myotonic dystrophy and have to be actively investigated with modern neuroradiologic investigations.

Posterior spinal artery infarct.

Acute medullary syndrome developed in a patient in whom glue had been inadvertently injected into the right posterior radiculomedullary artery during endovascular occlusion of a spinal dural arteriovenous fistula at T-11. MR imaging 40 days after the procedure showed signal changes and contrast enhancement in the posterior and right lateral column at T10-11. Circumscribed signal changes in the same areas without contrast enhancement were seen 4 months later. MR imaging was able to show this posterior spinal artery infarct.

Bilateral fibromuscular dysplasia in identical twins.

Fibromuscular dysplasia is an arterial occlusive disorder that often affects the renal arteries and leads to renovascular hypertension. The cause of this disease is unknown. However, the occurrence in siblings suggests that genetic factors may play a role. We describe two cases involving hypertensive identical twins with fibromuscular dysplasia of the renal arteries. This unique clinical case reinforces a possible hereditary nature of this arterial occlusive disorder.

Differential quantitative blood cultures in the diagnosis of catheter-related sepsis in intensive care units.

The aim of this prospective study was to compare differential blood cultures and quantitative catheter tip cultures for the diagnosis of catheter-related sepsis. Over a period of 2 years, 283 central venous catheters were inserted in 190 adult patients. Catheters were removed when they were no longer needed or when infection was suspected. Immediately before removal of the central venous catheters, blood cultures were performed, with blood drawn simultaneously from the catheter and the peripheral vein. After removal, quantitative catheter culture was performed according to the Brun-Buisson modified Cleri technique. Fifty-five quantitative catheter cultures were positive. They were classified as contaminated (n = 18), colonized (n = 23), or infected (n = 14). Differential blood cultures correctly identified 13 infections. With a catheter/peripheral cfu ratio of 8, differential blood cultures had a sensitivity of 92.8% and a specificity of 98.8%. When the catheters were removed because of suspected infection, differential blood cultures had a sensitivity of 92.8% and a specificity of 100%. Differential blood culture, a technique that does not necessitate catheter removal, seems effective in the diagnosis of catheter-related sepsis in patients in the intensive care unit.

Case report. MRI and MR angiography of basilar artery dissection in a child.

MRI showed a pontine infarct and mural thickening of intermediate signal in T1-weighted images proximal to occlusion of the basilar artery in a 10-year-old boy. Two days later the mural thickening was of high signal, consistent with methaemoglobin formation and MR angiography (MRA) showed nonspecific lack of flow in the mid-segment of the basilar artery, which corresponded to a tapered occlusion at arteriography. MRI is more useful than MRA for noninvasive diagnosis of basilar artery dissection.

MRI and MR angiography of vertebral artery dissection.

A review of 4,500 angiograms yielded 11 patients with dissection of the vertebral arteries who had MRI and (in 4 patients) MR angiography (MRA) in the acute phase of stroke. One patient with incidental discovery at arteriography of asymptomatic vertebral artery dissection and two patients with acute strokes with MRI and MRA findings consistent with vertebral artery dissection were included. Dissection occurred after neck trauma or chiropractic manipulation in 4 patients and was spontaneous in 10. Dissection involved the extracranial vertebral artery in 9 patients, the extra-intracranial junction in 1, and the intracranial artery in 4. MRI demonstrated infarcts in the brain stem, cerebellum, thalamus or temporo-occipital regions in 7 patients with extra- or extra-intracranial dissections and a solitary lateral medullary infarct in 4 patients (3 with intracranial and 1 with extra-intracranial dissection). In 2 patients no brain abnormality related to vertebral artery dissection was found and in one MRI did not show subarachnoid haemorrhage revealed by CT. Intramural dissecting haematoma appeared as crescentic or rounded high signal on T1-weighted images in 10 patients examined 3-20 days after the onset of symptoms. The abnormal vessel stood out in the low signal cerebrospinal fluid in intracranial dissections, whereas it was more difficult to detect in extracranial dissections because of the intermediate-to-high signal of the normal perivascular structures and slow flow proximal and distal to the dissection. In two patients examined within 36 h of the onset, mural thickening was of intermediate signal intensity on T1-weighted images and high signal on spin-density and T2-weighted images. MRA showed abrupt stenosis in 2 patients and disappearance of flow signal at and distal to the dissection in 5. Follow-up arteriography, MRI or MRA showed findings consistent with occlusion of the dissected vessel in 6 of 8 patients.

Identification of the feeding arteries of spinal vascular lesions via phase-contrast MR angiography with three-dimensional acquisition and phase display.

PURPOSE: To determine whether identification of the feeding arteries of spinal vascular lesions with phase-contrast MR angiography benefits from the higher spatial resolution of three-dimensional (volume) acquisitions and flow-direction information provided by the phase reconstruction of two-dimensional acquisitions. METHODS: Fifteen patients with high- or low-flow spinal vascular lesions proved by spinal arteriography underwent MR angiography with phase-contrast techniques. Arteriographic and MR angiographic studies were reviewed to identify the arterial feeders of spinal vascular lesions. RESULTS: On modulus reconstructions of coronal 2-D or 3-D acquisitions, three of four arteries feeding high-flow lesions and three of 14 arteries feeding low-flow lesions were identified as hypertrophic vessels joining the parent intercostal or cervical arteries. Of 11 intradural veins draining dural arteriovenous fistulas, three were identified on coronal 2-D acquisitions and six on coronal 3-D acquisitions as vessels that coursed from a neural foramen to a midline tangle of vessels. Phase reconstruction showed ascending and descending flow patterns in two patients with intramedullary arteriovenous malformations, and diverging flow in perimedullary veins draining a hemangioblastoma. In nine patients with dural arteriovenous fistulas, phase reconstruction provided information as to the level of the arterial feeders. Phase reconstruction in coronal plane acquisitions also provided evidence of centripetal flow. CONCLUSION: Three-dimensional acquisitions and phase display of 2-D acquisitions improved the visibility of arterial pedicles of spinal vascular lesions at phase-contrast MR angiography.

