86 research outputs found
Brain volume perfusion CT performed with 128-detector row CT system in patients with cerebral gliomas: A feasibility study
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
Hemodynamic alterations in unilateral chronic middle cerebral artery stenosis patients and the effect of percutaneous transluminal angioplasty and stenting: a perfusion-computed tomography study
Differences in perfusion CT parameter values with commercial software upgrades: a preliminary report about algorithm consistency and stability
On the normalization of cerebral blood flow.
International audienceCerebral blood flow (CBF) is the most common parameter for the quantification of brain's function. Literature data indicate a widespread dispersion of values that might be related to some differences in the measurement conditions that are not properly taken into account in CBF evaluation. Using recent high-resolution imaging of the complete cortical microvasculature of primate brain, we perform extensive numerical evaluation of the cerebral perfusion. We show that blood perfusion associated with intravascular tracers should be normalized by the surface of the voxel rather than by its volume and we consistently test this result on the available literature data
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