Martin Tornai

Overview:

The major research focus of my laboratory concerns high resolution and sensitivity molecular imaging of normalcy and/or disease in the breast using dedicated molecular 3D imaging techniques. Particular attention is paid to improved patient comfort such that no breast compression is necessary, which then dictates novel physics and engineering approaches to obtaining the highest quality data. The term "molecular imaging" means determining the spatial distribution of biological materials based on their molecular characteristics. Two examples include: the in vivo detection and spatial localization of tracer quantities of discretely emitted nuclear radiation which can be used to quantitatively measure aspects of the biological system (e.g. reaction kinetics, hyper/hypo-metabolism, etc.), and the in vivo spatial localization of objects based on their intrinsic physical properties, e.g. differentiation of skin, fat and connective tissue based on differences in their intrinsic electron densities.

Two classes of devices have been developed, are in refinement and are undergoing patient studies: (1) a dedicated, fully 3D, volumetric imaging Single Photon Emission Computed Tomograph (SPECT) device which produces functional molecular images with high resolution and sensitivity; and (2) a dedicated, fully 3D, volumetric x-ray CT device which incorporates a novel quasi-monochromatic x-ray source allowing more optimal imaging with lower radiation doses which produces molecular anatomical images. Along with geometric calibration objects, small animals and cadaveric breast tissue samples have been scanned, yielding high resolution and high quality in vivo images. Patient imaging has successfully begun on these novel developed systems. We have integrated a flexible patient bed to help comfortably position patients in each systems' field of view. Further, the individual systems have been integrated to form a hybrid SPECT/CT mammotomograph providing inherently coregistered, fully 3D, complementary molecular/anatomical information for the same patient and in a common field of view. These technologies could be used for diagnostic purposes, monitoring therapy and/or treatment planning, screening difficult or otherwise inconclusive breasts or scanning women at high risk for breast cancer. Due to the very low x-ray radiation doses possible to obtain the 3D images, the CT system could potentially be used to screen the population at large.

Positions:

Associate Professor of Radiology

Radiology
School of Medicine

Member of the Duke Cancer Institute

Duke Cancer Institute
School of Medicine

Education:

B.S. 1989

Cornell University

Ph.D. 1997

University of California - Los Angeles

Graduate Student Researcher I-IV, Pharmacology, Radiology And Oncology, Biomedical Physics Graduate Program

University of California - Los Angeles

Grants:

X-Ray Scatter and Phase Imaging for Explosive Detection

Administered By
Electrical and Computer Engineering
Awarded By
US Department of Homeland Security
Role
Co-Principal Investigator
Start Date
End Date

Design, Implementation, and Characterization of a Dedicated Breast Computed MamoTomography (CmT) System for Enhanced Detection and Characterization of Lesions

Administered By
Radiology
Awarded By
Department of Defense
Role
Principal Investigator
Start Date
End Date

Two Day Workshop on the Nuclear Radiology of Breast Cancer

Administered By
Radiology
Awarded By
National Institutes of Health
Role
Principal Investigator
Start Date
End Date

Publications:

High sensitivity dedicated dual-breast PET/MR imaging: Concept and preliminary simulations

© 2020 SPIE. This paper presents a new high-sensitivity PET geometry for high fidelity MRI-compatible PET breast imaging which can scan both breasts simultaneously and have: high sensitivity and resolution; compatibility with MR-breast imaged volume; complete visualization of both breasts, mediastinum and axilla; and a modular design. Whereas contemporary dedicated X-ray and molecular breast imaging devices only scan one breast at a time, this approach relies on an unconventional PET geometry, and is able to provide a PET field of view (FOV) larger than that from dedicated breast MRI. The system geometry is evaluated with GATE Monte Carlo simulations of intrinsic system parameters. Various sized lesions (4-6mm) having [6:1 to 4:1] lesion:background radioactivity ratios mimicking different biological uptake are simulated, strategically located throughout a volumetric anthropomorphic torso. Dedicated breast PET (dbPET) imaging is compared with contemporary clinical PET. The dbPET system sensitivity is >6X greater than for contemporary whole-body PET. The novel, non-conventional system geometry allows for simultaneous dual-breast imaging, along with full medial and axillary imaging. Iteratively reconstructed full-volumetric images illustrate sharper visualization of 4mm lower uptake [4:1] lesions throughout the FOV compared with clinical PET. Image overlap between dedicated breast PET and MRI FOVs is excellent. Simulation results indicate clear superiority over conventional, high-sensitivity whole-body PET systems, as well as improved sensitivity over single-breast dbPET systems. This proposed system potentially facilitates both early detection and diagnosis, especially by increasing specificity of MRI, as well as visualizing tissue heterogeneity, monitoring therapeutic efficacy, and detecting breast cancer recurrence throughout the entire mediastinum.
Authors
Tornai, MP; Samanta, S; Majewski, S; Williams, MB; Turkington, TG; Register, AZ; Jiang, J; Dolinsky, S; O'Sullivan, JA; Tai, YC
MLA Citation
Tornai, M. P., et al. “High sensitivity dedicated dual-breast PET/MR imaging: Concept and preliminary simulations.” Proceedings of Spie  the International Society for Optical Engineering, vol. 11513, 2020. Scopus, doi:10.1117/12.2563650.
URI
https://scholars.duke.edu/individual/pub1448617
Source
scopus
Published In
Smart Structures and Materials 2005: Active Materials: Behavior and Mechanics
Volume
11513
Published Date
DOI
10.1117/12.2563650

