Comparison of Quantitative MRI Perfusion Methods With Quantitative PET Perfusion Imaging

Study Overview
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Brief Summary
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This work seeks to develop, evaluate and use new MRI methods for non-invasive quantitative assessment of myocardial perfusion and perfusion reserve (MPR), and to compare with quantitative PET imaging.

Detailed Description
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This project aims to determine the validity of quantitative MRI perfusion methods by comparison with quantitative PET imaging. First pass dynamic contrast enhanced MRI scans will be performed at rest and during hyperemia caused by either adenosine infusion or regadenoson. After custom reconstruction and post-processing the data will be fit to a compartment model and quantitative perfusion and MPR values obtained. On another day, the subjects will have quantitative PET imaging with O-15 labeled radioactive water. This will be done at rest and hyperemia caused by either adenosine or regadenoson. A low dose CT scan will be acquired to perform attenuation correction of the PET images. The images will be reconstructed and processed as reported in the literature to provide reference standard perfusion and MPR values. These values will be compared with those obtained by MRI.

Official Title
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Comparison of New MRI Methods for Quantitative Assessment of Myocardial Perfusion With Quantitative PET Perfusion Imaging

Conditions
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MRI Scans

Intervention / Treatment
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* Drug: Adenosine
* Drug: Regadenoson
* Drug: O-15 labeled radioactive water
* Device: MRI
* Device: PET Imaging


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: All participants will be over the age of 18 and able to provide consent Both healthy and subjects with cardiac disease (including atrial fibrillation but not required) will be recruited. Exclusion Criteria: Critically ill patients, patients on ventilators, patients with unstable angina or with hypotension, asthmatics, and other patients whose medical care or safety may be at risk from undergoing an MRI examination will be excluded. Patients with claustrophobia will also be excluded from the study if this cannot be controlled with standard methods (valium or benadryl). Patients with contraindication to MRI (pacemaker, metal implants, or certain types of heart valves), pregnant patients, minors, mentally disabled patients and prisoners will be excluded from this study. (All criteria apply to patients and normal volunteers). Gadolinium nephrotoxicity will be addressed by having patients with abnormal kidney function (GFR<30) excluded from the study due to the (very small) risk associated with gadolinium contrast agents. This threshold may be modified, depending on practices determined by the Radiology Department and the IRB. Patients with a known allergy or contraindication to Adenosine and/or Regadenoson will be excluded from stress (hyperemia) cohorts. All participants that will receive a stress agent will refrain from consuming caffeine for at least 12 hours prior to each study

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Health Services Research
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: MRI perfusion vs. PET Imaging perfusion<br>Adenosine Regadenoson O-15 labeled radioactive water MRI PET Imaging | Drug: Adenosine<br>* Adenosine: 0.14mg/kg/min for 6 min. IV injection for MRI perfusion<br>* Other names: Adenocard;Drug: Regadenoson<br>* Regadenoson: 0.4mg in 5ml, given as a rapid (10 seconds) IV injection for MRI perfusion.<br>* Other names: Lexiscan;Drug: O-15 labeled radioactive water<br>* O-15 labeled radioactive water: Up to 50mCi IV injection at rest and again at hyperemia for PET Imaging<br>* Other names: O-15 water;Device: MRI<br>* Pass dynamic contrast enhanced MRI scans will be performed at rest and during hyperemia caused by either adenosine infusion or regadenoson<br>Device: PET Imaging<br>* Quantitative PET imaging with O-15 labeled radioactive water will be given at a different day.<br>* Other names: Positron Emission Tomography Imaging;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Myocardial perfusion values from MRI | Myocardial perfusion in segments and coronary territories will be computed in ml/min/g from the dynamic MRI data. The perfusion values will be compared to PET data to determine how similar the values are. | The scan will take  1-2 hours. The MRI will be done within 2 months of the PET scan. | 
| Myocardial perfusion values from PET | Myocardial perfusion in segments and coronary territories will be computed in ml/min/g from the dynamic PET data. The perfusion values will be compared to MRI data to determine how similar the values are. | The scan will take  1-2 hours. The PET scan will be done within 2 months of the MRI. |