AJNR. American journal of neuroradiology
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AJNR Am J Neuroradiol · May 2000
Neck infection associated with pyriform sinus fistula: imaging findings.
Acute suppurative neck infections associated with branchial fistulas are frequently recurrent. In this study, we describe the imaging findings of acute suppurative infection of the neck caused by a third or fourth branchial fistula (pyriform sinus fistula). ⋯ When an inflammatory infiltration or abscess is present between the pyriform fossa and the thyroid bed in the lower left part of the neck, an infected third or fourth branchial fistula should be strongly suspected.
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AJNR Am J Neuroradiol · May 2000
Quantitative measurement of microvascular permeability in human brain tumors achieved using dynamic contrast-enhanced MR imaging: correlation with histologic grade.
Dynamic contrast-enhanced MR imaging may be used to quantify tissue fractional blood volume (fBV) and microvascular permeability. We tested this technique in patients with brain tumors to assess whether these measurements correlate with tumor histologic grade. ⋯ This relatively simple method of analysis provides quantitative estimates of fBV and microvascular permeability in human brain tumors, with the permeability being predictive of pathologic grade. The technique can be easily implemented on clinical scanners and may prove useful in the assessment of tumor biology and in therapeutic trials.
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AJNR Am J Neuroradiol · Apr 2000
Peripheral spinal cord hypointensity on T2-weighted MR images: a reliable imaging sign of venous hypertensive myelopathy.
MR findings reported in conjunction with spinal dural arteriovenous fistula (SDAVF) include cord swelling, increased T2 signal within the spinal cord, and parenchymal enhancement, each of which is nonspecific. Enlarged vessels on the cord surface, the most specific MR finding, is noted in only half of SDAVF patients. Nevertheless, we have frequently observed MR peripheral hypointensity of the spinal cord in SDAVF on T2-weighted images, which is not characteristic of nonvascular or nonhemorrhagic causes of myelopathy and which has not been described in association with SDAVF. We hypothesized that peripheral cord hypointensity might reliably suggest the diagnosis of SDAVF or other causes of venous hypertensive myelopathy. ⋯ In the absence of spinal hemorrhage, T2 hypointensity involving the periphery of the spinal cord suggests venous hypertensive myelopathy as a cause of spinal cord dysfunction.
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AJNR Am J Neuroradiol · Mar 2000
A CT method to measure hemodynamics in brain tumors: validation and application of cerebral blood flow maps.
CT is an imaging technique that is routinely used for evaluating brain tumors. Nonetheless, imaging often cannot show the distinction between radiation necrosis and neoplastic growth among patients with recurrent symptoms after radiation therapy. In such cases, a diagnostic tool that provides perfusion measurements with high anatomic detail would show the separation between necrotic areas, which are characterized by low perfusion, from neoplastic areas, which are characterized by elevated CBF. We attempted to validate a dynamic contrast-enhanced CT method for the measurement of regional CBF in brain tumors, and to apply this method by creating CBF maps. ⋯ The dynamic CT method presented herein provides absolute CBF measurements in brain tumors that are accurate and precise. Preliminary CBF maps derived with this method demonstrate their potential for depicting areas of different blood flow within tumors and surrounding tissue, indicating its possible use in the clinical setting.