RESUMO
To develop a new method for diagnosing necrotizing enterocolitis and prediction of severity with the use of computed tomography [CT]. Urine specimens from 63 premature neonates were obtained at 4-hours interval for 24 hours duration after administration of iodinated water-soluble contrast material [Iohexol] entrally for 45 neonates from them. Twelve neonates had definite necrotizing enterocolitis [NEC] [group I] and 10 neonates had suspected NEC [group II]. Urine from another two groups without any clinical evidence of NEC [at the time these studies were performed] was collected, 23 neonates [group III] received Iohexol [who underwent upper gastrointestinal study], and 18 neonates [group IV] did not receive Iohexol. The attenuation coefficient of each urine specimen was determined with CT [equivalent to the concentration of the Iohexol in urine]. The mean CT attenuation coefficient of urine from neonates who did not receive Iohexol [group IV] was 5.2 +/- 3.5 HU [Hounsfield unit], and that from neonates without NEC [group III] [who underwent upper gastrointestinal study] was 6.8 +/- 3.0 HU. The mean CT attenuation coefficient of urine from patients with suspected necrotizing enterocolitis [group II] was 28.0 +/- 3.8 HU, and that from patients with definite necrotizing enterocolitis [group I] was 73.0 +/- 19.8 HU. The mean CT attenuation coefficient in neonates with NEC were significantly higher than that from suspected group and than that from patients without NEC whether received the Iohexol or not [P<0.01]. Follow up samples revealed significant reduction in the CT attenuation coefficient after treatment. Urine from neonates with necrotizing enterocolitis show significantly higher CT attenuation coefficients than those from patients without necrotizing enterocolitis. CT examination of urine may allow early diagnosis of necrotizing enterocolitis, effect of treatment as well as severity prediction