Dural arteriovenous fistula at the craniocervical junction with perimedullary venous drainage.

MR imaging showed swelling and diffuse signal changes in the spinal cord in two patients with progressive myelopathy. MR angiography revealed slow-flow perimedullary vessels extending to the skull base, which are consistent with drainage vessels of a dural arteriovenous fistula at the craniocervical junction. This fistula was subsequently seen in both patients on selective arteriograms of the ascending pharyngeal and vertebral arteries.

MR angiography of spinal vascular malformations.

PURPOSE: To determine the potential and limitations of MR angiography in the evaluation of spinal vascular malformations. METHODS: Eleven consecutive patients with spinal vascular malformations proved with spinal selective arteriography underwent two-dimensional phase-contrast MR angiography. RESULTS: Abnormal vessels within the spinal canal were identified with MR angiography in 10 patients. In 1 patient with a dural arteriovenous fistula no definite vascular abnormality was seen with MR angiography. Correlation of MR angiography with spinal selective arteriography showed that the former allowed identification of the arterial feeder in 3 patients with intramedullary arteriovenous malformations and 2 with perimedullary arteriovenous fistula, whereas the source of intradural draining vein was seen in only 2 of 6 patients with dural arteriovenous fistula. CONCLUSION: MR angiography is a promising complementary tool to MR imaging for detection and characterization of spinal vascular malformations.

Balloon occlusion of the carotid artery in the treatment of cavernous giant aneurysms: two cases.

Over recent years, endovascular occlusion of the carotid artery has become a valid alternative to its more traditional surgical ligation in the treatment of cavernous giant aneurysms. The authors report two cases treated with balloon occlusion in two patients with clinical signs of cavernous sinus syndrome. The procedure consisted of occluding the aneurysm and the carotid by means of detachable balloons. This was preceded by a 30-minute clinically monitored occlusion test aimed at evaluating the functioning of Willis' circle. The treatment was carried out under neuroleptoanalgesia, so optimal control of the neurological condition of the patient was possible. Partial symptom regression was obtained in both cases.

Comparative effects of laryngeal mask and tracheal tube on total respiratory resistance in anaesthetised patients.

We compared the effects of the laryngeal mask and tracheal tube on total respiratory resistance in 10 anaesthetised, mechanically ventilated patients undergoing otological microsurgery. The subjects were randomly divided into two groups. In the first group, the tracheal tube (Rüsch) was inserted for the first series of measurements. This was then replaced by a laryngeal mask (Intavent) and a second series of measurements was made during the first hour of operation. In the second group, the same protocol was applied with inverse order in the use of the devices. From the measurement of respiratory flow and pressure at the airway opening, total respiratory resistance was calculated by multiple linear regression. The data were corrected to eliminate the previously determined nonlinear resistance of the two devices. Arterial blood pressure, electrocardiogram, oxygen saturation and end-tidal carbon dioxide concentration were continuously monitored. With the laryngeal mask and the tracheal tube, mean (SE) minute ventilation was 9.4(0.9)l.min-1 and 8.1(0.9)l.min-1, respectively for end-tidal carbon dioxide concentrations between 3.6 and 4.1%. Although the glottic resistance was included in the measurement performed with the laryngeal mask but not with the tracheal tube, mean (SE) total respiratory resistance was not significantly different with the two devices (0.61(0.32) and 0.69(0.35) kPa.l-1.s, respectively). Leakage was avoided with the laryngeal mask because the insufflation pressure never exceeded 1.7 kPa except in one patient suffering from severe chronic obstructive pulmonary disease who had a total respiratory resistance of 1.45 kPa.l-1.s. During the first hour of the operation all respiratory variables remained stable irrespective of the device used.

[Venous angioma associated with cavernous angioma. Presentation of three cases]. / Associazione di angioma venoso ed angioma cavernoso. Presentazione di tre casi.

Cavernous angiomas and venous angiomas may be discovered as associated lesions in the same patient. Most Authors report that Venous angiomas are not true vascular malformation; they should be considered as variant of normal venous drainage, consisting of tortuous medullary veins converging into a dilated draining one. By rule, they are quite asymptomatic, and very rarely bleed. On the other side, cavernous angiomas are true vascular malformations, usually angiographically occult. Their association is relatively rare, but it is important because of the possibility of bleeding, which should be related to the presence of the cavernous malformation. We report the cases of three patients studied by Computed Tomography, Magnetic Resonance and Digital Angiography in our Neuroradiologic Department.

Iopamidol and metrizamide in cervical myelography: side effects, EEG, and CSF changes.

Two nonionic contrast media, iopamidol and metrizamide (Amipaque), were used for cervical myelography (C1-C2 puncture) in 95 consecutive patients. Both contrast media gave excellent radiographic results. Headache and vagal symptoms were similar in both groups, whereas metrizamide produced more electroencephalographic changes and epileptic seizures. Meningeal irritation occurred in both groups and was severe in three cases. Cerebrospinal fluid showed protein and cellular changes of inflammatory type in both groups. Iopamidol is considered to be the more suitable contrast medium for cervical myelography despite its slight neurotoxicity.

Cervical myelography with iopamidolo.

A new non-ionic water-soluble contrast medium was used for cervical myelography in 65 patients. The contrast medium was injected suboccipitally or by the latent C1-C2 approach. The films were of equally good quality as those obtained with other contrast media and tolerance has been superior. The contrast medium is Iopamidolo and is available in ampoules which is further positive quality.