Using frequency domain optical coherence tomography (FD-OCT) to obtain coronary measurements yields images that are more accurate than measurements obtained by intravascular ultrasound (IVUS) and quantitative coronary angiography, according to a study published online Sept. 4 in JACC: Cardiovascular Imaging. The modality was also more sensitive than IVUS in making certain stent measurements.
“Several studies have shown excellent ability of FD-OCT to qualitatively assess coronary plaque morphologies,” wrote the authors, led by Takashi Kubo, MD, PhD, of Wakayama Medical University in Wakayama, Japan. “However, the accuracy of quantitative FD-OCT measurement has not been fully elucidated.”
Researchers studied 100 patients with coronary artery disease in five different facilities using angiography, FD-OCT and IVUS. They also looked at five phantom models with known lumen measurements using the same tools.
The average minimum lumen diameter (MLD) measured by quantitative coronary angiography was significantly smaller than the MLD measured by FD-OCT. MLD by IVUS was significantly greater than MLD by FD-OCT. However, IVUS and FD-OCT measurements were also significantly correlated, although the root-mean-squared deviation between measurements was about twice as high for IVUS compared with FD-OCT.
FD-OCT and IVUS were in good agreement in terms of interobserver reproducibility and they were also directly correlated with each other.
In addition, “FD-OCT was much more sensitive in detecting intrastent tissue protrusion, incomplete stent apposition, stent edge dissection and intrastent thrombus compared with IVUS,” the researchers found.
With the phantom models, the average of the lumen areas using FD-OCT measurements was equivalent to the actual average of the model. Using IVUS, the mean and standard deviations of the phantom lumen was significantly higher than what was measured by FD-OCT.
These findings, the authors argued, suggest that FD-OCT may have some clinical applicability. “These results indicate that FD-OCT provides reliable quantitative measurements of coronary dimensions in the clinical setting,” they wrote.