Mechanism of contrast enhancement in breast lesions at MR imaging.
OBJECTIVE
The aim of the study was to explain why breast lesions are enhanced by contrast medium at MR imaging and to elucidate the histopathological basis for the overlap in the enhancement patterns of benign and malignant breast lesions.


METHODS
Ten invasive breast carcinomas and 10 benign breast lesions were selected for the study. Of the 10 carcinomas, 5 showed a strong and early contrast enhancement, and 5 did not. Of the 10 benign lesions, 5 showed a strong and early contrast enhancement, and 5 showed no enhancement. The following morphometric variables were evaluated: proliferation cell index of neoplastic parenchymal cells, S-phase fraction, nuclear ploidy analysed by image DNA-cytometry, microvessel density, and the percentage proportion of the interstitial area.


RESULTS
Contrast enhancement was related to the proliferating activity of the hyperplastic or neoplastic parenchymal cells and was inversely correlated with the interstitial area in carcinomas as well as in benign tumours and non-neoplastic lesions of the breast.


CONCLUSIONS
Morphometric variables play an important role in the general mechanism of MR contrast enhancement in examinations of the breast and explain the histopathological basis for the overlap in the enhancement patterns of benign and malignant breast lesions.
Department of Diagnostic Radiology, Karolinska Institute, Huddinge University Hospital, Sweden.
B
B
Boné
M K
MK
Wiberg
C
C
Parrado
U
U
Falkmer
P
P
Aspelin
A
A
Gad
D001940:Breast / Q000473:pathology*; D001941:Breast Diseases / Q000175:diagnosis; D001943:Breast Neoplasms / Q000175:diagnosis* / Q000235:genetics; D002277:Carcinoma / Q000175:diagnosis / Q000235:genetics; D002452:Cell Count; D002455:Cell Division / Q000235:genetics; D003287:Contrast Media / Q000008:administration & dosage*; D004273:DNA, Neoplasm / Q000032:analysis; D003937:Diagnosis, Differential; D005260:Female; D019786:Gadolinium DTPA / Q000008:administration & dosage; D006801:Humans; D019044:Image Cytometry; D007089:Image Enhancement; D007150:Immunohistochemistry; D007262:Infusions, Intravenous; D008279:Magnetic Resonance Imaging; D011003:Ploidies; D011897:Random Allocation; D012189:Retrospective Studies
D003287:Contrast Media; D004273:DNA, Neoplasm; D019786:Gadolinium DTPA