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W Montanera

Publications and source records attributed to W Montanera.

28 records · Page 2Linked to original sources
PubMedDate not supplied

MR features of tuberculous arachnoiditis.

Although tuberculosis is an uncommon cause of spinal arachnoiditis, it needs to be differentiated from other causes of arachnoiditis because it is a treatable disease. Myelography, which is the imaging modality of choice for the chronic adhesive stage of tuberculous arachnoiditis, usually reveals irregularity of the thecal sac, nodularity and thickening of nerve roots, clumping of roots to each other or to the thecal sac, or CSF block. Recently Gd-diethylenetriamine pentaacetic acid enhanced MRI has been found to be useful for the active phase of tuberculous infection, effectively demonstrating abnormally thickened and enhancing meninges, intra- and extramedullary tuberculous nodules, and spinal cord changes. We present the MRI features in a case of acute tuberculous arachnoiditis.

Adult↗
PubMedDate not supplied

Tortuous, engorged pial veins in intracranial dural arteriovenous fistulas: correlations with presentation, location, and MR findings in 122 patients.

BACKGROUND AND PURPOSE: Tortuous, engorged veins can be identified on the venous phase of the brain circulation in patients with venous congestion related to an intracranial dural arteriovenous fistula (DAVF). The term pseudophlebitic pattern (PPP) has been used to describe this finding. The purpose of this study was to determine the prevalence of PPP in patients with intracranial DAVF and to analyze the relationship of this sign to presentation, location of the fistula, presence of retrograde leptomeningeal venous drainage, and MR findings. METHODS: We retrospectively reviewed the charts and imaging findings of 130 patients with intracranial DAVF. In 122 patients the venous phase of the brain circulation was adequately assessed. The PPP was graded as mild, moderate, or severe. RESULTS: PPP was found in 51 patients (42%). Thirty-two (73%) of the 44 patients who had a hemorrhage, neurologic deficit, or seizure had PPP as compared with 16 (21%) of the 75 who had a bruit or orbital signs. The three patients with either congestive heart failure or increasing head circumference had PPP. Fourteen (88%) of the 16 who had fistula of the superior sagittal sinus, straight sinus, or superior petrosal sinus had PPP. PPP was seen in 46 (81%) of 57 patients who had retrograde leptomeningeal venous drainage and in five (8%) of the 65 who had only sinosal drainage. Fourteen (88%) of the 16 who had white matter T2 hyperintensity on MR images had severe PPP. CONCLUSION: The PPP reflects venous congestion and is associated with an aggressive presentation with or without retrograde leptomeningeal venous drainage. PPP may be a useful prognostic indicator and should be considered in treatment decisions.

Adolescent↗
PubMedDate not supplied

Hypertrophic olivary degeneration: metaanalysis of the temporal evolution of MR findings.

BACKGROUND AND PURPOSE: Hypertrophic olivary degeneration (HOD) is usually caused by a lesion in the triangle of Guillain and Mollaret and presents clinically as palatal tremor. Although the imaging features have been well described, the temporal course of hypertrophy and T2 signal increase in the inferior olivary nucleus (ION) has not been fully characterized. Our purpose was to evaluate the time course of MR imaging features of HOD caused by a lesion within the triangle of Guillain and Mollaret. METHODS: The temporal progression of HOD in 45 patients with symptomatic palatal tremor was obtained by extrapolation of combined MR imaging data from six patients treated at our institution and 39 patients reported in the literature. The MR examinations and reports were reviewed for presence of hyperintense signal in the ION on T2-weighted images, hypertrophy of the ION, and an inciting lesion in the triangle of Guillain and Mollaret. The interval between the MR examination and the inciting lesion was determined. RESULTS: Increased olivary signal on T2-weighted images first appeared 1 month after the inciting lesion and persisted for at least 3 to 4 years. Olivary hypertrophy initially developed 6 months after the acute event and resolved by 3 to 4 years. CONCLUSION: Visible changes on MR images in the ION in patients with a lesion in the triangle of Guillain and Mollaret correlate well with the described sequential histopathologic findings.

Disease Progression↗
PubMedDate not supplied

Micro-arteriovenous malformations of the brain: superselective angiography in diagnosis and treatment.

PURPOSE: We assessed the usefulness of superselective angiography in patients with micro-arteriovenous malformations. PATIENTS AND METHODS: Five patients had superselective angiography for either diagnosis or treatment of brain arteriovenous malformations having a nidus of less than 1 cm. All patients presented with an intracerebral hematoma. RESULTS: In one patient superselective angiography confirmed the presence of a shunt that was suspected due to visualization of an early vein on the follow-up angiogram; in another patient superselective angiography was helpful in defining the topography of the malformation; in the remaining three patients, superselective angiography was used for embolization of the malformation. We were unsuccessful in achieving a complete angiographic cure in these 3; however, superselective angiography revealed an aneurysm in one that was obliterated by the liquid adhesive embolic agent. CONCLUSION: With the recent advances in microcatheters, superselective angiography has a promising role in defining the topography and angioarchitecture of micro-arteriovenous malformations. Micro-arteriovenous malformations may not be angiographically evident at the time of initial hemorrhage due to the hematoma. With future technical advances it may be possible to completely obliterate these malformations by embolization alone.

Adolescent↗
PubMedDate not supplied

Posttreatment MR findings in spinal dural arteriovenous malformations.

PURPOSE: To review the MR findings in 17 patients with spinal dural arteriovenous malformations and compare posttreatment MR with clinical outcome in 10 patients. METHODS: Extramedullary flow voids, cord swelling, and intramedullary signal changes were recorded in 17 patients. Enhancement and vessel cospicuity were assessed in 10 patients given gadopentetate dimeglumine. In 10 patients, follow-up MR was correlated with clinical outcome. RESULTS: Of the 17 patients, 14 (82%) had abnormal subarachnoid vessels, 11 (65%) had cord enlargement, and 16 (94%) had hyperintensity on T2-weighted images. In 3 patients, the vessels were better seen with contrast, and 6 had cord enhancement. On posttreatment MR, the vessels were no longer evident in 7 of 10 patients, cord swelling resolved in 9 of 9 patients, the the T2 hyperintensity resolved or was less evident in 9 of 9 patients. Eight patients had clinical improvement, and 2 stabilized. CONCLUSIONS: Follow-up MR showed resolution of most of the findings in spinal dural arteriovenous malformation. There was some correlation between MR and clinical outcome, but MR evaluation could not distinguish those who had improved from those who stabilized.

Adult↗