Learn · Part 3. Choosing · 4 min read

Side by side: comparing the tests

An interactive, cited comparison of what eight tests show, what they need and where they are limited.

60-second take

The table compares characteristics, not appropriateness. It does not rank the tests, and the published ratings are explicitly not competitive rankings.
Use the toggles to highlight tests that show ischemia, do not need exercise, avoid radiation or avoid iodinated contrast. Dimming is not an exclusion.
Local availability, expertise and the individual patient still decide the choice. The table cannot weigh those for you.
For how the published criteria rate each test for a specific scenario, open the scenario builder.

A comparison of characteristics, not a ranking

Choosing a test starts with knowing what each one offers and what it asks of the patient. The table below puts eight test types side by side on practical characteristics: what each mainly shows, whether it needs a stressor, whether it uses ionizing radiation or a contrast agent, and its usual constraints, strengths and limits. Entries carry a citation unless they follow directly from what the test is (for example, an exercise ECG takes no pictures of the heart), so you can see where each one came from.

This is not a ranking, and it does not tell you which test is appropriate. The 2023 multimodality criteria rate tests for clinical scenarios and say explicitly that the ratings are not competitive rankings . How appropriate a test is for a particular patient is what the scenario builder shows, so use this page to learn the characteristics and the tool to see the criteria.

Highlight what matters to you

Pick one or more to highlight rows. This only filters descriptions: it does not rate or rank anything.

