Modules 17b - Myocardial Blood Flow with 82Rb PET Imaging Case Reviews-Myocardial Blood Flow with 82Rb PET Imaging Case Reviews (Presentation)

Video Transcription
Video Summary
In this video, Mouaz Mallah, the Director of Cardiovascular PET at Houston Methodist DeBakey Heart and Vascular Institute, discusses several cases related to cardio-blood flow with rubidium perfusion imaging. He acknowledges Dr. Talal Nabilsi's contribution to the discussion. The video aims to describe the steps for quality control in blood flow data, explain the findings from rubidium PET images, and show the effective use of myocardial blood flow in patient management.<br /><br />The first case involves an 81-year-old woman with a history of hypertension and dyslipidemia who was referred for chest pain evaluation. The patient's images show normal perfusion imaging without evidence of perfusion defects. Her resting ejection fraction was 67%, which increased to 73% with vasodilator stress. The patient underwent coronary angiography, which revealed no evidence of obstructive disease, confirming the high negative predictive value of normal blood flow in ruling out obstructive disease.<br /><br />The second case involves a 58-year-old woman with moderate aortic stenosis and chest pain. Her perfusion imaging shows no perfusion defects, but an increase in cavity size with stress, likely related to aortic stenosis. Her flow numbers indicate elevated resting flow, likely due to outflow tract obstruction from aortic stenosis, and a lack of significant increase in stress flow. Coronary angiography confirms non-obstructive disease and the progression of aortic stenosis.<br /><br />The third case involves a 60-year-old man with hypertension, dyslipidemia, and obstructive sleep apnea, referred for evaluation of dyspnea. The perfusion imaging shows a mild to moderate defect in the inferior wall, indicating ischemia. The patient's resting flow numbers are normal globally, but there is a reduction in flow in the area of the perfusion defect. This case highlights the use of myocardial blood flow in identifying patients with low likelihood of obstructive coronary disease, even in the presence of high calcium scores.<br /><br />The fourth case involves a 74-year-old man with end-stage renal disease on hemodialysis and elevated troponin levels. The rest perfusion imaging shows poor counts and lack of uptake in the myocardium due to pooling of rubidium in the left subclavian and superior vena cava. The resting flow numbers are inaccurate due to issues related to the patient's left brachiocephalic vein stenosis. This case emphasizes the importance of checking wider field fusion images to ensure proper injection quality and accurate flow measurements.<br /><br />The fifth case involves a 65-year-old man with a history of moderate lesions in the right coronary artery and left anterior descending artery, referred for chest pain evaluation. The images show no clear perfusion defects, but the resting flow numbers are elevated. However, upon closer examination, it is revealed that the resting flow numbers are inaccurate due to misplacement of the tracker used to define the ventricle and blood pool. Repositioning the tracker corrects the abnormality, and the patient's flow measurements indicate normal perfusion.<br /><br />The final case involves a 72-year-old woman with hypertension and hyperlipidemia referred for preoperative evaluation. The perfusion imaging shows normal perfusion, but the resting flow numbers are very high. It is discovered that the resting flow numbers were inaccurate due to misplacement of the tracker. Repositioning the tracker corrects the abnormality, and the patient's flow measurements indicate normal perfusion.<br /><br />In conclusion, these cases demonstrate the importance of proper quality control and accurate measurements in blood flow imaging. Normal perfusion, more than 5% ejection fraction augmentation with stress, normal flow reserve, and absence of very low calcium score are markers of low-risk scans. Misregistration of emission and transmission scans can result in perfusion artifacts, and it is crucial to check for fusion images to identify uncommon misregistration artifacts. Quality assurance of dynamic images is essential to ensure accurate flow measurements.
Keywords
Cardiovascular PET
rubidium perfusion imaging
quality control
myocardial blood flow
obstructive disease
aortic stenosis
perfusion defects