scispace - formally typeset
Search or ask a question
Topic

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.


Papers
More filters
Journal ArticleDOI
TL;DR: In patients with ischemic stroke with a proximal cerebral arterial occlusion and salvageable tissue on CT perfusion imaging, early thrombectomy with the Solitaire FR stent retriever, as compared with alteplase alone, improved reperfusion, early neurologic recovery, and functional outcome.
Abstract: Background Trials of endovascular therapy for ischemic stroke have produced variable results. We conducted this study to test whether more advanced imaging selection, recently developed devices, and earlier intervention improve outcomes. Methods We randomly assigned patients with ischemic stroke who were receiving 0.9 mg of alteplase per kilogram of body weight less than 4.5 hours after the onset of ischemic stroke either to undergo endovascular thrombectomy with the Solitaire FR (Flow Restoration) stent retriever or to continue receiving alteplase alone. All the patients had occlusion of the internal carotid or middle cerebral artery and evidence of salvageable brain tissue and ischemic core of less than 70 ml on computed tomographic (CT) perfusion imaging. The coprimary outcomes were reperfusion at 24 hours and early neurologic improvement (≥8-point reduction on the National Institutes of Health Stroke Scale or a score of 0 or 1 at day 3). Secondary outcomes included the functional score on the modified Rankin scale at 90 days. Results The trial was stopped early because of efficacy after 70 patients had undergone randomization (35 patients in each group). The percentage of ischemic territory that had undergone reperfusion at 24 hours was greater in the endovascular-therapy group than in the alteplase-only group (median, 100% vs. 37%; P<0.001). Endovascular therapy, initiated at a median of 210 minutes after the onset of stroke, increased early neurologic improvement at 3 days (80% vs. 37%, P = 0.002) and improved the functional outcome at 90 days, with more patients achieving functional independence (score of 0 to 2 on the modified Rankin scale, 71% vs. 40%; P = 0.01). There were no significant differences in rates of death or symptomatic intracerebral hemorrhage. Conclusions In patients with ischemic stroke with a proximal cerebral arterial occlusion and salvageable tissue on CT perfusion imaging, early thrombectomy with the Solitaire FR stent retriever, as compared with alteplase alone, improved reperfusion, early neurologic recovery, and functional outcome. (Funded by the Australian National Health and Medical Research Council and others; EXTEND-IA ClinicalTrials.gov number, NCT01492725, and Australian New Zealand Clinical Trials Registry number, ACTRN12611000969965.)

4,562 citations

Journal ArticleDOI
TL;DR: The results suggest that functional activity of the bilateral superior parietal lobules is closely related to performance time on the TMT-A, which might be a promising index of dysfunction of the superiorParietal area among mild AD patients.
Abstract: Background/Aims: The Trail Making Test (TMT) has long been used to investigate deficits in cognitive processing speed and executive function in humans. However, t

2,862 citations

Journal ArticleDOI
23 May 1990-JAMA
TL;DR: Follow-up and angiography together suggest pulmonary embolism occurred among 12% of patients with low-probability scans, and clinical assessment combined with the ventilation/perfusion scan established the diagnosis or exclusion of pulmonary emblism only for a minority of patients--those with clear and concordant clinical and ventilation-perfusions scan findings.
Abstract: To determine the sensitivities and specificities of ventilation/perfusion lung scans for acute pulmonary embolism, a random sample of 933 of 1493 patients was studied prospectively. Nine hundred thirty-one underwent scintigraphy and 755 underwent pulmonary angiography; 251 (33%) of 755 demonstrated pulmonary embolism. Almost all patients with pulmonary embolism had abnormal scans of high, intermediate, or low probability, but so did most without pulmonary embolism (sensitivity, 98%; specificity, 10%). Of 116 patients with high-probability scans and definitive angiograms, 102 (88%) had pulmonary embolism, but only a minority with pulmonary embolism had high-probability scans (sensitivity, 41%; specificity, 97%). Of 322 with intermediate-probability scans and definitive angiograms, 105 (33%) had pulmonary embolism. Follow-up and angiography together suggest pulmonary embolism occurred among 12% of patients with low-probability scans. Clinical assessment combined with the ventilation/perfusion scan established the diagnosis or exclusion of pulmonary embolism only for a minority of patients--those with clear and concordant clinical and ventilation/perfusion scan findings.

2,468 citations

Journal ArticleDOI
TL;DR: Endovascular thrombectomy for ischemic stroke 6 to 16 hours after a patient was last known to be well plus standard medical therapy resulted in better functional outcomes than standard medical Therapy alone among patients with proximal middle‐cerebral‐artery or internal‐carotid‐arterY occlusion and a region of tissue that was ischeMIC but not yet infarcted.
Abstract: Background Thrombectomy is currently recommended for eligible patients with stroke who are treated within 6 hours after the onset of symptoms. Methods We conducted a multicenter, randomized, open-label trial, with blinded outcome assessment, of thrombectomy in patients 6 to 16 hours after they were last known to be well and who had remaining ischemic brain tissue that was not yet infarcted. Patients with proximal middle-cerebral-artery or internal-carotid-artery occlusion, an initial infarct size of less than 70 ml, and a ratio of the volume of ischemic tissue on perfusion imaging to infarct volume of 1.8 or more were randomly assigned to endovascular therapy (thrombectomy) plus standard medical therapy (endovascular-therapy group) or standard medical therapy alone (medical-therapy group). The primary outcome was the ordinal score on the modified Rankin scale (range, 0 to 6, with higher scores indicating greater disability) at day 90. Results The trial was conducted at 38 U.S. centers and termina...

2,292 citations

Journal ArticleDOI
TL;DR: Perfusion images of a freeze-injured rat brain have been obtained, demonstrating the technique's ability to detect regional abnormalities in perfusion.
Abstract: A technique has been developed for proton magnetic resonance imaging (MRI) of perfusion, using water as a freely diffusable tracer, and its application to the measurement of cerebral blood flow (CBF) in the rat is demonstrated. The method involves labeling the inflowing water proton spins in the arterial blood by inverting them continuously at the neck region and observing the effects of inversion on the intensity of brain MRI. Solution to the Bloch equations, modified to include the effects of flow, allows regional perfusion rates to be measured from an image with spin inversion, a control image, and a T1 image. Continuous spin inversion labeling the arterial blood water was accomplished, using principles of adiabatic fast passage by applying continuous-wave radiofrequency power in the presence of a magnetic field gradient in the direction of arterial flow. In the detection slice used to measure perfusion, whole brain CBF averaged 1.39 +/- 0.19 ml.g-1.min-1 (mean +/- SEM, n = 5). The technique's sensitivity to changes in CBF was measured by using graded hypercarbia, a condition that is known to increase brain perfusion. CBF vs. pCO2 data yield a best-fit straight line described by CBF (ml.g-1.min-1) = 0.052pCO2 (mm Hg) - 0.173, in excellent agreement with values in the literature. Finally, perfusion images of a freeze-injured rat brain have been obtained, demonstrating the technique's ability to detect regional abnormalities in perfusion.

1,500 citations


Network Information
Related Topics (5)
Magnetic resonance imaging
61K papers, 1.5M citations
88% related
Ejection fraction
47.6K papers, 1.6M citations
82% related
Coronary artery disease
77.6K papers, 2.2M citations
81% related
Ischemia
53.6K papers, 1.9M citations
80% related
Stroke
112.7K papers, 3.7M citations
80% related
Performance
Metrics
No. of papers in the topic in previous years
YearPapers
2023181
2022372
2021394
2020362
2019407
2018336