J Nucl Med. 2009; 50 (Supplement 2):598
Cardiovascular: Clinical ScienceHybrid Instrumentation |
Clinical evaluation of a low-dose, X-ray-based transmission imaging for attenuation correction of SPECT myocardial perfusion images
Jamshid Maddahi1,
Richard Conwell2,
Ricardo Mendez1,
Hetal Babla2,
Chuanyong Bai2,
Joel Kindem2,
Charles Ezell, Jr1 and
Rex N. Old2
1 David Geffen School of Medicine at UCLA, Dept of Molecular and Medical Pharmacology, Los Angeles, CA
2 Digirad Corporation, Poway, San Diego, CA
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Objectives: A novel x-ray-based transmission (Tx) approach to cardiac SPECT attenuation correction (AC) has been developed that produces high-quality Tx scans with negligible (5 µSv) patient dose and a very low incidence of misregistration. Clinical utility of this AC approach was evaluated by assessing its effect on normal SPECT myocardial perfusion count distribution.
Methods: 69 patients (44 males and 25 females) with a low pre-SPECT likelihood of coronary artery disease underwent same-day rest-stress SPECT with a Tc-99m labeled agent. A triple head, upright solid-state camera was used for emission and Tx scans. Using x-ray fluorescence, a mono-energetic, collimated line source was formed which allowed Tx scans to be completed in one minute. Rest (R) and stress (S) Myocardial count distributions were quantified (as % maximum) for 5 myocardial regions and 17 myocardial segments before (no AC) and after AC.
Results: Effect of AC on S and R regional counts are shown in [Table] (*p<0.05, AC vs. no AC). These trends were similar in male and female subgroups. By 17-segment analysis, myocardial count variance (expressed as % sq.) decreased after AC on S (80 vs. 69, p<0.05) and R images (64 vs. 48, p<0.001).
Conclusions: The newly developed X-ray based transmission imaging significantly improves normal SPECT myocardial perfusion count uniformity and is promising for attenuation correction of upright SPECT.
