Perfusion scanning

About: Perfusion scanning is a research topic. Over the lifetime, 9496 publications have been published within this topic receiving 223860 citations. The topic is also known as: perfusion imaging.

Coronary microvascular ischemia in hypertrophic cardiomyopathy - a pixel-wise quantitative cardiovascular magnetic resonance perfusion study

Abstract: Background Microvascular dysfunction in HCM has been associated with adverse clinical outcomes. Advances in quantitative cardiovascular magnetic resonance (CMR) perfusion imaging now allow myocardial blood flow to be quantified at the pixel level. We applied these techniques to investigate the spectrum of microvascular dysfunction in hypertrophic cardiomyopathy (HCM) and to explore its relationship with fibrosis and wall thickness.

Variability of physiological brain perfusion in healthy subjects - A systematic review of modifiers. Considerations for multi-center ASL studies.

Abstract: Quantitative measurements of brain perfusion are influenced by perfusion-modifiers. Standardization of measurement conditions and correction for important modifiers is essential to improve accuracy and to facilitate the interpretation of perfusion-derived parameters. An extensive literature search was carried out for factors influencing quantitative measurements of perfusion in the human brain unrelated to medication use. A total of 58 perfusion modifiers were categorized into four groups. Several factors (e.g., caffeine, aging, and blood gases) were found to induce a considerable effect on brain perfusion that was consistent across different studies; for other factors, the modifying effect was found to be debatable, due to contradictory results or lack of evidence. Using the results of this review, we propose a standard operating procedure, based on practices already implemented in several research centers. Also, a theory of ‘deep MRI physiotyping’ is inferred from the combined knowledge of factors influencing brain perfusion as a strategy to reduce variance by taking both personal information and the presence or absence of perfusion modifiers into account. We hypothesize that this will allow to personalize the concept of normality, as well as to reach more rigorous and earlier diagnoses of brain disorders.

Magnetic resonance imaging of regional myocardial perfusion in patients with single-vessel coronary artery disease: quantitative comparison with (201)Thallium-SPECT and coronary angiography.

Abstract: The clinical value of magnetic resonance perfusion imaging (MRI) was investigated by quantitative comparison with 201thallium-single-photon emission computed tomography (201TI-SPECT) and quantitative coronary angiography (QCA). Short-axis imaging was performed during dipyridamole administration in 13 patients with single-vessel coronary artery disease. Using inner and outer contours, the myocardium was divided into 30 contiguous, radial regions. Defining a perfusion defect as a region with less than 90% of maximum 201TI intensity, nine patients had a matching perfusion defect, two had no defect on both 201TI-SPECT or MRI, and one had a defect on 201TI-SPECT but not on MRI. One patient had a defect on both modalities but with inaccurate localization. Three perfusion parameters were investigated: a) maximum contrast enhancement (MCE); b) slope of the signal intensity versus time curve; and c) inverse mean transit time (1/MTT). The sensitivity and specificity of MCE in the detection of perfusion abnormalities with TI-SPECT as the reference method were 71% and 71%, respectively (slope 77% and 61%, 1/MTT 44% and 70%). Furthermore, correlations were calculated per patient for the entire circumference of the short-axis myocardium. Median correlations were as follows: MCE 0.92, slope 0.91, and 1/MTT 0.40. Mismatches between 201TI defects and defects on MRI resulted in low mean correlations (MCE 0.45, slope 0.46, and 1/MTT 0.26). There was a trend between severity of perfusion defects on MRI (using MCE) and QCA stenosis area (r = −0.56, P = 0.06). Thus, MRI and 201TI-SPECT demonstrate fair agreement in the assessment of perfusion defects but show moderate correlation when the entire short-axis myocardium is correlated. J. Magn. Reson. Imaging 2000;11:607–615. © 2000 Wiley-Liss, Inc.

The use of perfusion CT for the evaluation of therapy combining AZD2171 with gefitinib in cancer patients

Abstract: The purpose of this study was to determine the feasibility of dynamic contrast-enhanced perfusion CT (CTP) in evaluating the hemodynamic response of tumors in the chest and abdomen treated with a combination of AZD2171 and gefitinib. Thirteen patients were examined just before and every 4-6 weeks after starting therapy. Following intravenous injection of a contrast agent, dynamic image acquisition was obtained at the level of a selected tumor location. To calculate perfusion, the maximum-slope method was used. Pre-treatment average perfusion for extra-hepatic masses was 84 ml/min/100 g, for liver masses arterial perfusion was 25 ml/min/100 g, and a portal perfusion of 30 ml/min/100 g was found. After the administration of AZD2171 and gefitinib, in extra-hepatic masses an initial decrease in perfusion of 18% was followed by a plateau and in liver masses an initial decrease of 39% within the lesions and of 36% within a rim region surrounding the lesions was followed by a tendency to recovery of hepatic artery flow. In conclusion, CTP is feasible in showing changes of perfusion induced by anti-angiogenic therapy.