Superconducting open-configuration MR imaging system for image-guided therapy.
OBJECTIVE
To develop a superconducting magnetic resonance (MR) imager that provides direct access to the patient and permits interactive MR-guided interventional procedures.


METHODS
A 0.5-T superconducting magnet that allows a region of vertical access to the patient was designed and constructed. This magnet was integrated with newly designed shielded gradient coils, flexible surface coils, and nonmagnetic displays and with position-monitoring probes and device-tracking instrumentation.


RESULTS
The magnet homogeneity was 12.3 ppm, and the gradient field was linear to within 1% over an imaging region 30 cm in diameter. The signal-to-noise ratio was 10% higher than in a comparable 0.5-T superconducting imager. Images were obtained in several anatomic regions with use of routine pulse sequences. Interactive image plane selection and near real-time imaging, with use of fast gradient-recalled echo sequences, were demonstrated at a rate of one image every 1.5 seconds.


CONCLUSIONS
MR-guided interventional procedures can be performed with full patient access with use of an open-configuration, superconducting MR magnet with near real-time imaging and interactive image plane control.
Schenck
J F
JF
General Electric Corporate Research and Development Center, General Electric Co, Schenectady, NY 12309, USA.
Jolesz
F A
FA
Roemer
P B
PB
Cline
H E
HE
Lorensen
W E
WE
Kikinis
R
R
Silverman
S G
SG
Hardy
C J
CJ
Barber
W D
WD
Laskaris
E T
ET
D006801:Humans; D008279:Magnetic Resonance Imaging / Q000295:instrumentation* / Q000379:methods