Dr. Dominic Crotty Profile

Dr. Dominic Crotty

PhD Student at GE Healthcare

SPIE Involvement:

Author

Publications (13)

Proceedings Article | 9 March 2018 Paper

Automated exposure control for CT using a task-based image quality metric

P. Khobragade, Jiahua Fan, Franco Rupcich, Dominic Crotty, Taly Gilat Schmidt

Proceedings Volume 10573, 1057316 (2018) https://doi.org/10.1117/12.2294625

KEYWORDS: Reconstruction algorithms, Image quality, Modulation transfer functions, Computed tomography, Spatial resolution, Radiology

Read Abstract +

Proceedings Article | 10 March 2017 Paper

Effects of window width and window level adjustment on detection tasks in computed tomography images

P. Khobragade, Jiahua Fan, Franco Rupcich, Dominic Crotty, Taly Gilat Schmidt

Proceedings Volume 10136, 101361G (2017) https://doi.org/10.1117/12.2255575

KEYWORDS: Computed tomography, Image display, Image quality, Visualization, Optical filters, Image filtering, Bone, Image quality standards, Visual process modeling, Visual system, Modulation transfer functions, Medicine

Read Abstract +

Proceedings Article | 10 March 2017 Paper

Fractal dimension metric for quantifying noise texture of computed tomography images

P. Khobragade, Jiahua Fan, Franco Rupcich, Dominic Crotty, Taly Gilat Schmidt

Proceedings Volume 10136, 101361F (2017) https://doi.org/10.1117/12.2255077

KEYWORDS: Fractal analysis, Computed tomography, Image quality, Reconstruction algorithms, Bone, Image quality standards, Optical filters, Image filtering, Spatial frequencies, Visualization, Medicine

Read Abstract +

Proceedings Article | 24 March 2016 Paper

Task-based detectability comparison of exponential transformation of free-response operating characteristic (EFROC) curve and channelized Hotelling observer (CHO)

P. Khobragade, Jiahua Fan, Franco Rupcich, Dominic Crotty, Taly Gilat Schmidt

Proceedings Volume 9787, 97870C (2016) https://doi.org/10.1117/12.2216505

KEYWORDS: Systems modeling, Reconstruction algorithms, Computed tomography, Image quality, Imaging systems, Detector development, Image analysis, Signal detection, Image visualization, Medicine, Optical filters

Read Abstract +

Proceedings Article | 22 March 2010 Paper

Investigating the dose distribution in the uncompressed breast with a dedicated CT mammotomography system

Dominic Crotty, Samuel Brady, D'Vone Jackson, Greta Toncheva, Colin Anderson, Terry Yoshizumi, Martin Tornai

Proceedings Volume 7622, 762229 (2010) https://doi.org/10.1117/12.845433

KEYWORDS: Breast, Calibration, Nipple, Imaging systems, X-ray computed tomography, Mammography, Tomography, Tissues, X-rays, Monte Carlo methods

Read Abstract +

Proceedings Article | 14 March 2009 Paper

Initial investigation of novel trajectories to improve chest wall imaging in a dedicated breast computed tomography system

Dominic Crotty, Randolph McKinley, Priti Madhav, Spencer Cutler, Martin Tornai

Proceedings Volume 7258, 72585L (2009) https://doi.org/10.1117/12.812500

KEYWORDS: Breast, Imaging systems, Chest, Optical spheres, Head, X-rays, Image quality, X-ray computed tomography, Computer aided design, Visualization

Read Abstract +

Proceedings Article | 21 March 2007 Paper

Evaluation of lesion distortion at various CT system tilts in the development of a hybrid system for dedicated mammotomography

Priti Madhav, Dominic Crotty, Randolph McKinley, Martin Tornai

Proceedings Volume 6510, 65101F (2007) https://doi.org/10.1117/12.713541

KEYWORDS: Breast, Imaging systems, Modulation transfer functions, Distortion, Single photon emission computed tomography, Optical spheres, Spherical lenses, 3D image processing, Reconstruction algorithms, 3D acquisition

Read Abstract +

A hybrid SPECT-CT system for dedicated 3D breast imaging (mammotomography) is currently under development. Each imaging system will be placed on top of a single rotation stage and moved in unison azimuthally, with the SPECT system additionally capable of polar and radial motions. In this initial prototype, the CT system will initially be positioned at a fixed polar tilt. Using a phantom with three tungsten wires, the MTF of the CT system was measured in 3D for different CT system tilts. A phantom with uniformly arranged 0.5cm diameter acrylic spheres was suspended in air in the CT field of view, and also placed at multiple locations and orientations inside an oil-filled breast phantom to evaluate the effect of CT system tilt on lesion visibility and distortion. Projection images were collected using various simple circular orbits with fixed polar tilts ranging between ±15°, and complex 3D saddle trajectories including combined polar and azimuthal motions at maximum polar tilt angles. Reconstructions were performed using an iterative reconstruction algorithm on 4x4 binned projection images with 0.508mm3 voxels. There was minor variation in the MTF in the imaged volume for the CT system at all trajectories, potentially due to the use of an iterative reconstruction algorithm. Results from the spherical cross phantoms indicated that there was more reconstruction inaccuracy and geometric distortion in the reconstructed slices with simple circular orbits with fixed tilt in contrast to complex 3D trajectories. Line profiles further showed a cupping artifact in planes farther away from the flat plane of the x-ray cone beam placed at different tilts. However, this cupping artifact was not seen for images acquired with complex 3D trajectories. This indicated that cupping artifacts can also be caused by undersampled cone beam data. These findings generally indicate that despite insufficient sampling with the cone beam imaging geometry, it is possible to place the CT system at a stationary polar tilt with the CT tube positioned upward such that a patient can be comfortably placed above the system and allow complete sampling near the top of the pendant, uncompressed breast and chest wall. However, a complex 3D trajectory allows for more complete sampling of the entire image volume.

