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Thallium-201 imaging with pharmacologic vasodilation: Comparison between dipyridamole and adenosine in detection of coronary artery disease
JOURNAL OF NUCLEAR CARDIOLOGY Volume 2, Number 2, Part 2
Abstracts Monday morning, April 24, 1995
S05-017
S05-019
DOBUTAMINE STRESS TEST FOR THE ASSESSMENT OF PATIENTS WITH REDUCED LEFT VENTRICULAR FUNCTION BEFORE AND AFTER CABG J. Postma-Tjoa, JH. Cornel, E. Boersma, PM. Fioretti. Department of Nuclear Medicine and Thoraxcenter, University Hospital Dijkzigt, Rotterdam, the Netherlands.
THREE-DIMENSIONAL THRESHOLD ANALYSIS OF 1-123 IODOPHENYLPENTADECANOIC ACID MYOCARDIAL SCINTIGRAPHY.
Aims: to assess the changes of stress induced ischemia and of left ventricular (LV) function after uncomplicated surgical revascularization (CABG) in 35 patients with a reduced LV EF (<50%). Methods: high dose dobutamine (up to 40 pg/kg/min)-atropine Thallium-reinjection SPECT (6 major LV regions, visual and quantitative assessment) and gated blood pool ventriculography (at rest and low-dose, 10 pg/kg/min, dobutamine) were repeated before and 3 months after CABG. Results: 1) stress induced ischemia: no complication occurred during the test; the number of patients with transient perfusion defects decreased after CABG from 28 to 17. Consistently, the number of LV regions with ischemia decreased from 101 to 55. 2) LV function: pre-operative LV ejection fraction, peak filling and peak ejection rate were respectively 33+-11%, 1.3• and 2.1 +_0.81, increased during low-dose dobutamine to 43+_11, 2.3_+0.9 and 3.6_+1.04 (p<0.01), but were unchanged after CABG. Conclusions: dobutamine stress test is a feasible and useful test for the functional assessment of patients with reduced LV function after CABG. The results of the present study indicate a significant reduction of stress induced ischemia without a concomitant recovery of LV function after CABG.
Joseph K Russell, Seydl Aksut, Nasaraiah Nallamothu, Jaekyeong Heo, And S Iskandrian. Philadelphia Heart Institute, Presbyterian Medical Center, Philadelphia, PA. This study examined the optimal threshold setting for a threedimensional surface shaded image (3D) using 1-123 iodophenylpentadecanoic acid (IPPA) acquired at different times. SPECT images of 180" were acquired using 32 frames, over 8 min following injection of 4 mCi at rest in 10 normal volunteers aged 415:8 years. The images were obtained at 4 min, 15 min and 25 rain post-injection. Images were evaluated independently by 4 observers using threshold settings at 40, 45, 50, 55, 60 and 65% for image quality. The 4 min images were considered of high quality using the 50% and 55% thresholds. The 15 min images were considered of high quality using the 55% threshold. None of the thresholds was satisfactory for the 25 min images.
In conclusion, the optimal threshold setting for 3D IPPA images was 55%. The rapid myocardial washout of IPPA may degrade the late 3D images. Thus, 3D imaging may not be practical to study initial and redistribution IPPA images.
S05-018
S05-020
THALLIUM-201 I M A G I N G W I T H P H A R M A C O L O G I C VASODILATION: COMPARISON BETWEEN DIPYRIDAMOLE AND ADENOSINE IN DETECTION OF CORONARY ARTERY DISEASE. A. Gagnon, R, Taillefer, R, Amyot, S. Turpin, R. Lambert., R. Essiambre, C. Pilon. Httel-Dieu de Montrtal, Canada. Both dipyridamole (DIP) and adenosine (ADE) are widely used as pharmacologic stressor with 201-TI (T1) imaging for detection of CAD. The purpose of this study was to directly compare DIP and ADE TI imaging in patients with proven CAD. Thirthy-three patients were submitted to two planar TI studies: one with DIP and the other with ADE. The time interval between the 2 studies varied from 2 to 7 days and the order was randomly assigned.Three standard planar views were obtained at 10 min. and 4 hours after injection of 3 mCi of T1. Administrationof DIP was as follows: 0.142 mg/kg/min during 4 min., slight exercise and injection. The infusion of ADE was as follows: 0.142 mg/kg/min, during 6 min. with injection of T1 after the third minute of infusion, Patients were asked to give their preference considering the number, severity, and duration of side effects on a scale from 0 (worst) to 5 (best). Reading was done by 2 experienced observers.The heart was divided into 3 segments/view.The change in systolic blood pressure was -11 • 11 mmHg for ADE and -6 • 9 for DIP (p=0.0006) and the change in heart rate was +18 • 8 bpm for ADE and +9 • 8 bpm for DIP (p=0.0001). Using ROI's, ischemic/normal waal ratios were determined: 0.79 • 0.06 for ADE and 0.82 • 0.08 for DIP (p=0.005). ADE detected 178 normal, 105 ischemic and 14 scar while DIP detected 204, 78 and 15 respectively. Patients prefered ADE (4.1 • 1.0 for ADE vs 3.5 • 1,5 for DIP, (p=0.04) mainly because of the short duration of side effects. In conclusion,this preliminary study shows that the use of ADE with 201-T1 imaging may have advantagesover DIP.
