Brain perfusion-CT in acute stroke patients

Abstract

The role of neuro-imaging in the evaluation of acute stroke has changed dramatically in the past decade. Previously, neuro-imaging was used in this setting to provide anatomic imaging that indicated the presence or absence of acute cerebral ischemia and excluded lesions that produce symptoms or signs mimicking those of stroke, such as hemorrhage and neoplasms. More recently, the introduction of thrombolysis has changed the goals of neuro-imaging from providing solely anatomic information to providing physiologic information that could help to determine which patients might benefit from therapy. In particular, significant emphasis has been placed on the delineation of the ischemic penumbra, also called tissue at risk. Modern CT survey, consisting of three indissociable elements: noncontrast CT (NCT) of course, perfusion-CT (PCT) and CT-angiography (CTA), fulfill all the requirements for hyperacute stroke imaging. CTA can define the occlusion site, depict arterial dissection, grade collateral blood flow, and characterize atherosclerotic disease, whereas PCT accurately delineates the infarct core and the ischemic penumbra. CT offers a number of practical advantages over other cerebral perfusion imaging methods, including its wide availability. Using PCT and CTA to define new individualized strategies for acute reperfusion will allow more acute stroke patients to benefit from thrombolytic therapy.

Renal Safety of CT Angiography and Perfusion Imaging in the Emergency Evaluation of Acute Stroke

“…[5][6][7] Advantages of multimodal CT over MR imaging include its rapid accessibility, lower costs, shorter scanning time intervals, better patient tolerability, and higher spatial resolution. 8,9 Although it is not yet clear whether the information provided by multimodal CT improves stroke outcomes, the increasing use of these imaging methods warrants more thorough assessment of their safety profiles.…”

Steroid-Responsive Large Vessel Vasculitis: Application of Whole-Brain 320-Detector Row Dynamic Volume CT Angiography and Perfusion

“…The advantage of the 16-cm craniocaudal coverage in comparison with 64-section imaging is that the later subvolume scanning focuses on the basal ganglia because ACA, MCA, and PCA territories are all represented on these sections. 3,4 This can be especially limiting in vasculitis because important pathology such as regions of low CBV may not be associated with a specific vascular territory. In cases such as this one with regions of very low CBV, calculations of MTT and TTP (not shown) will be largely influenced by noise, and these maps, when obtained, should be used with caution.…”

“…3,4 The major drawback of PCT to date has been the limited volume coverage achieved with 64-section CT imaging. 3 The 320 ϫ 0.5 mm detector configuration overcomes this limitation and enables assessment of the entire brain using iodinated contrast opacification for a period of time, so-called "dynamic volume CT." The specific advantage in vasculitis is that abnormalities may not follow vascular distributions, requiring whole-brain PCT to identify all findings.…”

CTP-Based Tissue Outcome: Promising Tool to Prove the Beneficial Effect of Mechanical Recanalization in Acute Ischemic Stroke

“…Non-contrast-enhanced CT (NECT) was used for infarct and bleeding detection. Patients with hemorrhagic strokes were excluded [15,16]. NECT was performed using a routine protocol (120 kV, 320 mAs, collimation 2 × 20 × 0.6 mm).…”