A simple methodology for the manufacture and calibration of polyacrylamide gel (PAG) for magnetic resonance imaging (MRI) radiation dosimetry is presented to enable individuals to undertake such work in a routine clinical environment. Samples of PAG were irradiated using a linear accelerator and imaged using a 0.5 T (22 MHz) Philips Gyroscan MRI sc...
The axial field of view (AFOV) of the current generation of clinical whole-body PET scanners range from 15-22 cm, which limits sensitivity and renders applications such as whole-body dynamic imaging or imaging of very low activities in whole-body cellular tracking studies, almost impossible. Generally, extending the AFOV significantly increases the...
We present a method based on spectral theory for the shape analysis of carpal bones of the human wrist. We represent the cortical surface of the carpal bone in a coordinate system based on the eigensystem of the two-dimensional Helmholtz equation. We employ a metric—global point signature (GPS)—that exploits the scale and isometric invariance of ei...
Detecting cancerous lesions is a major clinical application in emission tomography. In previous work, we have studied penalized maximum-likelihood (PML) image reconstruction for the detection task and proposed a method to design a shift-invariant quadratic penalty function to maximize detectability of a lesion at a known location in a two dimension...
Mammography has served the population of women who are at-risk for breast cancer well over the past 30 years. While mammography has undergone a number of changes as digital detector technology has advanced, other modalities such as computed tomography have experienced technological sophistication over this same time frame as well. The advent of lar...
We have used noise-equivalent count (NEC) rates to optimize count rate performance for 3D acquisition in PET in a wide range of situations, with particular reference to imaging of the torso. We have also compared NEC performance for 2D and 3D acquisition in order to establish the conditions under which 3D mode offers an improvement over 2D mode. Me...
