title: Exposure of extremely low birth weight infants to diagnostic X-Rays: a longitudinal study.
abstract: OBJECTIVE
  To quantify the number of chest and abdominal radiograms performed in surviving singleton extremely low birth weight (ELBW) infants in order to examine whether changes in imaging application occurred during the last 21 years (1987-2007).
  
  
  METHODS
  Clinical and radiological data of 225 out of 229 surviving infants were obtained and associations with time and clinical variables were evaluated.
  
  
  RESULTS
  The number of chest X-Rays performed per infant was 10.3 +/- 11.1 (mean +/- SD), median = 7; range = 0-77 and the number of abdominal radiograms was 5.6 +/- 7.1, median = 3; range = 0-61. The number of chest and abdominal X-Rays performed per patient during 1987-1996 was very similar to that of 1997-2007, and no appreciable change of trend was observed along the years. There were negative and statistically significant correlations between the gestational age and the number of radiograms performed per patient (chest X-Rays: r =-0.402; p < 0.001, abdominal X-Rays: r =-0.182; p = 0.006). Controlling for gestational age, reduced numbers of radiograms per patient (abdominal: b =-1.20, p = 0.235; chest: b =-3.08, p = 0.035) were demonstrated in the second period. Patients with complicated clinical course were exposed to significantly more radiograms.
  
  
  CONCLUSIONS
  Controlling for gestational age, a reduced number of exposures to chest radiograms was demonstrated during 1997-2007 compared with 1987-1996. Measures to reduce radiation, especially in complicated cases, are advocated.
authors.affiliation: Department of Neonatology, Hadassah-Hebrew University Medical Center, Jerusalem, Israel. arad@hadassah.org.il
authors.forename: Ilan
authors.initials: I
authors.lastname: Arad
authors.forename: Natalia
authors.initials: N
authors.lastname: Simanovsky
authors.forename: Rony
authors.initials: R
authors.lastname: Braunstein
mesh_terms: D006801:Humans; D052577:Infant, Extremely Low Birth Weight; D007231:Infant, Newborn; D008137:Longitudinal Studies; D011860:Radiography, Abdominal / Q000706:statistics & numerical data*; D013902:Radiography, Thoracic / Q000706:statistics & numerical data*