Acquisition Parameters :Acquisition Parameters Guillermo J. Villalonga NMT 2534 Group # 4


Objectives :Objectives To learn about the planes of the heart Short axis Vertical long axis Horizontal long axis Compare different acquisition parameters Gated SPECT Whole body Static Spect


180° Study of the Heart :180° Study of the Heart


Orientations of the Heart :Orientations of the Heart


Orientations of the Heart :Orientations of the Heart


Case Study :Case Study Patient History Patient is a 59 year old female who presented with a single episode of chest pain, dizziness, diaphoresis, and lightheadedness. The patient had no prior history of any previous episodes of this type. There was no prior history of chest pain on exertion. Height: 65 inches; weight: 210 lbs.


Case Study :Case Study Imaging Procedure The One Day Cardiolite Protocol was used, and rest imaging was performed first. Imaging was done on a GE Millennium Dual Head Camera with 36 stops/detector, 180 degrees


Slide 8:Acquisition Parameters: Target heart rate (85% of maximum heart rate): 136 bpm. Maximal heart rate achieved on treadmill: 147 bpm.


GE Millennium Dual Head Camera :GE Millennium Dual Head Camera Imaging AnalysisBoth the rest and stress studies were count rich. Stress counts within a circular ROI over the heart were 13,228; stress maximum pixel value was 134. Rest counts were 9881; rest maximum pixel value was 85. The guideline for an adequate count study for this many projection images is to have 2500 or more counts within a tight circular ROI around the epicardial edge of the myocardium on an anterior view. The maximum pixel value within this ROI should be at least 50 counts. These values can be automatically determined in the MyoSPECT protocol


Slide 10:Both the rest and stress projection images show some attenuation. The slices were reconstructed using the Cardiac SPECT Protocol. Both the rest and stress short axis images show a decrease of counts in the anterior wall. The counts in the anterior wall of the vertical long axis images are also diminished. Note: Reconstruction and reformatting could have been done by QGS/QPS, Cardiac SPECT, or the ECToolbox (they all use the same format) or by the MyoSPECT protocol


Slide 11:The data was first processed with the CEqual option of the EC Toolbox. The fixed nature of the anterior defect is clearly seen in the CEqual plots. However, the standard deviation plots show that these defects are not very severe, only two to three SD below normal


Slide 12:The beating slices for this patient thicken and brighten normally at systole. When a perfusion defect is not visible consistently at both diastole and systole, it is more likely to be an attenuation artifact than a true defect


Slide 13:The data was then processed with QGS to give additional functional and 3D information. QGS will use as input the slices created in the ECToolbox. There is no need to reconstruct the data in QGS. The left ventricular function appeared normal The ES Perfusion Map shows good perfusion in the anterior wall at end systole. Normal function would strongly favor breast attenuation as a cause of the anterior fixed defect


Slide 14:MyoSPECT was then used for additional information. Since the slices were already created, there was no need to reconstruct them in MyoSPECT. The 3D surfaces visually reinforce the artifactual nature of the defect since they show no defect in the anterior wall.The beating plot created from the stress gated images also shows that the defect is not present at end-systole


Slide 15:EKG Results: There was adequate and appropriate blood pressure response to exercise. There weren't any exercise induced ischemic repolarization changes or any significant arrhythmias.


Slide 16:Findings: There wasn’t any evidence of stress induced myocardial ischemia. The left ventricular function was normal. There was mild diminished perfusion in the anterior wall consistent with breast attenuation.


Heart Study- Stress & RestConventional Protocol with 201Ti :Heart Study- Stress & RestConventional Protocol with 201Ti


Thyroid Cancer Scan :Thyroid Cancer Scan


Bone SPECT :Bone SPECT


Bone Scan :Bone Scan


Conclusion :Conclusion Acquisition parameters help us to set standards in our quality of work, and help us to reduce radiation exposure to patients by minimizing time of the study


References :References http://www.gehealthcare.com/usen/fun_img/nmedicine/myosight/products/casestudy2.html Essentials of Nuclear Medicine Imaging. Fifth Edition. Fred a. Mettler, Jr. Milton J. Guiberteau South Miami Hospital


Questions :Questions 1. The energy window for 99mTc is: a) 345 KeV b) 140 KeV c) 81 KeV b) 140 KeV


Slide 24:2. What type of collimator is used for a Heart study? a) Low energy b) Medium energy c) High energy a) Low energy


Slide 25:3. What type of orbit is used for a thyroid study? a) Circular b) Non circular c) Body contour b) Non circular


Slide 26:4. What size of matrix is used for a bone scan? a) 64 x 64 b) 128 x 128 c) 256 x 256 c) 256 x 256


Slide 27:T/F 5. The window size used for a bone scan is 30 % window. False