Funktionelle Magnetresonanztomografie in der klinischen Routine

Zusammenfassung

Die funktionelle Magnetresonanztomografie (fMRT) wird überwiegend in der neurowissenschaftlichen Forschung eingesetzt, um Hirnfunktionen nicht invasiv zu messen und bildlich darzustellen. Klinisch-wissenschaftliche Applikationen dienen der Untersuchung krankheitsbedingter Veränderungen von Hirnfunktionen oder von therapeutischen Effekten, haben aber meist keinen direkten Nutzen für den individuellen Patienten. Als diagnostische Anwendung in der klinischen MR-Bildgebung ist die prächirurgische Lokalisation motorischer Areale und von Sprachzentren mit Bestimmung der sprachdominanten Hirnhemisphäre, bei Patienten mit Hirntumoren und Epilepsien etabliert. Ziel ist es, den Patienten individuell optimierte Behandlungsstrategien anzubieten, möglichst radikal und gleichzeitig funktionserhaltend. Hierfür wird die fMRT seit Mitte der 1990er-Jahre eingesetzt. Das Verfahren ist validiert und hat einen festen Platz in der MR-Diagnostik. Voraussetzung ist die Optimierung und Standardisierung von fMRT-Untersuchungen, Auswertung und neuroradiologischer Befundinterpretation. Dieser Artikel bietet relevantes Hintergrundwissen und einen Überblick zum aktuellen Stand der klinischen fMRT.

Summary

Functional magnetic resonance imaging (fMRI) is widely used for neuroscientific research to measure and visualise brain function. Clinical research applications focus on pathological alterations in brain function and on therapeutic effects, usually not providing direct benefit for the individual patient. The presurgical localisation of the motor cortex and of language areas including the determination of the language-dominant brain hemisphere is established as part of clinical MRprotocols, in patients with brain tumours and epilepsy in order to provide individually tailored strategies for radical, but function preserving treatment. To this end fMRI has been used since the mid 1990s. The method is considered valid and has been implemented into routine MR-imaging. Prerequisites for clinical use are optimisation and standardisation of fMRI protocols, data processing and neuroradiological interpretation. This article provides relevant methodological information and reviews the current status of clinical fMRI.

