Nuklearmedizin 2020; 59(02): 138
DOI: 10.1055/s-0040-1708275
Wissenschaftliche Poster
Medizinische Physik I
© Georg Thieme Verlag KG Stuttgart · New York

Comparison of Two Dual Energy Quantitative CT Methods to Measure the Volume Fraction of Water, Fat and Mineral Bone to Characterize the Bone Marrow Composition

M Salas Ramirez
1   Universität Würzburg, Klinik und Poliklinik für Nuklearmedizin, Universitätsklinikum Würzburg, Würzburg
,
J Tran-Gia
1   Universität Würzburg, Klinik und Poliklinik für Nuklearmedizin, Universitätsklinikum Würzburg, Würzburg
,
U Gbureck
2   Universität Würzburg, Lehrstuhl für Funktionswerkstoffe der Medizin und der Zahnheilkunde, Universitätsklinikum Würzburg, Würzburg
,
M Lassmann
1   Universität Würzburg, Klinik und Poliklinik für Nuklearmedizin, Universitätsklinikum Würzburg, Würzburg
› Author Affiliations
Further Information

Publication History

Publication Date:
08 April 2020 (online)

 

Ziel/Aim This study compares two dual energy quantitative computed tomography (DEQCT) methods to measure the volume fraction of fat, water and mineral bone for calculation of patient-specific radionuclide S values for bone marrow dosimetry.

Methodik/Methods First, two DEQCT methods were implemented in an integrated multiple energy (SPECT/)CT system (SIEMENS Intevo Bold). The first method [1] is phantom-independent (based on spectral x-ray attenuation) and the second method [2] is phantom-dependent (external calibration rods). The quantification of the volume fraction of water, fat and mineral bone was performed in a phantom composed of two vials (A and B), which were located in a water-filled NEMA phantom to simulate soft tissue attenuation. The two vials were composed of water (agar) (47.5 %), fat (paraffin) (47.5 %) and mineral bone (hydroxyapatite, HA) (5 %). CT images of the phantom were acquired with 80 kV and 130 kV. Images were reconstructed with an iterative kernel (I41 s).

Ergebnisse/Results The decomposition of the three materials using the first DEQCT method was not possible. Therefore, a two-material decomposition (water equivalent and hydroxyapatite) was applied. The relative errors of HA quantification using the first method were 7.5 % and 5.56 % for vial A and B respectively. By using the second method, it was possible to decompose the three materials. In vials A and B, the relative errors for the quantification of were 9 % and 7.4 % (HA), −5.39 % and −2.84 % (agar), and 4.44 % and 2.06 % (paraffin), respectively.

Schlussfolgerungen/Conclusions The first method showed similar relative errors compared to the second method. Furthermore, the three material decomposition was feasible using the second method. More studies are required with different fat and hydroxyapatite volume fraction in an anthropomorphic phantom to validate the performance of the phantom-dependent method.

 

  • Literatur/References:

  • 1 Liu X. et al. Med. Phys. 36. , 5, May 2009.
  • 2 Goodsitt J. et al. Med. Phys. 41. , 5, May 2014