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.

Imaging of Diffusion and Microcirculation with Gradient Sensitization: Design, Strategy, and Significance'

Abstract: Recent developments in the use of magnetic resonance (MR) to measure and image diffusion and blood microcirculation (“perfusion”) are summarized. After a brief description of the effects of diffusion and perfusion on the MR signal, the different methods (conventional spin-echo, stimulated-echo, gradient-echo, and echo-planar imaging) that have been proposed and used to image and measure diffusion and perfusion by gradient sensitization are presented, along with their advantages and limitations. The difficulties of diffusion/ perfusion imaging related to both hardware and software are then discussed. Special attention is given to specific problems encountered with in vivo studies and data analysis. Finally, the potential biologic and clinical applications are outlined, and some examples are presented.

Differentiation of glioblastoma multiforme and single brain metastasis by peak height and percentage of signal intensity recovery derived from dynamic susceptibility-weighted contrast-enhanced perfusion MR imaging.

Abstract: BACKGROUND AND PURPOSE: Glioblastoma multiforme (GBM) and single brain metastasis (MET) are the 2 most common malignant brain tumors that can appear similar on anatomic imaging but require vastly different treatment strategy. The purpose of our study was to determine whether the peak height and the percentage of signal intensity recovery derived from dynamic susceptibility-weighted contrast-enhanced (DSC) perfusion MR imaging could differentiate GBM and MET. MATERIALS AND METHODS: Forty-three patients with histopathologic diagnosis of GBM ( n = 27) or MET ( n = 16) underwent DSC perfusion MR imaging in addition to anatomic MR imaging before surgery. Regions of interest were drawn around the nonenhancing peritumoral T2 lesion (PTL) and the contrast-enhancing lesion (CEL). T2* signal intensity-time curves acquired during the first pass of gadolinium contrast material were converted to the changes in relaxation rate to yield T2* relaxivity (ΔR2*) curve. The peak height of maximal signal intensity drop and the percentage of signal intensity recovery at the end of first pass were measured for each voxel in the PTL and CEL regions of the tumor. RESULTS: The average peak height for the PTL was significantly higher ( P = .04) in GBM than in MET. The average percentage of signal intensity recovery was significantly reduced in PTL (78.4% versus 82.8%; P = .02) and in CEL (62.5% versus 80.9%, P < .01) regions of MET compared with those regions in the GBM group. CONCLUSIONS: The findings of our study show that the peak height and the percentage of signal intensity recovery derived from the ΔR2* curve of DSC perfusion MR imaging can differentiate GBM and MET.

The physiologic basis of dobutamine as compared with dipyridamole stress interventions in the assessment of critical coronary stenosis.

Abstract: Noninvasive cardiac imaging with echocardiography or thallium-201 scintigraphy utilizing pharmacologic agents as alternatives to exercise is gaining popularity. We investigated the physiologic rationale underlying the optimal choice of pharmacologic stress for functional versus perfusion imaging. With the use of an open-chest dog model, a critical stenosis of the left circumflex coronary artery was produced with total ablation of hyperemic response to a 15 sec period of complete occlusion. Regional left ventricular wall thickening was assessed by quantitative two-dimensional echocardiography. Regional myocardial blood flow was determined by microspheres in both the flow-restricted left circumflex area and the control area supplied by the left anterior descending artery. Eight dogs received 15 micrograms/kg/min dobutamine intravenously for 10 min, and nine dogs received 0.14 mg/kg/min dipyridamole intravenously for 4 min. Dobutamine induced wall thickening abnormalities in all dogs while dipyridamole induced dysfunction in only 55% of the animals studied (p less than .01). Subendocardial blood flow to the left circumflex area was unchanged after both dobutamine and dipyridamole when compared with baseline blood flow. However, subendocardial blood flow increased markedly after dipyridamole in the control area. Regional subendocardial blood flow ratio (left anterior descending/left circumflex) was 3.74 +/- 0.09 (mean +/- SEM) after dipyridamole versus 1.27 +/- 0.09 after dobutamine (p less than .001).(ABSTRACT TRUNCATED AT 250 WORDS)

Detection of hemodynamically significant coronary artery stenosis: incremental diagnostic value of dynamic CT-based myocardial perfusion imaging.

Abstract: Dynamic CT-based stress myocardial perfusion imaging may allow for determination of the hemodynamic relevance of coronary artery stenosis by providing quantitative perfusion estimates.