3.0 Tesla vs 1.5 Tesla breast magnetic resonance imaging in newly diagnosed breast cancer patients

Table 1 1.5 and 3.0 Tesla magnetic resonance imaging protocol

Parameter	Axial T2	Axial T1 3D GRE no FS	Axial T1 pre 3D GRE	Axial T1 post 3D GRE
1.5 Tesla
TR (ms)	5811	8.3	5.2	5.2
TE (ms)	60	4.5	2.42	2.42
Fat saturation	STIR	No	Yes	Yes
Flip angle	165	20	10	10
Field of view (mm)	340	340	340	340
Matrix	384 × 230	320 × 320	320 × 320	320 × 320
Slice thickness (mm)	5	1	1	1
Voxel size (mm3)	0.8 × 1.4 × 5.0	1.0 × 1.0 × 1.0	1.0 × 1.0 × 1.0	1.0 × 1.0 × 1.0
Bandwidth (Hz/pixel)	250	347	391	391
Imaging time (min:s)	2:50	2:50	2:2	2:26
3.0 Tesla
TR (ms)	11660	4.57	4.57	3.99
TE (ms)	69	2.46	2.46	1.61
Fat saturation	STIR	No	Yes	Yes
Flip angle	120	10	10	9
Field of view (mm)	324	323	323	323
Matrix	384 × 384	448 × 448	448 × 448	448 × 448
Slice thickness (mm)	3	0.7	0.7	0.7
Voxel size (mm3)	0.8 × 0.8 × 3.0	0.7 × 0.7 × 0.7	0.7 × 0.7 × 0.7	0.7 × 0.7 × 0.7
Bandwidth (Hz/pixel)	246	319	698	698
Imaging time (min:s)	2:45	2:33	2:33	2:33

TR: Repetition time; TE: Echo time; GRE: Gradient echo sequence; FS: Fat suppression.

Table 2 Patient and index cancer characteristics n (%)

Characteristic	1.5 Tesla	3.0 Tesla	P value
Age (yr)
median (range)	56	55	0.59
	(35-85)	(26-85)
Family history of breast cancer
None	77 (79)	101 (74)	0.53
Weak1	10 (10)	19 (14)	0.43
Intermediate2	5 (5)	11 (8)	0.44
Strong3	6 (6)	5 (4)	0.53
Index cancer size (mm)
Mean (range)	17.3	18.1	0.68
	(4.0-70.0)	(3.0-92.0)
Index cancer histology
Invasive ductal carcinoma	67 (68)	91 (67)	0.13
Not otherwise specified	65 (66)	86 (63)	0.14
Mucinous type	1 (1)	3 (2)
Medullary type	0	1 (0.7)
Papillary type	0	1 (0.7)
Tubular type	1 (1)	0
Invasive lobular carcinoma	3 (3)	3 (2)	0.11
Mixed invasive lobular and ductal carcinoma	3 (3)	5 (4)	0.70
Ductal carcinoma in situ	25 (26)	37 (27)	0.56

¹Weak family history: second degree or other relatives;

²Intermediate family history: single post-menopausal first-degree relative;

³Strong family history: premenopausal first-degree relative or multiple post-menopausal first-degree relatives. Unless otherwise indicated, data are number of patients and data in parentheses are percentages.

Table 3 Suspicious lesion characteristics n (%)

Characteristic	1.5 Tesla	3.0 Tesla	P value
Suspicious lesions (n)	98	206	0.001
Average number/imaged patient	1 (98/98)	1.4 (206/136)
Range	0-6	0-8
Size (mm)
mean (range)	11.9	10.5	0.27
	(3-60)	(3-94)
Biopsied lesions	88 (90)	198 (96)	0.04
Average number/biopsied patient	1.7 (88/52)	2.6 (198/75)
Method of biopsy
MRI–guided needle biopsy	43 (49)	87 (44)	0.44
Ultrasound-guided needle biopsy	13 (15)	37 (19)	0.50
Stereotactic needle biopsy	3 (3)	2 (1)	0.18
Surgical biopsy	29 (33)	72 (36)	0.60
Reason for no biopsy
Another representative lesion biopsied	6	4
Not visualized at MRI-guided biopsy	2	3
Benign correlate on ultrasound	1	1
Lost to follow-up	1	0
Morphology
Mass	37 (38	87 (42)	0.53
Nonmass-like enhancement	40 (41)	62 (30)	0.07
Focus	21 (21)	57 (28)	0.26
Kinetics
Wash-out	22 (22)	60 (29)	0.27
Plateau	41 (42)	71 (35)	0.25
Persistent	35 (36)	75 (36)	1.00
Distribution
Multifocal	34 (35)	80 (39)	0.53
Multicentric	33 (34)	50 (24)	0.10
Contralateral	31 (32)	76 (37)	0.44

Unless otherwise indicated, data are number of patients and data in parentheses are percentages. MRI: Magnetic resonance imaging.

Table 4 Magnetic resonance imaging-detected cancer characteristics n (%)

Characteristic	1.5 Tesla	3.0 Tesla	P value
Cancers (n)	23	54
Positive biopsy rate	23/88 (26)	54/198 (27)	0.89
Size (mm)
mean (range)	12.4	10.9	0.65
	(3-50)	(4-70)
Method of biopsy
MRI–guided needle biopsy	4 (17)	10 (19)
Ultrasound-guided needle biopsy	6 (26)	19 (35)
Stereotactic needle biopsy	1 (4)	1 (2)
Surgical biopsy	12 (52)	24 (44)
Morphology
Mass	13 (57)	29 (53)	1.00
Nonmass-like enhancement	3 (13)	14 (26)	0.25
Focus	7 (30)	11 (20)	0.38
Kinetics
Wash-out	6 (26)	19 (35)	0.65
Plateau	10 (44)	21 (39)	0.80
Persistent	7 (30)	14 (26)	0.78
Distribution
Multifocal	16 (70)	33 (61)	0.61
Multicentric	4 (17)	12 (22)	0.76
Contralateral	3 (13)	9 (17)	1.00
Histology
Infiltrating ductal carcinoma	14 (61)	30 (55)	0.80
Infiltrating lobular carcinoma	0 (0)	1 (2)	1.00
Ductal carcinoma in situ	9 (39)	23 (43)	0.81

Unless otherwise indicated, data are number of patients and data in parentheses are percentages. MRI: Magnetic resonance imaging.

Table 5 Patient biopsy outcomes n (%)

Characteristic	1.5 Tesla	3.0 Tesla	P value
Imaged patients	98	136
Benign	25 (26)	30 (22)	0.20
High-risk	13 (13)	12 (9)	1.00
Malignant	14 (14)	33 (24)	0.07
Multifocal	9 (9)	22 (16)	0.17
Multicentric	4 (4)	9 (7)	0.57
Ipsilateral	13 (13)	31 (23)	0.09
Contralateral	3 (3)	7 (5)	0.53
Biopsied patients	52 (53)	75 (55)	0.79
Benign	25 (48)	30 (40)	0.47
High-risk	13 (25)	12 (16)	0.26
Malignant	14 (27)	33 (44)	0.06
Multifocal	9 (17)	22 (29)	0.14
Multicentric	4 (8)	9 (12)	0.56
Ipsilateral	13 (25)	31 (41)	0.06
Contralateral	3 (6)	7 (9)	0.52
PPV of abnormal MRI	14/52 (27)	33/75 (44)	0.06

Unless otherwise indicated, data are number of patients and data in parentheses are percentages. MRI: Magnetic resonance imaging; PPV: Positive predictive value.