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Myocardial fluorodeoxyglucose uptake with glucose-insulin-potassium infusion
JOURNALOF NUCLEARCARDIOLOGY Volume 2, Number 2, Part 2
Abstracts Tuesday afternoon, April 25, 1995
P15-313
P15-315
ANALYSIS O F T e - 9 9 m S E S T A M I B I P L A S M A CLEARANCE USING A 2-COMPARTMENT MODEL WS Richter, M Cordes, H Amthauer, H Eichstaedt, R Felix. Strahlenklinik, Klinikum Rudolf Virehow, Freie Universit~it Berlin, Germany
A COMPARISON OF MANUAL AND AUTOMATIC LEFT VENTRICLE AXIS ALIGNMENT IN SPECT
Aim of the study was the characterization of the sestamibi plasma clearance. In 16 patients (12m, 4w, age: 54.2_+8.5 years) blood samples were taken from 1 min after injection of 300-350 MBq Tc-99m sestamibi up to 150 min p.i. Sestamibi plasma clearance data were fitted using an open 2-compartment model (central compartment-plasma; disposition compartmentintracellular space). Results: Sestamibi clearance exhibited a bi-exponential behaviour. The half-lifes of the fast (FC) and slow (SC) components were 1.54 rain and 78.0 min, respectively. They accounted for 36.7% (FC) and 63% (SC) of the total sestamibi plasma clearance. The kinetic rate constants calculated from the compartment model were 0.28/min for the flux from plasma to the intracellular space and 0.022/min for the backflux from the cells to plasma. Conclusion: The data point to the existence of transmembrane shifts of sestamibi after its initial intracellular uptake up to 150 min p.i. These phenomena may be important in myocardial scintigraphy, especially when imaging is performed with substantial delay after injection.
MYOCARDIALPERFUSION IMAGING. G.W. Middleton. University Hospital of Wales, Cardiff, UK Accurate comparison of stress and rest SPECT myocardial perfusion images requires correct reorientation of both datasets orthogonal to the left ventricle (LV) axis. Manual and automatic LV axis alignment were compared in 30 patients imaged following stress and rest using 400MBq 99Tcm Tetrofosmin Reorientation angles, a horizontal angle (HA) on a transverse slice and a vertical angle (VA) on a sagittal slice, were obtained automatically using the minimum count angle on a LV angular profile (AP) and the slope of a linear regression of the minimum count positions on LV linear profiles (LP). Mean HA using manual alignment and mean VA using LP were significantly smaller (p<0.05) for both stress and rest. The variances were smallest for AP, but only significantly different (p<005) compared with LP The mean differences between stress and rest for HA and VA, were smaller (p<0.05) using AP. Automatic axis alignment, easily implemented using standard angular profile software, is more reproducible than either manual or LP alignment, particularly for the horizontal angle
P15-314
P15-316
MYOCARDIAL FLUORODEOXYGLUCOSE UPTAKE W I T H GLUCOSE-INSULIN-POTASSIUM INFUSION. M.Merhige, J.Gona, S.Husain, B.Murphy, P.Galantowitz, D.Wack, SUNYAB & VAMC PET Center, Buffalo, NY, U S A
CHOOSING THE APPROPRIATE TIME FOR TI-20I SPECT MYOCARDIAL ACQUISITION AFTER REINJECTION: 15 VS 60 MIN. D, Daou, M. Pueyo, F. Archambaud, R. Lebtahi, D. Leguillouzic, B.O. Helal. Bicetre Hospital, France.
Myocardial uptake of Fluorodeoxyglucose (FDG) is unpredictable after oral glucose loading (OGL). We measured FDG uptake during infusion of glucose (300 gm/L), insulin (60 U Reg Humulin/L) and potassium (40-60 mEq/L) (GIK) at 1.5 ml/kg/hr in 8 nondiabetic coronary patients. Plasma G and K were drawn at baseline and 15 min. intervals. FDG was given 30 min. after starting GIK and PET imaging performed. Peak myocardial and blood pool (M:B) activity was compared in i 0 0 G L patients. FDG activity was significantly more predictable after GIK than OGL: M:B for GIK= 6.8 +/- 2.0 vs OGL = 9.7 +/-7.2 (p<.01) K fell in all GIK patients; 2 required supplemental K. Conclusions: GIK is practical and results in predictably high myocardial FDG uptake. K should be monitored when insulin is used in PET myocardial viability studies.
T1-201 reinjection (R) increase the sensitivity for defect (D) reversibility as compared to redistribution. The most appropriate time for R and acquisition (A) remains unsolved. We compared in 11 pts the SPECT image quality at 15rain (A15), 60min (A60) and 24h after T1-201 R. The R was done 165min after stress. Were visually compared by two independent observers (O1, 02) the impact on D size and intensity and on the final SPECT report. The reconstructed heart image was divided into 13 segments (S), each scored as: 0:normal, l:mild, 2:moderate, 3:severe or 4:absent T1-201 uptake. There were NS difference between respectively A 15 and A60 on: 1) image quality evaluated by heart to pulmonary (2,5 +0,4 vs 2,5+0,3) and to abdominal activity ratio (1,4+0,3 vs 1,4+0,3) 2) the number of all segment defect (SD) (O1: 2,2+_2,4 vs 2,3+_1,9; 02:2,6+_2,5 vs 2,5+_2) 3) the number of SD improving their score by >1 (O1:2,2+_2 vs 2,5+_2,2; 02:2,5+_2,2 vs 2,9_+2,5) or >2 scores (O1: 1,5+1,8 vs 1,6+1,6; 02:1,3+_1,5 vs 1,4+_1,6) 4) final SPECT report did not differ whether considering A15 or A60. We conclude that A 15 as compared to A60 appears to have similar SPECT image quality and diagnostic value.
