Detection of misery perfusion with split-dose 123I-iodoamphetamine single-photon emission computed tomography in patients with carotid occlusive diseases.
OBJECTIVE
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 [123I] N-isopropyl-p-iodoamphetamine SPECT (123I-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 123I-IMP SPECT with an acetazolamide challenge could be useful for screening patients with misery perfusion in carotid occlusive diseases.
Imaizumi
Masao
M
Division of Tracer Kinetics, Osaka University Graduate School of Medicine, Suita, Osaka, Japan. imaizumi@tracer.med.osaka-u.ac.jp
Kitagawa
Kazuo
K
Hashikawa
Kazuo
K
Oku
Naohiko
N
Teratani
Tadamasa
T
Takasawa
Masashi
M
Yoshikawa
Takuya
T
Rishu
Piao
P
Ohtsuki
Toshiho
T
Hori
Masatsugu
M
Matsumoto
Masayasu
M
Nishimura
Tsunehiko
T
D000086:Acetazolamide; D000328:Adult; D000368:Aged; D001810:Blood Volume; D001921:Brain / Q000098:blood supply* / Q000000981:diagnostic imaging*; D002340:Carotid Artery Diseases / Q000000981:diagnostic imaging*; D002560:Cerebrovascular Circulation / Q000187:drug effects; D004791:Enzyme Inhibitors; D005260:Female; D006801:Humans; D007457:Iodine Radioisotopes; D020367:Iofetamine; D018810:Magnetic Resonance Angiography; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D010101:Oxygen Consumption; D011237:Predictive Value of Tests; D019275:Radiopharmaceuticals; D012680:Sensitivity and Specificity; D014055:Tomography, Emission-Computed; D015899:Tomography, Emission-Computed, Single-Photon
D004791:Enzyme Inhibitors; D007457:Iodine Radioisotopes; D019275:Radiopharmaceuticals; D020367:Iofetamine; D000086:Acetazolamide