Test	What it mainly shows	Needs a stressor?	Ionizing radiation	Contrast agent	Typical practical constraints	Main strengths	Main limits
Exercise ECG	Symptoms, exercise capacity, heart rate and blood pressure response, arrhythmias and exercise-induced ECG changes. No images of the heart are taken.	Exercise only: graded exercise until fatigue, limiting symptoms, marked ischemia or a drop in blood pressure.	None. There is no imaging step.	None.	Suited to patients without disabling comorbidity who can reach about 5 METs or more, and whose resting ECG can be read for ST changes. Abnormal resting ST changes, digoxin, left bundle branch block, pre-excitation or a paced rhythm are listed constraints.	Low cost and widely available, with diagnostic and prognostic information such as functional capacity. The 2021 guideline lists it as the lowest-cost diagnostic procedure apart from CAC scoring.	Does not image the heart. The 2023 AUC rates exercise testing on the assumption that the patient can exercise adequately and the ECG is interpretable.
Stress echocardiography	Ventricular function and regional wall motion at rest; with stress, it can define how severe ischemia is and help stratify risk. The same study can evaluate valve disease, diastolic parameters, pulmonary hypertension, myocardial and pericardial disease.	Exercise or pharmacologic stress.	None.	Optional ultrasound-enhancing (microbubble) agent, recommended when two or more contiguous segments or a coronary territory are not adequately seen.	Needs adequate acoustic windows, for example limited in COPD, obesity or breast implants. Hypersensitivity to perflutren matters if that agent is used.	Absence of radiation or gadolinium and a cost advantage make it attractive for many patients.	Limited acoustic windows (COPD, obesity, breast implants).
Stress SPECT	Perfusion abnormalities, left ventricular function and high-risk findings such as transient ischemic dilation.	Pharmacologic vasodilation, or pharmacologic or exercise stress. Exercise is the preferred way to stress patients who can exercise adequately.	About 10 mSv average effective dose for Tc-99m SPECT. The 2026 ASNC guideline describes 3 to 20 mSv for Tc-99m SPECT or F-18 flurpiridaz PET.	No contrast agent is listed. An injected radiotracer (for example Tc-99m) is used.	Vasodilator stress is contraindicated if caffeine was used within the last 12 hours. Other vasodilator-related restrictions are listed.	Can be done with vasodilator or with pharmacologic or exercise stress.	Attenuation, motion and soft-tissue artifacts may underestimate the extent of disease; radiation exposure.
Stress PET	Perfusion and function, plus quantified myocardial blood flow and flow reserve, which improve diagnosis and prognostication and may allow detection of microvascular disease.	Pharmacologic in most settings: exercise is not widely available with PET. An F-18 tracer can be used with exercise or pharmacologic stress.	About 3 mSv average effective dose for Rb-82 PET. The 2026 ASNC guideline describes under 3 mSv for Rb-82, N-13 ammonia or O-15 water, and 3 to 20 mSv for F-18 flurpiridaz.	No contrast agent is listed. An injected radiotracer (for example Rb-82) is used.	Vasodilator stress is contraindicated if caffeine was used within the last 12 hours. Exercise PET is not widely available.	Can quantify peak myocardial blood flow and flow reserve.	Not widely available with exercise; radiation exposure.
Stress cardiac MRI (CMR)	Wall motion, ischemia and infarction in one study, with myocardial blood flow quantification and viability testing.	Vasodilator stress perfusion is more common than inotropic (dobutamine) stress. A treadmill exercise protocol is described as an alternative.	None.	Gadolinium-based contrast agent for perfusion imaging. Reduced GFR (below 30 mL/min/1.73 m²) is a listed contraindication.	Significant claustrophobia, implanted devices that are not MRI-safe or that cause artifact, caffeine within 12 hours when a vasodilator is used. Caffeine is best avoided for 12 to 24 hours.	Assesses wall motion, ischemia and infarction in one study, and can perform viability testing.	Claustrophobia, artifacts, and safety precautions with metallic medical devices. Gadolinium may be undesirable in kidney disease.
CAC score	The presence and amount of calcified coronary plaque, with robust prognostic value. It describes calcified plaque, not ischemia.	None.	Yes: it is a CT scan, scored from a non-contrast acquisition. The documents reviewed do not give a dose.	None needed.	Table A lists no specific limitation. A visual estimate of calcification on an earlier non-cardiac chest CT can sometimes provide the same information.	Robust prognostic value and no contrast agent. Exercise ECG is the lowest-cost diagnostic procedure apart from CAC scoring.	Describes calcified plaque only.
Coronary CT angiography (CCTA)	Extent and severity of nonobstructive and obstructive plaque, plaque composition and high-risk features. Can identify non-cardiac causes of some symptoms. CT stress perfusion and CT-derived FFR can assess for ischemia.	None for the angiogram itself. CT stress perfusion, an optional add-on, images the heart muscle during hyperemia.	Effective doses of about 3 to 5 mSv for most patients.	Iodinated contrast. Allergy to iodinated contrast and renal impairment (as defined by local protocols) are listed constraints.	Ability to follow breath-hold instructions, heart rate and rhythm, and whether beta-blockade or nitroglycerin can be used if needed.	Detects both nonobstructive and obstructive plaque.	Reduced quality with morbid obesity, high or irregular heart rates, or severe coronary calcification; radiation exposure.
Invasive coronary angiography	Presence and severity of a luminal narrowing, including its location, length and diameter, to judge whether revascularization is feasible and needed. Pressure-wire indices (FFR, iFR) add functional information.	None for the angiogram itself.	Averages 4 to 10 mSv during an interventional procedure, depending on duration and complexity.	Iodinated contrast. The 2023 CCD guideline discusses limiting contrast volume and the risk of contrast-induced kidney injury when PCI is needed in chronic kidney disease.	An invasive procedure with procedural complications.	Can add physiologic testing, intravascular imaging, testing for coronary spasm and microvascular disease, and hemodynamic assessments in the same procedure.	Procedural complications and radiation. Resolution of about 0.3 mm cannot show 0.1 mm arterioles, so a normal angiogram does not exclude abnormal coronary vascular function.

