Table 1.

Pros and cons of each viability modality

Modality	Advantages	Disadvantages
SPECT	Readily available. Part of routine stress/rest protocol. More sensitive than DSE.	Highest radiation exposure. All-or-none interpretation with inability to assess for hibernation resulting in lower specificity. Prone to attenuation artifacts, especially in obese patients.
DSE	Readily available. No radiation exposure. More specific than SPECT. Can utilize other predictors of viability such as LV wall thickness.	Image quality dependent on patient factors (body habitus, lung disease) and experience of sonographer. Lower sensitivity. Contraindicated in patients with tachyarrhythmias and uncontrolled hypertension.
CMR	High-resolution imaging. High sensitivity and specificity. No radiation exposure. Evaluates transmural extent of scar and gold standard for LV volumes and EF assessment. Non-contrast viability methods: dobutamine stress and LV EDWT. Simultaneous evaluation for other etiologies of cardiomyopathy.	Less available. Higher cost. Image quality dependent on ECG gating and breath-holding. Contraindicated in claustrophobia, certain metal objects, and advanced renal disease for contrast use.
PET	Better spatial resolution, attenuation correction, and diagnostic accuracy than SPECT allowing for better image quality. High sensitivity and specificity. Can differentiate hibernating myocardium from scar.	Less available. Higher cost. Radiation exposure, although less than SPECT. Requires fasting and controlled blood glucose levels.

CMR = Cardiac Magnetic Resonance; DSE = Dobutamine Stress echo; EDWT = End diastolic wall thickness; PET = Positron Emission Tomography; SPECT = Single-Photon Emission CT.