Detection of Misery Perfusion With Split-Dose ¹²³ I-Iodoamphetamine Single-Photon Emission Computed Tomography in Patients With Carotid Occlusive Diseases

Abstract

Background and Purpose-Patients with carotid occlusive disease and stage 2 cerebral hemodynamic failure, characterized by an increased oxygen extraction fraction (OEF) as measured by positron emission tomography (PET) and otherwise known as misery perfusion, have a high risk of cerebral ischemia and subsequent stroke. In clinical practice, the detection of patients with misery perfusion through the use of widely available, noninvasive, and cost-effective modalities such as single-photon emission computed tomography (SPECT) is extremely important. Methods-We evaluated the relationships between the regional hemodynamic status of cerebral circulation, measured with split-dose [ 123 I] N-isopropyl-p-iodoamphetamine SPECT ( 123 I-IMP SPECT) and an acetazolamide challenge, and hemodynamic parameters, including OEF measured with PET, in 27 patients with both unilateral and bilateral carotid occlusive diseases. Results-A significant negative correlation was found between the SPECT-measured cerebrovascular reserve after acetazolamide administration and both the PET-measured OEF and cerebral blood volume. Neither the cerebrovascular reserve nor the cerebral blood flow index, when expressed as a SPECT-measured cerebrum-to-cerebellum ratio, was useful for detecting lesions with an elevated OEF. However, a combination of the cerebrovascular reserve and cerebral blood flow index showed high sensitivity, specificity, and positive predictive value for the detection of misery perfusion. Conclusions-Our study suggests that split-dose 123 I-IMP SPECT with an acetazolamide challenge could be useful for screening patients with misery perfusion in carotid occlusive diseases.

Combination of a Mean Transit Time Measurement with an Acetazolamide Test Increases Predictive Power to Identify Elevated Oxygen Extraction Fraction in Occlusive Carotid Artery Diseases

“…Many earlier studies have evaluated the relationships between OEF and CVR (8,9,13,14). Most of these studies have concluded that there is a significant correlation between OEF and CVR to acetazolamide (13,14).…”

“…Most of these studies have concluded that there is a significant correlation between OEF and CVR to acetazolamide (13,14). However, in these studies, the number of patients included was low.…”

Ipsilateral Motor-Related Hyperactivity in Patients With Cerebral Occlusive Vascular Disease

“…Depending on their clinical conditions, the patients underwent [ 16 The details of SPECT procedure were reported previously. 16 Based on the neuroradiological reports, the degree of CBF impairment in the affected ICA or MCA region was categorized into 3 classes: no significant CBF reduction at rest (class A), CBF reduction at rest but with preserved vasoreactivity to acetazolamide (class B), and reduction at rest with impaired vasoreactivity (Ͻ23% increase) to acetazolamide as determined by a split-dose method (class C).…”

“Brush Sign” on Susceptibility-Weighted MR Imaging Indicates the Severity of Moyamoya Disease

“…The CVR is often measured by SPECT or xenon-CT before and after administering a vasodilator, such as CO 2 or acetazolamide, 6 and the combination of the lower CVR and lower CBF is a reliable index for accurately detecting the existence of increased OEF, which is known as misery perfusion. 7 Recently, the advancement of MR imaging modalities has enabled to investigators to evaluate small venous structures and iron in the brain. In particular, SWI has been accepted as a method available to evaluate deep venous flow in acute or chronic ischemia and to demonstrate increased oxygen extraction in focal cerebral ischemia.…”