Abstract 2542: Accuracy of Multislice Computed Tomography for the Quantification of Plaque Volume. Validation with Magnetic Resonance Imaging.
Multislice Computed Tomography (MDCT) has been recently suggested to be a potential tool to assess atherosclerotic (AT) plaque volume. Magnetic Resonance Imaging (MRI) is the gold standard for the noninvasive assessment of plaque volume.
Aim To assess whether MDCT can accurately quantify AT plaque volume in an animal model of AT, compared vs. MRI.
Methods AT lesions were induced in New Zealand Rabbits (n=12) by 9-month atherogenic diet and aortic denudation. At the end of AT induction, animals underwent an MRI and 64-Slice CT the same day. MRI images (1.5T) were acquired by scanning the abdominal aorta in = mm thick consecutive segments. MDCT study covered the same area, and axial images were reconstructed in = mm thick segments matched to the MRI ones. Segmental plaque volume was calculated with both techniques as: 3 x (total vessel area-lumen area). MDCT display settings were manipulated as follows. For lumen: window width (WW) 1and level (WL) 65% of lumen attenuation. For outer vessel boundaries: WW 155% and WL 65%, according to previous reports.
Results A strong correlation was seen between MRI and MDCT for lumen and total vessel volumes (R=0.94, p<0.001 and R=0.91, p<0.001 respectively). A highly significant (p<0.001) correlation (R=0.6) between MRI and MDCT for plaque volume quantification was found. Bland and Altman analysis showed that there was a good agreement between plaque volume in MRI and MDCT (mean bias -0.7mm3, limits of agreement 3.7mm3/-5mm3). Figure⇓.
Conclusion A significant correlation was found between MRI and MDCT for the volume quantification of experimental AT plaque lesions. MDCT may represent an alternative modality for AT burden assessment.