$79
Abstracts Tuesday afternoon, April 25, 1995
P15-313
P15-315
ANALYSIS O F T e - 9 9 m S E S T A M I B I P L A S M A CLEARANCE USING A 2-COMPARTMENT MODEL WS Richter, M Cordes, H Amthauer, H Eichstaedt, R Felix. Strahlenklinik, Klinikum Rudolf Virehow, Freie Universit~it Berlin, Germany
A COMPARISON OF MANUAL AND AUTOMATIC LEFT VENTRICLE AXIS ALIGNMENT IN SPECT
Aim of the study was the characterization of the sestamibi plasma clearance. In 16 patients (12m, 4w, age: 54.2_+8.5 years) blood samples were taken from 1 min after injection of 300-350 MBq Tc-99m sestamibi up to 150 min p.i. Sestamibi plasma clearance data were fitted using an open 2-compartment model (central compartment-plasma; disposition compartmentintracellular space). Results: Sestamibi clearance exhibited a bi-exponential behaviour. The half-lifes of the fast (FC) and slow (SC) components were 1.54 rain and 78.0 min, respectively. They accounted for 36.7% (FC) and 63% (SC) of the total sestamibi plasma clearance. The kinetic rate constants calculated from the compartment model were 0.28/min for the flux from plasma to the intracellular space and 0.022/min for the backflux from the cells to plasma. Conclusion: The data point to the existence of transmembrane shifts of sestamibi after its initial intracellular uptake up to 150 min p.i. These phenomena may be important in myocardial scintigraphy, especially when imaging is performed with substantial delay after injection.
MYOCARDIALPERFUSION IMAGING. G.W. Middleton. University Hospital of Wales, Cardiff, UK Accurate comparison of stress and rest SPECT myocardial perfusion images requires correct reorientation of both datasets orthogonal to the left ventricle (LV) axis. Manual and automatic LV axis alignment were compared in 30 patients imaged following stress and rest using 400MBq 99Tcm Tetrofosmin Reorientation angles, a horizontal angle (HA) on a transverse slice and a vertical angle (VA) on a sagittal slice, were obtained automatically using the minimum count angle on a LV angular profile (AP) and the slope of a linear regression of the minimum count positions on LV linear profiles (LP). Mean HA using manual alignment and mean VA using LP were significantly smaller (p<0.05) for both stress and rest. The variances were smallest for AP, but only significantly different (p<005) compared with LP The mean differences between stress and rest for HA and VA, were smaller (p<0.05) using AP. Automatic axis alignment, easily implemented using standard angular profile software, is more reproducible than either manual or LP alignment, particularly for the horizontal angle
P15-314
P15-316
MYOCARDIAL FLUORODEOXYGLUCOSE UPTAKE W I T H GLUCOSE-INSULIN-POTASSIUM INFUSION. M.Merhige, J.Gona, S.Husain, B.Murphy, P.Galantowitz, D.Wack, SUNYAB & VAMC PET Center, Buffalo, NY, U S A
CHOOSING THE APPROPRIATE TIME FOR TI-20I SPECT MYOCARDIAL ACQUISITION AFTER REINJECTION: 15 VS 60 MIN. D, Daou, M. Pueyo, F. Archambaud, R. Lebtahi, D. Leguillouzic, B.O. Helal. Bicetre Hospital, France.
Myocardial uptake of Fluorodeoxyglucose (FDG) is unpredictable after oral glucose loading (OGL). We measured FDG uptake during infusion of glucose (300 gm/L), insulin (60 U Reg Humulin/L) and potassium (40-60 mEq/L) (GIK) at 1.5 ml/kg/hr in 8 nondiabetic coronary patients. Plasma G and K were drawn at baseline and 15 min. intervals. FDG was given 30 min. after starting GIK and PET imaging performed. Peak myocardial and blood pool (M:B) activity was compared in i 0 0 G L patients. FDG activity was significantly more predictable after GIK than OGL: M:B for GIK= 6.8 +/- 2.0 vs OGL = 9.7 +/-7.2 (p<.01) K fell in all GIK patients; 2 required supplemental K. Conclusions: GIK is practical and results in predictably high myocardial FDG uptake. K should be monitored when insulin is used in PET myocardial viability studies.
T1-201 reinjection (R) increase the sensitivity for defect (D) reversibility as compared to redistribution. The most appropriate time for R and acquisition (A) remains unsolved. We compared in 11 pts the SPECT image quality at 15rain (A15), 60min (A60) and 24h after T1-201 R. The R was done 165min after stress. Were visually compared by two independent observers (O1, 02) the impact on D size and intensity and on the final SPECT report. The reconstructed heart image was divided into 13 segments (S), each scored as: 0:normal, l:mild, 2:moderate, 3:severe or 4:absent T1-201 uptake. There were NS difference between respectively A 15 and A60 on: 1) image quality evaluated by heart to pulmonary (2,5 +0,4 vs 2,5+0,3) and to abdominal activity ratio (1,4+0,3 vs 1,4+0,3) 2) the number of all segment defect (SD) (O1: 2,2+_2,4 vs 2,3+_1,9; 02:2,6+_2,5 vs 2,5+_2) 3) the number of SD improving their score by >1 (O1:2,2+_2 vs 2,5+_2,2; 02:2,5+_2,2 vs 2,9_+2,5) or >2 scores (O1: 1,5+1,8 vs 1,6+1,6; 02:1,3+_1,5 vs 1,4+_1,6) 4) final SPECT report did not differ whether considering A15 or A60. We conclude that A 15 as compared to A60 appears to have similar SPECT image quality and diagnostic value.
$79