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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: The radiological protocol used shows a high sensitivity and excellent specificity for detecting the cerebral circulatory arrest that accompanies BD and is a promising alternative to conventional 4-vessel angiography.
Abstract: Although the diagnosis of brain death (BD) is usually based on clinical criteria, in sedated patients, ancillary techniques are needed. This study was designed to assess the accuracy of cerebral multislice computed tomographic angiography (CTA) and CT perfusion (CTP) in diagnosing BD. Prospective observational study in 27 BD patients. All patients were diagnosed as BD based on clinical and electroencephalogram findings. After BD diagnosis, CTP was performed followed by 64-detector multislice CTA from the aortic arch to the vertex. Images were reconstructed from 0.5 mm sections. In 24 patients, a lack of cerebral blood flow (CBF) was detected by CTP, and CTA revealed luminal narrowing of the internal carotid artery in the neck and absence of anterior and posterior intracranial circulation (sensitivity 89%). CTA detected CBF exclusively in extracranial portions of the internal carotid and vertebral arteries. Two patients with anoxic brain injury and decompressive craniectomy showed CBF in the CTA such that the CTP results were considered false negatives, given BD had been confirmed by clinical and EEG findings, along with evoked potentials. In one clinically BD patient, in whom an alpha rhythm was detected in the electroencephalogram, CBF was only observed in the intracranial internal carotid with no posterior circulation noted. This patient was therefore considered exclusively brain stem dead. The radiological protocol used shows a high sensitivity and excellent specificity for detecting the cerebral circulatory arrest that accompanies BD. As a rapid, non-invasive, and widely available technique it is a promising alternative to conventional 4-vessel angiography.

94 citations

Journal ArticleDOI
01 Dec 2015-Stroke
TL;DR: CTP seems useful for predicting functional outcome, but cannot reliably identify patients who will not benefit from intra-arterial therapy.
Abstract: Background and Purpose— The utility of computed tomographic perfusion (CTP)–based patient selection for intra-arterial treatment of acute ischemic stroke has not been proven in randomized trials and requires further study in a cohort that was not selected based on CTP. Our objective was to study the relationship between CTP-derived parameters and outcome and treatment effect in patients with acute ischemic stroke because of a proximal intracranial arterial occlusion. Methods— We included 175 patients who underwent CTP in the Multicenter Randomized Clinical Trial of Endovascular Treatment for Acute Ischemic Stroke in The Netherlands (MR CLEAN). Association of CTP-derived parameters (ischemic-core volume, penumbra volume, and percentage ischemic core) with outcome was estimated with multivariable ordinal logistic regression as an adjusted odds ratio for a shift in the direction of a better outcome on the modified Rankin Scale. Interaction between CTP-derived parameters and treatment effect was determined using multivariable ordinal logistic regression. Interaction with treatment effect was also tested for mismatch (core 1.2; penumbra core >10 mL). Results— The adjusted odds ratio for improved functional outcome for ischemic core, percentage ischemic core, and penumbra were 0.79 per 10 mL (95% confidence interval: 0.71–0.89; P P =0.002), and 0.97 per 10 mL (96% confidence interval: 0.92–1.01; P =0.15), respectively. No significant interaction between any of the CTP-derived parameters and treatment effect was observed. We observed no significant interaction between mismatch and treatment effect. Conclusions— CTP seems useful for predicting functional outcome, but cannot reliably identify patients who will not benefit from intra-arterial therapy.

