No radiation protection reasons for restrictions on 14C urea breath tests in children

No radiation protection reasons for restrictions on ¹⁴C urea breath tests in children

M Gunnarsson, PhD ¹ S Leide-Svegborn, PhD ¹^,2 K Stenström, PhD ³ G Skog, PhD ⁴ L-E Nilsson, BSc ⁵ R Hellborg, PhD ³ and S Mattsson, PhD ¹

¹ Department of Radiation Physics, Lund University, Malmö University Hospital, SE-205 02 Malmö, ² Department of Laboratory and Imaging Sciences, Malmö University College, Malmö University Hospital, SE-205 02 Malmö, ³ Department of Nuclear Physics, Lund University, Box 118, SE-221 00 Lund, ⁴ Department of Quaternary Geology, Lund University, Tornavägen 13, SE-223 63 Lund ⁵ Department of Clinical Physiology, Lund University, Malmö University Hospital, SE-205 02 Malmö, Sweden

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Figure 1. ¹⁴C activity in exhaled air, given as percentage of administered ¹⁴C urea activity per hour, in samples taken 20 min after administration and measured with accelerator mass spectrometry. A normalized ¹⁴C activity >2.2% of administered activity per hour indicates that the patient is Helicobacter pylori (HP) positive. YCh, younger children (3–6 years); Ch, older children ( $>=$ ge;7 years).

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Figure 2. Fractional excretion of ¹⁴C in exhaled air as a function of time after administration of ¹⁴C urea. Lines correspond to the curves fitted to the data for older children ( $>=$ ge;7 years) and symbols to those of younger children (3–6 years).

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Figure 3. Fractional excretion of ¹⁴C in urine as a function of time after administration of ¹⁴C urea. Lines correspond to the curves fitted to the data for older children ( $>=$ ge;7 years) and symbols to those of younger children (3–6 years).