Determination of acute vascular injury and edema in porcine carotid arteries by T2 weighted cardiovascular magnetic resonance.
Inflammation plays an essential role for destabilization and rupture of carotid atherosclerotic plaques causing embolic ischemic stroke. Inflammation of the vessel wall may result in the formation of edema. This study investigated whether edema in the carotid artery wall induced by acute balloon injury could be detected by cardiovascular magnetic resonance (CMR) using a T2-weighted short-tau inversion recovery sequence (T2-STIR). Edema was induced unilaterally by balloon injury in the carotid artery of six pigs. Four to nine days (average six) post injury, the carotid arteries were assessed by T2-STIR and multi-contrast weighted sequences. CMR images were matched to histopathology, validated against Evans blue, and correlated with the amount of fibrinogen in the arterial wall used as an edema marker. T2-STIR images showed that the carotid signal intensity (SI) divided by the sternocleid muscle SI of the injured carotid artery was on average 223% (P = 0.03) higher than that of the uninjured carotid artery. Using a threshold value of 4SD, T2-STIR detected edema in the vessel wall (i.e., hyperintense signal intensity) with a sensitivity of 100% and a specificity of 75%. Agreement was observed between carotid artery wall hyperintense signal intensity and Evans blue uptake (X(2) = 17.1, P < 0.001). The relative signal intensity correlated in a linear fashion with the amount of fibrinogen detected by histopathology (ρ = 0.9, P < 0.001). None of the multi-contrast weighted sequences detected edema in the carotid artery with reasonable sensitivity or specificity. T2-STIR CMR allowed carotid artery wall edema detection and may therefore be a useful non-invasive diagnostic tool for determination of inflammatory activity in the carotid artery wall.
Department of Cardiothoracic and Vascular Surgery, Aarhus University Hospital Skejby, Brendstrupsgaardsvej 100, Aarhus N 8200, Denmark. fjord@mr.au.dk
Steen Fjord
SF
Pedersen
Won Yong
WY
Kim
William P
WP
Paaske
Troels
T
Thim
Erling
E
Falk
Steffen
S
Ringgaard
Samuel A
SA
Thrysøe
D000800:Angioplasty, Balloon; D000818:Animals; D002339:Carotid Arteries / Q000473:pathology*; D020212:Carotid Artery Injuries / Q000209:etiology / Q000473:pathology*; D004195:Disease Models, Animal; D004487:Edema / Q000209:etiology / Q000473:pathology*; D005260:Female; D007249:Inflammation / Q000209:etiology / Q000473:pathology*; D008279:Magnetic Resonance Imaging; D015588:Observer Variation; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D013552:Swine; D057772:Vascular System Injuries / Q000209:etiology / Q000473:pathology*