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pFAST program for gated SPECT imaging : 3-dimensional displays of regional wall motion and perfusion and wall thickness assessment
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Abstracts Wednesday afternoon, April 21, 1999
54.44 THREE DIMENSIONAL GATED BLOOD POOL SPECT IN PATIENTS WITH SEVERE CORONARY ARTERY DISEASE. M. W. Groch, R. C. Marshall, W. D. Erwin, R.C. Hendel, and S. M. Spies. Northwestern University Medical School, Chicago, IL Crated blood SPECI" (GBPS), inherently three dimensional (3-D), allows assessment of regional wall motion without chamber overlap and may facilitate assessment of right ventricular function from equilibrium sttu:lies. Methods: GBPS studies were acquired in 5 normals and 10 patients with severe coronary artery disease (>85% stenosis), without documented myocardial infarction, and processed using several 3-D methods. Regional LV function was assessed by calculation of regional ejection fraction (REF) from time-activity curves. Three models were used: a fixed center of mass point at end diastole (COM), a floating center of mass in the 16 gated frames, ~ d a long axis model of the heart (Slager method modified to 3-D). Four, 8, 12 and t8 segmental REFs were analyzed, and a lower limit of normal REF for each of the segments was determined from the normal volunteers. Segmental GBPS function was correlated against coronary artery disease (CAD) assessed by coronary arteriography cineangiography, in the ten patients. Results: Using a lower limit of normal REF - 2 o for the LV, the sensitivity (SENS) ranged from 82-100% and specificity (SPEC) from 75-96%, for all models when compared to coronary arteriogmphy. The highest accuracy was provided by the floating COM model using 8 segments, (SENS=100%/SPEC=92%). The long axis model yielded the poorest results. Global RVEF was successfully computed for the 10 patients (mean RVEF=62.5%). Conclusion: Evaluation of RV function using GBPS is possible. Quantitative gated blood pool SPECT appears to be a sensitive method for assessing LV wall motion defects in myocardia perfused by severely diseased coronary arteries.
W E D N E S D A Y P M A P R I L
Journal of Nuclear Cardiology January/February 1999, Part 2
54.46
pFAST PROGRAM FOR GATED SPECT IMAGING : 3DIMENSIONAL DISPLAYS OF REGIONAL WALL MOTION AND PERFUSION AND WALL THICKNESS ASSESSMENT. Y. Katagiri,Y. Odawara, M. Kuroda, K.Sakuta, T. Nakata, M. Eguchi,and K. Shimamoto. SapporoMedicalUniversitySchoolof Medicine, Sapporo,Japan. Although myocardial gated SPECT technique enables to simultaneously assess myocardial perfusion and function, there has not been a established method to use and display the the 3-dimensional data. We recently developed an automated quantitative method for perfusion and function assessment by gated SPECT (pFAST program). In the new version, in addition to quantitative assessment of global and regional cardiac functions, simultaneous 3-dimensional displays of regional wall motion and perfusion were possible. Furthermore, the method of regional wall thickness of left ventricle at end-diastole and end-systole was established by our phantom experiment and the results were compared with those by 2-dimensional echocardiography. There were close correlations in wall-thickness at end-diastole and end-systole between between 2-dimensional echocardiography and pFAST program: r=0.870, y=O.886x+1.12, P
54.45
54.47
LEFT VENTRICULAR EJECTION FRACTION ASSESSED USING IMAGE INVERSION ANALYSIS FROM 99TCM-TETROFOSMIN GATED SPECT STUDIES, V A L I D A T E D W I T H M U L T I - G A T E D B L O O D POOL. Ian Jones, Derby City General Hospital, Derby, UK.
