UK audit of analysis of quantitative parameters from renography data generated using a physical phantom.

Background: In this second UK audit of quantitative parameters obtained from renography, phantom simulations were used in cases in which the 'true' values could be estimated, allowing the accuracy of the parameters measured to be assessed.

Materials And Methods: A renal physical phantom was used to generate a set of three phantom simulations (six kidney functions) acquired on three different gamma camera systems. A total of nine phantom simulations and three real patient studies were distributed to UK hospitals participating in the audit.

A novel method for more accurately mapping the surface temperature of ultrasonic transducers.

This paper introduces a novel method for measuring the surface temperature of ultrasound transducer membranes and compares it with two standard measurement techniques. The surface temperature rise was measured as defined in the IEC Standard 60601-2-37. The measurement techniques were (i) thermocouple, (ii) thermal camera and (iii) novel infra-red (IR) "micro-sensor.

(18)F-FDG PET-CT simulation for non-small-cell lung cancer: effect in patients already staged by PET-CT.

Purpose: Positron emission tomography (PET), in addition to computed tomography (CT), has an effect in target volume definition for radical radiotherapy (RT) for non-small-cell lung cancer (NSCLC). In previously PET-CT staged patients with NSCLC, we assessed the effect of using an additional planning PET-CT scan for gross tumor volume (GTV) definition.

Methods And Materials: A total of 28 patients with Stage IA-IIIB NSCLC were enrolled.

Personnel radiation dose considerations in the use of an integrated PET-CT scanner for radiotherapy treatment planning.

The acquisition of radiotherapy planning scans on positron emission tomography (PET)-CT scanners requires the involvement of radiotherapy radiographers. This study assessed the radiation dose received by these radiographers during this process. Radiotherapy planning (18)F-fluorodeoxyglucose ((18)F-FDG) PET-CT scans were acquired for 28 non-small cell lung cancer patients.

UK audit of glomerular filtration rate measurement in 2001.

Objective: To investigate the consistency of glomerular filtration rate (GFR) calculation from plasma sampling in the UK.

Methods: Ten patients' data sets from plasma sampling measurements of GFR were distributed throughout the UK. The data included count rates from four samples taken between 2 and 4 h after injection, a diluted sample of injected dose for standardisation, the patient's height, weight, age and sex.

A method for synchronizing an external respiratory signal with a list-mode PET acquisition.

A method is proposed to synchronize positron emission tomography (PET) list-mode data with an externally recorded respiratory signal in the absence of a master clock. When the respiratory signal reaches a user-defined threshold, a trigger mark is stored in the list-mode file. After the acquisition, synchronization is achieved when the stored trigger marks are superimposed on the respiratory curve to form a horizontal line over time at the user-defined threshold.

Fuzzy hidden Markov chains segmentation for volume determination and quantitation in PET.

Accurate volume of interest (VOI) estimation in PET is crucial in different oncology applications such as response to therapy evaluation and radiotherapy treatment planning. The objective of our study was to evaluate the performance of the proposed algorithm for automatic lesion volume delineation; namely the fuzzy hidden Markov chains (FHMC), with that of current state of the art in clinical practice threshold based techniques. As the classical hidden Markov chain (HMC) algorithm, FHMC takes into account noise, voxel intensity and spatial correlation, in order to classify a voxel as background or functional VOI.

The role of PET/CT scanning in radiotherapy planning.

The introduction of functional data into the radiotherapy treatment planning process is currently the focus of significant commercial, technical, scientific and clinical development. The potential of such data from positron emission tomography (PET) was recognized at an early stage and was integrated into the radiotherapy treatment planning process through the use of image fusion software. The combination of PET and CT in a single system (PET/CT) to form an inherently fused anatomical and functional dataset has provided an imaging modality which could be used as the prime tool in the delineation of tumour volumes and the preparation of patient treatment plans, especially when integrated with virtual simulation.

A Monte Carlo analysis technique applied to cerebral perfusion SPECT scans.

Objective: Voxel-based techniques are used to provide objective analyses of SPECT scans. The aim of this study was to develop a voxel-based analysis technique that uses a Monte Carlo method of statistical inference and assess this analysis technique for application to cerebral perfusion SPECT scans.

Methods: Assessment of the validity of this non-parametric, Monte Carlo method of statistical inference has been performed for a range of study designs, image characteristics and analysis parameters using phantom SPECT and Gaussian images.

UK audit of left ventricular ejection fraction estimation from equilibrium ECG gated blood pool images.

Purpose: To examine the variability of results obtained from computer analysis of left ventricular gated blood pool (LVGBP) images by nuclear medicine centres in the UK.

Methods: Twelve data sets of LVGBP images were distributed via commercial software suppliers to nuclear medicine centres in the UK. Two of the data sets were duplicates and three were acquired from the same patient with different total counts in the images.

UK audit of relative lung function measurement from planar radionuclide imaging.

Background: Quantitative measurements of regional lung ventilation and perfusion are useful adjuncts to image interpretation.

Aim: This study investigated the accuracy and precision of the software used to carry out such measurements in the UK.

