Despeckle Filtering for Multiscale Amplitude-Modulation Frequency-Modulation (AM-FM) Texture Analysis of Ultrasound Images of the Intima-Media Complex

Table 4

Comparison of the mean, standard deviation (STD), median, and different quartile ranges between the high, medium and low AM-FM features extracted from the IMC for the three different age groups, below 50 (<50), between 50 and 60 (50–60) and above 60 (>60) years old for the original, the DsFhybrimedian and the DsFkuhawara filters. Here, the IA and IF values have been pre-multiplied by 100 for better visualization. Recall that the original images were normalized to a maximum brightness value of 1. Thus, the IA values represent a percentage of the maximum input image intensity. The instantaneous frequency magnitude, IF, is measured in cycles/mm (100x, Magnified by 100).

		Mean	STD	Median	P5%	P10%	P25%	P75%	P90%	P95%
Original	LIA: <50	2.47	0.45	2.29	1.81	1.9	2.2	2.8	3.0	3.4
	LIA: 50–60	2.88	0.66	2.62	2.31	2.5	2.5	2.7	4.0	4.3
	LIA: >60	2.6	0.42	2.48	1.91	2.26	2.33	2.81	3.33	3.35
	LIF: <50	145	4.1	145	140	141	142	146	147	154
	LIF: >60	144	5.2	144	135	137	139	145	150	153
	LIF: 50–60	143	3.8	145	136	137	139	146	147	147
	MIF: 50–60	285	8.0	284	275	276	280	289	296	303
	MIF: >60	284	8.7	282	273	275	278	289	295	303
	HIF: <50	574	2.8	574	545	546	556	578	599	641
	HIF: >60	566	1.6	564	541	545	557	574	585	597
DsFhybrimedian	LIA: <50	2.5	0.44	2.3	1.88	2.06	2.19	2.78	3.03	3.42
	LIA: 50–60	2.64	0.64	2.64	2.32	2.36	2.45	2.78	3.92	4.33
	LIA: >60	1.95	0.37	1.86	1.47	1.52	1.68	2.16	2.58	2.75
	LIF: <50	146	3.89	146	142	143	144	149	150	155
	LIF: >60	144	4.71	143	137	138	141	148	151	152
	LIF: 50–60	143	5.82	146	136	137	141	147	147	148
	MIF: 50–60	284	8.22	283	273	274	279	287	296	301
	MIF: >60	283	8.35	281	274	275	276	290	296	302
	HIF: <50	564	17.76	568	539	541	550	570	586	599
	HIF: >60	556	12.6	553	540	543	545	566	575	580
DsFKuhawara	LIA: <50	2.5	0.44	2.32	1.89	2.07	2.18	2.77	3.03	3.41
	LIA: 50–60	2.63	0.62	2.61	2.3	2.37	2.41	2.79	3.91	4.32
	LIA: >60	2.58	0.39	2.49	1.92	2.27	2.32	2.77	3.24	3.41
	LIF: <50	146	3.89	146	142	142	144	148	149	155
	LIF: >60	144	4.71	143	137	138	141	148	151	152
	LIF: 50–60	144	3.82	146	136	137	141	147	148	149
	MIF: 50–60	284	8.22	283	273	274	279	287	296	301
	MIF: >60	283	8.3	281	274	275	276	290	296	303
	HIF: <50	564	17.8	568	539	541	550	570	586	599
	HIF: >60	556	12.5	553	540	543	546	566	575	580

IMC: Intima-media-complex.