Keywords:
Molecular imaging, Radiation physics, Radioprotection / Radiation dose, PET-CT, Dosimetry, Quality assurance
Authors:
A. Samartzis1, A.-A. Foteina2, E. Tzampazidou2, V. Chatonidis2, N. Bertsekas2, I. E. Datseris2; 1Ilioupoli/GR, 2Athens/GR
DOI:
10.26044/ecr2019/C-2578
Methods and materials
Radiation dose in a CT scanner is expressed as the Computed Tomography Dose Index (CTDI) and it measures the average absorbed dose of adjacent slices.
CTDI is calculated as CTDI=2/3 CTDI100 (periphery) + 1/3 CTDI100 (centre).
[1] The values of CTDIvol for whole-body examinations were determined by the operator's console of the scanner.
Many organizations in Europe,
such as International Commission on Radiological Protection (ICRP),
have determined DRLs for diagnostic CT procedures based on the 75th percentile of CTDI values.
[6],
[7],
[8]
Patient age,
sex,
weight,
height,
computed tomography dose index (CTDIvol),
dose length product (DLP) and activity parameters for whole-body PET/CT examinations were recorded,
using a sample of 368 randomly chosen patients during the period from June to September 2018.
For whole body examinations,
all patients were examined with the radiopharmaceutical 18F-fluorodeoxyglucose (18F-FDG).
From these acquired data,
mean,
median and 75th percentile values were calculated.
Pearson’s correlation coefficient was determined between CTDIvol and activity values.
Histograms of CTDIvol and activity values were constructed by Statistical Package for the Social Sciences (SPSS) software.