Monte Carlo simulation of the acquisition conditions for Lu molecular imaging of hepatic tumors.

Objective: To examine the impact of acquisition time on Lutetium-177 (Lu) single-photon emission computed tomography (SPECT) images using Monte Carlo simulation.

Methods: A gamma camera simulation based on the Monte Carlo method was performed to produce SPECT images. The phantom was modeled on a NEMA IEC BODY phantom including six spheres as tumors.

Evaluating and comparing the image quality and quantification accuracy of SiPM-PET/CT and PMT-PET/CT.

Objective: The aim of this study was to evaluate the image quality and the quantification accuracy of Biograph Vision PET/CT scanner as a SiPM-PET in comparison to the conventional PMT-PET, Biograph mCT PET/CT scanner.

Methods: This study consisted of a phantom study and a retrospective clinical analysis where patients underwent F-FDG PET/CT in both PET systems. The body phantom of the NEMA IEC with 10-37 mm diameter spheres were filled with an F-FDG solution.

[Evaluation of the Number of Sampling Angles in Three Dimensional Ordered Subset Expectation Maximization: Comparison of Step and Shoot Acquisition and Continuous Acquisition].

Three dimensional ordered subset expectation maximization (3D-OSEM) improves spatial resolution and contrast. Continuous acquisition, and step and shoot acquisition are used in single photon emission computed tomography (SPECT). The purpose of this study was to evaluate the effect of 3D-OSEM when acquisition method was different.

The Influence of Minimal Misalignment on the Repeatability of PET Images Examined by the Repositioning of Point Sources.

We aimed to evaluate the influence of minimal misalignment of a hot spot on the repeatability of PET images using repositioning of point sources. Point sources with an inner diameter of 1 mm were made with 1 μL of F solution. Seven point sources were placed on the -axis in the field of view.

Evaluation of the Reconstruction Parameters of Brain Dopamine Transporter SPECT images Obtained by a Fan Beam Collimator: A Comparison with Parallel-hole Collimators.

Objectives: The purpose of this study was to examine the optimal reconstruction parameters for brain dopamine transporter SPECT images obtained with a fan beam collimator and compare the results with those obtained by using parallel-hole collimators.

Methods: Data acquisition was performed using two SPECT/CT devices, namely a Symbia T6 and an Infinia Hawkeye 4 (device A and B) equipped with fan-beam (camera A-1 and B-1), low- and medium-energy general-purpose (camera A-2 and B-2), and low-energy high-resolution (camera A-3 and B-3) collimators. The SPECT images were reconstructed using filtered back projection (FBP) with Chang's attenuation correction.

Time-of-Flight Information Improved the Detectability of Subcentimeter Spheres Using a Clinical PET/CT Scanner.

Recent advancements in clinical PET/CT scanners have improved the detectability of small lesions. However, the ideal reconstruction parameters for detecting small lesions have not yet been sufficiently clarified. The purpose of this study was to investigate the detectability of subcentimeter spheres using a clinical PET/CT scanner.

Comparison of TOF-PET and Bremsstrahlung SPECT Images of Yttrium-90: A Monte Carlo Simulation Study.

Objectives: Yttrium-90 (Y) is a beta particle nuclide used in targeted radionuclide therapy which is available to both single-photon emission computed tomography (SPECT) and time-of-flight (TOF) positron emission tomography (PET) imaging. The purpose of this study was to assess the image quality of PET and Bremsstrahlung SPECT by simulating PET and SPECT images of Y using Monte Carlo simulation codes under the same conditions and to compare them.

Methods: In-house Monte Carlo codes, MCEP-PET and MCEP-SPECT, were employed to simulate images.

Characteristics of Smoothing Filters to Achieve the Guideline Recommended Positron Emission Tomography Image without Harmonization.

Objectives: The aim of this study is to examine the effect of different smoothing filters on the image quality and SUV to achieve the guideline recommended positron emission tomography (PET) image without harmonization.

Methods: We used a Biograph mCT PET scanner. A National Electrical Manufacturers Association (NEMA) the International Electrotechnical Commission (IEC) body phantom was filled with F solution with a background activity of 2.

The Efficiency of Respiratory-gated F-FDG PET/CT in Lung Adenocarcinoma: Amplitude-gating Versus Phase-gating Methods.

Objectives: In positron emission tomography (PET) studies, thoracic movement under free-breathing conditions is a cause of image degradation. Respiratory gating (RG) is commonly used to solve this problem. Two different methods, i.

Edge Artifacts in Point Spread Function-based PET Reconstruction in Relation to Object Size and Reconstruction Parameters.

Objectives: We evaluated edge artifacts in relation to phantom diameter and reconstruction parameters in point spread function (PSF)-based positron emission tomography (PET) image reconstruction.

Methods: PET data were acquired from an original cone-shaped phantom filled with F solution (21.9 kBq/mL) for 10 min using a Biograph mCT scanner.

Estimation of ambient dose equivalent distribution in the F-FDG administration room using Monte Carlo simulation.

In this study, we estimated the ambient dose equivalent rate (hereafter "dose rate") in the fluoro-2-deoxy-D-glucose (FDG) administration room in our hospital using Monte Carlo simulations, and examined the appropriate medical-personnel locations and a shielding method to reduce the dose rate during FDG injection using a lead glass shield. The line source was assumed to be the FDG feed tube and the patient a cube source. The dose rate distribution was calculated with a composite source that combines the line and cube sources.

