Evaluation of the effect of reducing administered activity on assessment of function in cardiac gated SPECT

UMMS Affiliation

Department of Radiology

Publication Date


Document Type



Cardiology | Radiology


BACKGROUND: We previously optimized several reconstruction strategies in SPECT myocardial perfusion imaging (MPI) with low dose for perfusion-defect detection. Here we investigate whether reducing the administered activity can also maintain the diagnostic accuracy in evaluating cardiac function.

METHODS: We quantified the myocardial motion in cardiac-gated stress 99m-Tc-sestamibi SPECT studies from 163 subjects acquired with full dose (29.8 +/- 3.6 mCi), and evaluated the agreement of the obtained motion/thickening and ejection fraction (EF) measures at various reduced dose levels (uniform reduction or personalized dose) with that at full dose. We also quantified the detectability of abnormal motion via a receiver-operating characteristics (ROC) study. For reconstruction we considered both filtered backprojection (FBP) without correction for degradations, and iterative ordered-subsets expectation-maximization (OS-EM) with resolution, attenuation and scatter corrections.

RESULTS: With dose level lowered to 25% of full dose, the obtained results on motion/thickening, EF and abnormal motion detection were statistically comparable to full dose in both reconstruction strategies, with Pearson's r > 0.9 for global motion measures between low dose and full dose.

CONCLUSIONS: The administered activity could be reduced to 25% of full dose without degrading the function assessment performance. Low dose reconstruction optimized for perfusion-defect detection can be reasonable for function assessment in gated SPECT.


CAD, MPI, SPECT, gated SPECT, image reconstruction

DOI of Published Version



J Nucl Cardiol. 2018 Nov 7. doi: 10.1007/s12350-018-01505-x. [Epub ahead of print] Link to article on publisher's site

Journal/Book/Conference Title

Journal of nuclear cardiology : official publication of the American Society of Nuclear Cardiology

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Link to Article in PubMed

PubMed ID