Sensitivity of in Vivo X-Ray Fluorescence Determination of Skeletal Lead Stores

Abstract

Eighteen patients with known past occupational lead exposure underwent parenteral diagnostic chelation with ethylenediaminetetraacetic acid and x-ray fluorescent determination of in vivo skeletal lead stores at the distal styloid process of the ulna and at the temporal base bone using a cobalt 57 source and measuring lead K_a x-rays. X-ray fluorescent lead measurements in both locations correlated with results of diagnostic chelation. Using a post-chelation urinary excretion of > 600μ lead/24 h as the definition of “high-” lead stores, sensitivity of x-ray fluorescence at the wrist and temple was 56% and 39%, respectively.