The Combination of In vivo 124I-PET and CT small animal imaging for evaluation of thyroid physiology and dosimetry

TY - JOUR

T1 - The Combination of In vivo 124I-PET and CT small animal imaging for evaluation of thyroid physiology and dosimetry

AU - El Ali, Henrik H.

AU - Eckerwall, Martin

AU - Skovgaard, Dorthe Charlotte

AU - Larsson, Erik

AU - Strand, Sven-Erik

AU - Kjær, Andreas

PY - 2013/6/5

Y1 - 2013/6/5

N2 - Objective: A thyroid rat model combining functional and anatomical information would be of great benefit for better modeling of thyroid physiology and for absorbed dose calculations. Our aim was to show that 124I-PET and CT small animal imaging are useful as a combined model for studying thyroid physiology and dose calculation. Methods: Seven rats were subjects for multiple thyroid 124I-imaging and CT-scans. S-values [mGy/MBqs] for different thyroid sizes were simulated. A phantom with spheres was designed for validation of performances of the small animal PET and CT imaging systems. Results: Small animal PET/CT based measurements of the activity amount and the volumes of the spheres with a priori known volumes showed a good agreement with their corresponding actual volumes. The CT scans of the rats showed thyroid volumes from 34 – 70 mL. Conclusions: The wide span in volumes of thyroid glands indicates the importance of using an accurate volume-measuring technique such as the small animal CT. The small animal PET system was on the other hand able to accurately estimate the activity concentration in the thyroid volumes. We conclude that the combined small animal PET/CT imaging is essential for quantitative thyroid imaging and accurate thyroid absorbed dose calculation.

AB - Objective: A thyroid rat model combining functional and anatomical information would be of great benefit for better modeling of thyroid physiology and for absorbed dose calculations. Our aim was to show that 124I-PET and CT small animal imaging are useful as a combined model for studying thyroid physiology and dose calculation. Methods: Seven rats were subjects for multiple thyroid 124I-imaging and CT-scans. S-values [mGy/MBqs] for different thyroid sizes were simulated. A phantom with spheres was designed for validation of performances of the small animal PET and CT imaging systems. Results: Small animal PET/CT based measurements of the activity amount and the volumes of the spheres with a priori known volumes showed a good agreement with their corresponding actual volumes. The CT scans of the rats showed thyroid volumes from 34 – 70 mL. Conclusions: The wide span in volumes of thyroid glands indicates the importance of using an accurate volume-measuring technique such as the small animal CT. The small animal PET system was on the other hand able to accurately estimate the activity concentration in the thyroid volumes. We conclude that the combined small animal PET/CT imaging is essential for quantitative thyroid imaging and accurate thyroid absorbed dose calculation.

KW - Faculty of Health and Medical Sciences

KW - Thyroid rat model

KW - Rat S-values

KW - 124I-thyroid imaging

KW - molecular imaging

KW - Animal PET/CT co-registration

KW - small animal dosimetry

U2 - 10.3390/diagnostics2020010

DO - 10.3390/diagnostics2020010

M3 - Journal article

C2 - 26859394

SN - 2075-4418

VL - 2

SP - 10

EP - 22

JO - Diagnostics

JF - Diagnostics

IS - 2

ER -