NONINVASIVE DIAGNOSIS OF MESENTERIC ISCHEMIA USING A SQUID MAGNETOMETER

Objective The authors assessed the ability of a Superconduct ng Quantu m Interference Device (SQUID) magnetometer to noninvasively detect mes enteric ischemia in a rabbit model. Summary Background Data Supercondu cting Quantum Interference Device magnetometers have been used to dete ct magnetic fields created by the basic electrical rhythm (BER) and to detect changes in BER of exteriorized bowel of anesthetized rabbits d uring mesenteric ischemia. Methods The BER of rabbit ileum was noninva sively measured transabdominally using a SQUID magnetometer and compar ed with the electrical activity recorded with surgically implanted ser osal electrodes before, during, and after snare occlusion of the super ior mesenteric artery. Results Transabdominal SQUID recording of BER f requency was highly correlated to the measurements obtained with elect rodes (R = 0.91). Basic electrical rhythm frequency decreased from 16. 4 +/- 0.8 to 8.3 +/- 0.3 cpm (p < 0.001) after 25 minutes of ischemia. Reperfusion of ischemic bowel resulted in recovery of BER frequency t o 14.3 +/- 0.4 cpm 10 minutes after brood flow was restored. Conclusio ns A SQUID magnetometer is capable of noninvasively detecting mesenter ic ischemia reliably and at an early stage by detecting a significant drop in BER frequency. These positive findings have encouraged the aut hors to continue development of clinically useful, noninvasive, detect ion of intestinal magnetic fields using SQUID magnetometers.