Tc-99m HMPAO 뇌 SPECT와 Lassen 알고리즘을 이용한 뇌혈관 예비능의 정량화 ( Quantification of Cerebrovascular Reserve Using Tc-99m HMPAO Brain SPECT and Lassen`s Algorithm ) () |
Author |
김경민(Kyeong Min Kim),이동수(Dong Soo Lee),김석기(Seok Ki Kim),이재성(Jae Sung Lee),강건욱(Keon Wook Kang),여정석(Jeong Seok Yeo),정준기(June Key Chung),이명철(Myung Chul Lee), |
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Affiliation |
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Abstract |
Purpose: For quantitative estimation of cerebrovascular
reserve (CVR), we estimated the cerebral blood flow
(CBF) using Lassen's nonlinearity correction algorithm
and Tc-99m HMPAO brain SPECT images acquired with
consecutive acquisition protocol. Using the values of
CBF in basal and acetazolamide (ACZ) stress states, CBF
increase was calculated. Materials and Methods: In 9
normal subjects (age: 72¡¾4 years), brain SPECT was
performed at basal and ACZ stress states consecutively
after injection of 555 MBq and 1,110 MBq of Tc-99m
HMPAO, respectively. Cerebellum was automatically
extracted as reference region on basal SPECT image
using threshold method. Assuming basal CBF of
cerebellum as 55 ml/100 g/min, CBF was calculated for
every pixel at basal states using Lassen's algorithm.
Cerebellar blood flow at stress was estimated comparing
counts of cerebellum at rest and ACZ stress and
Lassen's algorithm. CBF of every pixel at ACZ stress
state was calculated using Lassen's algorithm and ACZ
cerebellar count. CVR was calculated by subtracting
basal CBF from ACZ stress CBF for every pixel. The
percent CVR was calculated by dividing CVR by basal
CBF. The CBF and percentage CVR parametric images were
generated. Results: The CBF and percentage CVR
parametric images were obtained successfully in all the
subjects. Global mean CBF were 49.6¡¾5.5 ml/100g/min
and 64.4¡¾10.2 ml/100g/min at basal and ACZ stress
states, respectively. The increase of CBF at ACZ stress
state was 14.7¡¾9.6 ml/100g/min. The global mean
percent CVR was 30.7% and was higher than the 13.8%
calculated using count images. Conclusion: The blood
flow at basal and ACZ stress states and cerebrovascular
reserve were estimated using basal/ACZ Tc-99m-HMPAO
SPECT images and Lassen's algorithm. Using these
values, parametric images for blood flow and
cerebrovascular reserve were generated. (Korean J Nucl
Med 2000;34:322-35) |
Keyword |
Tc-99m HMPAO, Quantification, Cerebral blood flow, Cerebrovascular reserve, Lassen`s algorithm |
Full text Article |
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