In vivo evaluation of focused ultrasound ablation surgery (FUAS)-induced coagulation using echo amplitudes of the therapeutic focused ultrasound transducer

Figures & data

Figure 1. Photo of experimental setup of the in vivo FUAS on a live goat.

Table 1. Comparison of echo amplitude changes of the FUS transducer and gray levels in sonography and FUAS-induced lesion areas in the liver of goats.

Goat	Treatment spot	Acoustic window	Depth (mm)	Acoustic power (W)	Irradiation settings (m s on and n s off for k repeats)	Echo amplitude of the FUS transducer			Hyperecho	Lesion area (mm^2)
						Pre-operation (mV)	Post-operation (mV)	Changes (mV)
#1	1	between rib 2 and 3	62	400	m = 2, n = 2, k = 30	1070 ± 34	2203 ± 55	1133 ± 24	no	180 ± 2.01
	2		30	400	m = 2, n = 2, k = 30	329 ± 11	725 ± 23	396 ± 15	no	87 ± 1.37
	3		50	400	m = 2, n = 2, k = 30	1328 ± 46	3600 ± 112	2272 ± 86	yes	216 ± 2.26
	4	between rib 3 and 4	70	400	m = 2, n = 2, k = 30	730 ± 18	980 ± 13	250 ± 11	no	80 ± 1.54
	5		55	400	m = 2, n = 2, k = 30	850 ± 31	1389 ± 44	539 ± 25	no	84 ± 1.79
	6		35	400	m = 2, n = 2, k = 30	1427 ± 27	4250 ± 174	2823 ± 174	yes	237 ± 2.41
#2	1	between rib 2 and 3	50	400	m = 2, n = 2, k = 20	460 ± 25	646 ± 17	186 ± 18	no	na
	2		50	400	m = 2, n = 2, k = 20	784 ± 33	960 ± 21	176 ± 22	no	9.12 ± 0.97
	3		32	400	m = 2, n = 2, k = 20	820 ± 19	1025 ± 14	205 ± 15	no	14.32 ± 1.12
	4	between rib 3 and 4	57	400	m = 2, n = 2, k = 20	421 ± 8	432 ± 17	11 ± 4	no	na
	5		53	400	m = 2, n = 2, k = 20	498 ± 22	780 ± 11	282 ± 21	no	10.40 ± 0.65
	6		50	400	m = 2, n = 2, k = 20	978 ± 13	2478 ± 44	1500 ± 27	yes	18.33 ± 1.20
#3	1	between rib 1 and 2	45	400	m = 2, n = 2, k = 30	975 ± 18	1575 ± 22	590 ± 14	no	43.55 ± 2.12
	2		30	400	m = 2, n = 2, k = 30	1228 ± 25	3430 ± 112	2202 ± 107	yes	106.75 ± 2.43
	3	between rib 2 and 3	60	400	m = 2, n = 2, k = 30	880 ± 28	981 ± 24	101 ± 14	no	na
	4		40	400	m = 2, n = 2, k = 30	1044 ± 11	1577 ± 19	533 ± 18	no	22.36 ± 1.75
	5	between rib 3 and 4	54	400	m = 2, n = 2, k = 30	550 ± 14	730 ± 26	180 ± 16	no	na
	6		40	400	m = 2, n = 2, k = 30	1214 ± 21	3637 ± 107	2423 ± 96	yes	23.48 ± 2.22

Table 2. Comparison of echo amplitude changes of the FUS transducer and gray levels in sonography and FUAS-induced lesion areas in the kidney of goats.

Goat	Treatment spot	Depth (mm)	Acoustic power (W)	Irradiation settings (m s on and n s off for k repeats)	Echo amplitude of the FUS transducer			Hyperecho	Lesion area (mm^2)
					Pre-operation (mV)	Post-operation (mV)	Changes (mV)
#1	1	54	400	m = 2, n = 2, k = 20	1675 ± 45	2636 ± 56	961 ± 31	no	16.51 ± 1.32
	2	47	400	m = 2, n = 2, k = 20	794 ± 22	876 ± 19	82 ± 13	no	na
	3	50	400	m = 2, n = 2, k = 20	1402 ± 26	1421 ± 25	19 ± 7	no	na
#2	1	66	400	m = 2, n = 2, k = 20	965 ± 15	1383 ± 18	428 ± 17	no	12.12 ± 1.79
	2*	46	400	m = 2, n = 2, k = 20	608 ± 32	770 ± 26	162 ± 16	no	na
	3	36	400	m = 2, n = 2, k = 20	1801 ± 20	2945 ± 79	1144 ± 69	yes	54.45 ± 1.33
#3	1	53	400	m = 2, n = 2, k = 20	900 ± 14	950 ± 29	50 ± 18	no	na
	2	40	400	m = 2, n = 2, k = 20	923 ± 22	936 ± 27	13 ± 4	no	na
	3*	28	400	m = 2, n = 2, k = 20	1345 ± 31	1540 ± 17	195 ± 16	no	na

*: no coagulative necrosis, but apparent hemorrhage.

