OCT versus IVUS: accuracy versus clinical utility.

The technology of optical coherence tomography (OCT) has evolved from time-domain to frequencydomain imaging. Time-domain OCT is most often performed using proximal balloon occlusion; as such, dimensions are smaller than measured using intravascular ultrasound (IVUS), presumably due to diminished perfusion pressure. Conversely, frequency-domain OCT does not require proximal balloon occlusion, theoretically resulting in more accurate measurements.