J Korean Soc Magn Reson Med.  2011 Apr;15(1):77-81. 10.13104/jksmrm.2011.15.1.77.

Diagnosis of Vertebral Artery Ostial Stenosis on Contrast-Enhanced MR Angiography: Usefulness of a Thin-Slab MIP Technique

• Kim SM
• Lee DH
• Choi JW
• Choi BS
• In HS

• KMID: 2041231
• DOI: http://doi.org/10.13104/jksmrm.2011.15.1.77

Abstract

It is a well-known clinical fact that contrast-enhanced magnetic resonance angiography exaggerates vertebral arterial ostial stenosis and sometimes shows pseudostenosis. Considering the clinical significance of a lesion in the posterior circulation ischemia, the importance of an accurate imaging diagnosis of ostial stenosis should not be underestimated. We were able to differentiate pseudostenosis of the ostium from true stenosis using thin-slab maximum-intensity-projection(MIP) images which are thought to be helpful for minimizing standard full thickness MIP images.

Keyword

Vertebral artery ostial stenosis; Contrast-enhanced MRA; Thin-slab MIP technique

MeSH Terms

Constriction, Pathologic
Ischemia
Magnetic Resonance Angiography
Vertebral Artery

Figure

• 

  Fig. 1 (a) Oblique digital subtraction angiography image. (b) Oblique gadolinium-enhanced sagittal thick (40-mm) MR angiography. (c) Thin-slab MIP (slab thickness of 1 mm) image. Digital subtraction andgiography and MR angiography show concordant results of severe ostial stenosis (arrow) of the left VA. The thin-slab MIP image shows no signal in the left VA os. This case represents true VA ostial stenosis.

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  Fig. 2 (a) The findings on oblique gadolinium-enhanced MR angiography shows a loss of signal in the right VA os, which is considered to represent severe stenosis. (b) Thin-slab MIP (slab thickness of 1 mm) image shows a mild signal defect (arrowhead) in the right VA os and intact luminal patency of the right VA os. (c) Oblique DSA image shows no significant VA stenosis. Using the thin-slab MIP image, we were able to differentiate the pseudostenosis from true stenosis of the right VA os.

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