Feasibility study of a novel general purpose CZT-based digital SPECT camera: initial clinical results

Elinor Goshen,Ronen Goldkorn,Simona Ben-Haim,Eli Stern,Leonid Beilin,Tal Kenig

doi:10.1186/s40658-018-0205-z

Abstract

BackgroundThe performance of a prototype novel digital single-photon emission computed tomography (SPECT) camera with multiple pixelated CZT detectors and high sensitivity collimators (Digital SPECT; Valiance X12 prototype, Molecular Dynamics) was evaluated in various clinical settings.Images obtained in the prototype system were compared to images from an analog camera fitted with high-resolution collimators. Clinical feasibility, image quality, and diagnostic performance of the prototype were evaluated in 36 SPECT studies in 35 patients including bone (n = 21), brain (n = 5), lung perfusion (n = 3), and parathyroid (n = 3) and one study each of sentinel node and labeled white blood cells. Images were graded on a scale of 1–4 for sharpness, contrast, overall quality, and diagnostic confidence.ResultsDigital CZT SPECT provided a statistically significant improvement in sharpness and contrast in clinical cases (mean score of 3.79 ± 0.61 vs. 3.26 ± 0.50 and 3.92 ± 0.29 vs. 3.34 ± 0.47 respectively, p < 0.001 for both). Overall image quality was slightly higher for the digital SPECT but not statistically significant (3.74 vs. 3.66).ConclusionCZT SPECT provided significantly improved image sharpness and contrast compared to the analog system in the clinical settings evaluated. Further studies will evaluate the diagnostic performance of the system in large patient cohorts in additional clinical settings.

Highlights

The performance of a prototype novel digital single-photon emission computed tomography (SPECT) camera with multiple pixelated cadmium zinc telluride (CZT) detectors and high sensitivity collimators (Digital SPECT; Valiance X12 prototype, Molecular Dynamics) was evaluated in various clinical settings
Gamma cameras with digital solid-state cadmium zinc telluride (CZT) detectors and tungsten collimators have been reported to provide improved images when compared to those produced by conventional analog cameras, fitted with thallium-doped sodium iodide (NaI [Tl]) detectors and lead collimators [1, 2]
There were no findings seen on conventional SPECT which were not visualized on the corresponding digital SPECT studies

Summary

Introduction

The performance of a prototype novel digital single-photon emission computed tomography (SPECT) camera with multiple pixelated CZT detectors and high sensitivity collimators (Digital SPECT; Valiance X12 prototype, Molecular Dynamics) was evaluated in various clinical settings. There is a significant improvement of energy resolution using CZT detectors, 5% at 140 keV compared to 10% with a conventional camera [5,6,7] Another intrinsic advantage of digital CZT detection technology over analog technology is the significantly higher count rate afforded by the new technology [3], which facilitates dynamic SPECT [8, 9], together with significant reductions in radiation exposure and imaging times [10]. The improved proximity and sampling coupled with proprietary reconstruction algorithms results in further improvement to spatial resolution when compared to conventional SPECT systems, even when the digital system is equipped with high-sensitivity collimators [1, 3]

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