UK national survey on nuclear medicine in-house clinical software: the calm before the storm.

Introduction: The use of in-house developed software as a medical device (IHD-SaMD) is core to many nuclear medicine (NM) services in the UK, including applications in nonimaging studies and image processing. Expected regulatory changes in 2025 could have significant implications due to a lack of resources and expertise in the implementation and maintenance of software Quality Management Systems (QMS) and associated standards. This survey investigated the national use of IHD-SaMD and the readiness of services to adapt to the upcoming regulatory changes.

UK audit of variation in nuclear medicine occupational exposure calculations in 2021.

It is a core requirement of UK ionising radiations regulations 2017 (IRR17) compliance for radiation risk assessments and the investigation of accidental exposure scenarios that the magnitude of doses likely to be encountered are evaluated. A novel national audit was undertaken to investigate the variation in dose estimations for a range of foreseeable accidental exposure scenarios in nuclear medicine (NM). Participants were asked to estimate the levels of exposure in 15 foreseeable scenarios; covering whole-body and extremity exposures from external sources, internal exposure and exposures from skin (surface contamination and needle-stick injury) and eye contamination.

Tailoring the sampling time of single-sample GFR measurement according to expected renal function: a multisite audit.

Background: The 2018 BNMS Glomerular Filtration Rate (GFR) guidelines recommend a single-sample technique with the sampling time dictated by the expected renal function, but this is not known with any accuracy before the test. We aimed to assess whether the sampling regime suggested in the guidelines is optimal and determine the error in GFR result if the sample time is chosen incorrectly. We can then infer the degree of flexibility in the sampling regime.

Calculating the precision of slope-intercept glomerular filtration rate measurements.

Glomerular filtration rate (GFR) can be measured by observing the clearance of a suitable tracer from blood plasma after an intravenous injection. Slope-intercept GFR is an estimate of GFR calculated from an exponential fit to multiple blood sample measurements. The precision of the result depends on the uncertainties on all the measured quantities, but the most important factor is the error on the slope and intercept of the fit.

The prevalence of image degradation due to motion in rest-stress rubidium-82 imaging on a SiPM PET-CT system.

Background: Motion of the heart is known to affect image quality in cardiac PET. The prevalence of motion blurring in routine cardiac PET is not fully appreciated due to challenges identifying subtle motion artefacts. This study utilizes a recent prototype Data-Driven Motion Correction (DDMC) algorithm to generate corrected images that are compared with non-corrected images to identify visual differences in relative rubidium-82 perfusion images due to motion.

A preliminary evaluation of a high temporal resolution data-driven motion correction algorithm for rubidium-82 on a SiPM PET-CT system.

Background: In myocardial perfusion PET, images are acquired during vasodilator stress, increasing the likelihood of intra-frame motion blurring of the heart in reconstructed static images to assess relative perfusion. This work evaluated a prototype data-driven motion correction (DDMC) algorithm designed specifically for cardiac PET.

Methods: A cardiac torso phantom, with a solid defect, was scanned stationary and being manually pulled to-and-fro in the axial direction with a random motion.

Assessment of motion correction in dynamic rubidium-82 cardiac PET with and without frame-by-frame adjustment of attenuation maps for calculation of myocardial blood flow.

Background: Patient motion during pharmacological stressing can have substantial impact on myocardial blood flow (MBF) estimated from dynamic PET. This work evaluated a motion correction algorithm with and without adjustment of the PET attenuation map.

Methods: Frame-by-frame motion correction was performed by three users on 30 rubidium-82 studies.

Assessing Reliability of Myocardial Blood Flow After Motion Correction With Dynamic PET Using a Bayesian Framework.

The estimation of myocardial blood flow (MBF) in dynamic PET can be biased by many different processes. A major source of error, particularly in clinical applications, is patient motion. Patient motion, or gross motion, creates displacements between different PET frames as well as between the PET frames and the CT-derived attenuation map, leading to errors in MBF calculation from voxel time series.

Impact of pharmacological stress agent on patient motion during rubidium-82 myocardial perfusion PET/CT.

Background: Patient motion has been demonstrated to have a significant impact on the quality and accuracy of rubidium-82 myocardial perfusion PET/CT. This study aimed to investigate the effect on patient motion of two pharmacological stressing agents, adenosine and regadenoson.

Methods And Results: Dynamic data were retrospectively analyzed in 90 patients undergoing adenosine (n = 30), incremental adenosine (n = 30), or regadenoson (n = 30) rubidium-82 myocardial perfusion PET/CT.

The impact of prompt gamma compensation on myocardial blood flow measurements with rubidium-82 dynamic PET.

Background: Rubidium-82 myocardial perfusion imaging is a well-established technique for assessing myocardial ischemia. With continuing interest on myocardial blood flow (MBF) and myocardial flow reserve (MFR) measurements, there is a requirement to fully appreciate the impact of technical aspects of the process. One such factor for rubidium-82 is prompt gamma compensation (PGC).

Radionuclide Imaging of Cardiovascular Infection.

Owing to expanding clinical indications, cardiac implantable electronic devices (CIEDs) are being increasingly used. Despite improved surgical techniques and the use of prophylactic antimicrobial therapy, the rate of CIED-related infection is also increasing. Infection is a potentially serious complication, with clinical manifestations ranging from surgical site infection and local symptoms in the region of the generator pocket to fulminant endocarditis.

The performance of quantitation methods in the evaluation of cardiac implantable electronic device (CIED) infection: A technical review.

Background: Quantitative assessment of [F]-FDG PET/CT images has been shown to be useful in the diagnosis of cardiac implantable electronic device (CIED) infection. This study aimed to compare the accuracy of various quantitative methods, using the same patient cohort and to assess the utility of dual time point imaging.

Methods: The study comprised a retrospective review of 80 [F]-FDG PET/CT studies.