Magnetic resonance imaging of spinal arteriovenous malformations

Magnetic resonance imaging (MRI) was performed on 12 patients with spinal arteriovenous malformations (AVM's). Six lesions were intramedullary, five were dural, and one was in a posterior extramedullary location. Serpentine filling defects similar to the classic myelographic findings were demonstrated within the high-signal cerebrospinal fluid on T2-weighted coronal scans. The intramedullary nidus was identified by MRI as an area of low-signal intensity within the cord in all six intramedullary AVM's. Neither the dural nor the posterior extramedullary lesions showed intramedullary components. It is concluded that MRI may noninvasively provide the initial diagnosis of a spinal AVM and distinguish intramedullary from dural and extramedullary lesions.     

Volumetric myelographic magnetic resonance imaging to localize difficult-to-find spinal dural arteriovenous fistulas

Although more prevalent in males in the 6th and 7th decade of life, spinal dural arteriovenous fistulas (SDAVFs) are an uncommon cause of progressive myelopathy. Magnetic resonance imaging and more recently Gd bolus MR angiography have been used to diagnose, radiographically define, and preprocedurally localize the contributing lumbar artery. Three-dimensional myelographic MR imaging sequences have recently been developed for anatomical evaluation of the spinal canal. The authors describe 3 recent cases in which volumetric myelographic MR imaging with a 3D phase-cycled fast imaging employing steady state acquisition (PC-FIESTA) and a 3D constructive interference steady state (CISS) technique were particularly useful not only for documenting an SDAVF, but also for providing localization when CT angiography, MR imaging, MR angiography, and spinal angiography failed to localize the fistula. In a patient harboring an SDAVF at T-4, surgical exploration was performed based on the constellation of findings on the PC-FIESTA images as well as the fact that the spinal segments leading to T-4 were the only ones that the authors were unable to catheterize. In a second patient, who harbored an SDAVF at T-6, after 2 separate angiograms failed to demonstrate the fistula, careful assessment of the CISS images led the authors to focus a third angiogram on the left T-6 intercostal artery and to perform superselective microcatheterization. In a third patient with an SDAVF originating from the lateral sacral branch, the PC-FIESTA sequence demonstrated the arterialized vein extending into the S-1 foramen, leading to a second angiogram and superselective internal iliac injections. The authors concluded that myelographic MR imaging sequences can be useful not only as an aid to diagnosis but also for localization of an SDAVF in complex cases.     

Intracerebral hematomas in cases of dural arteriovenous malformation and carotid-cavernous fistula

Intracerebral hematomas in cases of dural arteriovenous malformation and carotid cavernous fistula are reported. The origin of hemorrhage is concluded to have been the engorged cortical veins through which the arterial blood drained in a retrograde fashion. The necessity of early treatment of the underlying condition is stressed, as retrograde drainage may cause acute complications.     

影像学研究硬脊膜动静脉瘘进展

硬脊膜动静脉瘘(SDAVF)为低发病率脊柱血管畸形,临床表现不典型且较为隐匿,易误诊。早期诊断SDAVF主要依靠影像学检查,包括MRI、CT血管造影及数字减影血管造影,三者各有其优势。本文就影像学研究SDAVF进展进行综述。     

Intracerebral arteriovenous malformation angiographically resembling a dural malformation

A case of intracerebral arteriovenous malformation with a purely external carotid contribution is presented. This case is not only rare, but also instructive in terms of the pathogenesis of the dural arterial supply to the intracerebral arteriovenous malformations.     

Magnetic resonance imaging of cerebral arteriovenous malformations

Magnetic resonance imaging (MRI) was performed in 15 patients with small to very large supratentorial arteriovenous malformations (AVMs). Unlike non-contrast infused computed tomographic (CT) scanning, MRI demonstrated the AVM in all cases. The nidus had a characteristic honeycomb appearance, and in all cases feeding arteries and deep or superficial draining veins were demonstrated without intervening bone artifact. The relationship of the AVM to surrounding cortical areas, deep nuclei, important white matter tracts, and the ventricular system was well appreciated. These characteristics make MRI useful for the diagnosis of cerebral AVMs and add to the accuracy of systems that grade operability on the basis of the angiographic demonstration of size, location, depth, arterial supply, and venous drainage. In many cases, based on the MRI appearance of the AVM and its relationship to important brain structures, the lesion can be deemed inoperable or unsuitable for other forms of treatment, making angiography unnecessary. Thus, the superior anatomical and morphological resolution of MRI, the lower false-negative rate, and the independence from x-ray and contrast material make MRI more useful than CT scanning for the diagnosis of AVMs and as an aid in the management of specific cases.     

Magnetic resonance imaging in spinal disorders

Summary The value of M.R.I. in diagnosing spinal disorders has been tested in a series of 100 patients. C.T., myelography, discography and the operative findings are compared with the M.R.I. findings. The results indicate that M.R.I. is a valuable diagnostic investigation.

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Résumé L'intérêt de l'imagerie par résonance magnétique (IRM) dans le diagnostic des lésions rachidiennes a été évalué sur une série de cent malades. Les données de la tomodensitométrie, de la myélographie, de la discographie et les constatations opératoires ont été comparées aux données de l'IRM. Les résultats prouvent que l'IRM est un examen de valeur sur le plan du diagnostic.

