Table 3.

A comparison between inter-observer errors, stratified decision forests (Oktay et al., 2017), and different agents using fixed-scale (FS) and multi-scale (MS) search strategies for the detection of apex and center of mitral valve landmarks in cardiac MR images. Distance errors are in mm. Bold text shows the highest achieved localization accuracy for each landmark.

Method	Apex (AP)		Mitral Valve (MV)
Inter-observer Errors	5.79 ± 3.28		5.30±2.98
Decision Forests (Oktay et al., 2017)	6.74 ± 4.12		6.32 ± 3.95
Proposed RL Agents	FS	MS	FS	MS
DQN	7.49 ± 4.05	4.47±2.63	8.33 ± 4.70	5.73±4.16
DDQN	8.13 ± 5.60	4.53±2.78	8.82 ± 4.80	5.20±2.82
Duel DQN	7.17±4.21	4.42 ± 2.67	8.82 ± 4.80	5.76 ± 3.89
Duel DDQN	7.59 ± 4.17	5.43±3.37	8.63±4.58	5.28±2.61