inosinic-acid and Arterial-Occlusive-Diseases

The accuracy of the acetazolamide (ACZ) challenge test using semiquantitative SPECT in detecting Stage II hemodynamic failure, i.e. cerebral misery perfusion, in patients so diagnosed with PET has yet to be determined. This study was carried out in 53 patients who had a unilateral occlusion or severe stenosis of their cerebral artery. Asymmetry index (AI) was used to determine relative CBF distribution on each SPECT image. DeltaAI (regional vasodilatory capacity) values were compared with the values of several PET parameters. We also repeated SPECT and PET studies in 15 patients after a mean interval of 2.6 years from entry. The correlation between changes in DeltaAI and PET data were examined. The DeltaAI value closely correlated with the ipsilateral OEF value (r=-0.64, p<0.001). Sensitivity-specificity curve analysis revealed that the optimal cut-off value for detecting Stage II hemodynamic failure was -13.5% of DeltaAI, at which point the diagnostic accuracy was 82%. In follow-up studies, changes in DeltaAI correlated significantly with changes in OEF values (r=-0.68, p<0.01). Semiquantitative SPECT examination with ACZ challenge detects Stage II hemodynamic failure with a diagnostic accuracy of 82%. An improvement in reduced vasodilatory capacity as determined by SPECT coincides with a reduction in OEF values.

Topics: Acetazolamide; Aged; Arterial Occlusive Diseases; Blood Volume; Carbonic Anhydrase Inhibitors; Cerebral Arterial Diseases; Cerebral Palsy; Female; Follow-Up Studies; Hemodynamics; Humans; Inosine Monophosphate; Iodine Radioisotopes; Male; Middle Aged; Predictive Value of Tests; Sensitivity and Specificity; Tomography, Emission-Computed; Tomography, Emission-Computed, Single-Photon

Early and delayed single photon emission computed tomography (SPECT) using N-isopropyl-p-(123I)iodoamphetamine (IMP) was performed on 28 subjects (2 normal, 12 with cerebrovascular diseases and 14 with brain tumors) to evaluate the reversibility of the cerebral abnormality and cerebral viability. The results were compared with X-ray CT, 99mTc brain scintigraphy and rCBF by 133Xe inhalation method. Three types of IMP kinetics were observed. Initial hypoactivity that changed over 4 to 6 hours approaching a normal pattern suggests a hypofunctional parenchyma without significant tissue damage: long-lasting abnormalities on IMP SPECT indicates cellular damage.

Topics: Adolescent; Adult; Aged; Arterial Occlusive Diseases; Brain Neoplasms; Cerebrovascular Disorders; Child; Child, Preschool; Female; Humans; Inosine Monophosphate; Inosine Nucleotides; Male; Middle Aged; Moyamoya Disease; Tomography, Emission-Computed