     

Magnetic resonance imaging in spinal emergency

Summary We studied the diagnostic value of MRI in spinal emergency. One hundred patients were analyzed retrospectively and the MR-findings were compared with operative results or autopsy whenever available. The advantages of MRI compared to CT and conventional myelography are discussed. The limitations of MRI are addressed and the important features of appropriate diagnostic procedure are outlined with special attention to neurosurgical requirements.     

Magnetic resonance imaging of dural sinus thrombosis with resolution

Cerebral venous thrombosis is difficult to diagnose clinically. Often, the presence of this disorder is not suspected, and, when it is, proof of its existence has in the past required cerebral angiography. The authors present a case of cerebral venous thrombosis diagnosed with magnetic resonance imaging (MRI). Complete resolution of the thrombus was also documented by MRI. To the authors' knowledge, the latter use of MRI has never been reported before. Previous cases of cerebral venous thrombosis are also reviewed. The authors believe that MRI probably will become the test of choice in the diagnosis of this disorder.     

Magnetic resonance imaging of spinal injury

Magnetic resonance imaging (MRI) was performed on 30 patients following spinal injury (SI). Spin-echo sequences and surface coils were used for all patients. Plain radiographs, high-resolution computed tomography (CT), and MRI were compared for the delineation of bone, disc, and ligament injury, measurement of sagittal spinal canal diameter and subluxation, epidural hematoma, and spinal cord structure. Myelography or intrathecal contrast-enhanced CT were not performed on any of these patients. Magnetic resonance imaging accurately delineated intraspinal pathology in two of four patients with acute penetrating SI, and was normal in the other two patients. In 16 patients with acute nonpenetrating SI, MRI was superior to CT for visualizing injuries to discs, ligaments, and the spinal cord, while CT was superior to MRI in characterizing bony injury. Computed tomography and MRI provided similar measurements of subluxation in six of six patients and of sagittal spinal canal diameter in three of four patients. In ten patients with chronic SI, MRI demonstrated post-traumatic cysts, myelomalacia, spinal cord edema, and the presence or absence of spinal cord compression. In patients with acute penetrating SI and chronic SI, MRI provided comprehensive clinical information. In patients with acute nonpenetrating SI, the information obtained by MRI complemented the data given by plain radiographs and CT, allowing clinical decisions to be made without the need of invasive imaging modalities.     

Subacute diencephalic necrosis and dural arteriovenous malformation

We report a case of congestive venous necrosis involving the diencephalon symmetrically, presumably precipitated by a dural arteriovenous malformation (AVM). The patient presented with a 1-month history of intermittent confusion and gait ataxia. The initial radiological work-up revealed a dural AVM. The patient's subsequent deterioration was accompanied by computed tomographic findings of diencephalic congestion. Pathological examination showed subacute necrosis of the diencephalon. We discuss the pathogenesis of this case of subacute diencephalic necorsis and its possible relationship to the entity of subacute diencephalic angioencephalopathy.     

Multiple spinal dural arteriovenous fistulas

Summary Multiple spinal dural arteriovenous fistulas (DAVFs) have been rarely reported and only two such cases are found in the literature. A 71-year-old man complained of muscle weakness and hypesthesia in both legs and angiographically diagnosed as thoracic DAVF. The fistula was surgically treated, however, the symptoms recurred 14 months after the first treatment. Angiography revealed a new fistula in the lumbar region and this was also treated surgically. In the previously reported cases of multiple spinal DAVFs, the second fistulas were also diagnosed after the initial treatment. Symptomatic patients after the initial treatment of DAVF should be re-examined angiographically.     

Two surgically treated cases with dural arteriovenous malformation in the anterior cranial fossa

Dural arteriovenous fistulae(dAVF) in the anterior cranial fossa comprise about 6% of all dAVFs, and is usually detected after intracranial hemorrhage. However, non-hemorrhagic symptoms are uncommon. We encountered two patients with hemorrhagic and non-hemorrhagic dAVF in the anterior cranial fossa. Both cases were successfully treated using craniotomy and histopathological examination was performed. A 71-year-old male experienced sudden onset of nausea and headache, followed by progression of left hemiparesis and disturbance of consciousness due to intracerebral and subdural hematoma in 2005. Intracerebral venous aneurysm adjacent to the intracerebral hematoma originated from the draining cortical red vein was identified and successfully treated by operation. Histopathological examination revealed disappearance of the internal elastic lamina and scant muscle tissue in the venous aneurysmal wall originating from draining cortical vein. A 69-year-old male suffered sudden onset of mild headache, followed by progression of bruits in 2005. MRI suggested dAVF in the left anterior cranial fossa. 123I-IMP SPECT revealed an area of low perfusion in the left frontotemporal region. Histopathological examination after surgical treatment revealed thickening of the intima and an indistinct lamina elastica interna, indicating progressive degenerative changes of the arterialized vein likely to result in hemorrhage. Surgical obliteration of fistulae is reasonable even in the dAVF of the anterior cranial fossa with ischemic onset.     

Extensive dural arteriovenous malformation. Case report

A child with an extensive dural arteriovenous malformation (AVM) of the sigmoid sinus and bilateral occlusion of the transverse sinus is reported. His intracranial venous flow had become rerouted through the right cavernous sinus and then into the right ophthalmic veins. The AVM was associated with severe hydrocephalus and a progressive devastating neurological deficit. The hemodynamic and intracranial pressure changes as well as the mechanism of sinus thrombosis are discussed. The role of aggressive surgical treatment is emphasized.