Comparison of image quality and lesion detection between digital and analog PET/CT
The purpose of this study was to compare image quality and lesion detection capability between a digital and an analog PET/CT system in oncological patients.
Materials and methods
One hundred oncological patients (62 men, 38 women; mean age of 65 ± 12 years) were prospectively included from January–June 2018. All patients, who accepted to be scanned by two systems, consecutively underwent a single day, dual imaging protocol (digital and analog PET/CT). Three nuclear medicine physicians evaluated image quality using a 4-point scale (−1, poor; 0, fair; 1, good; 2, excellent) and detection capability by counting the number of lesions with increased radiotracer uptake. Differences were considered significant for a p value <0.05.
Improved image quality in the digital over the analog system was observed in 54% of the patients (p = 0.05, 95% CI, 44.2–63.5). The percentage of interrater concordance in lesion detection capability between the digital and analog systems was 97%, with an interrater measure agreement of κ = 0.901 (p < 0.0001). Although there was no significant difference in the total number of lesions detected by the two systems (digital: 5.03 ± 10.6 vs. analog: 4.53 ± 10.29; p = 0.7), the digital system detected more lesions in 22 of 83 of PET+ patients (26.5%) (p = 0.05, 95% CI, 17.9–36.7). In these 22 patients, all lesions detected by the digital PET/CT (and not by the analog PET/CT) were < 10 mm.
Digital PET/CT offers improved image quality and lesion detection capability over the analog PET/CT in oncological patients, and even better for sub-centimeter lesions.
KeywordsDigital PET/CT Analog PET/CT Lesion detection capability Image quality
Sources of funding
Funded in part by an unrestricted grant from Philips Healthcare.
Compliance with ethical standards
Conflict of interest
All authors declare no conflict of interest.
All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards. This article does not contain any studies with animals performed by any of the authors.
Informed consent was obtained from all individual participants included in the study.
- 2.Wright C, Binzel K, Zhang J, et al. Advanced functional tumor imaging and precision nuclear medicine enabled by digital PET technologies. Contrast Media Mol Imaging. 2017:5260305. https://doi.org/10.1155/2017/5260305.
- 3.Frach T, Prescher G, Degenhardt C, et al. The digital silicon photomultiplier: principle of operation and intrinsic detector performance. IEEE Nucl Sci Symp Conf Rec. 2009:1959–65.Google Scholar
- 4.Degenhardt C, Prescher G, Frach T, et al. The digital silicon photomultiplier: a novel sensor for the detection of scintillation light. IEEE Nucl Sci Symp Conf Rec. 2009:2383–6.Google Scholar
- 6.Rausch I, Ruiz A, Valverde-Pascual I, et al. Performance evaluation of the Philips Vereos PET/CT system according to the NEMA NU2–2012 standard. J Nucl Med. 2018: Oct 25. pii 118.21554.Google Scholar
- 7.Degenhardt C, Rodrigues P, Trindade A, et al. Performance evaluation of a prototype positron emission tomography scanner using digital photon counters (DPC). IEEE Nucl Sci Symp Conf Rec. 2012:2820–4.Google Scholar
- 8.Fuentes-Ocampo F, Paillahueque G, Lopez-Mora DA, et al. Digital vs. analog PET/CT: intrapersonal SUV comparison of target lesions and reference regions. Eur J Nucl Med Mol Imaging. 2018;45(Suppl 1):S212–3 OP-658.Google Scholar
- 12.Miller MGJ, Jordan D, Laurence T, et al. Initial characterization of a prototype digital photon counting PET system. J Nucl Med. 2014;55:658.Google Scholar