Hepatic metastases: liposomal Gd-DTPA-enhanced MR imaging.
Liposomal gadolinium diethylenetriaminepentaacetic acid (DTPA) encapsulated within 70- and 400-nm vesicles was tested as a contrast agent for magnetic resonance (MR) imaging of the liver in rats with hepatic metastases. Liposomal Gd-DTPA caused significant improvement in contrast between liver and tumor (P less than .005) on T1-weighted MR images. Smaller 70-nm liposomal Gd-DTPA vesicles caused greater contrast enhancement, reflecting the larger surface-area-to-volume ratio of the smaller vesicles. Liposomal Gd-DTPA-enhanced images permitted significant improvement in metastasis detection by five blinded radiologists (P less than .005). By comparison, free Gd-DTPA without liposomes caused a statistically significant reduction in contrast between tumor and liver and reduced lesion detection (P less than .01). Liposomal Gd-DTPA also resulted in sustained vascular enhancement for 1 hour after administration. The results suggest that paramagnetic liposomes may become a useful MR imaging contrast agent.
Unger
E C
EC
Department of Radiology, Fox Chase Cancer Center, Philadelphia.
Winokur
T
T
MacDougall
P
P
Rosenblum
J
J
Clair
M
M
Gatenby
R
R
Tilcock
C
C
D000818:Animals; D003287:Contrast Media; D005682:Gadolinium; D019786:Gadolinium DTPA; D008081:Liposomes; D008114:Liver Neoplasms, Experimental / Q000175:diagnosis*; D008279:Magnetic Resonance Imaging; D009942:Organometallic Compounds; D004369:Pentetic Acid; D051381:Rats
D003287:Contrast Media; D008081:Liposomes; D009942:Organometallic Compounds; D004369:Pentetic Acid; D005682:Gadolinium; D019786:Gadolinium DTPA