Simulation study comparing high-purity germanium and cadmium zinc telluride detectors for breast imaging

Campbell, Desmond L.; Peterson, Todd E.

doi:10.1088/0031-9155/59/22/7059

Cited by 5 publications

(8 citation statements)

References 24 publications

(53 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In our previous work comparing a single HPGe and CZT camera for breast imaging, we observed higher scatter fractions for CZT than HPGe (8.63% CZT versus 4.66% HPGe) [21]. This was due to the large asymmetric 15% energy window needed for CZT due to poorer energy resolution (~6.5% FWHM at 140 keV) and its low-energy tailing effect [6], [17].…”

Section: Discussionmentioning

confidence: 99%

“…The intrinsic properties of a benchtop HPGe detector were measured and used as inputs for our Monte Carlo model, followed by experimental validation of the model [21]. Current HPGe systems are not as large as those simulated here, however, this study serves as motivation to develop collimators and cameras of this type.…”

Section: Methodsmentioning

confidence: 99%

“…For equivalent activity imaged, the HPGe camera provided better relative sensitivity with similar tumor contrast and SNR while suppressing small-angle scatter events and background from the torso [21]. Other simulations investigating the feasibility of the HPGe camera with various parallel-hole collimators for MBI found that our choice of large-bore, square-hole collimation provided an 81% enhancement in count sensitivity and better suppression of events from the torso than the standard hexagonal-hole collimator [22].…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Molecular Breast Imaging Using Synthetic Projections From High-Purity Germanium Detectors: A Simulation Study

Campbell

Peterson

2017

IEEE Trans. Radiat. Plasma Med. Sci.

View full text Add to dashboard Cite

High-Purity Germanium (HPGe) gamma cameras are an emerging technology for Molecular Breast Imaging (MBI) due to their 2D lateral spatial resolution, depth-of-interaction (DOI) estimation, and superb energy resolution. In this simulation study, we investigate the potential imaging performance of an opposing view dual-head HPGe breast imaging system using a synthetic-projection technique, which utilizes DOI data with varying degrees of overlap in an iterative OSEM reconstruction algorithm to create 3D images from which new 2D projections are then created. The radiation transport simulator Monte Carlo N-Particle was employed to generate projections from 10-mm thick HPGe detectors using tungsten parallel-hole collimators with short and wide holes. Simulations modeling 140-keV emissions from various contrast-detail and breast-torso phantoms were conducted. Synthetic projections were generated along with conjugate-counting images from collected HPGe projections. Tumor contrast, SNR, and hot-spot detection measurements were used to compare images. Results show that the synthetic projections could resolve more low-contrast tumors compared to single-camera projections and conjugate-counting methods. MBI simulations also showed increased contrast and SNR in synthetic projections compared to individual projections. In conclusion, the HPGe imaging system employing a synthetic-projection technique may offer advantages over individual dual-camera projections or conjugate-counting methods in terms of contrast, SNR, and tumor detectability.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Molecular Breast Imaging Using Synthetic Projections From High-Purity Germanium Detectors: A Simulation Study

Campbell

Peterson

2017

IEEE Trans. Radiat. Plasma Med. Sci.

View full text Add to dashboard Cite

show abstract

“…The preferred collimator design for energy-independence was decided based on the TRS calculation. Contrast, mostly used to characterize the system performance[6][11][23] was calculated using the hot rod phantom with six rods to validate the preferred collimator design. Though the performances degraded at high energies, image contrast was preserved and CNR was shown to be consistent in Figure 6.…”

Section: Discussionmentioning

confidence: 99%

An energy-optimized collimator design for a CZT-based SPECT camera

Weng

Bagchi

Zan

et al. 2016

Nuclear Instruments and Methods in Physics Research Section A:

