IMAGING BLOOD-VESSELS OF THE HEAD AND NECK

The modern era of blood vessel imaging began in 1929 when Forssmann in jected himself with contrast medium through a large bore catheter.(1) Although recognised to be a hazardous procedure the diagnostic ability of angiography was quickly appreciated and a whole new field of neuro surgery rapidly emerged. Dott in Edinburgh wrapped a cerebral aneurysm in 1932(2) and Eastcott in London performed the first carotid endarte rectomy in 1954.(3) While angiographic techniques have continued to im prove, so has the appreciation of the risks; when the benefits of trea tment are minimal, such as in patients with low grade carotid stenosis , the risks of angiography can outweigh its benefits. This has led to the search for less invasive modalities to image the blood vessels. Th is article reviews these new methods, particularly Doppler ultrasonogr aphy (DUS), magnetic resonance angiography (MRA), and CT. It also disc usses what is the role for angiography other than its accepted use for vascular lesions in the head such as aneurysms and arteriovenous malf ormations. The remaining role of angiography in imaging the carotid bi furcation is the current subject of heated debate. The intensity of th is debate was recently increased by the North American Symptomatic Car otid Endarterectomy Trial (NASCET)(4) and the European Carotid Surgery Trial (ECST)(5) both of which showed that 70% stenosis, when measured from an angiogram, could select a group of patients that benefited fr om carotid surgery but that non-invasive measurement, when performed a s in NASCET, did not satisfactorily select these patients.(6)