Comparison of lipid‐rich necrotic core size in symptomatic and asymptomatic carotid atherosclerotic plaque: Initial results

To investigate the potential difference in the size of the lipid‐rich necrotic core (LRNC) in carotid plaques of symptomatic patients versus asymptomatic patients. Pathological studies established that a large LRNC is an important feature of vulnerable atherosclerotic plaque. Previously, we have demonstrated a high correlation between semiquantitative analysis of the LRNC size in T1‐weighted (w) turbo field echo (TFE) MR images and histology.

Thirty‐seven patients with carotid stenosis >70% with (n = 26) or without (n = 11) symptoms were included. Three independent MR readers quantified the amount of LRNC with a T1w TFE pulse sequence. The relative amount of LRNC (LRNC score) was defined as sum of cross‐sectional area percentages LRNC per carotid plaque.

Interreader agreement for the three MR readers was good, with an intraclass correlation coefficient (ICC, 95% confidence interval [CI]) of 0.72 (0.57–0.83). All three MR readers on average found a larger LRNC in the symptomatic group of patients, although this was not statistically significant. The mean LRNC score was 116 ± 129 and 59 ± 62 for symptomatic and asymptomatic patients, respectively (P = 0.13). Symptomatic patients showed wide ranges in LRNC scores (0–424), while the range was much lower in the asymptomatic group (0–170).

Single‐sequence T1w TFE may be a promising technique to study atherosclerotic plaque at risk of stroke. Larger studies are warranted to confirm these promising results. J. Magn. Reson. Imaging 2008;27:1356–1361. © 2008 Wiley‐Liss, Inc.