View full text Add to dashboard Cite

In single photon emission computed tomography, it is a challenging task to maintain reasonable performance using only one specific collimator for radio-tracers over a broad spectrum of diagnostic photon energies, since photon scatter and penetration in a collimator differ with the photon energy. Frequent collimator exchanges are inevitable in daily clinical SPECT imaging, which hinders throughput while subjecting the camera to operational errors and damage. Our objective is to design a collimator, which independent of the photon energy performs reasonably well for commonly used radiotracers with low- to medium-energy levels of gamma emissions. Using the Geant4 simulation toolkit, we simulated and evaluated a parallel-hole collimator mounted to a CZT detector. With the pixel-geometry-matching collimation, the pitch of the collimator hole was fixed to match the pixel size of the CZT detector throughout this work. Four variables, hole shape, hole length, hole radius/width and the source-to-collimator distance were carefully studied. Scatter and penetration of the collimator, sensitivity and spatial resolution of the system were assessed for four radionuclides including 57Co, 99mTc, 123I and 111In, with respect to the aforementioned four variables. An optimal collimator was then decided upon such that it maximized the total relative sensitivity (TRS) for the four considered radionuclides while other performance parameters, such as scatter, penetration and spatial resolution, were benchmarked to prevalent commercial scanners and collimators. Digital phantom studies were also performed to validate the system with the optimal square-hole collimator (23 mm hole length, 1.28 mm hole width, 0.32 mm septal thickness) in terms of contrast, contrast-to-noise ratio and recovery ratio. This study demonstrates promise of our proposed energy-optimized collimator to be used in a CZT-based gamma camera, with comparable or even better imaging performance versus commercial collimators such as low-energy high resolution (LEHR) and medium energy general purpose (MEGP) collimators.

show abstract

“…48 The MCNP code has been widely used for the simulation studies on cadmium-zinc-telluride (CZT), CdTe, and high-purity germanium (HPGe) semiconductor detectors for medical imaging. [49][50][51] The pinhole XRF imaging system has an imaging mechanism very similar to SPECT. 38 The model was benchmarked against the design and the dimension of the pinhole, as well as the type and the pixel size of the detector commonly used in preclinical pinhole SPECT.…”

Section: Modelmentioning

confidence: 99%

Pinhole X-ray fluorescence imaging of gadolinium and gold nanoparticles using polychromatic X-rays: a Monte Carlo study

Jung

Sung

2017

IJN

View full text Add to dashboard Cite

This work aims to develop a Monte Carlo (MC) model for pinhole K-shell X-ray fluorescence (XRF) imaging of metal nanoparticles using polychromatic X-rays. The MC model consisted of two-dimensional (2D) position-sensitive detectors and fan-beam X-rays used to stimulate the emission of XRF photons from gadolinium (Gd) or gold (Au) nanoparticles. Four cylindrical columns containing different concentrations of nanoparticles ranging from 0.01% to 0.09% by weight (wt%) were placed in a 5 cm diameter cylindrical water phantom. The images of the columns had detectable contrast-to-noise ratios (CNRs) of 5.7 and 4.3 for 0.01 wt% Gd and for 0.03 wt% Au, respectively. Higher concentrations of nanoparticles yielded higher CNR. For 1×10 11 incident particles, the radiation dose to the phantom was 19.9 mGy for 110 kVp X-rays (Gd imaging) and 26.1 mGy for 140 kVp X-rays (Au imaging). The MC model of a pinhole XRF can acquire direct 2D slice images of the object without image reconstruction. The MC model demonstrated that the pinhole XRF imaging system could be a potential bioimaging modality for nanomedicine.

show abstract

Simulation study comparing high-purity germanium and cadmium zinc telluride detectors for breast imaging

Cited by 5 publications

References 24 publications

Molecular Breast Imaging Using Synthetic Projections From High-Purity Germanium Detectors: A Simulation Study

Molecular Breast Imaging Using Synthetic Projections From High-Purity Germanium Detectors: A Simulation Study

An energy-optimized collimator design for a CZT-based SPECT camera

Pinhole X-ray fluorescence imaging of gadolinium and gold nanoparticles using polychromatic X-rays: a Monte Carlo study

Contact Info

Product

Resources

About