103 research outputs found
Brain volume perfusion CT performed with 128-detector row CT system in patients with cerebral gliomas: A feasibility study
Validation of the feasibility and efficacy of volume perfusion computed tomography (VPCT) in the preoperative assessment of cerebral gliomas by applying a 128-slice CT covering the entire tumour. Forty-six patients (25 men, 21 women; mean age 52.8 years) with cerebral gliomas were evaluated with VPCT. Two readers independently evaluated VPCT data, drawing volumes of interest (VOIs) around the tumour according to maximum intensity projection volumes, which were mapped automatically onto the cerebral blood volume (CBV), flow (CBF) and permeability (Ktrans) perfusion datasets. As control, a second VOI was placed in the contralateral healthy cortex. Correlation among perfusion parameters, tumour grade, hemisphere and VOIs was assessed. The diagnostic power of perfusion parameters was analysed by receiver operating characteristics curve analyses. VPCT was feasible in the assessment of the entire tumour extent. Mean values of Ktrans, CBV, CBF in high-grade gliomas were significantly higher compared with low-grade (p < 0.01). Ktrans demonstrated the highest diagnostic (97% sensitivity), positive (100%) and negative (94%) prognostic values. VPCT was feasible in all subjects. All areas of different perfusion characteristics are depicted and quantified in colour-coded 3D maps. The derived parameters correlate well with tumour histopathology, differentiating low- from high-grade gliomas
Quantitative analysis of CT-perfusion parameters in the evaluation of brain gliomas and metastases
<p>Abstract</p> <p>Background</p> <p>The paper reports a quantitative analysis of the perfusion maps of 22 patients, affected by gliomas or by metastasis, with the aim of characterizing the malignant tissue with respect to the normal tissue. The gold standard was obtained by histological exam or nuclear medicine techniques. The perfusion scan provided 11 parametric maps, including Cerebral Blood Volume (CBV), Cerebral Blood Flow (CBF), Average Perfusion (P<sub>mean</sub>) and Permeability-surface area product (PS).</p> <p>Methods</p> <p>The perfusion scans were performed after the injection of 40 ml of non-ionic contrast agent, at an injection rate of 8 ml/s, and a 40 s cine scan with 1 s interval was acquired. An expert radiologist outlined the region of interest (ROI) on the unenhanced CT scan, by using a home-made routine. The mean values with their standard deviations inside the outlined ROIs and the contralateral ROIs were calculated on each map. Statistical analyses were used to investigate significant differences between diseased and normal regions. Receiving Operating Characteristic (ROC) curves were also generated.</p> <p>Results</p> <p>Tumors are characterized by higher values of all the perfusion parameters, but after the statistical analysis, only the <it>PS</it>, <it>Pat</it><sub><it>Rsq </it></sub>(Patlak Rsquare) and <it>T</it><sub><it>peak </it></sub>(Time to Peak) resulted significant. ROC curves, confirmed both <it>Pat</it><sub><it>Rsq </it></sub>and <it>PS </it>as equally reliable metrics for discriminating between malignant and normal tissues, with areas under curves (AUCs) of 0.82 and 0.81, respectively.</p> <p>Conclusion</p> <p>CT perfusion is a useful and non invasive technique for evaluating brain neoplasms. Malignant and normal tissues can be accurately differentiated using perfusion map, with the aim of performing tumor diagnosis and grading, and follow-up analysis.</p
Timing and minimal access surgery for sciatica: a summary of two randomized trials
Scientific Assessment and Innovation in Neurosurgical Treatment Strategie
Un basculement de la tête vers le haut et l’hyperventilation entraînent des modifications semblabes de l’oxygénation cérébrale et du volume sanguin: étude comparative observationnelle utilisant la spectroscopie infrarouge proche
Reproducibility and Comparison of DCE-MRI and DCE-CT Perfusion Parameters in a Rat Tumor Model
Primary supratentorial intracerebral malignant paraganglioma
Paragangliomas are extra-adrenal neuroendocrine tumours that derive from neural crest. They are benign tumours in general but few cases had shown their tendency to metastasize. Malignant forms have been reported previously with intracranial metastasis from duodenal origin but primary intracranial origin represent a rare and unusual location for such tumours. We report a rare case for a 48 year old lady who presented with symptomatic right sided insular mass with negative metastatic work up. A complete surgical resection had been done with an unexpected diagnosis of primary gangliocytic paraganglioma with malignant features.</jats:p
Hemodynamic alterations in unilateral chronic middle cerebral artery stenosis patients and the effect of percutaneous transluminal angioplasty and stenting: a perfusion-computed tomography study
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