Christine P. Chao MD, Presenter: Nothing to Disclose

Sanjeeva Prasad Kalva MD, Abstract Co-Author: Research grant, Johnson & Johnson (Cordis Corporation) Research grant, Cook Group Incorporated Speaker, Johnson & Johnson (Cordis Corporation)

Stephan Wicky MD, Abstract Co-Author: Nothing to Disclose

Purpose of the exhibit is to: 1. Review the pathophysiology of segmental arterial mediolysis 2. Illustrate the imaging findings of segmental arterial mediolysis on US, angiography, CT and MR 3. Discuss the distinguishing features of SAM that aid in differentiating it from other vasculitides

I. Background, Presentation: A. Acute intraabdominal hemorrhage, hypotension, ischemic bowel B. Arteries: visceral-elderly; coronary-newborns; cerebral-young adults C. Pathology II. Imaging findings: Distribution; US, Angiography, CTA, MRA III. Differentials: Fibromuscular dysplasia, Polyarteritis nodosa, Mycotic pseudoaneurysm, etc. IV. Natural History, Treatment: Spontaneous resolution, High mortality acutely, Coil embolization, angioplasty, Surgical reconstruction, Stent graft

1. SAM is a rare noninflammatory, nonarteriosclerotic vascular disease characterized pathologically by arterial media weakening. 2. Imaging findings include alternating stenosis and saccular aneurysmal dilation, wall thickening, dissection, elongated and kinked vessels, AV fistula formation, and may be diagnostic when corroborated by clinical and laboratory exclusion of other differentials. 3. Early recognition of SAM may facilitate prompt appropriate treatment and improve mortality.

Chao, C, Kalva, S, Wicky, S, Segmental Arterial Mediolysis (SAM): Multimodality Imaging Findings.  Radiological Society of North America 2007 Scientific Assembly and Annual Meeting, November 25 - November 30, 2007 ,Chicago IL. http://archive.rsna.org/2007/5007066.html