The use of Gd-DOTA in magnetic resonance imaging of experimentally induced mammary tumors.
Gd-DOTA contrast enhancement of MR images was evaluated on induced mammary tumors in female rats. A single intravenous injection of the carcinogenic N-nitrosourea ENU was administered to Wistar rats; this simple treatment led to a high percentage of mammary tumors without causing death. All the induced tumors were adenocarcinoma and their heterogeneousness depended on their size. The induced tumors did not have intra- or extravascular inflammatory spaces caused by heterotopic lesions, as is the case with implanted tumors. Before injection of Gd-DOTA, appearance of the patchy internal structure was clearly demonstrated on spin-echo images performed with long repetition times. Three doses of the paramagnetic contrast agent (0.1, 0.2, and 0.5 mmol/kg) were evaluated on two different T1-weighted MR sequences. Images were recorded before and repeatedly after intravenous injection of Gd-DOTA, and signal intensities and relaxation times were measured. On images acquired with the spin-echo 500/28 as well as the inversion-recovery 928/26/300 sequences, the results showed that 0.2 mmol/kg Gd-DOTA was the optimal dose for contrast enhancement and for clear visualization of the heterogeneousness of the mammary tumor.
Bonnet
P A
PA
Laboratoire de Chimie Organique Pharmaceutique, UA CNRS 1111, Montpellier, France.
Michel
A
A
Fernandez
J P
JP
Cyteval
C
C
Rifai
A
A
Boucard
M
M
Chapat
J P
JP
Lamarque
J L
JL
D000230:Adenocarcinoma / Q000175:diagnosis*; D000818:Animals; D003287:Contrast Media / Q000008:administration & dosage; D005260:Female; D005682:Gadolinium; D006571:Heterocyclic Compounds; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008325:Mammary Neoplasms, Experimental / Q000175:diagnosis*; D009942:Organometallic Compounds; D051381:Rats; D011919:Rats, Inbred Strains; D013997:Time Factors
D003287:Contrast Media; D006571:Heterocyclic Compounds; D009942:Organometallic Compounds; C050823:gadolinium 1,4,7,10-tetraazacyclododecane-N,N',N'',N'''-tetraacetate; D005682:Gadolinium