Figure 3

Assessment of aneurysm rupture in animals with stable aortic aneurysm and in animals with fatal aortic rupture (longitudinal study). (A,B) Cross-sectional time-of-flight (TOF) angiographies (on the left), delayed-enhancement sequences after administration of the albumin-binding probe gadofosveset (centre) and delayed-enhanced images fused with magnetic resonance TOF angiography (right). These images show the suprarenal abdominal aorta of an ApoE^−/− mouse with AAA rupture (A) compared to a surviving ApoE^−/− mouse. (B) In the fusion images on the right, blue signal indicates little enhancement, whereas red signal indicates increased enhancement following administration of an albumin-binding probe. We see, that ApoE^−/− mice with AAA rupture show significantly increased signal enhancement, as measured by contrast-to-noise ratio (p = 0.047, see (C) and a smaller nonenhancing thrombus area (p = 0.001, see (D)). (E-G) show ROC curves for contrast-to-noise ratio, size of nonenhancing thrombus and a combination of both. (E) We see, that use of the signal from the albumin-binding probe (contrast-to-noise ratio) predicted AAA rupture risk with 80% sensitivity and 70% specificity. (F) Size of the nonenhancing thrombus area predicted AAA rupture with 100% sensitivity and 78% specificity. (G) The combined used of both parameters had the highest accuracy for predicting aneurysm rupture with 100% sensitivity and 86% specificity compared with each parameter alone. Abbreviations: Gadofosveset: albumin-binding probe. *Nonenhancing intraluminal thrombus area; ROC: Receiver operating characteristic; TOF-MRA: time-of-flight magnetic resonance angiography; +: vascular lumen in arterial TOF.