Aktuelle Anwendungen und mögliche zukünftige Applikationen der Magnetisierungstransfer-Technik in der Neuroradiologie

Zusammenfassung

Die Magnetisierungstransfer-(MT)-Technik ist ein spezielles MRT-Verfahren, mit dem selektiv das MR-Signal der an Makromoleküle gebundenen Protonen unterdrückt werden kann. Die wichtigsten Anwendungen dieser Technik in der Neuroradiologie sind der Nachweis von subtilen Veränderungen in ansonsten normal erscheinender weißer Hirnsubstanz, wie z. B. bei Multipler Sklerose (MS), Waller'scher Degeneration und Hydrozephalus, die Differenzierung von Läsionen der weißen Substanz, die durchgängig hohes Signal auf T₂-gewichteten MRT-Aufnahmen zeigen, wie z. B. MS-Plaques, Hirninfarkte oder Hirnödem, die Verlaufskontrolle von Erkrankungen der weißen Substanz mit der volumetrischen MT-Technik, und die Verbesserung der Abgrenzbarkeit kontrastmittelaufnehmender Hirnläsionen wie Hirnmetastasen. Wir beschreiben die MR-physikalischen Grundlagen der MT-Technik und stellen die wesentlichen aktuellen und möglichen zukünftigen Anwendungen zur Beantwortung klinischer und wissenschaftlicher Fragestellungen in der Neuroradiologie vor.

Abstract

Magnetization transfer (MT) imaging is a special MR technique used for selective suppression of the MR signal of protons bound on macromolecules. The most important applications in neuroradiology are (1) detection of subtle changes in otherwise normal-appearing cerebral white matter, for instance in multiple sclerosis (MS), Wallerian degeneration, and hydrocephalus, (2) differentiation of white matter lesions with high signal on T₂-weighted MR-images, like MS plaques, brain infarctions, and brain edema, (3) follow-up of cerebral white matter diseases using volumetric MT techniques, and (4) improvement in delineating of contrast enhancing brain lesions, such as cerebral metastases. We describe the physical rationale of the MT technique and present the most important current and possible future applications of MT imaging to answer clinical and scientific questions in neuroradiology.

Key words

Magnetic resonance (MR) - magnetization transfer contrast (MT) - central nervous system, MR - brain, diseases - cerebral white matter - multiple cclerosis

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