Capabilities of Modern Semiconductor Gamma Cameras in Radionuclide Diagnosis of Coronary Artery Disease

This paper presents a review of the literature concerning the clinical application of modern semiconductor (CZT) gamma cameras in the radioinuclide diagnosis of coronary artery disease. It contains information on the diagnostic efficacy of myocardial perfusion studies performed with those cameras compared with the widely used scintillation (Anger) cameras, an overview of their effectiveness in comparison with coronary angiography (also fractional flow reserve) and currently available clinical results of a myocardial flow reserve measured with a dynamic SPECT study. Introduction of this imaging modality to the measurement of a myocardial flow reserve aims to facilitate access to this type of study compared to the less available and more expensive PET method used so far.

Optimization of planning radionuclide diagnostic tests in osteoscintigraphy

Purpose of the study. Determining maximum possible number of high-quality radionuclide studies by days of the generator operation.Materials and methods. We studied the factors influencing the capacity of radionuclide diagnostic tests in osteoscintigraphy (OSG) by days of service life of a 99mTc generator GT-4K. The OSG capacity, the required resource of 99mTc and its efficiency in OSG were calculated. The optimal days for the generator delivery were determined.The Pirfotech 99mTc radiopharmaceutical (RFP) prepared with the generator was used for OSG.Scanning, data collection and processing of results were carried out on gamma-cameras of the systems Signature Series, Symbia T16 Siemens, and syngo M1 Applications VB10 Siemens.Parameters of the radioactivity of 99mTc were processed by mathematical methods using the Excel program.Results. We revealed specific factors influencing the OSG capacity: 1) three-hour accumulation of RFP after its administration to the patient; 2) generator activity by days of its operation; 3) the day of the week of the generator delivery. We calculated quantitative indicators of the maximum possible OSG capacity during the generator operation (maximum number of OSG procedures by days of operation, total capacity, preferred day of the week for the generator delivery).Conclusion. The most significant factors in optimal OSG planning by days of the generator operation are the generator specifications, quantity and frequency of generator supply, provision of gamma-cameras.The described technique for scheduling diagnostic procedures can be useful for the efficient use of the generator system which ensures the maximum amount of high-quality RFP from the generator eluate and contributes to the objectification of the cancer process in order to choose the treatment tactics.

What validation tests can be done by the clinical medical physicist while waiting for the standardization of quantitative SPECT/CT imaging?

Objective The aim of the study was to assess the accuracy of quantitative SPECT/CT imaging in a clinical setting and to compare test results from two nuclear medicine departments.Methods Phantom studies were carried out with two gamma cameras manufactured by GE Healthcare: Discovery NM/CT 670 and NM/CT 850, used in two nuclear medicine departments.Results The convergence of activity concentration recovery was validated for the two gamma cameras operating in two medical centres using a homogeneous 3D phantom. The comparison of results revealed a 5% difference in the calibration factor Bg. cal; 6% difference in COV, and a 0.6% difference in total activity deviation ∆Atot.Recovery coefficients (RCmax) for activity concentration in spheres of the anthropomorphic phantom was measured for different image reconstruction techniques. RCmax was in the range of 0.2-0.4 for the smallest sphere (ϕ10 mm), and 1.3-1.4 for the largest sphere (ϕ37 mm). Conversion factors for SUVmax and SUVmean for the gamma camera systems used were 0.99 and 1.13, respectively.Conclusions 1) Measurements taken in our study confirmed the clinical suitability of 5 parameters of image quality (Bg. cal- background calibration factor, ∆Atot- total activity deviation, COV- noise level estimation, QH- hot contrast, AM-accuracy of measurements or RC- recovery coefficient) for the validation of SPECT/CT system performance in terms of correct quantitative acquisitions of images. 2) This work shows that absolute SPECT/CT quantification is achievable in clinical nuclear medicine centers. Results variation of quantitative analyzes between centers is mainly related to the use of different reconstruction methods. 3) It is necessary to standardize the technique of measuring the SUV conversion factor obtained with different SPECT/CT scanners.

Modern possibilities of cardiovascular imaging using gamma cameras with cadmium–zinc–telluride-detectors

<p>Myocardial perfusion imaging is considered one of the leading non-invasive diagnostic tools for the assessment of patients with known or suspected coronary artery disease and other cardiac pathologies. The technical improvement of the currently used gamma-tomographic devices has increased the diagnostic capability of this technique. In recent years, the use of dedicated cardiac SPECT cameras with solid-state cadmium–zinc–telluride (CZT) technology has increased in nuclear imaging. These new CZT technologies have several advantages over existing scanner models. The development of new CZT detectors and their collimator configuration has increased scanning sensitivity and spatial resolution values. Also, due to the significantly higher sensitivity of new CZT detectors and new methods of data processing, radiologists have already introduced new scanning protocols and methods for radionuclide assessment of myocardial blood flow, reserve and non-invasive visualisation of the functioning of the sympathetic nervous system into clinical practice. The purpose of this review is to provide data on the main technical characteristics of gamma cameras equipped CZT detectors as well as the current possibilities of using CZT cameras for examining patients with various cardiovascular diseases.</p><p>Received 1 April 2020. Revised 22 April 2020. Accepted 30 April 2019.</p><p><strong>Funding:</strong> The work is supported by a grant of the Russian Science Foundation No. 17-75-20118.</p><p><strong>Conflict of interest:</strong> Authors declare no conflict of interest.</p><p><strong>Author contributions</strong><br />Conception and study design: S.M. Minin, K.V. Zavadovky, A.B. Romanov<br />Drafting the article: S.M. Minin, K.V. Zavadovky, N.A. Nikitin, A.V. Mochula, A.B. Romanov<br />Critical revision of the article: S.M. Minin, K.V. Zavadovky<br />Final approval of the version to be published: S.M. Minin, K.V. Zavadovky, N.A. Nikitin, A.V. Mochula, A.B. Romanov</p>