. Author manuscript; available in PMC: 2020 Sep 1.

Published in final edited form as: IEEE Trans Biomed Eng. 2020 Jan 16;67(9):2628–2637. doi: 10.1109/TBME.2020.2967033

TABLE I.

Mean thickness, incident angles and the percentage of phase difference less than 45° and 20° of all the measured spots on skulls 1-4 (n_total = 784).

		Incident Angle (°)		Percentage (%) of Phase Shift Difference

#Skull	Thickness (mm)	Outer Surface	Inner Surface	<45°		<20°

				Resonance vs Hydrophone	CT-based vs Hydrophone	Resonance vs Hydrophone	CT-based vs Hydrophone
Sk1	6.7 ± 0.6	5.5 ± 3.2	7.8 ± 4.5	67.4	59.1	36.2	22.8
Sk2	7.0 ± 1.5	4.5 ±2.5	9.0 ± 5.6	86.1	76.2	45.0	31.1
Sk3	5.3 ± 0.6	5.0 ± 2.8	9.1 ± 5.4	82.4	91.2	42.0	65.5
Sk4	8.5 ± 0.9	5.5 ± 3.2	9.2 ± 4.4	67.9	81.8	34.5	32.5

All 4 skulls				74.0	74.5	38.5	35.1

All 4 Skulls (incident angle < 5°)				80.9	76.2	45.4	37.2