A method for achieving quantitative single-photon emission computed tomography (SPECT) based upon corrections derived from x-ray computed tomography (CT) data is presented. A CT-derived attenuation map is used to perform transmission-dependent scatter correction (TDSC) in conjunction with non-uniform attenuation correction. The original CT data are also utilized to correct for partial volume ef...

Software anthropomorphic breast phantoms have been used in virtual clinical trials for preclinical validation of breast imaging systems. Virtual trial quality depends largely on the realism of the simulated breast anatomy. Our phantom design has been focused on the simulation of large-scale and mesoscale anatomical structures, including the breast outline, skin, and matrix of Cooper’s ligaments...

This report specifically describes the use of a unique anthropomorphic breast phantom to validate the accuracy of three-dimensional dose calculations performed by a commercial treatment-planning system for intact-breast tangential irradiation. The accuracy of monitor-unit calculations has been corroborated using ionization chamber measurements made in this phantom. Measured doses have been comp...

Monte Carlo (MC) modelling is widely used in the field of single photon emission computed tomography (SPECT) as it is a reliable technique to simulate very high quality scans. This technique provides very accurate modelling of the radiation transport and particle interactions in a heterogeneous medium. Various MC codes exist for nuclear medicine imaging simulations. Recently, new strategies exp...

PURPOSE To compare low dose volume and integral dose of various rotational arc radiation therapy modalities, including helical tomotherapy (HT) and other volumetric modulated arc therapies (VMAT). METHODS A digital cylindrical phantom and an anthropomorphic pelvic phantom were used in the study. HT treatment was planned on TomoTherapy Planning Station (Accuray) and VMAT plans were generated o...

Background: Placing a self-expandable metallic stent (SEMS) is safe and effective for the palliative treatment of malignant gastroduodenal (GD) strictures. SEMS abutment in the duodenal wall is associated with increased food impaction, resulting in higher stent malfunction and shorter stent patency. The desire to evaluate the mechanism and significance of stent abutment led us to design an in v...

This study was designed to estimate radiation-induced secondary cancer risks from high-dose-rate (HDR) brachytherapy and external radiotherapy for patients with cervical cancer based on measurements of doses absorbed by various organs. Organ doses from HDR brachytherapy and external radiotherapy were measured using glass rod dosimeters. Doses to out-of-field organs were measured at various loca...

Energy imparted is a measure of the total ionizing energy deposited in the patient during a radiologic examination and may be used to quantify the patient dose in diagnostic radiology. Values of the energy imparted per unit exposure-area product, omega (z), absorbed by a semi-infinite water phantom with a thickness z, were computed for x-ray spectra with peak x-ray tube voltages ranging from 50...

Radiotherapy treatment planning integrating positron emission tomography (PET) and computerized tomography (CT) is rapidly gaining acceptance in the clinical setting. Although hybrid systems are available, often the planning CT is acquired on a dedicated system separate from the PET scanner. A limiting factor to using PET data becomes the accuracy of the CT/PET registration. In this work, we us...