Detection and quantification of breast tumor necrosis with MR imaging: value of the necrosis-avid contrast agent Gadophrin-3.
OBJECTIVE
The authors evaluated the use of T1-weighted magnetic resonance (MR) imaging with Gadophrin-3 enhancement and of plain T2-weighted MR imaging to detect and quantify breast tumor necrosis.


METHODS
Twenty EMT-6 tumors (mouse mammary sarcoma), implanted into the mammary fat pad of BALB/c-AnNCrl mice, underwent MR imaging with plain T2-weighted and T1-weighted fast field echo sequences before and 24 hours after injection of Gadophrin-3, a new necrosis-avid contrast agent. Tumor necrosis on MR images was quantified by means of a dedicated segmentation program and was correlated with histologic findings.


RESULTS
In all tumors a central necrosis was revealed by histopathologic analysis, and central enhancement was seen with Gadophrin-3 on T1-weighted images. Small tumors (diameter, < 1 cm) showed an inhomogeneous central enhancement, whereas larger tumors (diameter, > 1 cm) enhanced mainly in the periphery of necrotic tissue. Plain T2-weighted images showed a hyperintense central area in only three of 20 cases with a large central necrosis.


CONCLUSIONS
Gadophrin-3-enhanced T1-weighted images are superior to plain T2-weighted images for the detection of necrosis in a murine tumor xenograft model.
Metz
Stephan
S
Department of Radiology, Technical University, Ismaninger Strasse 22, 81675 Munich, Germany.
Daldrup-Unk
Heike E
HE
Richter
Thomas
T
Räth
Christoph
C
Ebert
Wolfgang
W
Settles
Marcus
M
Rummeny
Ernst J
EJ
Link
Thomas M
TM
Piert
Morand
M
D000818:Animals; D003287:Contrast Media; D005260:Female; D019786:Gadolinium DTPA; D008279:Magnetic Resonance Imaging; D008325:Mammary Neoplasms, Experimental / Q000473:pathology*; D008665:Metalloporphyrins; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D009336:Necrosis; D009368:Neoplasm Transplantation; D012513:Sarcoma, Experimental / Q000473:pathology
D003287:Contrast Media; C476926:Gadophrin-3; D008665:Metalloporphyrins; D019786:Gadolinium DTPA