The challenge of imaging dense breast parenchyma: is magnetic resonance mammography the technique of choice? A comparative study with x-ray mammography and whole-breast ultrasound.
OBJECTIVE
To establish the value of magnetic resonance imaging (MRI) of the breast in comparison to x-ray mammography and ultrasound for breast cancer evaluation in women with dense breast parenchyma.


METHODS
Two hundred thirty-eight women with dense breast parenchyma who were suspicious for breast cancer or inconclusive for the presence of breast lesions based on clinical examination, ultrasound or x-ray mammography, and who underwent breast MRI at 1.5 T before and after administration of 0.1 mmol/kg gadobenate dimeglumine were evaluated. Lesions considered malignant (Breast Imaging Reporting and Data System (BI-RADS) 4 or 5) on x-ray mammography and/or ultrasound and as BI-RADS 3, 4, or 5 on MRI were evaluated histologically. Other lesions were followed up at 6 and/or 18 months. The diagnostic performance (sensitivity, specificity, accuracy, and positive and negative predictive values) of each technique was determined and compared using a general linear mixed model with appropriate correction for multiplicity.


RESULTS
At final diagnosis 121 of 238 (50.8%) women had one or more confirmed malignant lesions, whereas 117 (49.2%) had benign lesions or no lesions. Among 97 women who underwent all 3 techniques more lesions (malignant and benign) were detected with breast MRI (n = 135) than with x-ray mammography (n = 85) or ultrasound (n = 107) and diagnostic confidence was greater. In terms of patient-based diagnostic accuracy breast MRI was significantly (P[r] < 0.0001) superior to both x-ray mammography and ultrasound (96.9% accuracy for MRI vs. 60.8% for mammography and 66.0% for US). Malignant lesions were histologically confirmed in 55 of 97 women who underwent all 3 techniques. Breast MRI detected more cases of multifocal, multicentric, and contralateral disease and fewer misdiagnoses occurred. Overall, breast MRI led to a modification of the surgical approach for 28 (23.1%) of the 121 women with diagnosed malignant disease.


CONCLUSIONS
Breast MRI should be considered for routine breast cancer evaluation in women with dense breast parenchyma.
Pediconi
Federica
F
Department of Radiological Sciences, University of Rome La Sapienza, Rome, Italy. federica.pediconi@uniroma1.it
Catalano
Carlo
C
Roselli
Antonella
A
Dominelli
Valeria
V
Cagioli
Sabrina
S
Karatasiou
Angeliki
A
Pronio
AnnaMaria
A
Kirchin
Miles A
MA
Passariello
Roberto
R
D000293:Adolescent; D000328:Adult; D000368:Aged; D001943:Breast Neoplasms / Q000175:diagnosis*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008327:Mammography / Q000379:methods*; D008875:Middle Aged; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D016217:Ultrasonography, Mammary / Q000379:methods; D055815:Young Adult