MR-guided intravascular catheter manipulation: feasibility of both active and passive tracking in experimental study and initial clinical applications.
OBJECTIVE
To evaluate clinically the feasibility and usefulness of MR-guided intravascular procedures with either active or passive tracking.


METHODS
With an active MR tacking system and a 0.2 Tesla open MR imager, real-time and biplane displays of positions of a receive-only coil at the tip of catheters were obtained. For passive tracking, 4 Fr catheters with suitable susceptibility for passive tracking were used. Passive tracking with a 1.5 Tesla MR imager could be performed with parameters of TR 15-50 msec, TE 2.2-2.7 msec, and FA 30 degrees. The temperature of each tracking catheter was monitored in vitro. Clinical trials were performed on six patients (three each). The catheter was introduced to the superior mesenteric artery (SMA) under MR guidance by active or passive tracking to perform MR imaging during arterial portography.


RESULTS
The temperature increased minimally. In humans, the SMA and celiac artery could be easily introduced on active tracking. MR-guided manipulation of catheters by active or passive tracking in the model and in dogs' vessels was very successful. Introduction of the catheter into the SMA was successful in two cases of active tracking and in all cases of passive tracking.


CONCLUSIONS
The MR-guided intravascular manipulation of catheters by active or passive tracking may be a clinically feasible method.
Araki
Takuji
T
Department of Radiology, Yamanashi Medical University, Nakakoma-gun, Japan.
Aoki
Shigeki
S
Ishigame
Keiichi
K
Kumagai
Hiroshi
H
Nanbu
Atsushi
A
Hori
Masaaki
M
Ueki
Junko
J
Komiyama
Takafumi
T
Araki
Tsutomu
T
D002406:Catheterization, Peripheral / Q000295:instrumentation / Q000379:methods*; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D017538:Mesenteric Artery, Superior; D008875:Middle Aged; D011172:Portography / Q000295:instrumentation / Q000379:methods*; D015641:Radiography, Interventional