Diagnostic Accuracy of Cardiac CT Perfusion Compared to PET Imaging
| Status: | Active, not recruiting |
|---|---|
| Conditions: | Angina, Peripheral Vascular Disease, Cardiology |
| Therapuetic Areas: | Cardiology / Vascular Diseases |
| Healthy: | No |
| Age Range: | 20 - 80 |
| Updated: | 5/4/2018 |
| Start Date: | September 2011 |
| End Date: | December 31, 2019 |
This purpose of this research project is to test the diagnostic accuracy (i.e., sensitivity,
specificity, positive and negative predictive value, and receiver operator curve area under
the curve) of cardiac computed tomography (CT) perfusion as compared to the best non-invasive
test of blood flow -- cardiac positron emission transmission (PET) perfusion imaging.
The primary outcome of the study is to determine the CT perfusion technique with the highest
overall diagnostic accuracy measured by the highest area under the receiver operator curve.
The investigators will test 4 different CT perfusion techniques. (A) Qualitative, visual
inspection of the contrast-enhanced CT images (B) Enhanced voxel distribution analysis (C)
Rate of myocardial contrast enhancement analysis (D) Quantitative heart blood flow using a
distributed 2-region analysis
A second aim is to reduce the radiation dose needed to maintain CT perfusion diagnostic
accuracy. Using the CT perfusion data, the investigators will model the minimal number of
cardiac cycle radiation exposures needed to keep the diagnostic accuracy similar to the full
data set.
A third aim is to test the incremental diagnostic accuracy of CT angiography plus CT
perfusion to identify regions of low blood flow as compared to PET perfusion alone.
specificity, positive and negative predictive value, and receiver operator curve area under
the curve) of cardiac computed tomography (CT) perfusion as compared to the best non-invasive
test of blood flow -- cardiac positron emission transmission (PET) perfusion imaging.
The primary outcome of the study is to determine the CT perfusion technique with the highest
overall diagnostic accuracy measured by the highest area under the receiver operator curve.
The investigators will test 4 different CT perfusion techniques. (A) Qualitative, visual
inspection of the contrast-enhanced CT images (B) Enhanced voxel distribution analysis (C)
Rate of myocardial contrast enhancement analysis (D) Quantitative heart blood flow using a
distributed 2-region analysis
A second aim is to reduce the radiation dose needed to maintain CT perfusion diagnostic
accuracy. Using the CT perfusion data, the investigators will model the minimal number of
cardiac cycle radiation exposures needed to keep the diagnostic accuracy similar to the full
data set.
A third aim is to test the incremental diagnostic accuracy of CT angiography plus CT
perfusion to identify regions of low blood flow as compared to PET perfusion alone.
Chest pain and other symptoms can occur as a result of blockages in the arteries that supply
the heart; these arteries are called the "coronary arteries". Blockages in the coronary
arteries may decrease blood flow and oxygen delivery to the heart muscle, causing chest pain
or other "anginal" symptoms. Coronary angiography is a commonly used test to visualize
coronary artery disease or blockages but may not provide all the answers physicians need to
assess patients with symptoms like chest pain. Two options for coronary angiography exist,
invasive angiography and cardiac computed tomography angiography (CCTA). CCTA is completed by
injecting contrast into a peripheral vein (not an artery) and then imaging when the coronary
arteries fill with contrast. The imaged coronary arteries may be blocked partially,
completely or not at all. While a blockage that occludes greater than 70% of an artery is
highly correlated with chest pain or other anginal symptoms, occlusions of 40% or more may or
may not decrease heart blood flow. Often multiple imaging studies are needed to evaluate
whether blood flow is decreased in the setting of partial coronary artery blockages including
non-invasive heart imaging to assess heart blood flow.
One type of nuclear imaging is termed positron emission tomography (PET). In order to
differentiate blockages that have poor heart perfusion with activity, nuclear PET images are
taken at rest, when flow should be normal, and then repeated after the investigators "stress"
the heart with medications. If blood flow is decreased during stress, a "defect" on the PET
images is seen.
An alternative, non-invasive technique to test for heart blood flow/perfusion to to measure
heart blood flow as computed tomography (CT) contrast goes in and comes out. Preliminary
studies in animals and humans to assess heart blood flow/perfusion using contrast-enhanced
cardiac CT have been promising, but further work is needed. Combining CCTA with CT blood
flow/perfusion measurements in the same setting could lead to a single, accurate diagnostic
test that measures coronary artery blockage as well as blood flow.
