Search

Background: This study aimed to assess the impact of dedicated cardiac protocol (DCP) on diagnostic accuracy of state-of-the-art digital [ 18 F]-FDG-PET/CT in infective endocarditis (IE) and the intra-individual comparison of the performance with that of conventional whole-body approach (WBA) and to analyze the effects of the expertise level of the investigators., Methods: 44 patients suspected for IE underwent digital-FDG-PET/CT after overnight fasting. Each three consultants and trainees reread PET images blinded to the examination approach and clinical information. Visual and semiquantitative analyses were performed., Results: Digital-FDG-PET/CT with DCP revealed sensitivity, specificity, and accuracy of 89%, 93%, and 91% for native valve endocarditis (NVE) and 93%, 86%, and 91% for prosthetic valve endocarditis. Compared to WBA, substantial improvement of the diagnostic performance for NVE in DCP was evident, especially in trainees, but not as high compared to consultants. Digital-FDG-PET/CT enabled 79.5% reclassification of modified-Duke-Clinical-Criteria (mDC) with 34.1% upgrading and 45.4% downgrading., Conclusions: This study provides new data using state-of-the-art digital-FDG-PET/CT with DCP improving the diagnostic accuracy in challenging cases of possible IE, particularly in NVE, provided that the investigators involved have the necessary expertise. These findings may have a significant impact on IE-related morbidity, mortality, and patient's management and might be meaningful for updates on the prevailing opinion regarding the value of FDG PET/CT in NVE., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Purpose: This study aimed to evaluate the concordance and equivalence of results between the newly acquired digital PET/CT(dPET) and the standard PET/CT (sPET) to investigate possible differences in visual and semi-quantitative analyses., Methods: A total of 30 participants were enrolled and underwent a single 18 F-FDG injection followed by dual PET/CT scans, by a dPET scan, and immediately after by the sPET scan or vice versa. Two readers reviewed overall image quality using a 5-point scale and counted the number of suggestive 18 F-FDG avid lesions. The SUV values were measured in the background organs and in hypermetabolic target lesions. Additionally, we objectively evaluated image quality using the liver signal-to-noise ratio (SNR)., Results: The dPET identified 4 additional 18 F-FDG avid lesions in 3 of 30 participants with improved visual image quality. The standard deviations of SUV of the background organs were significantly lower with Digital PET than with sPET, and dPET could acquire images with better SNR (11.13 ± 2.01 vs. 8.71 ± 1.32, P  < 0.001). The reliability of SUV values between scanners showed excellent agreement. Bland-Altman plot analysis of 81 lesions showed an acceptable agreement between scanners for most of the SUVmax and SUVpeak values. No relationship between the SUV values and time delays of dual PET/CT acquisition was found., Conclusions: The dPET provides improved image quality and lesion detectability than the sPET. The semi-quantitative values of the two PET/CT systems of different vendors are comparable. This pilot study will be an important basis for possible interchangeable use of either system in clinical practice., Competing Interests: Conflict of InterestSung Hoon Kim, Bong-Il Song, Hae Won Kim, and Kyoung Sook Won declare that they have no conflict of interest., (© Korean Society of Nuclear Medicine 2020.)

Background: PET-based myocardial blood flow (MBF) quantification can be inaccurate when using high tracer activities. Our aim was to derive the maximal Rubidium-82 activity for MBF assessment using a new digital PET system and compare the results with conventional analog systems., Methods: 1.8 GBq Rubidium-82 was injected into the cardiac insert of an anthropomorphic torso phantom. Data were acquired for 10 min using an Ingenuity TF (Philips Healthcare), Discovery 690 (D690, GE Healthcare), and digital PET prototype system (Philips Healthcare). The dynamic ranges, defined as the maximal measured activity in the reconstructed images deviating < 10% from the true present activity, were determined in all scans., Results: The dynamic ranges were 312 MBq for Ingenuity TF, 650 MBq for D690, and 654 MBq for digital PET prototype., Conclusions: The maximal Rb-82 activity for MBF assessment using digital PET prototype is higher than that for its analog counterpart (Ingenuity TF), but seems comparable to the D690.