Dosimetric and performance analysis of Rhizophora spp. particleboards as phantom material for SPECT/CT imaging

The aim of this study is to investigate the dosimetric performance of the fabricated Rhizophora spp. particleboards as phantom for the in-vivo imaging of single photon emission computed tomography (SPECT/CT). The phantom made of the particleboards was fabricated based on the external dimension of the readily available Jaszczak phantom. Six vials made of Perspex® with diameters between 1.3 and 3.5 cm were also constructed to simulate the localization of radiopharmaceuticals of different volumes in conjunction with the 99mTc radiopharmaceuticals of 1.6 µCi/ml activity concentration. The SPECT/CT images of the particleboard phantoms were obtained based on the abdominal scanning protocols. The contrast at different SPECT filters and recovery coefficient, RC of the particleboard phantoms were determined and compared to that in the Perspex® and modified Jaszczak phantoms. The results showed that the contrast of the Rhizophora spp. particleboard phantom was in good agreement with that in the Jaszczak phantom. The contrast also increased linearly at higher cut-off frequency of SPECT filters. The evaluation of apparent to the actual size of the Rhizophora spp. particleboard phantom was also in agreement within 4.4 and 5.95% to the Perspex® and Jaszczak phantoms respectively for all vial sizes. The RC measured in the Rhizophora spp. particleboard phantom was also in good agreement to the Jaszczak with p-value of 0.185.A spill-over effect was also observed at larger vial diameters with values between 4.2 and 6.7%. The overall results indicated the suitability of particleboards made of Rhizophora spp. as an alternative phantom material for in-vivo imaging.