Schlüsselwörter

fMRT - Motor - somatosensorisch - Sprache - Hirntumor

Keywords

fMRI - motor - somatosensory - language - brain tumour

• Literatur

• 1 Belliveau JW. et al. Functional mapping of the human visual cortex by magnetic resonance imaging. Science 1991; 254: 716-9.
• 2 Ogawa S. et al. Intrinsic signal changes accompanying sensory stimulation: functional brain mapping with magnetic resonance imaging. PNAS USA 1992; 89: 5951-5.
• 3 Logothetis NK. et al. Neurophysiological investigation of the basis of the fMRI signal. Nature 2001; 412 (6843): 150-7.
• 4 Buckner RL. et al. Detection of cortical activation during averaged single trials of a cognitive task using functional magnetic resonance imaging. PNAS USA 1996; 93: 14878-83.
• 5 Stippich C. Clinical functional MRI: Presurgical functional Neuroimaging. Heidelberg: Springer Verlag; 2007
• 6 Weiller C. et al. Role of functional imaging in neurological disorders. JMRI 2006; 23: 840-50.
• 7 Biswal B. et al. Functional connectivity in the motor cortex of resting human brain using echoplanar MRI. Magn Reson Med 1995; 34: 537-41.
• 8 Le Bihan D. et al. Diffusion tensor imaging: concept and applications. JMRI 2001; 13: 534-46.
• 9 Naidich TP. et al. The motor cortex: anatomic substrates of function. Neuroimaging Clin N Am 2001; 11 (02) 171-93.
• 10 Naidich TP. et al. Anatomic substrates of language: emphasizing speech. Neuroimaging Clin N Am 2001; 11 (02) 305-41.
• 11 Yousry TA. et al. Localization of the motor hand area to a knob on the precentral gyrus. A new landmark. aBrain 1997; 12 (Pt 1): 141-57.
• 12 Fesl G. et al. Inferior central sulcus: variations of anatomy and function on the example of the motor tongue area. Neuroimage 2003; 20 (01) 601-10.
• 13 Stippich C. et al. Somatotopic mapping of the human primary somatosensory cortex by fully automated tactile stimulation using functional magnetic resonance imaging. Neurosci Lett 1999; 277 (01) 25-8.
• 14 Stippich C. et al. Robust localization of the contralateral precentral gyrus in hemiparetic patients using the unimpaired ipsilateral hand: a clinical functional magnetic resonance imaging protocol. Neurosci Lett 2000; 285 (02) 155-9.
• 15 Stippich C. et al. Somatotopic mapping of the human primary sensorimotor cortex during motor imagery and motor execution by functional magnetic resonance imaging. Neurosci Lett 2002; 331 (01) 50-4.
• 16 Stippich C. et al. Robust localization and lateralization of human language function: an optimized clinical functional magnetic resonance imaging protocol. Neurosci Lett 2003; 346 (1–2): 109-13.
• 17 Stippich C. et al. Fully automated localization of the human primary somatosensory cortex in one minute by functional magnetic resonance imaging. Neurosci Lett 2004; 364 (02) 90-3.
• 18 Stippich C. et al. Time-efficient localization of the human secondary somatosensory cortex by functional magnetic resonance imaging. Neurosci Lett 2005; 381 (03) 264-8.
• 19 Konrad F. et al. Does the individual adaptation of standardized speech paradigms for clinical functional magnetic resonance imaging (fMRI) effect the localization of the language-dominant hemisphere and of Broca’s and Wernicke’s areas?. RoFo 2005; 177: 381-5.
• 20 Partovi S. et al. Effects of covert and overt paradigms in clinical language fMRI. Acad Radiol 2012; 19: 518-25.
• 21 Blatow M. et al. Clinical functional MRI of sensorimotor cortex using passive motor and sensory stimulation at 3 Tesla. JMRI 2011; 34: 429-37.
• 22 Ulmer S. fMRI – Basics and clinical applications. Heidelberg: Springer Verlag; 2010
• 23 Jack CR. et al. Sensory motor cortex: correlation of presurgical mapping with functional MR imaging and invasive cortical mapping. Radiology 1994; 190 (01) 85-92.
• 24 Binder JR. et al. Lateralized human brain language systems demonstrated by task subtraction functional magnetic resonance imaging. Arch Neurol 1995; 52 (06) 593-601.
• 25 Stippich C. Presurgical functional magnetic resonance imaging. Radiologe 2010; 50: 110-22.
• 26 Desmond JE. et al. Functional MRI measurement of language lateralization in Wada-tested patients. Brain 1995; 118 (Pt 6): 1411-9.
• 27 Fitz DBGerald. et al. Location of language in the cortex: a comparison between functional MR imaging and electrocortical stimulation. AJNR Am J Neuroradiol 1997; 18 (08) 1529-39.
• 28 Lehericy S. et al. Correspondence between functional magnetic resonance imaging somatotopy and individual brain anatomy of the central region: comparison with intraoperative stimulation in patients with brain tumors. J Neurosurg 2000; 92 (04) 589-98.
