Local delivery of magnetic resonance (MR) contrast agent in kidney using thermosensitive liposomes and MR imaging-guided local hyperthermia: a feasibility study in vivo.
OBJECTIVE
To investigate the feasibility of local delivery of a magnetic resonance (MR) contrast agent in vivo using paramagnetic thermosensitive liposomes and infrared (IR) laser-induced local hyperthermia under real-time MR thermometry on rabbit kidney.


METHODS
Respiratory gated, radio frequency (RF)-spoiled gradient-echo sequences were used for precise MR temperature mapping (SD = 1 degrees C). In vivo heating experiments confirmed local release of MR contrast agent from liposomes.


RESULTS
T1 decreased from 800 msec to about 500 msec, as measured after tissue cooling, in those locations where the renal parenchyma was heated above the phase transition temperature of the liposome membrane.


CONCLUSIONS
The release of MR contrast agent has been demonstrated in rabbit kidney in vivo. This may be used as a reporter for simultaneous release of therapeutic agents.
Salomir
Rares
R
Molecular and Functional Imaging, Technological Research Unit, CNRS/University of Bordeaux 2, Bordeaux, France.
Palussière
Jean
J
Fossheim
Sigrid L
SL
Rogstad
Astri
A
Wiggen
Unni N
UN
Grenier
Nicolas
N
Moonen
Chrit T W
CT
D000818:Animals; D003287:Contrast Media / Q000493:pharmacokinetics*; D005240:Feasibility Studies; D006979:Hyperthermia, Induced; D007259:Infrared Rays; D007668:Kidney / Q000378:metabolism*; D008081:Liposomes; D008279:Magnetic Resonance Imaging; D011817:Rabbits; D013696:Temperature
D003287:Contrast Media; D008081:Liposomes