MR dynamic enhancement of breast lesions: high temporal resolution during the first-minute versus eight-minute study.
OBJECTIVE
To investigate the value of the early phase of MR enhancement of breast lesions.


METHODS
To study 63 breast lesions (size 5-45 mm in diameter) in 56 patients, whole-breast and lesion-targeted precontrast T1 -weighted gradient-echo 2D sequences were acquired. After intravenous injection of Gd-DTPA (0.1 mmol/Kg), four targeted scans, each every 15 seconds during the first minute (1-m), and seven whole-breast scans, each every minute up to 8 minutes (8-m), were performed. The subtraction technique was used, and percent enhancement curves were obtained. The final diagnosis was obtained by histology for 36 lesions, including 28 malignancies, and by fine-needle aspiration cytology and at least 1-year negative follow-up for the remaining 27 benign lesions.


RESULTS
Significant differences in enhancement between malignant and benign lesions were found using both techniques (p<0.0001). However the ratio between the median enhancement of malignant lesions and that of benign lesions was 6.7 (15 s), 4.8 (30 s), 4.6 (45 s), and 3.8 (60 s), descending from 4.3 to 2.5 from the second to the eighth minute. The overlap between the malignant and benign curves was 9% of the malignant range with the 1-m technique, and 50% with the 8-m technique. Three blinded observers obtained a 100% sensitivity with both techniques and a specificity of 94-97% with the 1-m technique and 83-89% with the 8-m technique.


CONCLUSIONS
The first minute of Gd-enhancement allows a more prominent differentiation between malignant and benign breast lesions than the following times.
Sardanelli
F
F
Department of Experimental Medicine, University of Genoa School of Medicine, San Martino Hospital, Genova. sardanelli@biomedicalspa.com
Rescinito
G
G
Giordano
G D
GD
Calabrese
M
M
Parodi
R C
RC
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000175:diagnosis*; D018270:Carcinoma, Ductal, Breast / Q000175:diagnosis*; D003287:Contrast Media; D005260:Female; D018226:Fibroadenoma / Q000175:diagnosis*; D019786:Gadolinium DTPA; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008875:Middle Aged; D012680:Sensitivity and Specificity; D013997:Time Factors
D003287:Contrast Media; D019786:Gadolinium DTPA