Preliminary experience with dynamic MR projection angiography in the evaluation of cervicocranial steno-occlusive disease

The application of a contrast-enhanced, two-dimensional MR technique, which provides dynamic projection angiograms at a subsecond temporal frame rate for depiction of the cervical and intracranial arteries, was evaluated in t hree healthy volunteers and seven patients with various cervicocranial sten o-occlusive diseases. Intra-arterial digital subtraction angiography (DSA) served as standard of reference for findings in the patients. Magnetic reso nance projection angiography (MRPA) was performed on a standard 1.5-T clini cal MR imaging system at intravenous injection of a single dose of contrast agent (0.1 mmol/kg GdDTPA-BMA). Sixty consecutive images of the cerebral c irculation were acquired at a temporal frame rate of 900 ms per image in th e coronal plane. The collateral flow and the perfusion of the compromised v essel territory were readily assessed by MPRA in patients with occlusion of the internal cerebral artery (ICA) or middle cerebral artery (MCA). The le ptomeningeal collateralisation of these patients was displayed in a dynamic fashion. Furthermore, quantitative perfusion measurement provided a differ ence between both MCA territories in the time to peak (Delta DTTP) of the c ontrast bolus of 1.12 +/- 0.28 s in five patients with severe stenosis or o cclusion of the ICA (healthy volunteers 0.19 +/- 0.05 s). However, importan t pathological findings, such as the evaluation of carotid artery stenoses and the intracranial collateral flow pattern in patients with severe caroti d stenoses, were not sufficiently assessable as compared with DSA. We concl ude that the possibility of obtaining simultaneously information about morp hology and perfusion dynamics of the cervicocranial vessels is unique in MP RA as compared with other MR techniques. However, in the applied form, the technique is not a reliable tool for the complete evaluation of the cervico cranial vessels in patients with steno-occlusive disease.