VALIDATION OF AUTOMATIC FAST GATED SPECT OBTAINED IN ONE SINGLE HEAD GAMMACAMARA .D Victoria, E Alexanderson,, A. Puente, J Apolo, E Becker, T Colmenares, P Lemus, D Bialostozky. Instituto Nacional de Cardiologia "Ignacio Chavez".Mexico City, MEXICO. Gated SPECT allow us to study simultaneously myocardial perfusion during stress and ventricular function at rest. We get from the technique left ventricle ejection fraction, wall motion, and wall thickening information. The average of time acquisition for gated SPECT is 40 seconds. The purpose of the study is to evaluate if the information obtained from Gated SPECT is reliable with a faster acquisition (18 seconds). METHOD : We studied 40 patients with one day rest-stress Tc -99m sestamibi protocol. Stress images were gating with the normal parameters. After normal acquisition time was completed, a new faster acquisition was performed (18 seconds by stop, 32 stops), using one single head Siemens Orbiter camera. Processing was performed using an ICON computer system.RESULTS: Perfusion result, wall motion and wall thickening were difficult to evaluate with the fast gated because of low counts.
This study reports the evaluation and implementation Of a semi-automatic program for qualitatively measuring LVEFs, from gated 99Tcm-tetrofosmin myocardial SPECT. The algorithm operates in two-dimensional space and uses the image inverted mid-ventricular V L A and H L A slices. Automatic edge registration of the endocardial surfaces is on all gating intervals of the cardiac cycle, deriving the relative L V cavity "counts" and calculating the global ejection from the E D and ES counts. Edge detection of the L V was successful in 18/18 of the studies. The calculated 8-interval gSPECT and M U G A L V E F s correlated well: averaged VLAIHLA r= 0.90 P<0.001, H L A r= 0.88 P<0.001, V L A r=0.88 P<0.001 However, the calculated limits of agreement between the average gSPECT and M U G A data suggest wide variability with an individual patient result varying by up to 14 percent. Despite potential problems in the automatic image inversion algorithm, the method is rapid and has a high correlation with M U G A . Caution is advised in using the results interchangeably for clinical assessment.
100 GATEDNORMAL 50 0
p
CONCLUSIONS: There is a good correlation between LVEF obtained from Gated SPECT with 40 seconds and from 18 seconds. Correlation is good for normal and abnormal cases. Wall motion and wall thickening analysis is difficult to do with fast gated.
Abstracts Wednesday afternoon, April 21, 1999
54.44 THREE DIMENSIONAL GATED BLOOD POOL SPECT IN PATIENTS WITH SEVERE CORONARY ARTERY DISEASE. M. W. Groch, R. C. Marshall, W. D. Erwin, R.C. Hendel, and S. M. Spies. Northwestern University Medical School, Chicago, IL Crated blood SPECI" (GBPS), inherently three dimensional (3-D), allows assessment of regional wall motion without chamber overlap and may facilitate assessment of right ventricular function from equilibrium sttu:lies. Methods: GBPS studies were acquired in 5 normals and 10 patients with severe coronary artery disease (>85% stenosis), without documented myocardial infarction, and processed using several 3-D methods. Regional LV function was assessed by calculation of regional ejection fraction (REF) from time-activity curves. Three models were used: a fixed center of mass point at end diastole (COM), a floating center of mass in the 16 gated frames, ~ d a long axis model of the heart (Slager method modified to 3-D). Four, 8, 12 and t8 segmental REFs were analyzed, and a lower limit of normal REF for each of the segments was determined from the normal volunteers. Segmental GBPS function was correlated against coronary artery disease (CAD) assessed by coronary arteriography cineangiography, in the ten patients. Results: Using a lower limit of normal REF - 2 o for the LV, the sensitivity (SENS) ranged from 82-100% and specificity (SPEC) from 75-96%, for all models when compared to coronary arteriogmphy. The highest accuracy was provided by the floating COM model using 8 segments, (SENS=100%/SPEC=92%). The long axis model yielded the poorest results. Global RVEF was successfully computed for the 10 patients (mean RVEF=62.5%). Conclusion: Evaluation of RV function using GBPS is possible. Quantitative gated blood pool SPECT appears to be a sensitive method for assessing LV wall motion defects in myocardia perfused by severely diseased coronary arteries.
