5-Year Prognostic Value of Quantitative Versus Visual MPI in Subtle Perfusion Defects

Miller

et al. 2019

J Nucl Med

Self Cite

There has been an evolutionary leap in SPECT imaging with the advent of camera systems that use solid-state crystals and novel collimator designs configured specifically for cardiac imaging. Solid-state SPECT camera systems have facilitated dramatic reductions in both imaging time and radiation dose while maintaining high diagnostic accuracy. These advances are related to simultaneous improvement in photon sensitivity due to the collimator and imaging geometry, as well as image resolution due to the improved energy resolution of the new crystals. Improved photon sensitivity has facilitated fast or low-dose myocardial perfusion imaging (MPI), and early dynamic imaging has emerged as a technique for assessing myocardial blood flow with SPECT. Lastly, general-purpose solid-state camera systems and hybrid SPECT/CT systems have also been developed that may have important clinical roles in cardiac imaging. This review summarizes state-of-the-art solid-state SPECT MPI technology and clinical applications, including emerging techniques for SPECT MPI flow estimation. We also discuss imaging protocols used with the new cameras, potential imaging pitfalls, and the latest data providing large-scale validation of the diagnostic and prognostic value of this new technology.

Section: Large-scale Clinical Validationmentioning

confidence: 99%

Section: Large-scale Clinical Validationmentioning

confidence: 99%

Section: Large-scale Clinical Validationmentioning

confidence: 99%

See 1 more Smart Citation

Solid-State Detector SPECT Myocardial Perfusion Imaging

Miller

et al. 2019

J Nucl Med

Self Cite

“…There is a growing evidence, including large multicenter studies, that these solid-state SPECT systems demonstrate excellent diagnostic and prognostic utility in cardiac imaging. [6][7][8] In the last few years, the equipment companies have also introduced general-purpose CZT-based SPECT systems to enable applications other than cardiac imaging. These cameras benefit from improved energy and image resolution due to the CZT detectors and have demonstrated improved image quality in early clinical implementation as compared to general-purpose Angerbased systems.…”

mentioning

confidence: 99%

Do we need dedicated cardiac SPECT systems?

Journal of Nuclear Cardiology

2021

Dedicated cardiac SPECT scanners have significantly improved in recent years, 1 reducing imaging time and radiation dose. In particular, cardiac scanners have entered clinical practice, 2,3 which use solid-state Cadmium-Zinc-Telluride (CZT) crystal detectors and feature innovative gantry designs, focusing on the heart. These new systems allow improvement in photon sensitivity (5-8 times higher) 4,5 for cardiac imaging, as well as image resolution (up to 2 times higher). 5 While solidstate CZT detectors are more expensive than traditional NaI(Tl) crystal detectors with photomultipliers, they do have important imaging advantages. The CZT detectors have improved energy response, which significantly reduces the scatter component of measured data. They also offer superior intrinsic spatial resolution compared to conventional Anger cameras. The use of less-bulky detectors (no need for photomultipliers) has resulted in more compact scanner size which has facilitated smallfootprint dedicated cardiac camera designs with custom imaging geometries and high-sensitivity collimation. There is a growing evidence, including large multicenter studies, that these solid-state SPECT systems demonstrate excellent diagnostic and prognostic utility in cardiac imaging. [6][7][8] In the last few years, the equipment companies have also introduced general-purpose CZT-based SPECT systems to enable applications other than cardiac imaging. These cameras benefit from improved energy and image resolution due to the CZT detectors and have demonstrated improved image quality in early clinical implementation as compared to general-purpose Angerbased systems. 9,10 GE has introduced general-purpose CZT-based cameras, the Discovery NM/CT 670 and 870, equipped with conventional collimators and CT attenuation correction. These cameras are not only designed for general-purpose imaging but also targeting cardiac imaging applications. The conventional collimator design of these cameras may avoid the difficulties in cardiac imaging, specific to the multipinhole collimation and small field-of-view on the dedicated cardiac cameras. 11 It is important, however, to point out that the general-purpose CZT cameras offer the same photon sensitivity as the conventional Anger systems, because the count sensitivity is related to the collimator and not the crystal. Thus, dedicated CZT cameras with specialized collimators can achieve much higher count sensitivity, consequently allowing faster acquisitions and lower injected doses. In particular, the 19-pinhole collimator, with each pinhole operating at a different focal depth, allows stationary image acquisition. Photons are acquired simultaneously through all the pinholes, allowing improved sensitivity as compared to the conventional camera with parallel collimators and rotating heads. For example, the reported measured system sensitivity of the Discovery NM/CT 670 CZT camera was 78 counts/s/MBq 12 compared to 460 counts/ s/MBq 5 for the dedicated GE 530 CZT design. Thus, in absolute terms, the sensitivity of the gen...

“…[29][30][31] In a large multicenter study, we showed that TPD allows more precise risk gradation for MACE, even in categories traditionally considered normal. 32 However, most MPI risk-stratification studies used perfusion defect size alone, without considering other imaging (PET flow, CAC), stress test, or clinical variables-or considered only subset of these variables. While physicians mentally attempt to combine all stress test and clinical variables when interpreting MPI, such integration is subjective and affected by individual bias and expertise.…”

mentioning

confidence: 99%

Leveraging latest computer science tools to advance nuclear cardiology

Journal of Nuclear Cardiology

2019

Nuclear cardiology has unique advantages compared to other modalities, since the image analysis is already much more automated compared to what is currently clinically performed for CT, MR, or echocardiography imaging. The diverse image and clinical data available to assess coronary disease function, perfusion, flow, and associated CT data provide new opportunities, but logistically these additional assessments increase the overall complexity of SPECT/ PET reporting, necessitating additional expertise and time. The advances in artificial intelligence software can be leveraged to obtain comprehensive risk predictions and diagnoses from all available data. They will allow nuclear cardiology to retain competitive edge compared to other modalities and improve its overall clinical utility. These tools will enhance diagnosis and risk prediction beyond what is possible by subjective visual analysis and mental integration of data by physicians.