94 citations

Journal ArticleDOI
01 May 2014-Stroke
TL;DR: VAH is a frequent vascular variant that can lead to a relative regional hypoperfusion in the PICA territory and additional research should clarify the pathophysiological role of VAH in PCI.
Abstract: Background and Purpose—Vertebral artery hypoplasia (VAH) is supposed to be a risk factor for posterior circulation ischemia (PCI), particularly in the territory of the posterior inferior cerebellar artery (PICA). The aim of our study was to determine whether VAH impedes perfusion in the dependent PICA territory even in the absence of manifest PCI. Methods—VA diameter was retrospectively measured in 934 consecutive patients who underwent whole-brain multimodal computed tomography because of suspected stroke. VAH was defined by a diameter of ≤2 mm and an asymmetry ratio of ≤1:1.7 of both VAs. We performed blinded computed tomography perfusion reading in patients with VAH without PCI (MRI-confirmed) and in control patients (ratio 1:2) with normal VAs. Four different perfusion maps were evaluated for a relative hypoperfusion in the PICA territory. Results—VAH was found in 146 of 934 patients (15.6%). It was more frequent on the right side (66.1%). Of 146 patients, 59 without PCI qualified for computed tomogra...

94 citations

Journal Article
TL;DR: The perfusion defects observed in chronic cocaine polydrug users are partially reversible with short-term abstinence and buprenorphine treatment, and the perfusion abnormalities observed with 99mTc-HMPAO SPECT are part of the results of the first SPECT study.
Abstract: Brain perfusion is abnormal in chronic cocaine users. To determine whether these perfusion abnormalities are reversible following treatment, we studied 10 cocaine-dependent polydrug users with 99mTc-HMPAO SPECT 2 to 3 days after admission to an inpatient treatment facility and at 7 to 8 days and 17 to 29 days after abstinence from drugs. The patients also received buprenorphine, an opioid mixed agonist-antagonist, beginning 10 days after admission and continuing to the end of the study. Imaging began 10-15 min after injection of 99mTc-HMPAO (20 mCi) using an annular gamma camera system. MRI was performed during hospitalization using a 1.5 Tesla system. SPECT and MRI were merged and five axial SPECT slices centered at the level of the basal ganglia were selected for analysis. Activity ratios were derived for cortical regions relative to cerebellar activity and were corrected for linearity with respect to regional cerebral blood flow. The cortical regions were classified as abnormal (activity ratio 0.72) based on the results of the first SPECT study. In abnormal zones, regional cerebral blood flow (rCBF) increased 11.0% +/- 9.0% at 7 to 8 days and 23.8% +/- 9.4% at 17 to 29 days after initiation of treatment. The increase in rCBF was 4.8% +/- 7.1% (7 to 8 days) and 11.1% +/- 8.0% (17 to 29 days) in borderline cortex and decreased 2.9% +/- 6.3% (7 to 8 days) and increased only 2.7% +/- 13.4% (17 to 29 days) in normal cortex. The increase in rCBF did not vary significantly by location. The perfusion defects observed in chronic cocaine polydrug users are partially reversible with short-term abstinence and buprenorphine treatment.

94 citations

Journal ArticleDOI
TL;DR: The important effect of lithium withdrawal on brain perfusion implies that after withdrawal of lithium, the brain develops an abnormal state of activity in limbic cortex.
Abstract: BACKGROUND Early manic relapse following lithium discontinuation offers an important opportunity to investigate the relationship between symptoms, effects of treatment and regional brain activation in bipolar affective disorder. METHOD Fourteen stable bipolar patients on lithium were examined with neuropsychological measures, clinical ratings and single photon emission computed tomography (SPECT) before and after acute double-blind withdrawal of lithium. Brain perfusion maps were spatially transformed into standard stereotactic space and compared pixel-by-pixel. A parametric analysis was used to examine the change in brain perfusion on lithium withdrawal, and the relationship between symptom severity and brain perfusion separately both between and within subjects. RESULTS Lithium withdrawal was associated with an important redistribution of brain perfusion, with increases in inferior posterior regions and decreases in limbic areas, particularly anterior cingulate cortex. Seven of the 14 patients developed manic symptoms during the placebo phase, correlating with relative increases in perfusion of superior anterior cingulate and possibly left orbito-frontal cortex. CONCLUSIONS The important effect of lithium withdrawal on brain perfusion implies that after withdrawal of lithium, the brain develops an abnormal state of activity in limbic cortex. The structures involved did not co-localise with those apparently modulated by manic symptoms.

94 citations


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