Y Contamination in the Interventional Radiology Suite: VARSKIN Estimation of Skin and Eye Injury and Review of Mitigation Strategies.

Our objective was to demonstrate, through computer simulations, radiation exposure levels from a Y contamination event during radioembolization procedures to calculate the radiation doses from various contamination scenarios. We also provide reasonable safety protocols to prevent contamination and minimize radiation exposure during decontamination. Simulations were performed using the computer code VARSKIN+, version 1.

Post-administration dosimetry in yttrium-90 radioembolization through micro-CT imaging of radiopaque microspheres in a porcine renal model.

The purpose of this study is to perform post-administration dosimetry in yttrium-90 radioembolization through micro-CT imaging of radiopaque microsphere distributions in a porcine renal model and explore the impact of spatial resolution of an imaging system on the extraction of specific dose metrics. Following the administration of radiopaque microspheres to the kidney of a hybrid farm pig, the kidney was explanted and imaged with micro-CT. To produce an activity distribution, 400 MBq of yttrium-90 activity was distributed throughout segmented voxels of the embolized vasculature based on an established linear relationship between microsphere concentration and CT voxel value.

Absorbed dose kernel and self-shielding calculations for a novel radiopaque glass microsphere for transarterial radioembolization.

Purpose: Radiopaque microspheres may provide intraprocedural and postprocedural feedback during transarterial radioembolization (TARE). Furthermore, the potential to use higher resolution x-ray imaging techniques as opposed to nuclear medicine imaging suggests that significant improvements in the accuracy and precision of radiation dosimetry calculations could be realized for this type of therapy. This study investigates the absorbed dose kernel for novel radiopaque microspheres including contributions of both short and long-lived contaminant radionuclides while concurrently quantifying the self-shielding of the glass network.

Butyrylcholinesterase-knockout reduces fibrillar β-amyloid and conserves FDG retention in 5XFAD mouse model of Alzheimer's disease.

Alzheimer's disease (AD) is the most common neurodegenerative disorder causing dementia. One hallmark of the AD brain is the deposition of β-amyloid (Aβ) plaques. AD is also a state of cholinergic dysfunction and butyrylcholinesterase (BChE) associates with Aβ pathology.

Early detection of cerebral glucose uptake changes in the 5XFAD mouse.

Brain glucose hypometabolism has been observed in Alzheimer's disease (AD) patients, and is detected with (18)F radiolabelled glucose, using positron emission tomography. A pathological hallmark of AD is deposition of brain β- amyloid plaques that may influence cerebral glucose metabolism. The five times familial AD (5XFAD) mouse is a model of brain amyloidosis exhibiting AD-like phenotypes.

Synthesis and preliminary evaluation of piperidinyl and pyrrolidinyl iodobenzoates as imaging agents for butyrylcholinesterase.

Purpose: The purpose of this study is to synthesize and evaluate specific agents for molecular imaging of butyrylcholinesterase (BuChE), known to be associated with neuritic plaques and neurofibrillary tangles in Alzheimer's disease (AD). In this study, these agents were tested in a normal rat model. The distribution of radiolabel was compared with known BuChE histochemical distribution in the rat brain.

The development of quality control standards for radiation therapy equipment in Canada.

Among the essential components of a comprehensive quality assurance program in radiotherapy are the quality control protocols to be used on the equipment and, in particular, the performance objectives and criteria. In the present work, we describe the development of a suite of quality control documents for use across Canada. Following a generic format, we are generating concise, clear standards for the most commonly used equipment in radiotherapy, with the emphasis on performance measures.

[Integration of digital angiography, magnetic resonance, x-ray computed tomography and positron emission tomography in stereotaxy].

Consecutively to drastic changes which occurred in cerebral imagery techniques, we have developed a stereotactic apparatus and system based on the integration of several new techniques allowing visualisation of the brain: tomodensitometry (TDM), digital subtraction angiography (DSA), magnetic resonance (MR) and positron emission tomography (PET). TDM, DSA and MR can be performed in stereotactic conditions with the apparatus in situ. They give the computer the anatomic references necessary for all calculations.

Integrated stereotaxic imaging with CT, MR imaging, and digital subtraction angiography.

A stereotaxic frame, compatible with digital subtraction angiography, computed tomography, and magnetic resonance imaging, is described along with a set of software programs that run in an independent imaging computer system, as well as in the computers associated with each modality. Plexiglas plates fastened to the sides of the frame contain fiducial markers that can be recognized in the images and from which the section position and in-plane coordinates of any point in the image relative to the frame may be determined. Coordinate measurements of isolated point targets may be made to an accuracy of better than +/- 1 mm within a 15-cm field of view in the plane of the section or projection on all modalities.

Stereoscopic digital subtraction angiography in neuroradiologic assessment.

Digital subtraction angiography (DSA) with stereoscopic imaging was performed in 40 patients for evaluation of a variety of cerebrospinal disorders. It was facilitated by a C-arm mounted x-ray tube and imaging chain with 7 degrees angulation between image pairs. Stereoscopic digital imaging proved particularly useful in the preoperative assessment of aneurysms, arteriovenous malformations, and primary and metastatic tumors.