High-Fidelity Simulation in an Undergraduate Ambulatory Care Nursing Course.

For a new ambulatory care nursing course in an undergraduate baccalaureate program, a standardized patient simulation was created to support the clinical component of the course. The goals were for students to enhance their critical thinking skills, apply the nursing process to an ambulatory setting, apply learned skills to the non-acute care setting, and increase their confidence. The simulation format included three stations: skills refresher, telehealth, and clinic.

Ambulatory care education: Preparing nurses for the future of healthcare.

In the current healthcare environment, ambulatory care nursing is increasingly recognized as an efficient and effective way of collaborating with clients to improve health outcomes and to focus on prevention. Nursing skills in ambulatory care are both valuable and necessary. However, few undergraduate nursing programs provide content on ambulatory care or significant clinical experience outside the context of an acute care setting.

Evaluation of a novel collimator for molecular breast tomosynthesis.

Purpose: This study investigated a novel gamma camera for molecular breast tomosynthesis (MBT), which is a nuclear breast imaging method that uses limited angle tomography. The camera is equipped with a variable angle, slant-hole (VASH) collimator that allows the camera to remain close to the breast throughout the acquisition. The goal of this study was to evaluate the spatial resolution and count sensitivity of this camera and to compare contrast and contrast-to-noise ratio (CNR) with conventional planar imaging using an experimental breast phantom.

Respiratory motion correction in gated cardiac SPECT using quaternion-based, rigid-body registration.

In this article, a new method is introduced for estimating the motion of the heart due to respiration in gated cardiac SPECT using a rigid-body model with rotation parametrized by a unit quaternion. The method is based on minimizing the sum of squared errors between the reference and the deformed frames resulting from the usual optical flow constraint by using an optimized conjugate gradient routine. This method does not require any user-defined parameters or penalty terms, which simplifies its use in a clinical setting.

Motion estimation for cardiac emission tomography by optical flow methods.

This paper describes a new method for estimating the 3D, non-rigid object motion in a time sequence of images. The method is a generalization of a standard optical flow algorithm that is incorporated into a successive quadratic approximation framework. The method was evaluated for gated cardiac emission tomography using images obtained from a mathematical, 4D phantom and a physical, dynamic phantom.

Estimation of images and nonrigid deformations in gated emission CT.

In this paper, we propose and test a new iterative algorithm to simultaneously estimate the nonrigid motion vector fields and the emission images for a complete cardiac cycle in gated cardiac emission tomography. We model the myocardium as an elastic material whose motion does not generate large amounts of strain. As a result, our method is based on minimizing an objective function consisting of the negative logarithm of a maximum likelihood image reconstruction term, the standard biomechanical model of strain energy, and an image matching term that ensures a measure of agreement of intensities between frames.

Modeling the axial extension of a transmission line source within iterative reconstruction via multiple transmission sources.

Reconstruction algorithms for transmission tomography have generally assumed that the photons reaching a particular detector bin at a particular angle originate from a single point source. In this paper, we highlight several cases of extended transmission sources, in which it may be useful to approach the estimation of attenuation coefficients as a problem involving multiple transmission point sources. Examined in detail is the case of a fixed transmission line source with a fan-beam collimator.

Transmission scanning system for a gamma camera coincidence scanner.

Unlabelled: The goal of this research was to develop and evaluate a practical transmission scanning system for attenuation correction on a 2-head gamma camera coincidence scanner.

Methods: The transmission system operates in singles mode and uses point sources of 137Cs that emit 662-keV gamma-radiation. Each point source is inserted between existing septa that are normally used to provide an approximately 2-dimensional emission acquisition geometry.

Quantitative pulmonary single photon emission computed tomography for radiotherapy applications.

