Copyright © Lippincott Williams & Wilkins. Unauthorized reproduction of this article is prohibited. UK audit of quantification of left-ventricular function using gated myocardial perfusion imaging Sarah C. Cade a , David O. Hall b , Bob Kenny c , Andy Knight d , Richard S. Lawson e , Lefteris Livieratos f , Kuldip S. Nijran g , Duncan White h and on behalf of the Institute of Physics and Engineering in Medicine Nuclear Medicine Software Quality Group Purpose The aim of the study was to evaluate UK-wide interinstitutional reproducibility of left-ventricular functional parameters, end-systolic volume, end-diastolic volume and ejection fraction, obtained from gated myocardial perfusion imaging (GMPI) studies using technetium-99m- labelled radiopharmaceuticals. The study was carried out by the UK Institute of Physics and Engineering in Medicine Nuclear Medicine Software Quality Group. Materials and methods Ten anonymized clinical GMPI studies, five with normal perfusion and five with perfusion defects, were made available in DICOM and proprietary formats for download and through manufacturers’ representatives. Two of the studies were duplicated in order to assess intraoperator repeatability, giving a total of 12 studies. Studies were made available in 8 and 16 frames/cycle. Results A total of 58 institutions across England, Scotland, Wales and Northern Ireland participated in this study using six different computer packages. Studies were processed at centres using their normal clinical computers and software. The overall mean±SD ejection fraction for all centres was 58.5±3%; the mean end-diastolic volume was 114±12 ml and the mean end-systolic volume was 54±6 ml. The results were affected by the number of frames per cycle and by the postprocessing computer package, but not by the reconstruction filter in the filtered back-projection. Conclusion Calculation of functional parameters from GMPI using technetium-99m-labelled radiopharmaceuticals is reliable and shows limited variability across the UK. Nucl Med Commun 00:000–000  c 2013 Wolters Kluwer Health | Lippincott Williams & Wilkins. Nuclear Medicine Communications 2013, 00:000–000 Keywords: ejection fraction, gated SPECT, interinstitutional reproducibility, left-ventricular volume a Royal United Hospital Bath NHS Trust, Bath, b Department of Medical Physics and Bioengineering, University Hospitals Bristol NHS Foundation Trust, Bristol, c Link Medical, Bramshill, d Sunderland Royal Hospital, Sunderland, e Central Manchester University Hospitals, Manchester, f Guy’s and St Thomas’ NHS Foundation Trust, g Imperial College Healthcare NHS Trust, London and h Barnsley Hospital NHS Foundation Trust, Barnsley, UK Correspondence to David O. Hall, PhD, Department of Medical Physics and Bioengineering, University Hospitals Bristol NHS Foundation Trust, Level 5 Old Building, Bristol Royal Infirmary, Upper Maudlin Street, Bristol, BS2 8HW, UK Tel: +44 117 342 4756; fax: +44 117 342 4570; e-mail: david.hall@uhbristol.nhs.uk Received 22 April 2013 Revised 4 June 2013 Accepted 4 June 2013 Introduction Gated myocardial perfusion imaging (GMPI) is widely used as a method of assessing not just myocardial perfusion but also function. Gating the acquisition to the ECG allows assessment of wall motion, which can give more confidence in clinical reporting. Software that allows the calculation of left-ventricular volume at end- diastole and end-systole, as well as the calculation of left- ventricular ejection fraction (EF), has been developed and is now used routinely in many nuclear medicine centres. However, there have been reports that the results of the calculations of EF are affected by the software package and the reconstruction filters used [1–3], although it has also been suggested that the differences may be statistically but not clinically sig- nificant [4]. Despite the known variability and interin- stitutional differences in planar multi-gated acquisition (MUGA) studies [5–7], MUGA studies are often considered the gold standard [8], particularly for assess- ment of cardiac function in patients treated with cardiotoxic chemotherapy [9]. However, in many centres more GMPI studies are carried out than MUGA studies, and hence it is important to consider whether these studies are reliable enough to be an alternative [10]. The aim of this study was to assess the interinstitutional variability in EFs and volumes assessed using GMPI. Three key acquisition and processing parameters have been shown to have an effect on the results of GMPI: the acquired frames per cycle [11–14], the reconstruction filter [1–3] and the postprocessing package [15–17]. All of them have been addressed in this study. The Nuclear Medicine Software Quality Group (NMSQG) is a subcommittee of the UK Institute of Data were presented at the Annual Congress of the European Association of Nuclear Medicine, 2012, and have been published as an abstract in Eur J Nucl Med Mol Imaging 2012; 39(Suppl 2): S171. Original article 0143-3636  c 2013 Wolters Kluwer Health | Lippincott Williams & Wilkins DOI: 10.1097/MNM.0b013e328363f86d