In positron emission tomography (PET) the measured radionuclide concentration or recovery coefficient (RC) in the transverse plane has been shown to be dependent on source size. The RC dependence on object size was therefore experimentally measured for gamma camera SPECT system to determine the influence of additional factors such as: (a) geometrical spatial resolution of each collimator type, (b) scattering effects at each photon energy due to surrounding background, (c) influence of choice of reconstruction filter and (d) photon penetration through the collimator septa. Data were acquired for different collimator types using 99Tcm (140 keV) and 131I (364 keV) to partly differentiate between photon scattering and collimator penetration effects. Results obtained demonstrated that thick septa collimators with low penetration fraction (theoretical leakage less than 3%) are required to minimize the measured response dependence on source size and to obtain a relatively unique relationship independent of photon energy and background activity. Measurements of this type are important for quantitative SPECT imaging in radioimmunoimaging or radioimmunotherapy.

Download full-text PDF

Source
http://dx.doi.org/10.1097/00006231-198605000-00006DOI Listing

Publication Analysis

Top Keywords

quantitative spect
8
spect imaging
8
object size
8
source size
8
photon energy
8
imaging influence
4
influence object
4
size
4
size positron
4
positron emission
4

Similar Publications

Purpose: To evaluate the predictive ability of 99mTc-galactosyl human serum albumin SPECT/CT quantitative parameters for posthepatectomy liver failure (PHLF).

Methods: Sixty-eight patients who underwent 99mTc-galactosyl human serum albumin scintigraphy as a preoperative examination for hepatectomy between July 2021 and December 2023 were prospectively evaluated. The patients were divided into PHLF and non-PHLF groups.

View Article and Find Full Text PDF

Purpose Of Review: This review evaluates recent advancements in Technetium-99 m pyrophosphate (99mTc-PYP) imaging for transthyretin amyloid cardiomyopathy (ATTR-CM). We summarize the advantages of single-photon emission computed tomography (SPECT) over planar imaging, the potential impact of quantitative methods, and emerging data for quantifying response to therapy.

Recent Findings: The current literature demonstrates the superior diagnostic accuracy of SPECT compared with planar imaging in 99mTc-PYP studies.

View Article and Find Full Text PDF

The goal of medial open-wedge high tibial osteotomy (MOW-HTO) is to redistribute load by realigning the lower limb. This surgery is indicated for mild to moderate medial compartment osteoarthritis with varus deformity in cases unresponsive to conservative treatment. Procedures for accompanying cartilage lesions, such as multiple drilling on the medial femoral condyle (MFC), are often performed simultaneously, potentially affecting bone metabolism along with load redistribution and union progression.

View Article and Find Full Text PDF

Advancements in molecular imaging probes for precision diagnosis and treatment of prostate cancer.

J Zhejiang Univ Sci B

January 2025

Department of Orthopedics, the First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou 310006, China.

Prostate cancer is the second most common cancer in men, accounting for 14.1% of new cancer cases in 2020. The aggressiveness of prostate cancer is highly variable, depending on its grade and stage at the time of diagnosis.

View Article and Find Full Text PDF

Our aim is to report methodology that has been developed to calibrate and verify PET and SPECT quantitative image accuracy and quality assurance for use with nonstandard radionuclides, especially with longer half-lives, in clinical imaging trials. Procedures have been developed for quantitative PET and SPECT image calibration for use in clinical trials. The protocol uses a 3-step approach: check quantitative accuracy with a previously calibrated radionuclide in a simple geometry, check the novel trial radionuclide in the same geometry, and check the novel radionuclide in a more challenging, complex geometry (the National Electrical Manufacturers Association [NEMA] NU-2 International Electrotechnical Commission [IEC] image-quality phantom).

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!