Exercise ECG
What it mainly shows
Symptoms, exercise capacity, heart rate and blood pressure response, arrhythmias and exercise-induced ECG changes. No images of the heart are taken.
Needs a stressor?
Exercise only: graded exercise until fatigue, limiting symptoms, marked ischemia or a drop in blood pressure.
Ionizing radiation
None. There is no imaging step.
Contrast agent
None.
Typical practical constraints
Suited to patients without disabling comorbidity who can reach about 5 METs or more, and whose resting ECG can be read for ST changes. Abnormal resting ST changes, digoxin, left bundle branch block, pre-excitation or a paced rhythm are listed constraints.
Main strengths
Low cost and widely available, with diagnostic and prognostic information such as functional capacity. The 2021 guideline lists it as the lowest-cost diagnostic procedure apart from CAC scoring.
Main limits
Does not image the heart. The 2023 AUC rates exercise testing on the assumption that the patient can exercise adequately and the ECG is interpretable.
Stress echocardiography
What it mainly shows
Ventricular function and regional wall motion at rest; with stress, it can define how severe ischemia is and help stratify risk. The same study can evaluate valve disease, diastolic parameters, pulmonary hypertension, myocardial and pericardial disease.
Needs a stressor?
Exercise or pharmacologic stress.
Ionizing radiation
None.
Contrast agent
Optional ultrasound-enhancing (microbubble) agent, recommended when two or more contiguous segments or a coronary territory are not adequately seen.
Typical practical constraints
Needs adequate acoustic windows, for example limited in COPD, obesity or breast implants. Hypersensitivity to perflutren matters if that agent is used.
Main strengths
Absence of radiation or gadolinium and a cost advantage make it attractive for many patients.
Main limits
Limited acoustic windows (COPD, obesity, breast implants).
Stress SPECT
What it mainly shows
Perfusion abnormalities, left ventricular function and high-risk findings such as transient ischemic dilation.
Needs a stressor?
Pharmacologic vasodilation, or pharmacologic or exercise stress. Exercise is the preferred way to stress patients who can exercise adequately.
Ionizing radiation
About 10 mSv average effective dose for Tc-99m SPECT. The 2026 ASNC guideline describes 3 to 20 mSv for Tc-99m SPECT or F-18 flurpiridaz PET.
Contrast agent
No contrast agent is listed. An injected radiotracer (for example Tc-99m) is used.
Typical practical constraints
Vasodilator stress is contraindicated if caffeine was used within the last 12 hours. Other vasodilator-related restrictions are listed.
Main strengths
Can be done with vasodilator or with pharmacologic or exercise stress.
Main limits
Attenuation, motion and soft-tissue artifacts may underestimate the extent of disease; radiation exposure.
Stress PET
What it mainly shows
Perfusion and function, plus quantified myocardial blood flow and flow reserve, which improve diagnosis and prognostication and may allow detection of microvascular disease.
Needs a stressor?
Pharmacologic in most settings: exercise is not widely available with PET. An F-18 tracer can be used with exercise or pharmacologic stress.
Ionizing radiation
About 3 mSv average effective dose for Rb-82 PET. The 2026 ASNC guideline describes under 3 mSv for Rb-82, N-13 ammonia or O-15 water, and 3 to 20 mSv for F-18 flurpiridaz.
Contrast agent
No contrast agent is listed. An injected radiotracer (for example Rb-82) is used.
Typical practical constraints
Vasodilator stress is contraindicated if caffeine was used within the last 12 hours. Exercise PET is not widely available.
Main strengths
Can quantify peak myocardial blood flow and flow reserve.
Main limits
Not widely available with exercise; radiation exposure.
Stress cardiac MRI (CMR)
What it mainly shows
Wall motion, ischemia and infarction in one study, with myocardial blood flow quantification and viability testing.
Needs a stressor?
Vasodilator stress perfusion is more common than inotropic (dobutamine) stress. A treadmill exercise protocol is described as an alternative.
Ionizing radiation
None.
Contrast agent
Gadolinium-based contrast agent for perfusion imaging. Reduced GFR (below 30 mL/min/1.73 m²) is a listed contraindication.
Typical practical constraints
Significant claustrophobia, implanted devices that are not MRI-safe or that cause artifact, caffeine within 12 hours when a vasodilator is used. Caffeine is best avoided for 12 to 24 hours.
Main strengths
Assesses wall motion, ischemia and infarction in one study, and can perform viability testing.
Main limits
Claustrophobia, artifacts, and safety precautions with metallic medical devices. Gadolinium may be undesirable in kidney disease.
CAC score
What it mainly shows
The presence and amount of calcified coronary plaque, with robust prognostic value. It describes calcified plaque, not ischemia.
Needs a stressor?
None.
Ionizing radiation
Yes: it is a CT scan, scored from a non-contrast acquisition. The documents reviewed do not give a dose.
Contrast agent
None needed.
Typical practical constraints
Table A lists no specific limitation. A visual estimate of calcification on an earlier non-cardiac chest CT can sometimes provide the same information.
Main strengths
Robust prognostic value and no contrast agent. Exercise ECG is the lowest-cost diagnostic procedure apart from CAC scoring.
Main limits
Describes calcified plaque only.
Coronary CT angiography (CCTA)
What it mainly shows
Extent and severity of nonobstructive and obstructive plaque, plaque composition and high-risk features. Can identify non-cardiac causes of some symptoms. CT stress perfusion and CT-derived FFR can assess for ischemia.
Needs a stressor?
None for the angiogram itself. CT stress perfusion, an optional add-on, images the heart muscle during hyperemia.
Ionizing radiation
Effective doses of about 3 to 5 mSv for most patients.
Contrast agent
Iodinated contrast. Allergy to iodinated contrast and renal impairment (as defined by local protocols) are listed constraints.
Typical practical constraints
Ability to follow breath-hold instructions, heart rate and rhythm, and whether beta-blockade or nitroglycerin can be used if needed.
Main strengths
Detects both nonobstructive and obstructive plaque.
Main limits
Reduced quality with morbid obesity, high or irregular heart rates, or severe coronary calcification; radiation exposure.
Invasive coronary angiography
What it mainly shows
Presence and severity of a luminal narrowing, including its location, length and diameter, to judge whether revascularization is feasible and needed. Pressure-wire indices (FFR, iFR) add functional information.
Needs a stressor?
None for the angiogram itself.
Ionizing radiation
Averages 4 to 10 mSv during an interventional procedure, depending on duration and complexity.
Contrast agent
Iodinated contrast. The 2023 CCD guideline discusses limiting contrast volume and the risk of contrast-induced kidney injury when PCI is needed in chronic kidney disease.
Typical practical constraints
An invasive procedure with procedural complications.
Main strengths
Can add physiologic testing, intravascular imaging, testing for coronary spasm and microvascular disease, and hemodynamic assessments in the same procedure.
Main limits
Procedural complications and radiation. Resolution of about 0.3 mm cannot show 0.1 mm arterioles, so a normal angiogram does not exclude abnormal coronary vascular function.

