Utility of Quantitative Assessment of Tc-99m-diethylenetriamine-penta-acetic acid-galactosyl Human Serum Albumin SPECT/CT in the Identification of Severe Liver Fibrosis: Its Complementary Diagnostic Value with Other Liver Function Indices.

Purpose: To evaluate the value of Tc-99m-diethylenetriamine-penta-acetic acid-galactosyl human serum albumin (Tc-GSA) single photon emission computed tomography (SPECT) for assessing liver fibrosis, and to assess its complementary value to other liver function indices such as fibrosis-4 (FIB-4) index and indocyanine green (ICG) clearance test parameters (ICG-R15 and ICG-K).

Procedures: Seventy-eight patients with chronic liver disease and hepatocellular carcinoma who underwent Tc-GSA scintigraphy and other liver function tests including ICG test and FIB-4 index prior to hepatectomy were studied. Tc-GSA imaging was performed with SPECT/CT scanner (Discovery NM/CT 670).

Effect of Gaussian Smoothing Filter Size for CT-Based Attenuation Correction on Quantitative Assessment of Bone SPECT/CT: A Phantom Study.

This study aims to determine the effect of Gaussian filter size for CT-based attenuation correction (CTAC) on the quantitative assessment of bone SPECT. An experiment was performed using a cylindrical phantom containing six rods, of which one was filled with water and five were filled with various concentrations of KHPO solution (120-960 mg/cm) to simulate different bone densities. Tc-solution of 207 kBq/ml was also included within the rods.

Quantitative assessment of Tc-methylene diphosphonate bone SPECT/CT for assessing bone metastatic burden and its prognostic value in patients with castration-resistant prostate cancers: initial results in a single-center retrospective study.

Purpose: To evaluate the prognostic value of the quantitative assessment of Tc-methylene diphosphonate (Tc-MDP) bone SPECT/CT in castration-resistant prostate cancer (CRPC) patients with bone metastases.

Methods: A total of 103 patients who underwent Tc-MDP bone SPECT/CT imaging from the neck to the proximal femur were included. First, in 65 patients without bone metastases, the normal range of standardized uptake value (SUV) of non-pathological bone was evaluated to determine an SUV threshold to reliably exclude most normal osseous activity.

Impact of CT tube-voltage and bone density on the quantitative assessment of tracer uptake in Tc-99m bone SPECT/CT: A phantom study.

Purpose: To evaluate the effect of computed tomography (CT) tube voltage and CT density for CT-based attenuation correction (CTAC) on quantification of tracer uptake in single photon emission computed tomography (SPECT)/CT.

Methods: A cylindrical phantom contained 7 cylinders with diameter of 30 mm. The central cylinder and background part were filled with 17 kBq/ml of Tc-pertechnetate solution.

Shine-through artifact due to high-radioactivity bladder and bowel gas in F-FDG PET/CT: impact of time-of-flight algorithm and radioactivity concentration of urine in the bladder on the occurrence of the artifacts.

Objective: Shine-though artifact can appear as regions with falsely increased uptake in the immediate vicinity of large hot sources in F-FDG PET/CT. This artifact may adversely affect the assessment of tumor involvement in the regions adjacent to the bladder. The purpose of this study was to evaluate the prevalence of shine-through artifacts in clinical F-FDG PET/CT examinations and the factors that can influence their occurrence and extent.

The value of Bayesian penalized likelihood reconstruction for improving lesion conspicuity of malignant lung tumors on F-FDG PET/CT: comparison with ordered subset expectation maximization reconstruction incorporating time-of-flight model and point spread function correction.

Objective: To evaluate the value of Bayesian penalized likelihood (BPL) reconstruction for improving lesion conspicuity of malignant lung tumors on F-fluoro-2-deoxy-D-glucose (FDG) positron emission tomography computed tomography (PET/CT) as compared with the ordered subset expectation maximization (OSEM) reconstruction incorporating time-of-flight (TOF) model and point-spread-function (PSF) correction.

Methods: Twenty-nine patients with primary or metastatic lung cancers who underwent F-FDG PET/CT were retrospectively studied. PET images were reconstructed with OSEM + TOF, OSEM + TOF + PSF, and BPL with noise penalty strength β-value of 200, 400, 600, and 800.

Respiratory-gated time-of-flight PET/CT during whole-body scan for lung lesions: feasibility in a routine clinical setting and quantitative analysis.

Purpose: To demonstrate the feasibility of respiratory gating during whole-body scan for lung lesions in routine F-FDG PET/CT examinations using a time-of-flight (TOF)-capable scanner to determine the effect of respiratory gating on reduction of both misregistration (between CT and PET) and image blurring, and on improvement of the maximum standardized uptake value (SUVmax).

Materials And Methods: Patients with lung lesions who received FDG PET/CT were prospectively studied. Misregistration, volume of PET (Vp), and SUVmax were compared between ungated and gated images.

Usefulness of abdominal belt for restricting respiratory cardiac motion and improving image quality in myocardial perfusion PET.

Background: The current study evaluated the usefulness of a belt technique for restricting respiratory motion of the heart and for improving image quality of N-ammonia myocardial PET/CT, and it assessed the tolerability of the belt technique in the clinical setting.

Methods: Myocardial N-ammonia PET/CT scanning was performed in 8 volunteers on Discovery PET/CT 690 with an optical respiratory motion tracking system. Emission scans were performed with and without an abdominal belt.

The Effect of Misregistration Between CT-Attenuation and PET-Emission Images in 13N-Ammonia Myocardial PET/CT.

Unlabelled: In 2-dimensional cardiac PET/CT, misregistration between the PET and CT images due to respiratory and cardiac motion causes tracer uptake to appear substantially reduced. The resolution and quality of the images have been considerably improved by the use of 3-dimensional (3D) PET acquisitions. In the current study, we investigated the impact that misregistration between PET and CT images has on myocardial (13)N-ammonia uptake in images reconstructed with 3D ordered-subset expectation maximization combined with time-of-flight and point-spread-function modeling.