IDENTIFICATION OF OPTIMAL ACQUISITION AND RECONSTRUCTION PARAMETERS FOR 123-IPPA MYOCARDIAL METABOLISM IMAGING. A Gagnon, R, Taillefer, G. Bavaria, C, Benjamin, S. Lacombe. Httel-Dieu de Montrtal, Canada. 123- IPPA is being investigated in phase flI clinical trials as an imaging agent for the assessment of viable myocardium and ability to predict functional recovery after CABG, Unlike 201-Thallium, acquisition and reconstrution protocols are not well established for the identification of viable myocardium. The purpose of this study is to evaluate the optimal acquisition and reconstructionparameters for 123-IPPA. Thirty normal volunteers (19 M, 11 F) were administered a dose of 4.9 mCi (in a fasting state). Count statistics obtained during tomographic acquisitions with a dual head gamma camera equiped with two GAP collimators were determined at 4, 20 and 30 minutes after 123-IPPA injection, From the data gathered, maximum count activity over the heart was evaluated and washout curves were drawn. Acquisition times of 20 sec/frame at 4 and 20 min. and 30 sec./frame at 30 min. were arbitrarely used. Seventeen patients with known CAD (12 M, 5 F) were also imaged at 4 and 30 minutes using the same parameters as before. All raw data was evaluated for patient motion. Three different types of reconstruction filters were evaluated: Butterworth with cutoff at .3, .35 and .4 Nyquist with a power of 5. Two experienced observerswere asked to give a preference on the resulting images based on count homogeinity and overall image quality. Results: Myocardial uptake as an absolute percentage at 4, 20 and 30 minutes was 100%, 97% and 65% respectively in women and 100%, 99.5% and 68% for men. Average count density in the full SPECT study over the heart was 363, 356 and 362 kcounts at 4, 20 and 30 minutes, The overall preference from the observer was reconstructionwith the use of the Butterworthat ,35 Nyquist cutoff and power at 5. The washout analysis confirmed that 4 and 30 minutes were optimal times to initiate imaging for identification of viable myocardium.
$5
Abstracts Monday morning, April 24, 1995
S05-017
S05-019
DOBUTAMINE STRESS TEST FOR THE ASSESSMENT OF PATIENTS WITH REDUCED LEFT VENTRICULAR FUNCTION BEFORE AND AFTER CABG J. Postma-Tjoa, JH. Cornel, E. Boersma, PM. Fioretti. Department of Nuclear Medicine and Thoraxcenter, University Hospital Dijkzigt, Rotterdam, the Netherlands.
THREE-DIMENSIONAL THRESHOLD ANALYSIS OF 1-123 IODOPHENYLPENTADECANOIC ACID MYOCARDIAL SCINTIGRAPHY.
Aims: to assess the changes of stress induced ischemia and of left ventricular (LV) function after uncomplicated surgical revascularization (CABG) in 35 patients with a reduced LV EF (<50%). Methods: high dose dobutamine (up to 40 pg/kg/min)-atropine Thallium-reinjection SPECT (6 major LV regions, visual and quantitative assessment) and gated blood pool ventriculography (at rest and low-dose, 10 pg/kg/min, dobutamine) were repeated before and 3 months after CABG. Results: 1) stress induced ischemia: no complication occurred during the test; the number of patients with transient perfusion defects decreased after CABG from 28 to 17. Consistently, the number of LV regions with ischemia decreased from 101 to 55. 2) LV function: pre-operative LV ejection fraction, peak filling and peak ejection rate were respectively 33+-11%, 1.3• and 2.1 +_0.81, increased during low-dose dobutamine to 43+_11, 2.3_+0.9 and 3.6_+1.04 (p<0.01), but were unchanged after CABG. Conclusions: dobutamine stress test is a feasible and useful test for the functional assessment of patients with reduced LV function after CABG. The results of the present study indicate a significant reduction of stress induced ischemia without a concomitant recovery of LV function after CABG.