How to use the toggles

The four toggles answer simple practical questions: Does this test show ischemia? Does it require exercise? Does it use radiation? Does it use iodinated contrast? Turning a toggle on dims the rows that do not fit it (for example, the rows that use radiation when “Avoid radiation” is on) and highlights the rows that do. Turn on several and only the rows that fit all of them stay highlighted. Dimming is not an exclusion. A dimmed test can still be the right one for a patient, and a highlighted test can still be a poor fit for other reasons, such as a contraindication, local availability or the question being asked.

Two columns need a note. In the “ischemia” toggle, CCTA and invasive angiography are marked as showing ischemia only with an add-on (CT-derived FFR or CT perfusion for CCTA, pressure-wire measurements for invasive angiography). CAC scoring describes calcified plaque and does not assess ischemia.

What the table cannot tell you

A table of characteristics cannot weigh your patient’s symptoms, prior test results, ability to exercise, kidney function, body habitus or the test types your own hospital performs well. The AUC authors expect the differences between tests, listed in their Table A, to be combined with clinical features, clinical judgment and local availability and expertise . When more than one test falls in the same rating category, they expect the choice to rest on clinician judgment, the advantages and disadvantages of each test, and local expertise .

The next lesson, How to think about choosing a test, goes through those patient-level questions. For a specific patient, open the scenario builder →: it shows how the published criteria rate each test for that scenario, the reasons behind each rating, and which patient factors raise a contraindication or caution.

The advantages and limitations of echo, SPECT, PET, CMR, CAC, CCTA and invasive angiography follow Table A of the 2023 multimodality AUC .
Descriptions of what each test shows, radiation doses for CCTA, invasive angiography, SPECT and PET, exercise ECG candidacy, and contraindications come from the 2021 chest pain guideline .
Exercise ECG and stress SPECT/PET details, including the radiation ranges, come from the 2026 ASNC stress-testing guideline .
Stress echocardiography details come from the 2019 ASE guideline , and stress CMR protocol and gadolinium details from the 2020 SCMR protocols .
CCTA and CAC details that go beyond the above come from the 2021 SCCT expert consensus , and the PET exercise-stress note from the 2025 PET AUC .

Try it in the tool

Open the scenario builder →

Sources cited on this page

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