Quantitative knowledge guides vital decisions in the life of animals and humans alike. The posterior parietal cortex in primates has been implicated in representing abstract quantity, both continuous (extent) and discrete (number of items), supporting the idea of a putative generalized magnitude system in this brain area. Whether or not single neurons encode different types of quantity, or how ...

The aim of this study was to describe our initial experience with a gold flexible linear fiducial marker and to evaluate the safety and technical and clinical efficacy of stereotactic body radiotherapy using this marker for malignant liver tumors. Between July 2012 and February 2015, 18 patients underwent percutaneous fiducial marker placement before stereotactic body radiotherapy for malignant...

OBJECTIVE To demonstrate that the shape of the configuration of fiducial points is an important factor governing target registration error (TRE) in point-based, rigid registration. METHODS We consider two clinical situations: cranial neurosurgery and pedicle screw placement. For cranial neurosurgery, we apply theoretical results concerning TRE prediction, which we have previously derived and ...

We describe the evaluation of the registration of Positron Emission Tomography (PET) scans with X-ray Computed Tomography (CT) scans of the human brain. A CT scan and a PET scan of the same person were obtained with fiducial markers placed on the person's head. The CT scan and the PET scan were then registered, first by using the fiducial markers, and next by applying the registration method cu...

Purpose: The aim of this study was to determine the feasibility of using gold seed fiducial markers within the daily treatment of prostate cancer patients as a means of improving treatment field placement accuracy and minimising the effect of interfractional prostate movement. Methods: Ten patients had three fiducial markers inserted into the prostate gland under ultrasound guidance. Daily veri...

In augmented reality (AR), a user can see a virtual world as well as the real world. To avoid registration problems between the virtual world and the real world, the user’s viewing pose in both worlds should be kept the same. Fiducial-tracking AR is an attractive approach to the registration problem. However, most of the developed fiducialtracking AR systems have restricted workspaces. To provi...

PURPOSE We investigated the accuracy and feasibility of a system that provides transrectal needle access to the prostate concurrent with 1.5 Tesla MRI which previously has not been possible. MATERIALS AND METHODS In 5 patients with previously diagnosed prostate cancer, MRI guided intraprostatic placement of gold fiducial markers (4 procedures) and/or prostate biopsy (3 procedures) was perform...

A simple interpretation of quantity calculus is given. Quantities are described as two-place functions from objects, states or processes (or some combination them) into numbers that satisfy the mutual measurability property. Quantity based on a notational simplification concept quantity. key element we consider units to be intentionally unspecified measures exactly specified processes. This com...

Radiotherapy for liver malignancy is increasing due to advances in radiotherapy technique. Visualization of the tumor as well as fiducial markers is essential. To see if improved visibility exists on computed tomography (CT) and magnetic resonance imaging (MRI), we evaluated an iron-containing fiducial marker. A patient with hepatocellular carcinoma and a patient with cholangiocarcinoma were en...