CZT gamma camera with pinhole collimator: Spectral measurements

Blevis, I.; Tsukerman, Leonid; Volokh, Lana; Hugg, James W.; Jansen, Floris; Bouhnik, Jean Paul

doi:10.1109/nssmic.2008.4774346

Cited by 17 publications

(6 citation statements)

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“…The second scan was acquired on a CZT camera with pinhole collimation (11). In this camera, the conventional sodium iodide crystals have been replaced by CZT semiconductor technology, which directly converts radiation into electric signals without any of the steps of violet light production, transport, and conversion that occur with sodium iodide crystals (12).…”

Section: Czt Image Acquisition and Reconstructionmentioning

confidence: 99%

Nuclear Myocardial Perfusion Imaging with a Cadmium-Zinc-Telluride Detector Technique: Optimized Protocol for Scan Time Reduction

Herzog¹,

Buechel²,

Katz³

et al. 2009

J Nucl Med

195

132

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We aimed at establishing the optimal scan time for nuclear myocardial perfusion imaging (MPI) on an ultrafast cardiac g-camera using a novel cadmium-zinc-telluride (CZT) solid-state detector technology. Methods: Twenty patients (17 male; BMI range, 21.7-35.5 kg/m 2 ) underwent 1-d 99m Tc-tetrofosmin adenosine stress and rest MPI protocols, each with a 15-min acquisition on a standard dual-detector SPECT camera. All scans were immediately repeated on an ultrafast CZT camera over a 6-min acquisition time and reconstructed from list-mode raw data to obtain scan durations of 1 min, 2 min, etc., up to a maximum of 6 min. For each of the scan durations, the segmental tracer uptake value (percentage of maximum myocardial uptake) from the CZT camera was compared by intraclass correlation with standard SPECT camera data using a 20-segment model, and clinical agreement was assessed per coronary territory. Scan durations above which no further relevant improvement in uptake correlation was found were defined as minimal required scan times, for which Bland-Altman limits of agreement were calculated. Results: Minimal required scan times were 3 min for low dose (r 5 0.81; P , 0.001; Bland-Altman, 211.4% to 12.2%) and 2 min for high dose (r 5 0.80; P , 0.001; Bland-Altman, 27.6% to 12.9%), yielding a clinical agreement of 95% and 97%, respectively. Conclusion: We have established the minimal scan time for a CZT solid-state detector system, which allows 1-d stress/rest MPI with a substantially reduced acquisition time resulting in excellent agreement with regard to uptake and clinical findings, compared with MPI from a standard dualhead SPECT g-camera.Key Words: clinical cardiology; SPECT; cadmium-zinc-telluride detector; myocardial perfusion imaging; ultrafast Ischemi c coronary artery disease is a major cause of morbidity and mortality in industrialized countries. The hemodynamic relevance of culprit lesions can be detected and quantified noninvasively by nuclear myocardial perfusion imaging (MPI), which has grown to become the most frequently used test in nuclear medicine (1) not only for accurate diagnosis of ischemic coronary artery disease but also for assessing prognosis and for imaging myocardial viability and function (2). However, time-consuming acquisitions and cumbersome MPI protocols, with the associated costs, impaired patient comfort, and radiation exposure, have been perceived as limitations. Several attempts to improve the MPI method by using iterative reconstruction algorithms (3,4), early-imaging protocols (5), or different tracers (6) provided valuable results but no breakthroughs translating into applications that improve daily clinical routine. The novel cadmium-zinc-telluride (CZT) detectors may have the potential to represent such a milestone in technical improvement of MPI. They offer a substantially improved count sensitivity as evidenced in preliminary reports (7) and first clinical studies (8,9) performed on a device (D-SPECT; Spectrum Dynamics) with 9 rotating CZT detectors. An alternative approach ...

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Section: Czt Image Acquisition and Reconstructionmentioning

confidence: 99%

Nuclear Myocardial Perfusion Imaging with a Cadmium-Zinc-Telluride Detector Technique: Optimized Protocol for Scan Time Reduction

Herzog¹,

Buechel²,

Katz³

et al. 2009

J Nucl Med

195

132

View full text Add to dashboard Cite

show abstract

“…The second scan was acquired on a CZT camera with pinhole collimation (15), for which the conventional sodium iodide (NaI) crystals have been replaced by CZT semiconductor detectors that directly convert radiation into electric signals without any of the steps of violet light production, transport, and conversion as occurs with NaI crystals (16). Compared with a dedicated cardiac g-camera (Ventri; GE Healthcare) (10,11), for the CZT camera the energy and spatial resolutions (radial resolution, 4.3 mm) were improved by a factor of 2, and the sensitivity (21.0 counts/s/MBq [21.0 counts/s/mCi]) was improved by a factor of almost 4.…”

Section: Czt Image Acquisition and Reconstructionmentioning

confidence: 99%

Validation of CT Attenuation Correction for High-Speed Myocardial Perfusion Imaging Using a Novel Cadmium-Zinc-Telluride Detector Technique

