Low-field 2D-time-of-flight MRA of intracranial and cervical blood vessels as a complementary technique in cerebrovscular ischaemic disease

Abstract

We set out to assess the utility of low-field two-dimensional time-of-flight (2D-TOF) MRA of intracranial and cervical blood vessels in patients with conventional MRI findings of cerebrovascular ischaemic disease. We examined 21 patients with stroke syndromes in the acute and subacute phases. Standard MRI cranial examination (spin-echo T1-, spin-density- and T2-weighted images) was followed by a 2D-TOF MRA of intracranial and cervical blood vessels. In 5 patients, a haemodynamic study of the circle of Willis was obtained by means of selective presaturation bands. Cranial MRI showed brain lesions (occlusive infarct, watershed and multifocal leukoencephalopathy). MRA showed findings consistent with steno-occlusion of the internal carotid artery in 14 patients, the middle cerebral artery in 4 and the posterior cerebral artery in 1. In 2 patients, MRA was negative. In all but 1 patient, there was a correlation between the side of brain lesions and the side and degree of intravascular signal abnormalities. Selective presaturation of individual vessels of the circle of Willis allowed demonstration of collateral supply to the compromised territory in 3 patients.