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

Abstract

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 three healthy volunteers and seven patients with various cervicocranial steno-occlusive diseases. Intra-arterial digital subtraction angiography (DSA) served as standard of reference for findings in the patients. Magnetic resonance projection angiography (MRPA) was performed on a standard 1.5-T clinical 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 circulation were acquired at a temporal frame rate of 900 ms per image in the coronal plane. The collateral flow and the perfusion of the compromised vessel territory were readily assessed by MPRA in patients with occlusion of the internal cerebral artery (ICA) or middle cerebral artery (MCA). The leptomeningeal collateralisation of these patients was displayed in a dynamic fashion. Furthermore, quantitative perfusion measurement provided a difference between both MCA territories in the time to peak (deltaDTTP) of the contrast bolus of 1.12 +/- 0.28 s in five patients with severe stenosis or occlusion of the ICA (healthy volunteers 0.19 +/- 0.05 s). However, important pathological findings, such as the evaluation of carotid artery stenoses and the intracranial collateral flow pattern in patients with severe carotid stenoses, were not sufficiently assessable as compared with DSA. We conclude that the possibility of obtaining simultaneously information about morphology and perfusion dynamics of the cervicocranial vessels is unique in MPRA as compared with other MR techniques. However, in the applied form, the technique is not a reliable tool for the complete evaluation of the cervicocranial vessels in patients with steno-occlusive disease.

Color Velocity Imaging Quantification in the Detection of Intracranial Collateral Flow

“…3,20,21 Sensitivity in anterior circulation varies from 89.2% to 95% and that in the posterior circulation from 81.3% to 97%. 12,13,22 In severe occlusive carotid disease, the accuracy of CVIQ in detecting intracranial collateral flow in this study is comparable to the above techniques, especially in anterior circulation (Table 4). Comparison of moderate disease with these techniques was not possible because previous studies were performed in severe carotid disease only.…”

Display of Dural Sinuses with Time-Resolved, Contrast-Enhanced Three-Dimensional MR Venography

“…Subsequently, 3D TR MRA sequences have been introduced for various neurovascular applications. Mainly due to their high temporal resolution, these sequences have proven helpful foremost for analyzing vascular diseases with arteriovenous shunts, such as dural arteriovenous fistula (DAVF), arteriovenous malformation, and vascular tumors, as well as arterial steno-occlusive disease [4,5,6,7,8,9,10,11,12]. The dynamic visualization of dural sinuses with TR MRA methods might be useful as the diagnosis of dural sinus thrombosis (DST) with standard MR venographic imaging has numerous important drawbacks.…”

Eco-Doppler ed angio-RM nella valutazione della stenosi carotidea

“…DSA is well known for its risks and limitations [10,12,14,19,32,33]. The urge to confirm the validity of noninvasive vascular imaging methods therefore aims at obtaining a drastic reduction in the risks of the examination and a better management of the patient [18].…”

“…Nonostante ciò, gli svantaggi della DSA, compresa la possibilità di complicazioni neurologiche nello 0,5%-1% di casi [12], più che i suoi limiti, hanno stimolato molti lavori scientifici alla definizione di metodiche non invasive che potrebbero costituire, da sole o in associazione con altre, una valida alternativa alla DSA. L'impulso verso la validazione di tali metodiche si può riscontrare nella letteratura sull'argomento [4,[13][14][15][16][17][18][19].…”

“…Nevertheless, the disadvantages of DSA, including the possibility of neurological complications in 0.5%-1% of cases [12], rather than its limitations, have prompted investigators to refine noninvasive methods that could, either alone or in association with others, provide an alternative to DSA. The urge towards the validation of such methods can be seen in literature on the subject [4,[13][14][15][16][17][18][19]. The improved quality and diagnostic importance of vascular imaging with magnetic resonance angiography (MRA), due to the introduction of MRA with contrast medium (gadolinium) that does not involve ionizing radiation, has an acceptable cost and is unaffected by complications.…”