Methods: Ten examples of perfusion distribution, representing the range of patterns expected in practice, were simulated on computer using a segmental model of the lung and real three-dimensional lung shapes obtained from magnetic resonance images.

Audit of nuclear medicine scientific and technical standards.

The British Nuclear Medicine Society has developed a process for the service-specific organizational audit of nuclear medicine departments. This process identified the need for a scheme suitable for the audit of the scientific and technical standards of a department providing such a service. This document has evolved following audit visits of a number of UK departments.

Value of sequential monitoring of left ventricular ejection fraction in the management of thalassemia major.

Regular monitoring of left ventricular ejection fraction (LVEF) for thalassemia major is widely practiced, but its informativeness for iron chelation treatment is unclear. Eighty-one patients with thalassemia major but no history of cardiac disease underwent quantitative annual LVEF monitoring by radionuclide ventriculography for a median of 6.0 years (interquartile range, 2-12 years).

A comparison of three radionuclide myocardial perfusion tracers in clinical practice: the ROBUST study.

Unlabelled: There are no large studies available to guide the selection of thallium (Tl), methoxyisobutylisonitrile (MIBI) or tetrofosmin (Tf) for myocardial perfusion imaging. Our objective was to compare the technical and clinical performance of the three in routine clinical practice. We randomised 2,560 patients to receive Tl, MIBI or Tf.

UK audit of single photon emission computed tomography reconstruction software using software generated phantoms.

The purpose of this study was to undertake an audit of the quantitative characteristics of single photon emission computed tomography software using projection data from an analytically generated software phantom and a measured line source. The phantom consisted of three structures. A uniformly filled cylinder, a series of cylindrical rods of various diameters in a background activity with a rod to background ratio of 2:1 and lastly, a set of three concentric rings of activity in the ratio 1:0:1.

UK audit and analysis of quantitative parameters obtained from gamma camera renography.

The purpose of this study was to perform an audit of quantitative values obtained from gamma camera renography in the UK. Ten patient image sequences representing normal and pathological renal function were obtained from archived studies and distributed to hospitals in the UK. Hospitals were asked to measure five parameters: relative function, renogram time-to-peak (left and right), and whole kidney mean transit time (left and right).

Influence of arm positioning on tomographic thallium-201 myocardial perfusion imaging and the effect of attenuation correction.

Lateral attenuation in single-photon emission tomography (SPET) myocardial perfusion imaging (MPI) has been attributed to the left arm if it is held by the patient's side during data acquisition. As a result MPI data are conventionally acquired with the arms held above the head. The aims of this study were to determine the effect of imaging arms down on reconstructed tomographic images depicting regional myocardial thallium-201 distribution and to assess whether attenuation-corrected (AC) myocardial perfusion images acquired arms down could replace uncorrected (NC) images acquired arms up for routine clinical service.

Quality assurance in myocardial perfusion tomography: a collaborative BNCS/BNMS audit programme. British Nuclear Cardiology Society/British nuclear Medicine Society.

The aim of this study was to assess the status of acquisition and reporting of myocardial perfusion tomography in the UK. Centres were asked to provide an expert panel with clinical and technical information, digital and hard copy of raw data and reconstructed tomograms, as well as their report (optional) for five randomly selected studies. Ninety studies were received from 18 centres; report text was provided for 66 studies.

UK audit of relative renal function measurement using DMSA scintigraphy.

A variety of software is used to determine quantitative parameters from radionuclide imaging procedures. Knowledge of the variability of parameter values found in different hospitals is an important aspect of clinical audit of these techniques. This study investigated the variation in relative renal function measurement from static DMSA scintigraphy in the UK.

Effect of attenuation correction on myocardial thallium-201 distribution in patients with a low likelihood of coronary artery disease.

Regional variation of tracer distribution is seen in uncorrected thallium-201 images of normal hearts. This study evaluates the effect of attenuation correction on myocardial 201T1 distribution in patients with low risk of coronary artery disease. An L-shaped dual-detector single-photon emission tomographic system equipped with a pair gadolinium-153 scanning line sources was used for sequential emission/transmission imaging in 36 patients (14 men and 22 women) with less than 5% risk for coronary artery disease.

Transmission scanning for attenuation correction of myocardial 201Tl images in obese patients.

For attenuation correction (AC) of 201Tl myocardial perfusion images, an accurate attenuation map is required. This study assessed whether prolonged transmission scanning is required in obese compared to normal-sized patients. Twenty-nine obese patients (mean body mass index 33 kg m-2) underwent sequential emission/transmission imaging for AC using an L-shaped, dual-headed gamma camera fitted with two 153Gd scanning line sources.

PET imaging using gamma camera systems: a review.

Optimized positron emission tomographs have begun to demonstrate an ever widening range of clinical applications for positron labelled pharmaceuticals. This potential has led to a renewed interest in the use of the more widely available Anger gamma camera detectors for imaging the 511 keV photons from the positron decay process. Two forms of detection can be considered: either the detection of the 511 keV photons as single events or the detection of coincidence events from the opposed pair annihilation photons.