OBJECTIVE: To compare data regarding dosimetry and photons fluence in different breast phantoms, discussing constancy tests and dosimetry applied to mammography. MATERIALS AND METHODS: Different homogeneous breast phantoms and one anthropomorphic voxel phantom were developed for collection of data regarding total absorbed dose in the phantom, absorbed dose in the glandular tissue material-equiv...

The GEMPix is a small gaseous detector with highly pixelated readout, consisting of drift region, three Gas Electron Multipliers (GEMs) for signal amplification, and four Timepix ASICs 55 µm pixel pitch total 262,144 pixels. A continuous flow gas mixture such as Ar:CO2:CF4, Ar:CO2 or propane-based tissue equivalent supplied externally at rate 5 L/h. This article reviews the medical applications...

Objective: In this study, we aimed to validate the accuracy of computed tomography-based attenuation correction (CTAC) using the bilinear scaling method.Methods: The measured attenuation coefficient (μm) was compared to a theoretical attenuation coefficient (μt ) using four different CT scanners and an RMI 467 phantom. The effective energy of the CT beam X-rays was calculated, using the aluminu...

Purpose This study explores the possibility of a new method for x-ray computed tomography (CT) calibration by means cross-calibration with proton CT (pCT) data. The proposed aims at more accurate conversion Hounsfield Units (HU) into stopping power ratio (SPR) relative to water be used in proton-therapy treatment planning. Methods X-ray scan was acquired on synthetic anthropomorphic phantom, co...

Introduction: Due to nuclear interactions between the tissues and high-energy protons, the particles, including neutrons, positrons, and photons arise during proton therapy. This study aimed at investigating the dose distribution of proton and secondary particles, such as positrons, neutrons, and photons using the Monte Carlo method. Material and Methods:<...

Introduction Accurate estimation of the absorbed dose in radiosensitive organs, located away from the target volume during radiotherapy, is one of the main reasons for the development of reference phantoms. The International Commission on Radiological Protection (ICRP) reference phantoms can provide a more realistic view of the human anatomy in comparison with the previously used mathematical p...

We have designed and constructed a multimodal multiplex Raman spectrometer which uses multi-wavelength excitation to better detect signals in the presence of fluorescence by taking advantage of the shift-variance of the Raman signal with respect to excitation frequency. Coupled with partial-least-squares (PLS) regression, the technique applied to ethanol estimation in a tissue phantom achieves ...

We describe a complex differential variance (CDV) algorithm for optical coherence tomography based angiography. The algorithm exploits both the intensity and phase changes of optical coherence tomography (OCT) signals from flowing blood to achieve high vascular contrast, and also intrinsically reject undesirable phase signals originating from small displacement axial bulk tissue motion and inst...