Table 1.

Description of studies included in the meta-analysis.

Study	Year	No. of patients	Patient age, mean (range)	Initial clinical stage	Histological subtype	Receptor status	Preoperative therapy regimen	Time between start of NAT and MRI	pCr rate	MRI magnetic field strength	Contrast agent	DCE temporal resolution (s)	DW-MRI $b$ values	Sensitivity	Specificity
Semiquantitative DCE-MRI studies
Parikh47	2014	36	49.8 (24–67)	I–III	35 IDC, 1 ILC	21 ER+, 6 HER2+	3*FEC → 4*T, 4*EC → 4*T HER2+ patients after 2010 received trastuzumab	3 cycles NAT	22.22%	1.5T	Dotarem (20 mL)	92		87.5%	82.1%
Rigter48	2013	246	48 (18–68)	I–IV	190 IDC, 33 ILC, 6 IDC/ILC	190 ER+, 246 PR+	3*AC → 3*AC, 3*AC → 3*TCa	3 cycles NAT	1.63%	1.5T	Gadolinium CA ($0.1\mathrm{mmol}/\mathrm{kg}$)	90		75.0%	33.2%
Yang46	2012	22	45 (35–67)	II–III	Not reported	Not reported	Antiangiogenic-cytotoxic combination therapy	2 cycles NAT	27.27%	1.5T	Magnevist ($0.1\mathrm{mmol}/\mathrm{kg}$)	70		78.0%	100.0%
Quantitative DCE-MRI studies
Tateishi49	2012	143	57 (43–72)	I–III	131 IDC, 11 ILC	100 ER+, 82 PR+, 111 HER2+	4*FEC → 12*T, 4*AC → 12*T, HER2+ patients received trastuzumab	2 cycles NAT	16.90%	3T	Magnevist ($0.1\mathrm{mmol}/\mathrm{kg}$)	10		51.7%	92.0%
Ah-See50	2008	28	46 (29–70)	II–III	21 IDC, 3 ILC	Not reported	6*FEC	2 cycles NAT	39.28%	1.5T	Magnevist ($0.1\mathrm{mmol}/\mathrm{kg}$)	12		94.0%	82.0%
DWI-MRI studies
Fangberget51	2011	31	50.7 (37–72)	Not reported	24 IDC, 7 ILC	21 ER+, 18 PR+, 11 HER2+, 5 TNBC	4*FEC → 2*FEC, 4*FEC-> 2*T, HER2+ patients received trastuzumab	4 cycles NAT	35.48%	1.5T			100, 250, 800	88.0%	80.0%
Minarikova44	2017	42	52 (29–74)	I–III	41 ID, 1 ILC	27 ER+, 13 PR+, 5 HER2+	ACT*6, ACT*8, AC → T	2 cycles NAT	16.67%	3.0T			0, 850	66.67%	100%
Multiparametric MRI studies
Li39	2015	37	45 (28–67)	II–III	Not reported	16 ER+, 16 PR+, 12 HER2+, 12 TNBC	4*AC → 4*T, 4*AC → 12*T, HER2+ patients received trastuzumab or other treatments	1 cycle NAT	35.14%	3T	Magnevist ($0.1\mathrm{mmol}/\mathrm{kg}$)	16	0, 500	92.0%	75.0%
Wu45	2015	31	48.4 (33–62)	II–III	Not Reported	24 ER+, 23 PR+, 16 HER2+	FEC, FEC → T, T, or other treatments	1 cycle NAT	9.70%	3.0T	Gadovist ($0.1\mathrm{mmol}/\mathrm{kg}$)	40–50	50, 600, 1000	90.9%	83.8%

Note: IDC, invasive ductal carcinoma; ILC, invasive lobular carcinoma; TNBC, triple negative breast cancer; A, doxorubicin; C, cyclophosphamide; T, taxane; F, fluorouracil; E, epirubicin; D, docetaxel; Ca = capecitabine.