W E D N E S D A Y P M A P R I L
Journal of Nuclear Cardiology January/February 1999, Part 2
54.46
pFAST PROGRAM FOR GATED SPECT IMAGING : 3DIMENSIONAL DISPLAYS OF REGIONAL WALL MOTION AND PERFUSION AND WALL THICKNESS ASSESSMENT. Y. Katagiri,Y. Odawara, M. Kuroda, K.Sakuta, T. Nakata, M. Eguchi,and K. Shimamoto. SapporoMedicalUniversitySchoolof Medicine, Sapporo,Japan. Although myocardial gated SPECT technique enables to simultaneously assess myocardial perfusion and function, there has not been a established method to use and display the the 3-dimensional data. We recently developed an automated quantitative method for perfusion and function assessment by gated SPECT (pFAST program). In the new version, in addition to quantitative assessment of global and regional cardiac functions, simultaneous 3-dimensional displays of regional wall motion and perfusion were possible. Furthermore, the method of regional wall thickness of left ventricle at end-diastole and end-systole was established by our phantom experiment and the results were compared with those by 2-dimensional echocardiography. There were close correlations in wall-thickness at end-diastole and end-systole between between 2-dimensional echocardiography and pFAST program: r=0.870, y=O.886x+1.12, P
54.45
54.47
LEFT VENTRICULAR EJECTION FRACTION ASSESSED USING IMAGE INVERSION ANALYSIS FROM 99TCM-TETROFOSMIN GATED SPECT STUDIES, V A L I D A T E D W I T H M U L T I - G A T E D B L O O D POOL. Ian Jones, Derby City General Hospital, Derby, UK.
VALIDATION OF AUTOMATIC FAST GATED SPECT OBTAINED IN ONE SINGLE HEAD GAMMACAMARA .D Victoria, E Alexanderson,, A. Puente, J Apolo, E Becker, T Colmenares, P Lemus, D Bialostozky. Instituto Nacional de Cardiologia "Ignacio Chavez".Mexico City, MEXICO. Gated SPECT allow us to study simultaneously myocardial perfusion during stress and ventricular function at rest. We get from the technique left ventricle ejection fraction, wall motion, and wall thickening information. The average of time acquisition for gated SPECT is 40 seconds. The purpose of the study is to evaluate if the information obtained from Gated SPECT is reliable with a faster acquisition (18 seconds). METHOD : We studied 40 patients with one day rest-stress Tc -99m sestamibi protocol. Stress images were gating with the normal parameters. After normal acquisition time was completed, a new faster acquisition was performed (18 seconds by stop, 32 stops), using one single head Siemens Orbiter camera. Processing was performed using an ICON computer system.RESULTS: Perfusion result, wall motion and wall thickening were difficult to evaluate with the fast gated because of low counts.
This study reports the evaluation and implementation Of a semi-automatic program for qualitatively measuring LVEFs, from gated 99Tcm-tetrofosmin myocardial SPECT. The algorithm operates in two-dimensional space and uses the image inverted mid-ventricular V L A and H L A slices. Automatic edge registration of the endocardial surfaces is on all gating intervals of the cardiac cycle, deriving the relative L V cavity "counts" and calculating the global ejection from the E D and ES counts. Edge detection of the L V was successful in 18/18 of the studies. The calculated 8-interval gSPECT and M U G A L V E F s correlated well: averaged VLAIHLA r= 0.90 P<0.001, H L A r= 0.88 P<0.001, V L A r=0.88 P<0.001 However, the calculated limits of agreement between the average gSPECT and M U G A data suggest wide variability with an individual patient result varying by up to 14 percent. Despite potential problems in the automatic image inversion algorithm, the method is rapid and has a high correlation with M U G A . Caution is advised in using the results interchangeably for clinical assessment.
100 GATEDNORMAL 50 0
p
CONCLUSIONS: There is a good correlation between LVEF obtained from Gated SPECT with 40 seconds and from 18 seconds. Correlation is good for normal and abnormal cases. Wall motion and wall thickening analysis is difficult to do with fast gated.