Sage Journals: Discover world-class research

Abstract

Italian

Our purpose was to evaluate a novel 3D Time-of-Flight (TOF) MR-Angiography (MRA) method, aimed at improving contrast resolution between vessels and static tissues.

The new method consists of the acquisition of two MRA sequences, the first with the conventional technique and the second with arterial saturation. After the acquisition, digital subtraction between the two sequences was carried out to obtain a set of partitions with high flow signal and very low parenchymal signal. Five healthy volunteers and 16 patients with vascular brain diseases were studied. The resulting images were then reconstructed with maximal intensity projection (MIP) and compared with TOF MRA.

In healthy volunteers subtraction-TOF showed higher contrast resolution and better visualization of small arterial vessels than the TOF technique. In the group of patients, visualization of turbulent flow lesions (i.e. aneurysms) was the same with both methods. In contrast, subtraction-TOF was superior to TOF for small vessel visualization (i.e. treated arteriovenous malformations) and for complete suppression of elevated signal intensity areas due to hematic debris (metahemoglobin).

In conclusion, subtraction-TOF is a useful technique if small brain vessel visualization is required or to suppress short T1 static tissues (i.e. metahemoglobin).

Keywords

magnetic resonance angiography magnetic resonance vascular studies cerebral blood vessels

Get full access to this article

View all access options for this article.

References

Adamis

: Dynamic contrast-enhancement subtraction MR angiography of the lower extremities: initial evaluation with a multisection two-dimensional time-of-flight sequence. Radiology 196: 689–695, 1995.

Atlas

: Magnetic resonance imaging of the brain and spine, 2nd edn. Lippincott-Raven, Philadelphia 1996: 1547–1618.

Creasy

Price

: Gadolinium-enhanced MR angiography. Radiology 175: 280–283, 1990.

Dousset

Franconi

: Use of magnetisation transfer contrast to improve cerebral 3D MR angiography. Neuroradiol 36: 188–192, 1994.

Edelman

Sungkee

: Improved time-of-flight MR angiography of the brain with magnetization transfert contrast. Radiology 184: 395–399, 1992.

KYJAM

de Haan

: Peripheral vascular tree stenoses: detection with subtracted and nonsubtracted MR angiography. Radiology 206: 673–681, 1998.

Huston

III Rüfenacht

: Intracranial aneurysms and vascular malformations: comparison of time-of-flight and phase-contrast MR angiography. Radiology 181: 721–730, 1991.

Marchai

Michiels

: Contrast-enhanced MRA of the brain. J Comput Assist Tomogr 16: 25–29, 1992.

Oelerich

Lentsching

: Intracranial vascular stenosis and occlusion: comparison of 3D time-of-flight and 3D phase-contrast MR angiography. Neuroradiol 40: 567–573, 1998.

10.

Tkach

Ruggieri

: Pulse sequence strategies for vascular contrast in time-of-flight MR angiography. J Magn Res Imaging 3: 811–820, 1993.

11.

Yano

Kodama

: Gadolinium-enhanced 3D time-of-flight MR angiography. Experimental and clinical evaluation. Acta Radiol 38: 47–54, 1997.

Improvement of Intracranial Time of Flight MR-Angiography with a Subtraction Method

Abstract

Keywords

Get full access to this article

References