Renal embolization: feasibility of magnetic resonance-guidance using active catheter tracking and intraarterial magnetic resonance angiography.
OBJECTIVE
Magnetic resonance (MR)-guidance of endovascular interventions offers various advantages, including the absence of ionizing radiation, excellent soft tissue contrast, and multiplanar and functional imaging capabilities. The objective of this study was to assess the feasibility of MR-guided renal embolization using active catheter tracking with automatic slice positioning and intraarterial contrast-enhanced MR angiography (MRA).


METHODS
MR-guided embolization of 16 kidneys was attempted in 15 pigs using real-time tracking of active 5-Fr. catheters. Embolization was monitored by selective intraarterial projection MRA. Intraarterial three-dimensional (3D) MRA was used for the assessment of embolization results. Additional pathologic correlation was available in 2 animals. The image quality of intraarterial 3D contrast-enhanced-MRA was rated by an independent radiologist who was not involved in the animal experiments.


RESULTS
Active catheter tracking with automatic slice positioning allowed reliable catheter guidance and catheterization of the renal artery in all animals. Embolization was successful in all kidneys (11 left, 5 right), as verified by intraarterial 3D contrast-enhanced MRA (ce-MRA) and/or pathology. The image quality of intraarterial 3D ce-MRA was rated excellent in 10 animals, moderate in 4 animals, and poor in 1 animal.


CONCLUSIONS
Renal embolization using active catheter tracking and intraarterial ce-MRA is feasible. Selective intraarterial ce-MRA allows the assessment of blood supply and organ perfusion before, during, and after therapeutic interventions, thereby complementing MR-guided endovascular interventions.
Fink
Christian
C
Department of Radiology (E010), Deutsches Krebsforschungszentrum (DKFZ), Heidelberg, Germany. c.fink@dkfz.de
Bock
Michael
M
Umathum
Reiner
R
Volz
Steffen
S
Zuehlsdorff
Sven
S
Grobholz
Rainer
R
Kauczor
Hans-Ulrich
HU
Hallscheidt
Peter
P
D000818:Animals; D002292:Carcinoma, Renal Cell / Q000628:therapy; D002406:Catheterization, Peripheral; D004195:Disease Models, Animal; D004621:Embolization, Therapeutic / Q000379:methods*; D007680:Kidney Neoplasms / Q000628:therapy; D018810:Magnetic Resonance Angiography; D008279:Magnetic Resonance Imaging; D012077:Renal Artery; D013552:Swine