2 research outputs found
Development of a Tissue Equivalent Gelatine Phantom for Accuracy Verification of Tissue Elasticity Measurement Using Shear Wave Elastography Ultrasound
Background Shearwave elastography ultrasound (SWE) has been increasing used in the recent decade to quantify tissue stiffness and viscoelastic properties correlate to a disease condition. Aims This study aimed to develop a low cost and reproducible gelatine phantom to verify the accuracy of tissue elasticity measurement using shear wave elastography (SWE). The effect of lesion’s size, stiffness and depth from the surface on the tissue elasticity measurement were also investigated. Methods A breast tissue-equivalent phantom embedded with spherical inclusions of different sizes, stiffness and depth from surface was constructed using gelatine. The elasticity of the spherical inclusions was determined using a commercial SWE system and compared to the elasticity determined using a high precision electromechanical microtester (gold standard for elasticity measurements). Results Statistically significant difference (p < 0.05) was found between the elasticity measured using SWE and electromechanical microtester, whereby the SWE overestimated the tissue elasticity by a mean value of 22.8 ± 15.0 kPa. The size and depth of the spherical inclusions have not imposed any effect on the elasticity measured by SWE, but the depth of shear wave detection was found limited to 8 cm from the surface. Conclusion The gelatine phantom constructed in this study could be used to verify the accuracy of the elasticity measured using SWE. The tissue elasticity measured by the SWE appeared to be overestimated compared to the gold standard. Further research would need to be carried out to determine the offset from the SWE measurement and to account for these differences
Radiation Doses to Paediatric Patients Undergoing Voiding Cystourethrography (VCUG) at Siriraj Hospital
Objective: The aims were to quantify and evaluate the radiation doses and to estimate the radiation risk for the
paediatric patients undergoing VCUG according to the protocol used in Siriraj Hospital.
Methods: Among 93 children of the age of 0-15 years who underwent VCUG at Siriraj Hospital, we reported the
patient’s data, the radiation doses determined by a DAP meter and the baseline data including the entrance skin
dose (ESD), dose area product (DAP) and the effective dose according to the patient’s age.
Results: The mean ESD, DAP and effective doses of 93 paediatric patients were 3.63 mGy, 92.9 cGycm2
and
0.20 mSv, respectively. The initial local DRLs of DAP for VCUG examination at Siriraj Hospital were 37, 77
and 105 cGy.cm2
in the age range of 0-1, >1-5, and >5-10 years, respectively. The ESD, DAP and effective doses
were in ranges of 0.36-81.96 mGy, 1.37-1506.90 cGy.cm2
and 0.003-3.16 mSv, respectively.
Conclusion: The initial local DRLs of DAP for VCUG examinations at Siriraj Hospital were less than in NRPB
and Siriwiladluk T, et al in the age range of 0-1, >1-5, and >5-10 years. Due to the small number of patients
at the age of >10-15 years (n=4), it was inconclusive of the dose level in this age group. The lifetime risk of
radiation induced cancer was approximately calculated to be 2.6 per 100,000