Phantom Evaluation of a Multi-Pinhole Cardiac SPECT Camera for 3D Molecular Breast Imaging

© 2017 IEEE. A tomographic clinical cardiac SPECT system consisting of many static CZT-based pinhole gamma cameras is evaluated for dedicated, pendant 3D molecular breast imaging. The reconstructed spatial resolution and linearity of the spherically symmetric FOV were evaluated with a multi-point source array. A series of anthropomorphic phantom imaging measurements using 0.4 and 0.9 mm diameter lesions was performed; lesion-to-background ratios ranged from[13:1] to[3:1] to simulate various biological uptake; three breasts used were 470-1730 mL in volume. Basic contrast, CNR and coefficient of variation were measured with the anthropomorphic torso+organ background. Decreasing acquisition times from 30030 sec were a surrogate for lower injected doses. All data was reconstructed using MLEM with various iterations on the commercial workstation. Results indicate that the system largely behaves in the expected way: better overall resolution, linearity, sensitivity, and uniformity closer to the detectors but within the FOV. Other key observations include: (1) higher lesion: background ratios yielded higher image contrast and CNR; (2) lesion contrast and CNR appeared independent of acquisition time; (3) breast size had less of an effect on lesion metrics, but yielded decreased out-of-field (e.g., cardiac and hepatic) contributions with larger breasts. These results indicate that lower injected doses could be utilized for 3D MBI. While additional optimization would be beneficial for breast imaging, this high sensitivity SPECT system could be used for dynamic 3D MBI for lesion diagnostics or therapeutic monitoring.
Authors
Tornai, MP; McDougal, FA
MLA Citation
Tornai, M. P., and F. A. McDougal. “Phantom Evaluation of a Multi-Pinhole Cardiac SPECT Camera for 3D Molecular Breast Imaging.” 2017 Ieee Nuclear Science Symposium and Medical Imaging Conference, Nss/Mic 2017  Conference Proceedings, 2018. Scopus, doi:10.1109/NSSMIC.2017.8532968.
URI
https://scholars.duke.edu/individual/pub1363365
Source
scopus
Published In
2017 Ieee Nuclear Science Symposium and Medical Imaging Conference, Nss/Mic 2017 Conference Proceedings
Published Date
DOI
10.1109/NSSMIC.2017.8532968

Three dimensional dose distribution comparison of simple and complex acquisition trajectories in dedicated breast CT - A Monte Carlo study

The purpose of this study was to characterize the three dimensional (3D) x-ray dose distributions in a target scanned with different acquisition trajectories for dedicated breast CT imaging. Monte Carlo simulations were used to evaluate two acquisition trajectories: circular azimuthal (no tilt) and complex sinusoidal (saddle) orbit with ±15° tilts around a pendant breast. Simulations were performed with tungsten (W) and cerium (Ce) filtration of a W-anode source; the simulated source flux was normalized to the measured exposure of a clinically used W-anode source. A water filled cylindrical phantom, was divided into 1cc voxels, and each voxel was set to track the cumulative energy deposited. Energy deposited per voxel was converted to dose, yielding the 3D distributed dose volumes. Results indicate that the mean absorbed dose at the isocenter of a volume for the un-tilted acquisition is ∼10% higher than that from a saddle scan, regardless of filtration used. © 2014 Springer International Publishing.
Authors
Shah, JP; Mann, SD; McKinley, RL; Tornai, MP
MLA Citation
Shah, J. P., et al. “Three dimensional dose distribution comparison of simple and complex acquisition trajectories in dedicated breast CT - A Monte Carlo study.” Lecture Notes in Computer Science (Including Subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics), vol. 8539 LNCS, Jan. 2014, pp. 187–94. Scopus, doi:10.1007/978-3-319-07887-8_27.
URI
https://scholars.duke.edu/individual/pub1040429
Source
scopus
Published In
Lecture Notes in Computer Science (Including Subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)
Volume
8539 LNCS
Published Date
Start Page
187
End Page
194
DOI
10.1007/978-3-319-07887-8_27

