MRI-derived measurements of fibrous-cap and lipid-core thickness: the potential for identifying vulnerable carotid plaques in vivo.
Vulnerable plaques have thin fibrous caps overlying large necrotic lipid cores. Recent studies have shown that high-resolution MR imaging can identify these components. We set out to determine whether in vivo high-resolution MRI could quantify this aspect of the vulnerable plaque. Forty consecutive patients scheduled for carotid endarterectomy underwent pre-operative in vivo multi-sequence MR imaging of the carotid artery. Individual plaque constituents were characterised on MR images. Fibrous-cap and lipid-core thickness was measured on MRI and histology images. Bland-Altman plots were generated to determine the level of agreement between the two methods. Multi-sequence MRI identified 133 corresponding MR and histology slices. Plaque calcification or haemorrhage was seen in 47 of these slices. MR and histology derived fibrous cap-lipid-core thickness ratios showed strong agreement with a mean difference between MR and histology ratios of 0.02 (+/- 0.04). The intra-class correlation coefficient between two readers for measurements was 0.87 (95% confidence interval, 0.73 and 0.93). Multi-sequence, high-resolution MR imaging accurately quantified the relative thickness of fibrous-cap and lipid-core components of carotid atheromatous plaques. This may prove to be a useful tool to characterise vulnerable plaques in vivo.
University Department of Radiology, Addenbrooke's Hospital, Cambridge, UK.
Rikin A
RA
Trivedi
Jean-Marie
JM
U-King-Im
Martin J
MJ
Graves
Jo
J
Horsley
Martin
M
Goddard
Peter J
PJ
Kirkpatrick
Jonathan H
JH
Gillard
D000368:Aged; D000369:Aged, 80 and over; D017536:Carotid Artery, Common / Q000473:pathology; D016893:Carotid Stenosis / Q000473:pathology*; D005260:Female; D005355:Fibrosis; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008055:Lipids; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012422:Rupture, Spontaneous / Q000473:pathology
D008055:Lipids