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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.


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Journal ArticleDOI
TL;DR: Patients with myalgic encephalomyelitis/chronic fatigue syndrome have a generalized reduction of brain perfusion, with a particular pattern of hypoperfusion of the brainstem, confirmed in all ME/CFS patients.
Abstract: We looked for brain perfusion abnormalities in patients with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). An initial pilot study revealed widespread reduction of regional brain perfusion in 24 ME/CFS patients, compared with 24 normal volunteers. Hypoperfusion of the brainstem (0.72 +/- 0.05 vs. 0.80 +/- 0.04, p < 0.0001) was marked and constant. We then tested whether perfusion to the brainstem in ME/CFS patients differs from that in normals, patients with major depression, and others with epilepsy. Data from a total of 146 subjects were included in the present study: 40 normal volunteers, 67 patients with ME/CFS (24 in the pilot study, 16 with no psychiatric disorders, 13 with ME/CFS and depression, 14 with ME/CFS and other psychiatric disorders), 10 epileptics, 20 young depressed patients and 9 elderly depressed individuals. Brain perfusion ratios were calculated using 99Tcm-hexamethylpropylene amine oxime (99Tcm-HMPAO) and single-photon emission tomography (SPET) with a dedicated three-detector gamma camera computer/system (GE Neurocam). Brain-stem hypoperfusion was confirmed in all ME/CFS patients. Furthermore, the 16 ME/CFS patients with no psychiatric disorders and the initial 24 patients in the pilot study showed significantly lower brainstem perfusion (0.71 +/- 0.03) than did depressed patients (0.77 +/- 0.03; ANOVA, p < 0.0001). Patients with ME/CFS have a generalized reduction of brain perfusion, with a particular pattern of hypoperfusion of the brainstem.

190 citations

Journal ArticleDOI
TL;DR: It is shown that correction of spatially inhomogeneous receiver coil characteristics is easily feasible and leads to clinically valuable perfusion examinations of kidneys without application of potentially nephrotoxic contrast media.
Abstract: Most arterial spin labeling (ASL) techniques apply echoplanar imaging (EPI) because this strategy provides relatively high SNR in short measuring times. Unfortunately, those techniques are very susceptible to static magnetic field inhomogeneities and perfusion signals from organs with fast transverse relaxation might decrease due to the exchange of water molecules in capillaries and organ tissue combined with relatively long echo times of EPI sequences. To overcome these problems a novel imaging technique, FAIR True-FISP, was developed. It combines a FAIR (flow-sensitive alternating inversion recovery) perfusion preparation and a true fast imaging with steady precession (True-FISP) data acquisition strategy. True-FISP was chosen since this sequence type does not show the mentioned disadvantages of EPI, but provides a similar SNR per measuring time. An important problem of this approach is that True-FISP sequences usually work in a steady state which is independent of a previous preparation of magnetization. For this reason a sequence structure had to be developed which keeps the advantages of True-FISP and makes the signal intensity sensitive to the FAIR preparation. Breathhold and nonbreathhold examinations of kidneys are presented and possible strategies to quantitative flow measurements are reported. It is shown that correction of spatially inhomogeneous receiver coil characteristics is easily feasible and leads to clinically valuable perfusion examinations of kidneys without application of potentially nephrotoxic contrast media.

188 citations

Journal ArticleDOI
TL;DR: The frequency and implications for mismatch classification of DLR are investigated using imaging from the EPITHET and DEFUSE studies and the impact of adjusting baseline diffusion lesion volume for DLR volume on perfusion-diffusion mismatch analyzed.
Abstract: Diffusion-weighted imaging (DWI) is commonly used to assess irreversibly infarcted tissue but its accuracy is challenged by reports of diffusion lesion reversal (DLR). We investigated the frequency and implications for mismatch classification of DLR using imaging from the EPITHET (Echoplanar Imaging Thrombolytic Evaluation Trial) and DEFUSE (Diffusion and Perfusion Imaging Evaluation for Understanding Stroke Evolution) studies. In 119 patients (83 treated with IV tissue plasminogen activator), follow-up images were coregistered to acute diffusion images and the lesions manually outlined to their maximal visual extent in diffusion space. Diffusion lesion reversal was defined as voxels of acute diffusion lesion that corresponded to normal brain at follow-up (i.e., final infarct, leukoaraiosis, and cerebrospinal fluid (CSF) voxels were excluded from consideration). The appearance of DLR was visually checked for artifacts, the volume calculated, and the impact of adjusting baseline diffusion lesion volume for DLR volume on perfusion-diffusion mismatch analyzed. Median DLR volume reduced from 4.4 to 1.5 mL after excluding CSF/leukoaraiosis. Visual inspection verified 8/119 (6.7%) with true DLR, median volume 2.33 mL. Subtracting DLR from acute diffusion volume altered perfusion-diffusion mismatch (T(max)>6 seconds, ratio>1.2) in 3/119 (2.5%) patients. Diffusion lesion reversal between baseline and 3 to 6 hours DWI was also uncommon (7/65, 11%) and often transient. Clinically relevant DLR is uncommon and rarely alters perfusion-diffusion mismatch. The acute diffusion lesion is generally a reliable signature of the infarct core.

187 citations

Journal ArticleDOI
01 Aug 1999-Stroke
TL;DR: Combining DWI and PWI in acute (<24 hours) ischemic stroke can predict infarct growth and final size and can detect hypoperfused brain tissue in good agreement with SPECT in acute stroke.
Abstract: Background and Purpose —More effective imaging methods are needed to overcome the limitations of CT in the investigation of treatments for acute ischemic stroke. Diffusion-weighted MRI (DWI) is sensitive in detecting infarcted brain tissue, whereas perfusion-weighted MRI (PWI) can detect brain perfusion in the same imaging session. Combining these methods may help in identifying the ischemic penumbra, which is an important concept in the hemodynamics of acute stroke. The purpose of this study was to determine whether combined DWI and PWI in acute (<24 hours) ischemic stroke can predict infarct growth and final size. Methods —Forty-six patients with acute ischemic stroke underwent DWI and PWI on days 1, 2, and 8. No patient received thrombolysis. Twenty-three patients underwent single-photon emission CT in the acute phase. Lesion volumes were measured from DWI, SPECT, and maps of relative cerebral blood flow calculated from PWI. Results —The mean volume of infarcted tissue detected by DWI increased from 46.1 to 75.6 cm3 between days 1 and 2 ( P <0.001; n=46) and to 78.5 cm3 after 1 week ( P <0.001; n=42). The perfusion-diffusion mismatch correlated with infarct growth ( r =0.699, P <0.001). The volume of hypoperfusion on the initial PWI correlated with final infarct size ( r =0.827, P <0.001). The hypoperfusion volumes detected by PWI and SPECT correlated significantly ( r =0.824, P <0.001). Conclusions —Combined DWI and PWI can predict infarct enlargement in acute stroke. PWI can detect hypoperfused brain tissue in good agreement with SPECT in acute stroke.

186 citations

Journal ArticleDOI
TL;DR: In patients with severe LV dysfunction, the amount of scar was a significant independent predictor of LV function recovery after revascularization, and a combination of PET and clinical parameters predicts the degree of recovery.

186 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
2023181
2022372
2021394
2020362
2019407
2018336