ª Springer Science+Business Media New York 2014
Abdominal Imaging
Abdom Imaging (2014) DOI: 10.1007/s00261-014-0270-2
The renal artery string-of-pearls sign Sheena Gurwara, Raymond B. Dyer Department of Radiology, Wake Forest Baptist Medical Center, Wake Forest University School of Medicine, Medical Center Blvd, Winston-Salem, NC 27157, USA
Fig. 1.
A string of pearls.
The ‘‘string-of-pearls’’ metaphor (Fig. 1) has been used to describe the angiographic appearance of the medialtype of fibromuscular dysplasia (FMD) [1–3]. FMD is an idiopathic vascular disease characterized by areas of smooth muscle and fibrous tissue proliferation within the arterial wall, which results in concentric luminal narrowing [2, 3]. Between the affected areas, the arterial wall is thinned with aneurysmal dilatation, giving a classic string-of-pearls appearance (Fig. 2) [1, 3]. Although originally described on traditional angiography, the condition may be diagnosed on both CT (Fig. 3) and MR angiography [1]. The most common form of FMD is the medialtype, and it most often involves the renal arteries [2, 3]. Other common sites of involvement are the internal carotid, cranial, mesenteric, and external iliac arteries [3]. FMD of the renal arteries tends to involve the mid
Correspondence to: Sheena Gurwara; email:
[email protected] Fig. 2. Angiographic image of a right renal artery injection which shows the ‘‘string-of-pearls’’ appearance in the right renal artery.
to distal third of the renal arteries, in contrast to atherosclerotic disease which involves the proximal portion [2]. FMD is one of the causes of renovascular hypertension, and is especially important to consider as a cause in children and middle-aged females [1, 3].
S. Gurwara, R. B. Dyer: The renal artery string-of-pearls sign
References 1. Dyer RB, Chen MY, Zagoria RJ (2004) Classic Signs of Uroradiology. Radiographics 24:S247–S280 2. Mandell J (2013) Core Radiology. Cambridge: Cambridge University Press, p 713 3. Zeitler E (ed) (2000) Radiology of Peripheral Vascular Diseases Berlin. Springer-Verlag: Germany, p 496
Fig. 3. Coronally reconstructed image during the arterial phase of enhancement in a hypertensive patient shows the ‘‘string-of-pearls’’ appearance in the mid to distal left renal artery. Note the sparing of the proximal main renal artery.