title: A comparison between upright and supine myocardial perfusion imaging with attenuation correction.
abstract: OBJECTIVE
  The Digirad Cardius XACT is an upright myocardial perfusion imaging (MPI) single photon emission computed tomography system offering low-dose computed tomography for attenuation correction (AC). This study compares patient acceptability and image appearance for both non-AC and AC images on the XACT with supine MPI performed on a GE Infinia Hawkeye.
  
  
  METHODS
  A total of 47 patients [29 male patients; mean (range) BMI, 29.1 (21.0-57.5) kg/m] referred for routine MPI underwent rest and stress MPI on the XACT and Infinia. Non-AC and AC bullseye plots were created and uptake scores were recorded in each of five segments. All studies were reported by an experienced observer with clinical details available. A patient questionnaire was used to determine the relative comfort with the two systems.
  
  
  RESULTS
  Perfusion patterns on upright and supine non-AC images were significantly different and displayed a notable distinction between sexes. Perfusion patterns on upright and supine AC images were similar for both male and female patients, although some discrepancies between diagnostic reports still existed. A strong preference for upright imaging was demonstrated by the patient questionnaire.
  
  
  CONCLUSIONS
  Changes in soft-tissue and diaphragmatic attenuation between upright and supine MPI can be overcome with the addition of AC. However, clinicians should still ensure that they are aware of typical artefacts produced by upright and supine imaging.
authors.affiliation: Nuclear Medicine Centre, Central Manchester University Hospitals NHS Foundation Trust, Manchester, UK.
authors.forename: Deborah
authors.initials: D
authors.lastname: Tout
authors.forename: Christine
authors.initials: C
authors.lastname: Tonge
authors.forename: Peter
authors.initials: P
authors.lastname: Austin
authors.forename: Joanne
authors.initials: J
authors.lastname: Adams
authors.forename: Parthiban
authors.initials: P
authors.lastname: Arumugam
mesh_terms: D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D055414:Myocardial Perfusion Imaging / Q000295:instrumentation / Q000379:methods*; D010342:Patient Acceptance of Health Care; D016683:Supine Position; D015899:Tomography, Emission-Computed, Single-Photon