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Updated: May 12, 2026
In Vivo Quantitative Assessment of Myocardial Structure, Function, Perfusion and Viability Using Cardiac Micro-computed Tomography
Published on: February 16, 2016
Variation in quantitative myocardial perfusion due to arterial input selection
Andres F Vasquez1, Nils P Johnson, K Lance Gould
1Weatherhead PET Center for Preventing and Reversing Atherosclerosis, Division of Cardiology, Department of Medicine, University of Texas Medical School and Memorial Hermann Hospital, Houston, Texas 77030, USA.
Insights
Choosing the best arterial input site for myocardial perfusion PET imaging improves accuracy. Customizing the site for each patient reduces variability in quantifying coronary flow reserve, unlike fixed sites.
Area of Science:
- Nuclear cardiology
- Cardiovascular imaging
- Physiological assessment
Background:
- Positron emission tomography (PET) provides noninvasive functional measures of physiologic severity using absolute myocardial perfusion and hyperemic reserve.
- Quantitative myocardial perfusion by PET relies on arterial input (AI) time-concentration curves.
- AI imaging in PET can be affected by partial volume effects, motion, and spillover, leading to variations at different anatomical sites.
Purpose of the Study:
- To compare the clinical implications of quantifying myocardial perfusion using various potential arterial input sites.
- To evaluate the impact of different arterial input sites on myocardial perfusion and coronary flow reserve quantification.
- To determine the optimal customized arterial input site for individual patients.
Main Methods:
- Patients underwent rubidium-82 PET imaging for myocardial perfusion quantification.
- Various anatomical arterial input sites were assessed: high ascending aorta (HAo), basal ascending aorta (BAo), descending aorta (DA), left atrium (LA), and left ventricular (LV) cavity.
- Customized arterial input sites were selected after excluding those with spillover or misregistration, and average whole heart flows and ischemic burden were compared.
Main Results:
- The left atrium (LA) was the most frequently selected customized arterial input site (roughly 50%), followed by the high ascending aorta (HAo).
- Using non-customized sites resulted in artifactually lower AI values, leading to higher reported rest and stress absolute flows (e.g., 46-49% higher for LV).
- While the ratio of coronary flow reserve was less affected, its confidence interval widened significantly with non-customized sites (up to 31% for LV).
Conclusions:
- The optimal arterial input site for myocardial perfusion quantification varies individually.
- Selecting a customized arterial input site for each patient enhances the accuracy of myocardial perfusion and coronary flow reserve quantification.
- Customized site selection reduces variability compared to using a single, fixed anatomical site for arterial input.
Objectives:
This study compared the clinical implications of quantifying myocardial perfusion among different potential arterial input sites: the high (HAo) and basal (BAo) ascending aorta, descending aorta (DA), left atrium (LA), and left ventricular (LV) cavity.
Background:
Absolute myocardial perfusion and its hyperemic reserve imaged by positron emission tomography (PET) can serve as noninvasive functional measures of physiologic severity. Quantitative myocardial perfusion by PET depends on the time-concentration of vascular activity, called arterial input (AI). However, arterial activity imaged by PET can vary among sites due to partial volume effects from anatomic size, cardiac or respiratory motion out of fixed regions of interest, and spillover from neighboring vascular structures.
Methods:
Patients underwent cardiac rubidium-82 PET imaging with flow quantification using various anatomic AI. After excluding sites with overt spillover or misregistration, we selected the customized, highest AI among the BAo, HAo, DA, and LA. Average whole heart flows and percent of LV with substantial definite ischemia were compared among sites.
Results:
Of 288 cases, LA was selected in roughly half, with HAo in another quarter to one-third. Compared with using the customized AI, rest and stress absolute flow were higher by 5% to 10% for HAo, 14% for BAo, 19% to 23% for DA, and 46% to 49% for LV due to artifactually low AI values. The ratio of coronary flow reserve to its customized value was less affected, although its 95% confidence interval increased among AI locations: 7% for LA, 16% for HAo, 20% for BAo, 28% for DA, and 31% for LV.
Conclusions:
The best customized site for AI activity varies for each patient among potential anatomic locations. Selection of the customized arterial site for each individual improved quantification of myocardial perfusion and coronary flow reserve with less variability compared with utilizing a single, pre-selected, fixed anatomic site.
