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.

Volumetric cerebral perfusion imaging in healthy adults: Regional distribution, laterality, and repeatability of pulsed continuous arterial spin labeling (PCASL)

Abstract: The regional distribution, laterality, and reliability of volumetric pulsed continuous arterial spin labeling (PCASL) measurements of cerebral blood flow (CBF) in cortical, subcortical, and cerebellar regions were determined in 10 normal volunteers studied on two occasions separated by 3 to 7 days. Regional CBF, normalized for global perfusion, was highly reliable when measured on separate days. Several regions showed significant lateral asymmetry; notably, in frontal regions CBF was greater in the right than left hemisphere, whereas left was greater than right in posterior regions. There was considerable regional variability across the brain, whereby the posterior cingulate and central and posterior precuneus cortices had the highest perfusion and the globus pallidus the lowest gray matter perfusion. The latter may be due to iron-induced T1 shortening affecting labeled spins and computed CBF signal. High CBF in the posterior cingulate and posterior and central precuneus cortices in this task-free acquisition suggests high activity in these principal nodes of the “default mode network.”

Cardiac magnetic resonance imaging with pharmacological stress perfusion and delayed enhancement in asymptomatic patients with systemic sclerosis

Abstract: ### Objective. To assess cardiac involvement in asymptomatic patients with systemic sclerosis (SSc) by cardiac magnetic resonance imaging (MRI). ### Methods. Ten asymptomatic patients with SSc (all female; mean age 59.5 ± 9.4 yrs) underwent contrast enhanced cardiac MRI on a 1.5 T MRI device. Adenosine triphosphate was used for stress and rest perfusion to assess perfusion defects due to microvascular impairment or ischemia, and delayed enhanced (DE) imaging was obtained for the assessment of myocardial necrosis and fibrosis. We evaluated the pathophysiological associations of stress perfusion combined with DE imaging with SSc disease severity measures. ### Results. Stress perfusion defects were seen in 5 out of 9 patients (56%): 4 had nonsegmental subendocardial perfusion defects and one had a segmental subendocardial perfusion defect. Three patients were found to have DE. DE was not observed in any patient without perfusion defect; and among the 5 patients with perfusion defects, 3 (60%) had DE. Two of the 3 had DE in segments not matching the region of nonsegmental perfusion defects. The remaining one had a segmental subendocardial DE matching the region of a segmental perfusion defect. Perfusion defects were seen in 75% of patients with a history of digital ulceration compared to only 20% of those without history of ulceration. ### Conclusion. Subclinical myocardial involvement, as detected by cardiac MRI, was frequent in asymptomatic patients with SSc. Cardiac MRI may aid in understanding the pathophysiological mechanism of SSc.

Altered cerebral perfusion measured by SPECT in relatives of patients with schizophrenia. Correlations with memory and P300.

Abstract: BACKGROUND Genetic studies in schizophrenia are hampered by the complex heterogeneous clinical phenotype. Biological variables identified as trait markers of risk could clarify the mode of inheritance, define clinical subgroups and provide clues about aetiology. AIMS To use single photon emission computed tomography (SPECT) to compare brain perfusion maps in patients with schizophrenia (n = 19), their asymptomatic 'high-risk' relatives (n = 36) and control subjects (n = 34) and to examine the relationships between imaging, memory and P300 event-related potential. METHOD SPECT, memory tests and P300 recording were carried out. RESULTS In the patients with schizophrenia and their relatives, perfusion was reduced in left inferior prefrontal and anterior cingulate cortex and increased bilaterally in a subcortical region. Perfusion significantly correlated with verbal memory and P300 amplitude in left inferior prefrontal cortex and with P300 latency in anterior cingulate cortex. CONCLUSIONS Medication- and symptom-free relatives had altered regional perfusion intermediate between subjects with schizophrenia and controls. Impaired perfusion, verbal memory and P300 appear to be related traits associated with an increased risk of illness.

Impact of anatomical and functional severity of coronary atherosclerotic plaques on the transmural perfusion gradient: a [15O]H2O PET study.

Abstract: Background Myocardial ischaemia occurs principally in the subendocardial layer, whereas conventional myocardial perfusion imaging provides no information on the transmural myocardial blood flow (MBF) distribution. Subendocardial perfusion measurements and quantification of the transmural perfusion gradient (TPG) could be more sensitive and specific for the detection of coronary artery disease (CAD). The current study aimed to determine the impact of lesion severity as assessed by the fractional flow reserve (FFR) on subendocardial perfusion and the TPG using [15O]H2O positron emission tomography (PET) imaging in patients evaluated for CAD. Methods and results Sixty-six patients with anginal chest pain were prospectively enrolled and underwent [15O]H2O myocardial perfusion PET imaging. Subsequently, invasive coronary angiography was performed and FFR obtained in all coronary arteries irrespective of the PET imaging results. Thirty (45%) patients were diagnosed with significant CAD (i.e. FFR ≤0.80), whereas on a per vessel analysis ( n = 198), 53 (27%) displayed a positive FFR. Transmural hyperaemic MBF decreased significantly from 3.09 ± 1.16 to 1.67 ± 0.57 mL min−1 g−1 ( P < 0.001) in non-ischaemic and ischaemic myocardium, respectively. The TPG decreased during hyperaemia when compared with baseline (1.20 ± 0.14 vs. 0.94 ± 0.17, P < 0.001), and was lower in arteries with a positive FFR (0.97 ± 0.16 vs. 0.88 ± 0.18, P < 0.01). A TPG threshold of 0.94 yielded an accuracy to detect CAD of 59%, which was inferior to transmural MBF with an optimal cutoff of 2.20 mL min−1 g−1 and an accuracy of 85% ( P < 0.001). Diagnostic accuracy of subendocardial perfusion measurements was comparable with transmural MBF (83 vs. 85%, respectively, P = NS). Conclusion Cardiac [15O]H2O PET imaging is able to distinguish subendocardial from subepicardial perfusion in the myocardium of normal dimensions. Hyperaemic TPG is significantly lower in ischaemic myocardium. This technique can potentially be employed to study subendocardial perfusion impairment in more detail. However, the diagnostic accuracy of subendocardial hyperaemic perfusion and TPG appears to be limited compared with quantitative transmural MBF, warranting further study.