Identification of human appendicitis by in vitro nuclear magnetic resonance

The spin-lattice relaxation time, T₁ as determined by nuclear magnetic resonance techniques, correlates positively with tissue water content. The latter relationship has been observed in rabbits with experimentally induced appendicitis whose inflamed appendiceal tissues had significantly higher T₁'s and water contents than tissue from normal controls. The present experiment studied these relationships in humans. Tissue water content and T₁ were measured on appendiceal tissue from 10 patients with documented appendicitis and from 6 controls without the disease. All T₁'s were determined within 30-60 min of removal of the appendix at operation. The mean in vitro T₁ of appendiceal tissue from patients with appendicitis was significantly higher than that of controls (527 ± 15 msec versus 430 ± 17 msec, mean ± SEM, P < 0.002). In addition, a strong positive correlation was noted between T₁ and tissue water content (r = 0.70, P < 0.01). Based on these findings, the use of in vivo magnetic resonance imaging techniques to detect human appendicitis noninvasively warrants investigation.