Edinburgh Imaging

MSc projects 1617 005

Half-time gated SPECT myocardial perfusion imaging; Impact of OSEM & resolution recovery on the assessment of myocardial perfusion & global left ventricular function- comparison with full-time imaging.

  • Background: Gated SPECT myocardial perfusion imaging has become widely used in clinical practice for diagnosis of suspected or established coronary artery disease. One of the advantages of this technique is the ability to provide prognostic information on left ventricular function and myocardial perfusion in a single study. Reducing radiation exposure to the patient is desirable. In addition, due to the current shortage of molybdenum supply, reducing administered radioactivity while maintaining diagnostic accuracy may help to preserve the increasingly limited supply of the radionuclide. Half time gated SPECT acquisition has been proposed, as a way of reducing imaging time and improving camera efficiency and patients’ throughput.
  • Methods: This paper offers the findings of a prospective study including 25 consecutive patients undergoing myocardial perfusion imaging at Guy’s hospital in the UK. The aim of the study was to explore the utility of half time gated SPECT cardiac imaging processed with ordered subset expectation maximisation with resolution recovery (OSEM-RR) and to compare results with full time studies reconstructed with filtered back projection (FBP). Secondary objectives were to compare results of full time images between a conventional gamma camera using gadolinium for attenuation correction and SPECT/CT camera, both reconstructed with filtered back projection (FBP). Ethics opinion was sought and the he study was registered as a service evaluation, patients consent was obtained before enrolment.
  • Results: 25 patients (mean age 59 +/- 11 standard deviation) underwent one day cardiac perfusion gated SPECT imaging. 19 had 2 sets of full time images (12 minutes each) and half time images (7 minutes). Reconstructed images were assessed for perfusion score, left ventricular function and were reported according to a 17 segment model. Incidental findings were observed. There were no major discrepancies in clinical reports between the full and half time data (92% concordance), no significant differences in perfusion scores (p> .05) and no significant differences in left ventricular function measurements except for end diastolic volume at rest and stress and end systolic volume at stress. Similar discrepancies were also found on comparing the two full time data (appendix 5).
  • Conclusion: Further study is suggested to explore different processing parameters and also to determine if there are any improvements to patient care and outcomes in terms of increased throughout and reduction in overall imaging time.
Project type:
  • Analysis of existing data
Imaging keywords:
  • SPECT, gated
  • Perfusion imaging, myocardial
Application / disease keywords:
  • 16-17