Joseph K Russell, Seydl Aksut, Nasaraiah Nallamothu, Jaekyeong Heo, And S Iskandrian. Philadelphia Heart Institute, Presbyterian Medical Center, Philadelphia, PA. This study examined the optimal threshold setting for a threedimensional surface shaded image (3D) using 1-123 iodophenylpentadecanoic acid (IPPA) acquired at different times. SPECT images of 180" were acquired using 32 frames, over 8 min following injection of 4 mCi at rest in 10 normal volunteers aged 415:8 years. The images were obtained at 4 min, 15 min and 25 rain post-injection. Images were evaluated independently by 4 observers using threshold settings at 40, 45, 50, 55, 60 and 65% for image quality. The 4 min images were considered of high quality using the 50% and 55% thresholds. The 15 min images were considered of high quality using the 55% threshold. None of the thresholds was satisfactory for the 25 min images.
In conclusion, the optimal threshold setting for 3D IPPA images was 55%. The rapid myocardial washout of IPPA may degrade the late 3D images. Thus, 3D imaging may not be practical to study initial and redistribution IPPA images.
S05-018
S05-020
THALLIUM-201 I M A G I N G W I T H P H A R M A C O L O G I C VASODILATION: COMPARISON BETWEEN DIPYRIDAMOLE AND ADENOSINE IN DETECTION OF CORONARY ARTERY DISEASE. A. Gagnon, R, Taillefer, R, Amyot, S. Turpin, R. Lambert., R. Essiambre, C. Pilon. Httel-Dieu de Montrtal, Canada. Both dipyridamole (DIP) and adenosine (ADE) are widely used as pharmacologic stressor with 201-TI (T1) imaging for detection of CAD. The purpose of this study was to directly compare DIP and ADE TI imaging in patients with proven CAD. Thirthy-three patients were submitted to two planar TI studies: one with DIP and the other with ADE. The time interval between the 2 studies varied from 2 to 7 days and the order was randomly assigned.Three standard planar views were obtained at 10 min. and 4 hours after injection of 3 mCi of T1. Administrationof DIP was as follows: 0.142 mg/kg/min during 4 min., slight exercise and injection. The infusion of ADE was as follows: 0.142 mg/kg/min, during 6 min. with injection of T1 after the third minute of infusion, Patients were asked to give their preference considering the number, severity, and duration of side effects on a scale from 0 (worst) to 5 (best). Reading was done by 2 experienced observers.The heart was divided into 3 segments/view.The change in systolic blood pressure was -11 • 11 mmHg for ADE and -6 • 9 for DIP (p=0.0006) and the change in heart rate was +18 • 8 bpm for ADE and +9 • 8 bpm for DIP (p=0.0001). Using ROI's, ischemic/normal waal ratios were determined: 0.79 • 0.06 for ADE and 0.82 • 0.08 for DIP (p=0.005). ADE detected 178 normal, 105 ischemic and 14 scar while DIP detected 204, 78 and 15 respectively. Patients prefered ADE (4.1 • 1.0 for ADE vs 3.5 • 1,5 for DIP, (p=0.04) mainly because of the short duration of side effects. In conclusion,this preliminary study shows that the use of ADE with 201-T1 imaging may have advantagesover DIP.
IDENTIFICATION OF OPTIMAL ACQUISITION AND RECONSTRUCTION PARAMETERS FOR 123-IPPA MYOCARDIAL METABOLISM IMAGING. A Gagnon, R, Taillefer, G. Bavaria, C, Benjamin, S. Lacombe. Httel-Dieu de Montrtal, Canada. 123- IPPA is being investigated in phase flI clinical trials as an imaging agent for the assessment of viable myocardium and ability to predict functional recovery after CABG, Unlike 201-Thallium, acquisition and reconstrution protocols are not well established for the identification of viable myocardium. The purpose of this study is to evaluate the optimal acquisition and reconstructionparameters for 123-IPPA. Thirty normal volunteers (19 M, 11 F) were administered a dose of 4.9 mCi (in a fasting state). Count statistics obtained during tomographic acquisitions with a dual head gamma camera equiped with two GAP collimators were determined at 4, 20 and 30 minutes after 123-IPPA injection, From the data gathered, maximum count activity over the heart was evaluated and washout curves were drawn. Acquisition times of 20 sec/frame at 4 and 20 min. and 30 sec./frame at 30 min. were arbitrarely used. Seventeen patients with known CAD (12 M, 5 F) were also imaged at 4 and 30 minutes using the same parameters as before. All raw data was evaluated for patient motion. Three different types of reconstruction filters were evaluated: Butterworth with cutoff at .3, .35 and .4 Nyquist with a power of 5. Two experienced observerswere asked to give a preference on the resulting images based on count homogeinity and overall image quality. Results: Myocardial uptake as an absolute percentage at 4, 20 and 30 minutes was 100%, 97% and 65% respectively in women and 100%, 99.5% and 68% for men. Average count density in the full SPECT study over the heart was 363, 356 and 362 kcounts at 4, 20 and 30 minutes, The overall preference from the observer was reconstructionwith the use of the Butterworthat ,35 Nyquist cutoff and power at 5. The washout analysis confirmed that 4 and 30 minutes were optimal times to initiate imaging for identification of viable myocardium.
$5