Abstract

BACKGROUND:

iMAP is a new intravascular ultrasound (IVUS) derived technique for tissue characterization using spectral analysis. Since there is a need for reproducibility data to design longitudinal studies, we sought to assess the in vivo reproducibility of this imaging technique.

METHODS:

iMAP (40 MHz, Boston Scientific Corporation) was performed in patients referred for elective percutaneous intervention and in whom a non-intervened vessel was judged suitable for a safe IVUS analysis. Overall 20 patients with 20 non angiographically significant lesions were assessed by 2 independent observers. Five out of these 20 patients received an additional iMAP analysis using a new IVUS catheter and using the same catheter after its engagement and re-engagement.

RESULTS:

The inter-observer relative difference in plaque area was 2.5%. Limits of agreement for lumen, vessel and plaque area measurements were 1.62, -2.47 mm(2) ; 2.09, -3.71 mm(2) ; 2.80, -3.72 mm(2) ; respectively. Limits of agreement for fibrotic, lipidic, necrotic and calcified measurements were 1.32, -1.44 mm(2) ; 0.24, -0.36 mm(2) ; 1.50, -2.26 mm(2) ; 0.09, -0.11 mm(2) ; respectively. The inter-catheter and intra-catheter relative difference in plaque area were 0.9% and 4.1%, respectively. Although the variability for compositional measurements increased using two different catheters or using the same catheter twice, the variability for compositional measurements keeps always below 10%.

CONCLUSIONS:

Our analysis demonstrates that the geometrical and compositional iMAP analysis is acceptably reproducible. © 2011 Wiley-Liss, Inc.

Copyright © 2011 Wiley-Liss, Inc.