• 29 Duffau H. New concepts in surgery of WHO grade II gliomas: functional brain mapping, connectionism and plasticity – a review. J Neurooncol 2006; 79 (01) 77-115.
• 30 Nimsky C. et al. Intraoperative visualization for resection of gliomas: the role of functional neuronavigation and intraoperative 1.5 T MRI. Neurol Res 2006; 28 (05) 482-7.
• 31 Dym RJ. et al. Is functional MR imaging assessment of hemispheric language dominance as good as the Wada-test?: a meta-analysis. Radiology 2011; 261: 446-55.
• 32 Powell HM. et al. The application of functional MRI of memory in temporal lobe epilepsy: a clinical review. Epilepsia 2004; 45: 855-63.
• 33 Rabin ML. et al. Functional MRI predicts post-surgical memory following temporal lobectomy. Brain 2004; 127: 2286-98.
• 34 Wengenroth M. et al. Diagnostic benefits of presurgical fMRI in patients with brain tumors in the primary sensorimotor cortex. Eur Radiol 2011; 21: 1517-25.
• 35 Stippich C. et al. Global activation of primary motor cortex during voluntary movements in man. Neuroimage 2007; 34: 1227-37.
• 36 Broca P. Remarques sur le siege de la faculte de la parole articulee, suives d’une observation d’aphemie (perte de parole). Paris: Bulletin de la Societe d’Anatomie; 1891
• 37 Wernicke C. The aphasic symptom complex: a psychological study on neurological basis. Kohn and Weigert, Breslau: Reprinted in Bostson. Studies in the philosophy of science, Vol 4. In: Cohen RS, MW Wartowsky. (eds.). Boston: Reidel; 1871
• 38 Geschwind N. Aphasia. N. Engl J Med 1971; 284: 654-6.
• 39 Dronkers NF. A new brain region for coordinating speech articulation. Nature 1996; 384: 159-61.
• 40 Fernandez G. et al. Language mapping in less than 15 minutes: real-time functional MRI during routine clinical investigation. Neuroimage 2001; 14: 585-94.
• 41 Stippich C. et al. Feasibility of routine preoperative functional magnetic resonance imaging for localizing and lateralizing language in 81 consecutive patients with brain tumors. Radiology 2007; 243: 828-36.
• 42 Hajnal JV. et al. Artifacts due to stimulus correlated motion in functional imaging of the brain. Magn Reson Med 1994; 31 (03) 283-91.
• 43 Hoeller M. et al. Movement artefacts and MR BOLD signal increase during different paradigms for mapping the sensorimotor cortex. Acta Neurochir (Wien) 2002; 144 (03) 279-84.
• 44 Krings T. et al. Functional MRI for presurgical planning: problems, artefacts, and solution strategies. J Neurol Neurosurg Psychiatry 2001; 70 (06) 749-60.
• 45 Weiskopf N. et al. Single-shot compensation of image distortions and BOLD contrast optimization using multi-echo EPI for real-time fMRI. Neuroimage 2005; 24 (04) 1068-79.
• 46 Wittek A. et al. Brain shift computation using a fully nonlinear biomechanical model. Med Image Comput Comput Assist Interv Int Conf Med Image Comput Comput Assist Interv 2005; 08 (Pt 2): 583-90.
• 47 Kuhnt D. et al. Brain shift compensation and neurosurgical image fusion using intraoperative MRI: current status and future challenges. Crit Rev Biomed Eng 2012; 40: 175-85.
• 48 Holodny AI. et al. The effect of brain tumors on BOLD functional MR imaging activation in the adjacent motor cortex: implications for imageguided neurosurgery. AJNR Am J Neuroradiol 2000; 21 (08) 1415-22.
• 49 Kim MJ. et al. The effect of prior surgery on blood oxygen level-dependent functional MR imaging in the preoperative assessment of brain tumors. AJNR Am J Neuroradiol 2005; 26 (08) 1980-5.
• 50 Ludemann L. et al. BOLD signal in the motor cortex shows a correlation with the blood volume of brain tumors. J Magn Reson Imaging 2006; 23 (04) 435-43.
• 51 Hou BL. et al. Effect of brain tumor neovasculature defined by rCBV on BOLD fMRI activation volume in the primary motor cortex. Neuroimage 2006; 32 (02) 489-97.
• 52 Lehericy S. et al. Arteriovenous brain malformations: is functional MR imaging reliable for studying language reorganization in patients? Initial observations. Radiology 2002; 223: 672-82.
• 53 Laurienti PJ. et al. Relationship between caffeineinduced changes in resting cerebral perfusion and blood oxygenation level dependent signal. AJNR 2003; 02: 1607-11.
• 54 Morton DW. et al. Systemic theophylline augments the blood oxygen level-dependent response to forepaw stimulation in rats. AJNR 2002; 23: 588-93.
• 55 Nimsky C. et al. Preoperative and intraoperative diffusion tensor imaging-based fiber tracking in glioma surgery. Neurosurgery 2007; 61: 178-85.