Proceedings Article | 21 March 2007 Paper

Investigating novel patient bed designs for use in a hybrid dual-modality dedicated 3D breast imaging system

Dominic Crotty, Priti Madhav, Randolph McKinley, Martin Tornai

Proceedings Volume 6510, 65101H (2007) https://doi.org/10.1117/12.713764

KEYWORDS: Imaging systems, Breast, Computer aided design, Single photon emission computed tomography, Chest, Sensors, X-ray computed tomography, 3D image processing, X-rays, Solid modeling

Read Abstract +

Proceedings Article | 14 March 2007 Paper

Analysis of patient bed positioning in SPECT-CT imaging for dedicated mammotomography

Kristy Perez, Priti Madhav, Dominic Crotty, Martin Tornai

Proceedings Volume 6510, 651037 (2007) https://doi.org/10.1117/12.713822

KEYWORDS: Breast, Imaging systems, Single photon emission computed tomography, Computed tomography, X-ray computed tomography, 3D image processing, Solids, Image resolution, Reconstruction algorithms, Breast imaging

Read Abstract +

Proceedings Article | 2 March 2006 Paper

Investigation of emission contamination in the transmission image of a dual modality computed mammotomography system

Dominic Crotty, Caryl Brzymialkewicz, Randolph McKinley, Martin Tornai

Proceedings Volume 6142, 614237 (2006) https://doi.org/10.1117/12.654580

KEYWORDS: Breast, Contamination, Sensors, X-rays, Image transmission, X-ray detectors, Signal to noise ratio, X-ray imaging, Imaging systems, Photons

Read Abstract +

A dual modality SPECT/CT computed mammotomography (CmT) system for dedicated functional/structural breast imaging is under development. In simultaneous, dual-modality imaging, contamination of the transmission (x-ray) image by emission photons from the uncompressed, pendant breast and torso is an important consideration in the design of hybrid imaging hardware. The lack of a collimator on the transmission image detector implies increased geometric efficiency of primary and scattered emission photons from the breast and neighboring torso region that potentially increase transmission image noise. This study investigates the nature and extent of this cross contamination. Projection and tomographic x-ray images are obtained with and without emission activity in a realistic anthropomorphic torso and various breast phantoms, and also with and without lead shielding on the torso for a variety of x-ray exposure times. Results for emission-source contamination of transmission images are quantified in terms of a mean and standard deviation of regions of interest. There was an observed trend of increased contamination with increasing emission radioactivity in the projection images when the x-ray detector was located immediately beneath the torso phantom, but no discernible effect when the detector was lateral to (and beneath) the torso. Torso shielding mitigated this contamination somewhat. Indeed, in reconstructed CmT data, there was both a decrease in SNR and concomitant decrease in mean attenuation coefficient with increasing emission radioactivity contamination. These results are consistent with the expected increased noise due to a uniform emission irradiation of the detector and hence the resulting apparent increase in detected x-ray transmission events (which yield a lower reconstructed attenuation coefficient value). Despite the emission contamination in both projection and reconstructed images, the contamination is uncorrelated, and indeed no reconstruction artifacts were observed under the various measured conditions. This indicates that a simple contamination correction may be possible to the projection data prior to reconstruction.

Proceedings Article | 2 March 2006 Paper

Experimental spectral measurements of heavy K-edge filtered beams for x-ray computed mammotomography

Dominic Crotty, Randolph McKinley, Martin Tornai

Proceedings Volume 6142, 61421V (2006) https://doi.org/10.1117/12.654611

KEYWORDS: Breast, Optical filters, X-rays, Cerium, Optical simulations, Tissues, Sensors, Imaging systems, Signal attenuation, Mammography

Read Abstract +

Proceedings Article | 20 April 2005 Paper

Design and development of a fully 3D dedicated x-ray computed mammotomography system

Martin Tornai, Randolph McKinley, Caryl Bryzmialkiewicz, Priti Madhav, Spencer Cutler, Dominic Crotty, James Bowsher, Ehsan Samei, Carey Floyd

Proceedings Volume 5745, (2005) https://doi.org/10.1117/12.595636

KEYWORDS: Breast, Imaging systems, X-rays, Computing systems, X-ray detectors, X-ray imaging, Sensors, Reconstruction algorithms, Prototyping, Distortion

Read Abstract +

Proceedings Article | 14 April 2005 Paper

Anthropomorphic breast phantoms for preclinical imaging evaluation with transmission or emission imaging

Martin Tornai, Randolph McKinley, Caryl Bryzmialkiewicz, Spencer Cutler, Dominic Crotty

Proceedings Volume 5746, (2005) https://doi.org/10.1117/12.596094

KEYWORDS: Breast, Imaging systems, Chest, Radiography, Image compression, Tissues, Signal attenuation, X-rays, Photography, Minerals

Read Abstract +

Showing 5 of 13 publications

View contact details

UPDATE YOUR PROFILE

Is this your profile? Update it now.

Sign into your SPIE.org account

Don’t have a profile and want one?

Create an account on SPIE.org

Keywords/Phrases

Search In:

Publication Years