Author + information
- Received November 11, 1994
- Revision received May 18, 1995
- Accepted May 25, 1995
- Published online October 1, 1995.
- Martin P. Sandler, MDa,b,*,
- Searle Videlefsky, MDa,b,
- Dominique Delbeke, MD, PhDa,b,
- James A. Patton, PhDa,b,
- Colin Meyerowitz, MDa,b,
- William H. Martin, MDa,b and
- Israel Ohana, PhDa,b,*
- ↵*Address for correspondence: Dr. Martin P. Sandler, Department of Radiology and Radiological Sciences, CCC-1108 MCN, Vanderbilt University Medical Center, 21st Avenue South and Garland. Nashville. Tennessee 37232-2675.
Objectives. This study sought to develop a dual-isotope single-acquisition single-photon emission computed tomographic (SPECT) protocol using a multihead SPECT camera equipped with an ultra-high energy collimator to evaluate rest metabolism/stress perfusion simultaneously with fluorine-18 (F-18) deoxyglucose/technetium-99m (Tc-99m) 2-hexakis-2-methoxy-2-methylpropyl isonitrile (MIBI).
Background. The most accurate and logistic method of identifying injured but viable myocardium remains a diagnostic challenge.
Methods. Sixty-five patients were given 25 to 50 g of glucose and, after ∼60 min, an injection of 370 MBq (10 mCi) of F-18 fluorodeoxyglucose. After a 35-min distribution phase, patients underwent exercise or pharmacologic stress followed by administration of 925 MBq (25 mCi) of Tc-99m MIBI. Five patients underwent F-18 fluorodeoxyglucose positron emission tomography before dualisotope SPECT.
Results. With a window of 20% for both photopeaks and a technetium-99m/fluorine-18 concentration of 3.2: 1, the “spillover” from fluorine-18 into the technetium-99m window is <6% of the total counts in the window in patients with a normal distribution of both radiopharmaceuticals. Phantom images clearly demonstrated cardiac defects measuring 2 × 1 and 2 × 0.5 cm. There was no significant difference in the images of the five patients who underwent both positron emission tomography and SPECT. Fifty-seven patients (mean [±SD] age 55 ± 15 years, range 25 to 83; 38 men, 19 women) had satisfactory images and were included in the study. Twenty-one patients had normal study results; 15 had mismatched defects; 14 had matched defects; and 7 had both matched and mismatched defects. Twenty-three patients (mean age 54 ± 6 years, range 30 to 83; 14 men, 9 women) underwent coronary angiography within 3 months of dual-isotope SPECT. There were seven normal studies, eight with mismatched defects, one with a matched defect and seven with matched and mismatched defects. When stenosis >70% was used as the criterion for a diagnosis of coronary artery disease, dual-isotope SPECT had a sensitivity of 100%, specificity of 88%, positive predictive value of 93%, negative predictive value of 100% and an accuracy of 96%.
Conclusions. Dual-isotope SPECT may provide an alternative, accurate, cost-effective method to nitrogen-13 ammonia/F-18 fluorodeoxyglucose positron emission tomography or thallium-201 reinjection for identifying injured or dysfunctional but viable myocardium.
This study was funded in part by Elscint, Inc., Hackensack. New Jersey.
- Received November 11, 1994.
- Revision received May 18, 1995.
- Accepted May 25, 1995.
- American College of Cardiology