Fig 1.

A, 71-year-old woman who initially presented with a cerebellar infarct. Posteroanterior (PA) left vertebral arteriogram reveals a high-grade stenosis of the proximal basilar artery, supplied only by this vessel (arrow). This lesion is concentric and measures <10 mm in length and is typical of lesions responding well to angioplasty alone. B, Appearance immediately after angioplasty, illustrating that safe suboptimal improvement is satisfactory. There is residual stenosis but flow is improved. C, Appearance 6 months. The patient is still asymptomatic; no repeat angioplasty was performed. D, Appearance 7 years after angioplasty shows that the lesion is stable. The patient remains asymptomatic.