Table 3. The differences in US features between the pCR and non-pCR tumors after one cycle of NAC.

Features changes	pCR (n=20)	Non-pCR (n=54)	t/χ2	P value
Size reduction (mm)
Maximum diameter reduction	13.65±14.68	2.65±8.85	3.922	0
Anteroposterior diameter reduction	7.16±6.61	3.24±5.39	2.609	0.011
Echogenicity change			2.956	0.118
Yes	3 [15]	2 [4]
No	17 [85]	52 [96]
Shape change			2.737	0.27
Yes	1 [5]	0
No	19 [95]	54 [100]
Orientation change			2.4	0.2
Yes	4 [20]	4 [7]
No	16 [80]	50 [93]
Margin after one cycle of NAC			11.759	0.001
Microlobulated or indistinct	4 [20]	35 [65]
Angular or spiculated	16 [80]	19 [35]
Posterior features after one cycle of NAC			0.015	0.903
Attenuation or combined feature	14 [70]	37 [69]
No feature or enhancement	6 [30]	17 [31]
Microcalcification change			4.029	0.045
Yes	2 [10]	18 [33]
No	18 [90]	36 [67]
Hyperechoic halo change			0.04	0.841
Yes	8 [40]	23 [43]
No	12 [60]	31 [57]
CDFI change			2.24	0.211
Adler 2–3→Adler 0–1	7 [35]	10 [19]
No	13 [65]	44 [81]

Data are presented as mean ± standard deviation or number [%]. US, ultrasound; pCR, pathologic complete response; NAC, neoadjuvant chemotherapy; CDFI, color Doppler flow image.