Method analysis for optimal continuous imaging using intravascular optical coherence tomography.
OBJECTIVE
Optical coherence tomography(OCT)is a high-resolution imaging method that can clearly visualize vessels through the displacement of blood with flushing agents. Continuous imaging methods have not been established. This study investigated optimal methods for continuous OCT imaging.


METHODS
Thirty-four arteries with stent implantation (24 peripheral and 10 coronary arteries)in 14 pigs were examined using OCT with a motorized pullback device. Two imaging methods (flush alone by liquid substance and flush with occlusion) were compared. Adequate image acquisition was defined as the entire circumferential intimal layer being detectable within continuous segments. To investigate factors that could influence image quality, stented regions were divided into 4-5 mm segments.


RESULTS
The flush with occlusion method provided better OCT images compared to flush alone (flush with occlusion: 60.9%, flush alone: 8.7%, p = 0.0002). Using the flush with occlusion method, the rate of adequate image acquisition was 64.4% and visualization of > 75% intimal circumference was 83.5%. Intravascular ultrasound could detect all stented regions. Segmental analyses found more adequate images were detected in smaller vessels (adequate segment: 3.8 +/- 0.4 mm, inadequate segment: 4.2 +/- 0.8 mm, p < 0.0001) or with centered image wire position (adequate segment: center 35%, inadequate segment: center 14%, p = 0.003). In addition, side branches did not affect image quality.


CONCLUSIONS
To acquire continuous OCT images, the flush with occlusion method was more effective compared to flush alone. Moreover, image quality is affected by vessel size and imaging wire position. These results suggest that optimized OCT imaging can provide continuous vessel detection.
Asawa
Koichiro
K
Department of Internal Medicine and Cardiology, Osaka City University Medical School, Asahimachi 1-4-3, Abeno-ku, Osaka 545-8585.
Kataoka
Toru
T
Kobayashi
Yoshiki
Y
Hasegawa
Takao
T
Nishioka
Hiroki
H
Yamashita
Hajime
H
Qiu
Zhaohui
Z
Ehara
Shoichi
S
Hirose
Makoto
M
Kamimori
Kimio
K
Shimada
Kenei
K
Yoshiyama
Minoru
M
Yoshikawa
Junichi
J
D000818:Animals; D001145:Arrhythmias, Cardiac / Q000209:etiology; D050197:Atherosclerosis / Q000175:diagnosis; D001808:Blood Vessels / Q000473:pathology*; D002318:Cardiovascular Diseases / Q000175:diagnosis; D003324:Coronary Artery Disease / Q000175:diagnosis; D003331:Coronary Vessels / Q000473:pathology; D005263:Femoral Artery / Q000473:pathology; D015999:Multivariate Analysis; D015607:Stents; D013552:Swine; D013556:Swine, Miniature; D041623:Tomography, Optical Coherence / Q000009:adverse effects / Q000379:methods*; D018084:Ultrasonography, Interventional