A new algorithm for calculating optimal viewing angles in coronary angiography based on 4-D cardiac computed tomography.
BACKGROUND
Coronary stenosis is the main cause of the coronary heart disease (CHD). However, coronary arteriography (CAG), which is considered as the 'gold standard' of determining the location and severity of CHD, hardly acquires a satisfactory image for some lesions by traditional viewing angles.


OBJECTIVE
We proposed a new approach to calculate the optimal viewing angles of CAG system to observe vessel segment of interest.


METHODS
Firstly, the 4-D coronary arteries are segmented to obtain a dynamic vessel model. Then, a "rendering" method in computer graphics is used to calculate the optimal viewing angles of the vessel segment in the entire cardiac cycle. At last, an intersection of these angles can be regarded as the optimal ones in the whole cardiac cycle.


RESULTS
Within the constraint of 2% foreshortening, the single phase data show 1% foreshortening without overlapping at the optimal angles proposed by our method, compared with 1.8% foreshortening at working angles set by clinical experts. And the multi-phase experiments also have good results.


CONCLUSIONS
The new approach can provide doctors optimal viewing angles of interested vessel segment in the whole cardiac cycle.
College of Precision Instrument and Opto-electronics Engineering, Tianjin University, Tianjin, China Key Laboratory of Opto-electronics Information Technology (Tianjin University), Ministry of Education, Tianjin, China.
Xiaodong
X
Chen
College of Precision Instrument and Opto-electronics Engineering, Tianjin University, Tianjin, China Key Laboratory of Opto-electronics Information Technology (Tianjin University), Ministry of Education, Tianjin, China.
Junwei
J
Li
College of Precision Instrument and Opto-electronics Engineering, Tianjin University, Tianjin, China Key Laboratory of Opto-electronics Information Technology (Tianjin University), Ministry of Education, Tianjin, China.
Zhaoxia
Z
Zhang
College of Precision Instrument and Opto-electronics Engineering, Tianjin University, Tianjin, China Key Laboratory of Opto-electronics Information Technology (Tianjin University), Ministry of Education, Tianjin, China.
Yi
Y
Wang
Department of Cardiovascular Medicine, People's Liberation Army 254 Hospital, Tianjin, China.
Zhongwei
Z
Jia
Department of Cardiovascular Medicine, People's Liberation Army 254 Hospital, Tianjin, China.
Kui
K
Pu
College of Precision Instrument and Opto-electronics Engineering, Tianjin University, Tianjin, China Key Laboratory of Opto-electronics Information Technology (Tianjin University), Ministry of Education, Tianjin, China.
Daoyin
D
Yu
D000465:Algorithms; D017023:Coronary Angiography / Q000379:methods*; D023921:Coronary Stenosis / Q000000981:diagnostic imaging; D003331:Coronary Vessels / Q000000981:diagnostic imaging; D056973:Four-Dimensional Computed Tomography / Q000379:methods*; D006801:Humans
3-D coronary segmentation; 4-D cardiac CT; coronary angiography (CAG); optimal viewing angles