This study was undertaken to investigate the relationship between several histological features and the degree of TI-201 uptake in brain tumors. T1-201 SPECT was performed on 52 patients with intracranial lesions. Histological examinations were carried out to determine the gradation of tumor cell density, vascularization, small-cell density, and matrix loosening, and the presence of necrosis, atypia, mitoses, and endothelial proliferation. The histological findings were classified into three categories. While the early uptake of T1-201 depended on the degree of necrosis of glial tumor, the delayed T1-201 uptake was closely related to the degree of necrosis, tumor cell density, and small-cell density, and may thus be of value for estimating the viability and degree of malignancy of glial tumors. In the non-glial tumors, the early and delayed T1-201 uptakes were closely related to all histological parameters, with the increase of necrosis and vascularization in the tumor tissue being particularly closely related to high uptake levels.
Brain perfusion single-photon emission computed tomography (SPECT) image quality varies depending on SPECT systems. This study aimed to evaluate the relationship between physical parameters and visual analysis for assessment of the brain SPECT image quality. We conducted our phantom study under various conditions in a multi-center and multi-vendor study.
Myocardial perfusion single-photon emission computed tomography (SPECT) studies are used widely in the evaluation and diagnosis of coronary artery disease. Although one method to improve the spatial resolution is zooming acquisition, truncation artifact occurs in reconstructed tomographic images. To date, it is unclear how much truncation (area and radioactivity) of projection data would affect myocardial image.The aim of this study is to investigate the combination of truncated projection data conditions and image reconstruction methods that do not require re-examination.We used a cylindrical and anthropomorphic torso phantom with 99mTc solution, and shifted the projection data to simulate truncated liver tissue.SPECT images were acquired using a dual-detector gamma camera and reconstructed using filtered back projection (FBP) and ordered subset expectation maximization (OSEM) to create transverse images.We compared truncation data and reference data (none truncated projection data) for count profile curve, uniformity, myocardial counts, and % uptake.Our findings indicate that prerequisite for truncation data and image reconstruction method would not affect the myocardial image, when the area of truncation was < 17.5% and the count of the truncation portion was lower than that in the myocardium using FBP.
