Electromagnetic flow measurement using a magnetic resonance imaging static field.
OBJECTIVE
Electromagnetic flowmeters have been used for many years as a standard method to determine blood flow in animal models. The use of a modified probe to measure electromagnetic induction in response to an external, large direct current (DC) field magnetic resonance (MR) imaging system was investigated.


METHODS
Extracted sheep iliac vessels were inserted into a pumped saline circuit with a modified probe and placed into a 2.0-T MR research imaging system. Voltage readings were collected at various flow rates ranging from 100 to 400 ml/min. Actual flows were measured with a graduated cylinder.


RESULTS
A correlation of .937 (p < .001) was observed between the measured voltage changes and the actual flows. Baseline drift was also linear and within specified limits.


CONCLUSIONS
The results indicate that electromagnetic induction in a conductive fluid can be accurately measured using electrodes and an MR imaging system and that this technique provides possible opportunities for in situ flow measurements in humans.
Burns
S M
SM
Biomedical Engineering Graduate Group, University of California, Davis 95817, USA.
Barlow
T W
TW
Katzberg
R W
RW
Brock
J M
JM
D000818:Animals; D001783:Blood Flow Velocity / Q000502:physiology*; D055590:Electromagnetic Phenomena / Q000295:instrumentation*; D004867:Equipment Design; D005240:Feasibility Studies; D007083:Iliac Artery / Q000502:physiology; D008279:Magnetic Resonance Imaging; D012044:Regression Analysis; D012756:Sheep