Evaluation of CT Perfusion in the Setting of Cerebral Ischemia: Patterns and Pitfalls

Lui, Yvonne W.; Tang, Elizabeth R.; Allmendinger, Andrew M.; Spektor, Vadim

doi:10.3174/ajnr.a2026

Cited by 121 publications

(91 citation statements)

References 64 publications

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“…CTP studies show that there is a high rate of intracerebral perfusion deficits that occur without subsequent ischemic lesions in the follow-up MRI. 11,[23][24][25] In ≤20% of patients without cerebral infarction, time-related maps, such as MMT and time to peak, showed a perfusion deficit, whereas CBF showed a perfusion deficit in 5% of the patients without infarction. 11 Our results indicate that infratentorial perfusion deficits, which sometimes are regarded as false-positive, can actually have a pathophysiologic background.…”

Section: May 2014mentioning

confidence: 99%

Vertebral Artery Hypoplasia

Thierfelder

Baumann

Sommer

et al. 2014

Stroke

104

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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, 59without PCI qualified for computed tomography perfusion analysis. Depending on the perfusion map, ≤42.4% (25/59) of patients with VAH, but only 7.6% (9/118) without VAH, showed an ipsilateral PICA hypoperfusion (P<0.001). Sensitivities in patients with VAH were as follows: time to drain 42.4% (25/59)>mean transit time 39.0% (23/59)>cerebral blood flow 25.4% (15/59). Cerebral blood volume was never affected. Conclusions-VAH is a frequent vascular variant that can lead to a relative regional hypoperfusion in the PICA territory.Additional research should clarify the pathophysiological role of VAH in PCI.

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Section: May 2014mentioning

confidence: 99%

Vertebral Artery Hypoplasia

Thierfelder

Baumann

Sommer

et al. 2014

Stroke

104

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“…[4][5][6] Additional known pitfalls of CTP analysis include incorrect placement of the perfusion volume, incorrect selection and variability of the AIF and VOF, chance of missing small infarcts due to the low resolution of CTP analysis, and changes in perfusion due to extracranial and intracranial stenosis. 7 On the other hand, it has recently been shown that despite the general belief, the order of scanning (CTA before or after CTP) has no significant influence on quantitative CTP parameters. 8 Although commercial software packages for CTP analysis are widely available, there is currently no standardized method for the analysis.…”

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confidence: 99%

Differences in CT Perfusion Summary Maps for Patients with Acute Ischemic Stroke Generated by 2 Software Packages

Fahmi

Marquering

Streekstra

et al. 2012

AJNR Am J Neuroradiol

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“…Previous cerebrovascular incidents may form internal weak spots which may converge with external circumstances (evacuation/pressure relief) resulting in a massive intracerbral bleeding and death [5,10]. Therefore, perfusion CT may be necessary before evacuating a large subdural hematoma to differentiate salvageable ischemic penumbra from unsalvageable infarcted brain tissue under the hematoma [18]. This may help identify patients most likely to benefit from hematoma evacuation and decrease the risk of secondary inctracerebral bleeding.…”

Section: Discussionmentioning

confidence: 99%

Extra Investigation Might Be Necessary in High-Risk CT-Negative Cerebrovascular Cases

Walid¹,

Zaytseva²

2013

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Cerebrovascular accidents occur in elderly patients in whom neurodegenerative changes increase the risk of vascular permeation and concomitant intracranial bleeding. In rare cases, intracerebral massive hemorrhage happens in hospitalized patients with apparently stable clinical picture. We report two cases illustrating this phenomenon, discuss the possible pathomechanism involved in those tragic incidents and suggest possible prevention measures for these patients. A negative CT image in a patient with neurological symptoms, especially who are on warfarin with or without considerably elongated coagulation time, may be subject to a sudden intracranial hemorrhage. Microvascular abnormalities might be detected on perfusion CT imaging and should therefore be performed in all CT negative patients with close observation for 24 hours before contemplating discharge.

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Evaluation of CT Perfusion in the Setting of Cerebral Ischemia: Patterns and Pitfalls

Cited by 121 publications

References 64 publications

Vertebral Artery Hypoplasia

Vertebral Artery Hypoplasia

Differences in CT Perfusion Summary Maps for Patients with Acute Ischemic Stroke Generated by 2 Software Packages

Extra Investigation Might Be Necessary in High-Risk CT-Negative Cerebrovascular Cases

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