TY - JOUR
T1 - Vectors through a cross-sectional image (VCI)
T2 - A visualization method for four-dimensional motion analysis for cardiac computed tomography
AU - Kidoh, Masafumi
AU - Utsunomiya, Daisuke
AU - Funama, Yoshinori
AU - Ashikaga, Hiroshi
AU - Nakaura, Takeshi
AU - Oda, Seitaro
AU - Yuki, Hideaki
AU - Hirata, Kenichiro
AU - Iyama, Yuji
AU - Nagayama, Yasunori
AU - Fukui, Toshihiro
AU - Yamashita, Yasuyuki
AU - Taguchi, Katsuyuki
N1 - Publisher Copyright:
© 2017 Society of Cardiovascular Computed Tomography
PY - 2017/11
Y1 - 2017/11
N2 - Background Cardiac computed tomography (CT) has the potential for fully four-dimensional (4D for 3D plus time) motion analysis of the heart. We aimed at developing a method for assessment and presentation of the 4D motion for multi-phase, contrast-enhanced cardiac CT data sets and demonstrating its clinical applicability. Methods Four patients with normal cardiac function, old myocardial infarction (OMI), takotsubo cardiomyopathy, and hypertrophic cardiomyopathy (HCM) underwent contrast-enhanced cardiac CT for one heartbeat using a 320-row CT scanner with no tube current modulation. CT images for 10 cardiac phases (with a 10%-increment of the R-R interval) were reconstructed with the isotropic effective resolution of (0.5 mm)3 An image-based motion-estimation (iME) algorithm, developed previously, has been used to estimate a time series of 3D cardiac motion, from the end-systole to the other nine phases. The iME uses down-sampled images with a resolution of (1.0 mm)3 deforms the end-systole images non-rigidly to match images at other phases. Once the agreement is maximized, iME outputs a 3D motion vector defined for each voxel for each phase, that smoothly changes over voxels and phases. The proposed visualization method, which is called “vectors through a cross-sectional image (VCI),” presents 3D vectors from the end-diastole to the end-systole as arrows with an end-diastole CT slice. We performed visual assessment of the VCI with calculated the mean vector lengths to evaluate regional left ventricular (LV) contraction. Results The VCI images showed the magnitude and direction of systolic 3D vectors, including the through-plane motion, and successfully visualized the relations of LV wall segments and abnormal regional wall motion. Decreased regional motion and asymmetric motion due to hypokinetic infarct segment, takotsubo cardiomyopathy, and hyper trophic cardiomyopathy was clearly observed. It was easy to appreciate the relation of the abnormal regional wall motion to the affected LV wall segments. The mean vector lengths of the affected segments with pathologies were clearly smaller than the other unaffected segments (1.2–1.7 mm versus 2.5–4.7 mm). Conclusions VCI images could capture the magnitude and direction of through-plane motion and show the relations of LV wall segments and abnormal wall motion.
AB - Background Cardiac computed tomography (CT) has the potential for fully four-dimensional (4D for 3D plus time) motion analysis of the heart. We aimed at developing a method for assessment and presentation of the 4D motion for multi-phase, contrast-enhanced cardiac CT data sets and demonstrating its clinical applicability. Methods Four patients with normal cardiac function, old myocardial infarction (OMI), takotsubo cardiomyopathy, and hypertrophic cardiomyopathy (HCM) underwent contrast-enhanced cardiac CT for one heartbeat using a 320-row CT scanner with no tube current modulation. CT images for 10 cardiac phases (with a 10%-increment of the R-R interval) were reconstructed with the isotropic effective resolution of (0.5 mm)3 An image-based motion-estimation (iME) algorithm, developed previously, has been used to estimate a time series of 3D cardiac motion, from the end-systole to the other nine phases. The iME uses down-sampled images with a resolution of (1.0 mm)3 deforms the end-systole images non-rigidly to match images at other phases. Once the agreement is maximized, iME outputs a 3D motion vector defined for each voxel for each phase, that smoothly changes over voxels and phases. The proposed visualization method, which is called “vectors through a cross-sectional image (VCI),” presents 3D vectors from the end-diastole to the end-systole as arrows with an end-diastole CT slice. We performed visual assessment of the VCI with calculated the mean vector lengths to evaluate regional left ventricular (LV) contraction. Results The VCI images showed the magnitude and direction of systolic 3D vectors, including the through-plane motion, and successfully visualized the relations of LV wall segments and abnormal regional wall motion. Decreased regional motion and asymmetric motion due to hypokinetic infarct segment, takotsubo cardiomyopathy, and hyper trophic cardiomyopathy was clearly observed. It was easy to appreciate the relation of the abnormal regional wall motion to the affected LV wall segments. The mean vector lengths of the affected segments with pathologies were clearly smaller than the other unaffected segments (1.2–1.7 mm versus 2.5–4.7 mm). Conclusions VCI images could capture the magnitude and direction of through-plane motion and show the relations of LV wall segments and abnormal wall motion.
KW - Cardiac computed tomography
KW - Cardiac wall motion
KW - Cardiomyopathy
KW - Image-based motion estimation
KW - Myocardial infarction
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U2 - 10.1016/j.jcct.2017.09.010
DO - 10.1016/j.jcct.2017.09.010
M3 - Article
C2 - 28967574
AN - SCOPUS:85030179878
SN - 1934-5925
VL - 11
SP - 468
EP - 473
JO - Journal of cardiovascular computed tomography
JF - Journal of cardiovascular computed tomography
IS - 6
ER -