Sensitivity of MRI versus mammography for detecting foci of multifocal, multicentric breast cancer in Fatty and dense breasts using the whole-breast pathologic examination as a gold standard.
OBJECTIVE
Our aim was to compare the effectiveness of mammography and MRI in the detection of multifocal, multicentric breast cancer.


METHODS
Ninety patients with planned mastectomies (nine bilateral) underwent mammography and dynamic gadolinium-enhanced MRI. Off-site reviewers aware of the entry criterion (planned mastectomy) evaluated both examinations for the presence of malignant foci, recording the density pattern on mammography. The gold standard was pathologic examination of the whole excised breast (slice thickness, 5 mm).


RESULTS
Of 99 breasts, pathologic findings revealed 52 unifocal, 29 multifocal, and 18 multicentric cancers for a total of 188 malignant foci (158 invasive and 30 in situ). Overall sensitivity was 66% (124/188) for mammography and 81% (152/188) for MRI (p < 0.001); 72% (113/158) and 89% (140/158) for invasive foci (p < 0.001); and 37% (11/30) and 40% (12/30) for in situ foci (p > 0.05, not significant), respectively. Mammography and MRI missed 64 and 36 malignant foci, respectively, with median diameters of 8 and 5 mm (p = 0.033) and an invasive-noninvasive ratio of 2.4:1 (45:19) and 1.0:1 (18:18) (p = 0.043), respectively. The overall positive predictive value (PPV) was 76% (124/164) for mammography and 68% (152/222) for MRI (not significant). In breasts with an almost entirely fatty pattern, sensitivity was 75% for mammography and 80% for MRI (not significant), and the PPV was 73% and 65% (not significant), respectively. In breasts with fibroglandular or dense pattern, the sensitivity was 60% and 81% (p < 0.001), and the PPV was 78% and 71% (not significant), respectively.


CONCLUSIONS
MRI was more sensitive than mammography for the detection of multiple malignant foci in fibroglandular or dense breasts. Mammography missed larger and more invasive cancer foci than MRI. A relatively low PPV was a problem for both techniques.
Sardanelli
Francesco
F
Department of Diagnostic Imaging, Istituto Policlinico San Donato, Via Morandi 30, San Donato Milanese, Milan 20097, Italy. f.sardanelli@grupposandonato.it <f.sardanelli@grupposandonato.it>
Giuseppetti
Gian M
GM
Panizza
Pietro
P
Bazzocchi
Massimo
M
Fausto
Alfonso
A
Simonetti
Giovanni
G
Lattanzio
Vincenzo
V
Del Maschio
Alessandro
A
D000273:Adipose Tissue / Q000473:pathology; D000328:Adult; D001943:Breast Neoplasms / Q000175:diagnosis* / Q000473:pathology; D016009:Chi-Square Distribution; D005260:Female; D005682:Gadolinium; D006571:Heterocyclic Compounds; D006801:Humans; D008279:Magnetic Resonance Imaging; D008327:Mammography; D008875:Middle Aged; D009942:Organometallic Compounds; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D018709:Statistics, Nonparametric
D006571:Heterocyclic Compounds; D009942:Organometallic Compounds; C062402:gadoteridol; D005682:Gadolinium