DIAGNOSING INTESTINAL ISCHEMIA USING A NONCONTACT SUPERCONDUCTING QUANTUM INTERFERENCE DEVICE

Intestinal ischemia is associated with changes of the basic electric r hythm (BER) of the small intestine. We hypothesized that these changes can be measured noninvasively using a superconducting quantum interfe rence device (SQUID). After general anesthesia, a laparotomy was perfo rmed on 10 animals and the jejunum was placed in a nomnagnetic recordi ng chamber containing Krebs' solution at 38 degrees C. Five animals ha d electrodes placed while five others were placed under the SQUID. Inj ection of thrombin into the mesenteric artery decreased blood flow (me asured with a laser doppler flow-meter) 95% within 5 minutes. SQUID me asurements showed significant decreases (P < 0.01 for all changes) in the frequency (15.5 +/- 0.3 to 8.9 +/- 0.2 cycles/min) and the propaga tion velocity of slow wares (3.5 +/- 0.2 to 1.9 +/- 0.3 sec). The chan ges in intestinal biomagnetic activity after ischemia were similar to the changes in electrical activity. The SQUID magnetometer is a reliab le noncontact device that can detect early intestinal ischemia in anim al models. We have recently recorded human small bowel biomagnetic act ivity using a SQUID magnetometer and believe further technical develop ments Hill permit the noninvasive diagnosis of mesenteric ischemia.