Herzog¹,

Buechel²,

Husmann³

et al. 2010

J Nucl Med

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The aim of this study was to validate attenuation correction (AC) using low-dose standard CT for myocardial perfusion imaging (MPI) on a novel ultra fast g-camera with cadmium-zinc-telluride (CZT) detector technology. Methods: Sixty-six patients (body mass index 6 SD, 27.2 6 3.5 kg/m 2 ; range, 19.1-36.0 kg/m 2 ) underwent a 1-d 99m Tc-tetrofosmin adenosine stress-rest imaging protocol with 15-min acquisitions on a standard dualhead SPECT camera. All scans were repeated within minutes on the CZT camera, with 3-min acquisitions for stress (low dose) and 2-min acquisitions for rest (high dose) as recently established. We compared maximum myocardial uptake (20-segment model) from CZT versus standard SPECT MPI by intraclass correlation without and with CT AC. In addition, clinical agreement for each coronary territory for all scans from both devices was assessed, and Bland-Altmann (BA) limits of agreement for percentage uptake were calculated. Results: The clinical agreement between CZT and standard SPECT cameras was 96% for noncorrected low-and high-dose images (r 5 0.90 and BA 5 218 to 15, and r 5 0.91 and BA 5 215 to 16, respectively), and agreement after AC was 96% for low-and 99% for high-dose images (r 5 0.87 and BA 5 216 to 14, and r 5 0.88 and BA 5 216 to 14, respectively). Conclusion: Our results support that AC of MPI on the novel CZT camera, compared with AC MPI on a conventional SPECT camera, is feasible because it provides a high correlation of segmental tracer uptake and an excellent clinical agreement.

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“…The second scan was acquired on a CZT camera with pinhole collimation [14], in which the conventional sodium iodide crystals had been replaced by CZT semiconductor technology, improving the sensitivity by a factor of almost four compared to a dedicated cardiac gamma camera (Ventri, GE Healthcare) as previously reported in detail [12]. In brief, the new CZT technology is extremely compact and this miniaturization has enabled a geometry with a stationary array of 19 small gamma cameras packed closely around the heart.…”

Section: Czt Image Acquisition and Reconstructionmentioning

confidence: 99%

Ultrafast assessment of left ventricular dyssynchrony from nuclear myocardial perfusion imaging on a new high-speed gamma camera

Pazhenkottil

Buechel

Herzog

et al. 2010

Eur J Nucl Med Mol Imaging

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Purpose To validate the ultrafast assessment of left ventricular (LV) dyssynchrony by phase analysis using high-speed nuclear myocardial perfusion imaging (MPI) on a new gamma camera with cadmium-zinc-telluride (CZT) solid-state detector technology. Methods In 46 patients rest MPI with 960 MBq 99m Tctetrofosmin was acquired on a dual-head detector SPECT camera (Ventri, GE Healthcare) and an ultrafast CZT camera (Discovery NM 530c, GE Healthcare) with acquisition times of 15 and 5 min, respectively. LV dyssynchrony was assessed using the Emory Cardiac Toolbox with established values for histogram bandwidth (male <62.4°; female <49.7°) and standard deviations (male <24.4°; female <22.1°) as the gold standard. Evaluating CZT scan times of 0.5, 1, 2, 3 and 5 min (list mode) in 16 patients revealed the preferred scan time to be 5 min, which was then applied in all 46 patients. Intraclass correlation and the level of agreement in dyssynchrony detection between the CZT and Ventri cameras were assessed. Results In LV dyssynchrony the mean histogram bandwidths with the CZT camera (n=8) and the Ventri camera (n=9) were 123.3±50.6°and 130.2±43.2°(p not significant) and 42.4±13.6°vs. 43.2±12.7°(p not significant). Normal bandwidths and SD obtained with the CZT camera (35.9± 7.7°, 12.6±3.5°) and the Ventri camera (34.8±6.6°, 11.1± 2.1°, both p not significant) excluded dyssynchrony in 38 and 37 patients, respectively. Intraclass correlation and the level of agreement between the CZT camera with a 5-min scan time and the Ventri camera were 0.94 (p<0.001, SEE 14.4) and 96% for histogram bandwidth and 0.96 (p<0.001, SEE 3.9) and 98% for SD. Conclusion This ultrafast CZT camera allows accurate assessment of LV dyssynchrony with a scan time of only 5 min, facilitating repeat measurements which would potentially be helpful for parameter optimization for cardiac resynchronization therapy.

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CZT gamma camera with pinhole collimator: Spectral measurements

Cited by 17 publications

References 0 publications

Nuclear Myocardial Perfusion Imaging with a Cadmium-Zinc-Telluride Detector Technique: Optimized Protocol for Scan Time Reduction

Nuclear Myocardial Perfusion Imaging with a Cadmium-Zinc-Telluride Detector Technique: Optimized Protocol for Scan Time Reduction

Validation of CT Attenuation Correction for High-Speed Myocardial Perfusion Imaging Using a Novel Cadmium-Zinc-Telluride Detector Technique

Ultrafast assessment of left ventricular dyssynchrony from nuclear myocardial perfusion imaging on a new high-speed gamma camera

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