Pulmonary imaging using single photon emission computed tomography (SPECT) is the focus of current radiotherapy research, including dose-response analysis and three-dimensional (3D) radiation treatment planning. Improvement in the quantitative capability of SPECT may help establish its potential role in this application as well as others requiring accurate knowledge of pulmonary blood flow. The purposes of this study were to quantitatively evaluate SPECT filtered backprojection (FBP) and ordered subset-expectation maximization (OS-EM) reconstruction implementations for measuring absolute activity concentration in lung phantom experiments, and to incorporate quantitative SPECT techniques in 3D-RTP for lung cancer.

Multimodality nuclear medicine imaging in three-dimensional radiation treatment planning for lung cancer: challenges and prospects.

The purpose of this study was to determine the utility of quantitative single photon emission computed tomography (SPECT) lung perfusion scans and F-18 fluorodeoxyglucose positron emission computed tomography (PET) during X-ray computed tomography (CT)-based treatment planning for patients with lung cancer. Pre-radiotherapy SPECT (n = 104) and PET (n = 35) images were available to the clinician to assist in radiation field design for patients with bronchogenic cancer. The SPECT and PET scans were registered with anatomic information derived from CT.

Transmission imaging for nonuniform attenuation correction using a three-headed SPECT camera.

Unlabelled: Our objective was to build and test a new system for transmission CT (TCT) imaging on a three-headed SPECT camera. The TCT images are intended for use in nonuniform attenuation correction of cardiac SPECT data.

Methods: The system consists of a transmission line source mounted to the camera gantry at the focal line of a long focal length, asymmetric fanbeam collimator.

Quantitative imaging of iodine-131 distributions in brain tumors with pinhole SPECT: a phantom study.

Unlabelled: A method of quantitatively imaging 131I distributions in brain tumors from intratumoral administration of activity was developed and investigated using pinhole SPECT of brain tumor phantoms.

Methods: Pinhole SPECT sensitivity and resolution were characterized using 131I point-source acquisitions with high-resolution lead (1.4-mm diameter aperture) and tungsten (1.

Effect of registration errors between transmission and emission scans on a SPECT system using sequential scanning.

Unlabelled: The purpose of this study was to evaluate the effects of patient motion on nonuniform attenuation correction of cardiac SPECT when the transmission and emission scans were performed sequentially. By using a sequential protocol rather than doing the scans simultaneously, contamination from the emission scan into the transmission scan could be eliminated, but registration of the two scans become a concern.

Methods: Transmission and emission scans were acquired using both an anthropomorphic thorax phantom containing a cardiac insert and a human volunteer.

Fully Bayesian estimation of Gibbs hyperparameters for emission computed tomography data.

In recent years, many investigators have proposed Gibbs prior models to regularize images reconstructed from emission computed tomography data. Unfortunately, hyperparameters used to specify Gibbs priors can greatly influence the degree of regularity imposed by such priors and, as a result, numerous procedures have been proposed to estimate hyperparameter values from observed image data. Many of these procedures attempt to maximize the joint posterior distribution on the image scene.

Approximate 3D iterative reconstruction for SPECT.

Compared with slice-by-slice approaches for SPECT reconstruction, three-dimensional iterative methods provide a more accurate physical model and an improved SPECT image. Clinical application of these methods, however, is limited primarily to their computational demands. This paper investigates the methods for approximate 3D iterative reconstruction that greatly reduce this demand by excluding from the reconstruction the smaller magnitude elements of the system matrix.

Evaluation of SPECT quantification of radiopharmaceutical distribution in canine myocardium.

Unlabelled: This study evaluates the quantitative accuracy of SPECT for in vivo distributions of 99mTc radiopharmaceuticals using fanbeam (FB) and parallel-beam (PB) collimators and compares uniform and nonuniform attenuation correction methods in terms of quantitative accuracy.

Methods: SPECT quantification of canine myocardial radioactivity was performed followed by well counter measurements of extracted myocardial tissue samples. Transmission scans using a line source and an FB collimator were performed to generate nonuniform attenuation maps of the canine thorax.

Quantitation of 211At in small volumes for evaluation of targeted radiotherapy in animal models.