Analysis of the influence of In on Y-bremsstrahlung SPECT based on Monte Carlo simulation.

Objective: Y-ibritumomab tiuxetan (Zevalin) which is used for the treatment of malignant lymphomas can be used for SPECT imaging based on bremsstrahlung from Y beta particles. However, gamma rays emitted by In, which is administered to evaluate the indication for the treatment, contaminate the Y bremsstrahlung images. Our objective is to investigate the influence of In on the Y SPECT images using Monte Carlo simulation.

Evaluation of Iterative Reconstruction Method and Attenuation Correction in Brain Dopamine Transporter SPECT Using an Anthropomorphic Striatal Phantom.

Objectives: The aim of this study was to determine the optimal reconstruction parameters for iterative reconstruction in different devices and collimators for dopamine transporter (DaT) single-photon emission computed tomography (SPECT). The results were compared between filtered back projection (FBP) and different attenuation correction (AC) methods.

Methods: An anthropomorphic striatal phantom was filled with (123)I solutions at different striatum-to-background radioactivity ratios.

Relationship between the image quality and noise-equivalent count in time-of-flight positron emission tomography.

Objective: The aim of this study was to investigate the relationship between the NEC and TOF-PET image quality.

Methods: The National Electrical Manufactures Association and International Electrical Commission (NEMA IEC) body phantom with a 10-mm diameter sphere was filled with an 18F-FDG solution with a 4:1 radioactivity ratio. The PET data were acquired in the three-dimensional list mode for 20 min.

Monte Carlo simulation of PET and SPECT imaging of 90Y.

Purpose: Yittrium-90 ((90)Y) is traditionally thought of as a pure beta emitter, and is used in targeted radionuclide therapy, with imaging performed using bremsstrahlung single-photon emission computed tomography (SPECT). However, because (90)Y also emits positrons through internal pair production with a very small branching ratio, positron emission tomography (PET) imaging is also available. Because of the insufficient image quality of (90)Y bremsstrahlung SPECT, PET imaging has been suggested as an alternative.

An anthropomorphic phantom study of brain dopamine transporter SPECT images obtained using different SPECT/CT devices and collimators.

Unlabelled: The aim of this study was to evaluate differences in dopamine transporter SPECT images among different SPECT/CT devices and to determine the most appropriate region of interest (ROI) for semiquantitative evaluation.

Methods: An anthropomorphic striatal phantom was filled with (123)I solutions of different striatum-to-background radioactivity ratios. Data were acquired using 2 SPECT/CT devices equipped with low- to medium-energy general-purpose and low-energy high-resolution (LEHR) collimators.

Improvement in PET/CT image quality in overweight patients with PSF and TOF.

Objective: The aim of this study was to evaluate the effect of the point spread function (PSF) and time of flight (TOF) on PET/CT images of overweight patients in relation to the iteration number and the acquisition time.

Methods: This study consisted of a phantom study and a clinical study. The NEMA IEC body phantom and a 40 cm diameter large phantom (LG phantom) simulating an overweight patient were used in this study.

A simple table lookup method for PET/CT partial volume correction using a point-spread function in diagnosing lymph node metastasis.

Objective: We evaluated the partial volume effect in PET/CT images and developed a simple correction method to address this problem.

Methods: Six spheres and the background in the phantom were filled with F-18 and we thus obtained 4 different sphere-to-background (SB) ratios. Thirty-nine cervical lymph nodes in 7 patients with papillary thyroid carcinoma (15 malignant and 24 benign) were also examined as a preliminary clinical study.

[Image quality and detection performance of a direct digital radiography system].

The physical characteristics of a direct amorphous Selenium (a-Se) digital fluoroscopy and radiography system were investigated. Pre-sampled modulation transfer functions (MTF) were measured using a slit method. Noise power spectra were determined for different input exposures by fast Fourier transform of uniformly exposed samples.

Physical imaging properties and low-contrast performance of a newly developed flat-panel digital radiographic system.

We investigated the clinical usefulness of a newly developed flat-panel detector (FPD) system by comparing its physical imaging properties and low-contrast detectability with those of a current FPD system. The newly developed CsI-based indirect FPD (Canon, CXDI-40C) and current Gd(2)O(2)S-based FPD (Canon CXDI-11) systems were used. Characteristic curves, resolution properties, radiographic noise, detective quantum efficiencies (DQEs) and low-contrast detectability for both systems were measured.

[Full-field digital mammography with amorphous silicon-based flat- panel detector: physical imaging characteristics and signal detection].

The physical characteristics of a clinical amorphous silicon-based flat-panel imager for full-field digital mammography were investigated. Pre-sampled modulation transfer functions (MTF) were measured by using a slit method. Noise power spectra were determined for different input exposures by fast Fourier transform.

[Canon's flat-panel detector].

We measured and evaluated digital, pre-sampling and overall imaging properties (characteristic curve, modulation transfer function (MTF), Wiener spectrum (WS), noise equivalent quanta (NEQ) ) for Cannon's flat-panel detector (FPD), Fuji computed radiography (FCR) and screen-film (S/F) systems, respectively. First, the digital and overall characteristic curves of FPD and FCR systems were more wide dynamic range than that of the S/F system. Second, the pre-sampling and overall MTF of FPD system were better than those of FCR system a little at lower spatial frequencies than 0.