Rapid expansion of abdominal aortic aneurysm on ultrasound

The ultrasound images were performed six months apart and show rapid (>0.5 cm) expansion of an abdominal aortic aneurysm (AAA) (A to B) and advancing hydronephrosis (white arrow) (C to D). Perianeurysmal fibrosis with secondary progressive ureteral obstruction, as would be seen with an inflammatory aneurysm, could explain these findings.