We have evaluated SPECT and two planar imaging methods, geometric mean (GM) and buildup factor (BF), for their potential to quantitate in vivo 211At distributions in rat spinal subarachnoid spaces using phantom studies. The use of medium-energy collimators and the small diameter (3 mm) of the subarachnoid space complicate quantitation. Net activities from distributions in various backgrounds were obtained using a large region of interest with background subtraction.

Volume and activity quantitation with iodine-123 SPECT.

Unlabelled: The goals of this study were to investigate the effect of septal penetration on 123I SPECT activity quantitation using low-energy, high-resolution collimators, and to evaluate a semi-automatic method for measuring volume and activity of 123I distribution with SPECT.

Methods: Data were acquired from experimental phantoms containing spheres filled with a high-purity 123I solution. The penetration study compared the reconstructed activity of a 3.

A 3D model of non-uniform attenuation and detector response for efficient iterative reconstruction in SPECT.

A 3D physical model for iterative reconstruction in SPECT has been developed and applied to experimental data. The model incorporates non-uniform attenuation using reconstructed transmission CT data and distance-dependent detector response based on response function measurements over a range of distances from the detector. The 3D model has been implemented in a computationally efficient manner with practical memory requirements.

An evaluation of lesion detectability with cone-beam, fanbeam and parallel-beam collimation in SPECT by continuous ROC study.

Unlabelled: To evaluate lesion detectability for clinical evaluation of cone-beam (CB), fanbeam (FB) and parallel-beam (PB) collimator sensitivity, experimentally acquired phantom data were used to assess the advantage of CB collimation over conventional collimation.

Methods: Lesion detectability with CB, FB and PB collimation in SPECT was compared using a three-dimensional brain phantom and continuous receiver operating characteristic (CROC) analysis. A simulated cold lesion was located near the posterior portion of the thalamus.

Fast transmission CT for determining attenuation maps using a collimated line source, rotatable air-copper-lead attenuators and fan-beam collimation.

We describe a technique using a line source and a rotatable air-copper-lead assembly to acquire gamma transmission computed tomographic (TCT) data for determining attenuation maps to compensate SPECT emission scans. The technique minimizes problems associated with discriminating 99mTc transmission and 201Tl emission photons and requires only a modest increase in total study time. A 99mTc line source and a stacked foil ("multislat") collimator are placed near the focal line of a fan-beam collimator (114 cm focal length) mounted on one detector of a triple-camera SPECT system.

An evaluation of maximum likelihood-expectation maximization reconstruction for SPECT by ROC analysis.

A ROC study was performed in order to evaluate whether the maximum likelihood expectation maximization (ML-EM) reconstruction algorithm improves diagnostic performance compared to the conventional filtered backprojection method in SPECT. Several implementations of the algorithm were tested including 25 and 50 iteration stopping points, with and without nonuniform attenuation compensation, and with and without Metz filtering. Filtered backprojection was with Metz filter and without attenuation compensation.

Simultaneous compensation for attenuation, scatter and detector response for SPECT reconstruction in three dimensions.

A three-dimensional reconstruction method for simultaneous compensation of attenuation, scatter and distance-dependent detector response for single photon emission computed tomography is described and tested by experimental studies. The method determines the attenuation factors recursively along each projection ray starting at the intersected source voxel closest to the detector. The method substracts the scatter energy window data from the primary energy window data for scatter compensation.

Quantitative SPECT reconstruction of iodine-123 data.

Many clinical and research studies in nuclear medicine require quantitation of iodine-123 (123I) distribution for the determination of kinetics or localization. The objective of this study was to implement several reconstruction methods designed for single-photon emission computed tomography (SPECT) using 123I and to evaluate their performance in terms of quantitative accuracy, image artifacts, and noise. The methods consisted of four attenuation and scatter compensation schemes incorporated into both the filtered backprojection/Chang (FBP) and maximum likelihood-expectation maximization (ML-EM) reconstruction algorithms.