One limitation of CT imaging is the amount of radiation that can be given. The CCTA radiation
dose is currently less than both nuclear PET imaging and invasive coronary angiography.
However, if CT blood flow imaging is added to routine CCTA to assess heart perfusion and
coronary blockages in one test, the radiation dose may be higher.
The primary purpose of this research project is to test the diagnostic accuracy of various
cardiac CT perfusion techniques as compared to the best non-invasive test of blood flow,
cardiac PET perfusion imaging. The investigators goal is to use the least amount of radiation
to achieve a high diagnostic accuracy for CCTA as well as CT blood flow/perfusion. The
investigators goal is to have CT heart blood flow/perfusion radiation doses that are the same
or less than nuclear blood flow imaging. The investigators have estimated that they need as
few as 4 low radiation dose images of the heart to allow accurate heart blood flow
measurement.
the heart; these arteries are called the "coronary arteries". Blockages in the coronary
arteries may decrease blood flow and oxygen delivery to the heart muscle, causing chest pain
or other "anginal" symptoms. Coronary angiography is a commonly used test to visualize
coronary artery disease or blockages but may not provide all the answers physicians need to
assess patients with symptoms like chest pain. Two options for coronary angiography exist,
invasive angiography and cardiac computed tomography angiography (CCTA). CCTA is completed by
injecting contrast into a peripheral vein (not an artery) and then imaging when the coronary
arteries fill with contrast. The imaged coronary arteries may be blocked partially,
completely or not at all. While a blockage that occludes greater than 70% of an artery is
highly correlated with chest pain or other anginal symptoms, occlusions of 40% or more may or
may not decrease heart blood flow. Often multiple imaging studies are needed to evaluate
whether blood flow is decreased in the setting of partial coronary artery blockages including
non-invasive heart imaging to assess heart blood flow.
One type of nuclear imaging is termed positron emission tomography (PET). In order to
differentiate blockages that have poor heart perfusion with activity, nuclear PET images are
taken at rest, when flow should be normal, and then repeated after the investigators "stress"
the heart with medications. If blood flow is decreased during stress, a "defect" on the PET
images is seen.
An alternative, non-invasive technique to test for heart blood flow/perfusion to to measure
heart blood flow as computed tomography (CT) contrast goes in and comes out. Preliminary
studies in animals and humans to assess heart blood flow/perfusion using contrast-enhanced
cardiac CT have been promising, but further work is needed. Combining CCTA with CT blood
flow/perfusion measurements in the same setting could lead to a single, accurate diagnostic
test that measures coronary artery blockage as well as blood flow.
One limitation of CT imaging is the amount of radiation that can be given. The CCTA radiation
dose is currently less than both nuclear PET imaging and invasive coronary angiography.
However, if CT blood flow imaging is added to routine CCTA to assess heart perfusion and
coronary blockages in one test, the radiation dose may be higher.
The primary purpose of this research project is to test the diagnostic accuracy of various
cardiac CT perfusion techniques as compared to the best non-invasive test of blood flow,
cardiac PET perfusion imaging. The investigators goal is to use the least amount of radiation
to achieve a high diagnostic accuracy for CCTA as well as CT blood flow/perfusion. The
investigators goal is to have CT heart blood flow/perfusion radiation doses that are the same
or less than nuclear blood flow imaging. The investigators have estimated that they need as
few as 4 low radiation dose images of the heart to allow accurate heart blood flow
measurement.
Inclusion Criteria:
- Patients referred for
1. clinically indicated PET imaging for assessment of myocardial ischemia
2. clinically indicated CCTA scanning with known coronary artery disease
- ≥20 years of age and ≤ 80 years of age
- Able to provide written informed consent
Exclusion Criteria:
- Contraindications to beta blockers or regadenoson
- Active reactive airway disease
- 2nd or 3rd degree heart block (without a pacemaker)
- Sick sinus syndrome (without a pacemaker)
- Long QT syndrome (QTC > 500 msec)
- Severe hypotension
- Decompensated heart failure
- Pregnancy
- Contraindications to undergoing any CT imaging procedure with contrast:
- Irregular heart rhythm despite beta blockade
- Creatinine >1.6 mg/dl
- Allergy to iodinated contrast medium
- Inability to lie flat
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