Table 3. Comparison of echo amplitude changes of the FUS transducer and gray levels in sonography and FUAS-induced lesion areas in the leg muscle of goats.

Goat leg	Treatment spot	Depth (mm)	Acoustic power (W)	Irradiation settings (m s on and n s off for k repeats)	Echo amplitude of the FUS transducer			Hyperecho	Lesion area (mm^2)
					Pre-operation (mV)	Post-operation (mV)	Changes (mV)
#1 right	1	48	300	m = 2, n = 2, k = 1	1956 ± 128	4796 ± 149	3200 ± 121	yes	265.72 ± 3.13
	2	45	300	m = 2, n = 2, k = 1	1807 ± 41	5943 ± 109	4136 ± 98	yes	217.90 ± 2.45
	3	52	300	m = 2, n = 2, k = 1	1644 ± 73	5243 ± 117	3599 ± 104	yes	156.40 ± 3.20
#2 left	1	52	250	m = 2, n = 2, k = 5	1991 ± 11	2522 ± 25	1031 ± 23	no	23.12 ± 1.11
	2	52	250	m = 2, n = 2, k = 5	2493 ± 42	3524 ± 39	531 ± 34	no	38.81 ± 1.34
	3	52	250	m = 2, n = 2, k = 5	1803 ± 94	2921 ± 169	1118 ± 95	no	28.22 ± 1.42
#2 right	1	91	400	m = 2, n = 2, k = 10	1202 ± 15	3697 ± 199	2495 ± 166	yes	44.19 ± 0.78
	2	88	300	m = 2, n = 2, k = 20	1261 ± 63	4861 ± 169	3600 ± 117	yes	145.30 ± 1.22
	3	83	250	m = 2, n = 2, k = 30	1502 ± 46	2990 ± 78	1488 ± 48	no	64.28 ± 1.56
#2 left	1	80	250	m = 2, n = 2, k = 30	2168 ± 110	3446 ± 193	1278 ± 143	yes	122.89 ± 2.45
	2	90	250	m = 2, n = 2, k = 30	1358 ± 76	2282 ± 82	924 ± 68	no	88.19 ± 2.10
	3	100	250	m = 2, n = 2, k = 30	1135 ± 42	2544 ± 71	1409 ± 44	no	72.44 ± 0.98
#3 right	1	100	300	m = 1, n = 2, k = 30	1067 ± 56	1699 ± 35	632 ± 38	no	114.30 ± 0.99
	2	92	300	m = 1, n = 2, k = 30	1349 ± 77	2920 ± 131	1517 ± 101	no	140.08 ± 1.67
	3	88	400	m = 1, n = 2, k = 30	1849 ± 47	2422 ± 92	573 ± 65	no	168.77 ± 2.31
#3 left	1	96	400	m = 1, n = 2, k = 20	1653 ± 53	3641 ± 180	1998 ± 154	yes	88.21 ± 0.67
	2*	90	400	m = 1, n = 2, k = 20	1856 ± 30	3859 ± 197	2003 ± 146	no	na

*: this data are excluded for analysis because of the significant motion.

Figure 2. Comparison of sonography (a) before and (b) after FUAS to the liver of the #1 live goat at six different positions, and (c) the corresponding coagulative necrosis after the dissection of treated samples.

Figure 3. Damage caused by FUAS in the kidney tissues of the #2 live goat (yellow arrow: coagulation necrosis, red arrow: congestion).

Figure 4. Coagulative necrosis in the leg muscles of the #1 live goat at six different positions after FUAS.

Figure 5. Comparison of sonograhy of treatment point ⑤ in the leg muscles in the #3 live goat (a) before and (b) after FUAS, and (c) the corresponding echo signals from the focal region.

Table 4. FUS echo difference of treatment points with/without grayscale changes in B-mode sonography.

organ	goat	echo amplitude changes (mV)		p value	post-operative echos’ standard deviation (mV)		p value
		with hyperechos	without hyperechos		with hyperechos	without hyperechos
liver	#1	2547 ± 390	468(360)	< 0.001	143 ± 44	33 ± 19	<0.001
	#2	1500 ± 27	186(176)	< 0.001	44 ± 12	16 ± 4	na
	#3	2313 ± 156	357(160)	< 0.001	109 ± 4	23 ± 3	<0.001
kidney	#1	1144 ± 69	122(42)	< 0.001	79 ± 22	27 ± 13	na
leg	#1	3525 ± 651	893 ± 317	< 0.001	125 ± 21	39(32)	<0.001
	#2	2458 ± 1161	1273 ± 305	< 0.001	187 ± 16	77 ± 6	<0.001
	#3	1988 ± 154	925 ± 560	< 0.001	180 ± 35	86 ± 48	na

Data availability statement

The data presented in this study are available on request from the corresponding author.