Quantitative Measurement of Regional Cerebrovascular Reactivity to Acetazolamide Using 123I-N-Isopropyl-p-Iodoamphetamine Autoradiography with SPECT: Validation Study Using H215O with PET

Journal of Nuclear Medicine

Masakazu Kobayashi¹  Hiroshi Ito¹  Kuniaki Ogasawara¹  Taku Okuguchi¹  Hirotsugu Yukawa¹  Masayuki Sasoh¹  Akira Ogawa¹  Kazunori Terasaki¹ 

关键词: cerebral blood flow quantitation;    cerebrovascular reactivity;    brain SPECT;    ¹²³I-N-isopropyl-p-iodoamphetamine;   

DOI  :  

学科分类：医学（综合）

来源: Society of Nuclear Medicine

【 摘 要 】

A simplified technique using 123I-N-isopropyl-p-iodoamphetamine (123I-IMP) autoradiography (ARG) with SPECT has been proposed recently for quantifying regional cerebral blood flow (rCBF). To validate the accuracy of 123I-IMP-ARG for quantifying regional cerebrovascular reactivity (rCVR) to acetazolamide, we compared rCVR determined using 123I-IMP-ARG with that determined using H215O PET. Methods: Thirty-nine patients with chronic stenoocclusive disease in a unilateral major cerebral artery underwent SPECT and PET studies before and after intravenous administration of acetazolamide. The rCBF images in the 4 conditions in each patient were calculated according to the ARG method. The same standard input function and the same distribution volume of 35 mL/mL were used in the calculation of rCBF images using the 123I-IMP-ARG method at resting state and with acetazolamide challenge. One large cortical region of interest (ROI) for a unilateral middle cerebral artery territory was bilaterally determined on each standardized summed rCBF image. On the basis of the rCBF values in each ROI, rCVR to acetazolamide was calculated as follows: rCVR (%) = ([acetazolamide challenge rCBF − resting rCBF]/resting rCBF) × 100. Results: Significant correlation was observed between rCVR values obtained using 123I-IMP-ARG and H215O PET methods in the 78 ROIs examined in the 39 patients (r = 0.820; P < 0.0001). When a rCVR lower than the mean − 2 SD of values obtained in healthy volunteers (18.4% for 123I-IMP-ARG and 18.2% for H215O PET) was defined as reduced, and when the H215O PET method was assumed to represent the true determinant of rCVR, 123I-IMP-ARG was 90% sensitive and 92% specific and displayed an 87% positive predictive value for detecting patients with reduced rCVR. Conclusion: These findings demonstrate that 123I-IMP-ARG methods accurately quantify rCVR and can adequately define subgroups of patients with reduced rCVR.

【 授权许可】

Unknown