Bienvenidos!

Authors
Tornai, M; Majewski, S; Williams, M; Duval, MA; Hofmann, M; Levin, C
MLA Citation
Tornai, M., et al. “Bienvenidos!.” Ieee Nuclear Science Symposium Conference Record, Jan. 2011. Scopus, doi:10.1109/NSSMIC.2011.6152965.
URI
https://scholars.duke.edu/individual/pub802498
Source
scopus
Published In
Ieee Nuclear Science Symposium Conference Record
Published Date
Start Page
2
DOI
10.1109/NSSMIC.2011.6152965

Novel patient optimized acquisition trajectories for dedicated breast SPECT imaging

Novel acquisition trajectories developed for our dedicated breast SPECT camera move 3 dimensionally within a hemispherical volume, fully contouring a patient's pendent breast to provide a high quality, high resolution 3D functional image. Each unique trajectory, created in under a minute, is tailored for each breast of each subject to obtain the highest image quality for a particular study. If a suspected lesion location is known prior to the scan, a trajectory can be created with many close and direct views of the lesion. A torso phantom with an attached 1730 mL breast phantom containing a 2.1 mL (0.8cm radius) spherical lesion was filled with clinical levels of activity: heart:liver:torso: breast: lesion concentration ratio 12:12:1:1:6. A variety of novel acquisition trajectories were employed to image the lesion. Sequentially increasing tilted parallel beam trajectories investigated signals obtained from different polar angles for imaging the breast and chest wall with contamination from the heart and liver. These studies yielded a bound on polar positions for all azimuthal locations in order to minimize background contamination. Other trajectories were created to obtain the best lesion signal. This study shows sinusoidal trajectories can recover the breast's shape and image into the chest wall best. Changing the camera's starting position or subtracting projection views can reduce cardiac and hepatic contamination in the reconstructed image. However, more than one trajectory may provide equivalent image quality. Acquisition trajectories can be created to meet specific imaging goals which consider certain patient factors, such as breast size, lesion location and cardiac and hepatic uptake. © 2008 IEEE.
Authors
Perez, KL; Cutler, SJ; Madhav, P; Tornai, MP
MLA Citation
Perez, K. L., et al. “Novel patient optimized acquisition trajectories for dedicated breast SPECT imaging.” Ieee Nuclear Science Symposium Conference Record, Dec. 2008, pp. 5629–34. Scopus, doi:10.1109/NSSMIC.2008.4774521.
URI
https://scholars.duke.edu/individual/pub802507
Source
scopus
Published In
Ieee Nuclear Science Symposium Conference Record
Published Date
Start Page
5629
End Page
5634
DOI
10.1109/NSSMIC.2008.4774521

Research Areas:

Absorption
Algorithms
Biophysics
Breast
Breast Neoplasms
Calibration
Cesium
Computer Simulation
Computers
Cone-Beam Computed Tomography
Electrons
Equipment Design
Gamma Cameras
Humans
Image Interpretation, Computer-Assisted
Mammography
Miniaturization
Monitoring, Intraoperative
Phantoms, Imaging
Radiation Dosage
Radiographic Image Enhancement
Radiographic Image Interpretation, Computer-Assisted
Radiography
Radiography, Thoracic
Radiology
Research
Scattering, Radiation
Scintillation Counting
Scintillation cameras
Semiconductors
Sensitivity and Specificity
Stochastic Processes
Subtraction Technique
Systems Integration
Tissue Distribution
Tomography, Emission-Computed, Single-Photon
Tomography, X-Ray Computed
Tungsten
X-Ray Intensifying Screens
X-Rays