Abstract
Intraoperative optical imaging (IOI) is a localization method for functional areas of the human brain cortex during neurosurgical procedures. The aim of the current work was to develop of a new analysis technique for the computation of two-dimensional IOI activity maps that is suited especially for use in clinical routine. The new analysis technique includes a stimulation scheme that comprises 30-s rest and 30-s stimulation conditions, in connection with pixelwise spectral power analysis for activity map calculation. A software phantom was used for verification of the implemented algorithms as well as for the comparison with the commonly used relative difference imaging method. Furthermore, the analysis technique was tested using intraoperative measurements on eight patients. The comparison with the relative difference algorithm revealed an averaged improvement of the signal-to-noise ratio between 95% and 130% for activity maps computed from intraoperatively acquired patient datasets. The results show that the new imaging technique improves the activity map quality of IOI especially under difficult intraoperative imaging conditions and is therefore especially suited for use in clinical routine.
This work was supported by Carl Zeiss Meditec AG, Oberkochen, Germany, and the Bundesministerium für Bildung und Forschung, Germany. Also, we would like to thank Anita Menschner, Enrico Noback, Titus Troisch, Falk Uhlemann, Hans Dietrich, and Andreas Schöppe for their technical assistance and support.
References
[1] Cannestra AF, Blood AJ, Black KL, Toga AW. The evolution of optical signals in human and rodent cortex. Neuroimage 1996; 3: 202–208.10.1006/nimg.1996.0022Search in Google Scholar PubMed
[2] Cannestra AF, Bookheimer SY, Pouratian N, et al. Temporal and topographical characterization of language cortices using intraoperative optical intrinsic signals. Neuroimage 2000; 12: 41–54.10.1006/nimg.2000.0597Search in Google Scholar PubMed
[3] Cannestra AF, Pouratian N, Bookheimer SY, Martin NA, Beckerand DP, Toga AW. Temporal spatial differences observed by functional MRI and human intraoperative optical imaging. Cereb Cortex 2001; 11: 773–782.10.1093/cercor/11.8.773Search in Google Scholar PubMed
[4] Cannestra AF, Pouratian N, Shomer MH, Toga AW. Refractory periods observed by intrinsic signal and fluorescent dye imaging. J Neurophysiol 1998; 80: 1522–1532.10.1152/jn.1998.80.3.1522Search in Google Scholar PubMed
[5] Haglund MM, Hochman DW. Optical imaging of epileptiform activity in human neocortex. Epilepsia 2004; 45(Suppl 4): 43–47.10.1111/j.0013-9580.2004.04010.xSearch in Google Scholar PubMed
[6] Haglund MM, Hochman DW. Furosemide and mannitol suppression of epileptic activity in the human brain. J Neurophysiol 2005; 94: 907–918.10.1152/jn.00944.2004Search in Google Scholar PubMed
[7] Haglund MM, Ojemann GA, Hochman DW. Optical imaging of epileptiform and functional activity in human cerebral cortex. Nature 1992; 358: 668–671.10.1038/358668a0Search in Google Scholar PubMed
[8] Lavine M, Haglund MM, Hochman DW. Dynamic linear model analysis of optical imaging data acquired from the human neocortex. J Neurosci Methods 2011; 199: 346–362.10.1016/j.jneumeth.2011.05.017Search in Google Scholar PubMed PubMed Central
[9] Meyer T, Sobottka SB, Kirsch M, et al. Intraoperative optical imaging of functional brain areas for improved image guided surgery. Biomed Tech 2012; 1 [accepted for publication].10.1515/bmt-2012-0072Search in Google Scholar PubMed
[10] Mrsic-Flogel T, Hübener M, Bonhoeffer T. Brain mapping: new wave optical imaging. Curr Biol 2003; 13: R778–R780.10.1016/j.cub.2003.09.022Search in Google Scholar PubMed
[11] Nariai T, Sato K, Hirakawa K, et al. Imaging of somatotopic representation of sensory cortex with intrinsic optical signals as guides for brain tumor surgery. J Neurosurg 2005; 103: 414–423.10.3171/jns.2005.103.3.0414Search in Google Scholar
[12] Noack F, Christ M, May SA, Steinmeier R, Morgenstern U. Assessment of dynamic changes in cerebral autoregulation. Biomed Tech 2007; 52:31–36.10.1515/BMT.2007.007Search in Google Scholar
[13] Pouratian N, Bookheimer SY, O’Farrell AM, et al. Optical imaging of bilingual cortical representations. Case report. J Neurosurg 2000; 93: 676–681.10.3171/jns.2000.93.4.0676Search in Google Scholar
[14] Pouratian N, Sheth SA, Martin NA, Toga AW. Shedding light on brain mapping: advances in human optical imaging. Trends Neurosci 2003; 26: 277–282.10.1016/S0166-2236(03)00070-5Search in Google Scholar
[15] Pouratian N, Sicotte N, Rex D, et al. Spatial/temporal correlation of BOLD and optical intrinsic signals in humans. Magn Reson Med 2002; 47: 766–776.10.1002/mrm.10096Search in Google Scholar PubMed
[16] Prakash N, Uhlemann F, Sheth SA, Bookheimer S, Martin N, Toga AW. Current trends in intraoperative optical imaging for functional brain mapping and delineation of lesions of language cortex. Neuroimage 2009; 47(Suppl 2): T116–T126.10.1016/j.neuroimage.2008.07.066Search in Google Scholar PubMed PubMed Central
[17] Purdon PL, Solo V, Weisskoff RM, Brown EN. Locally regularized spatiotemporal modeling and model comparison for functional MRI. Neuroimage 2001; 14: 912–923.10.1006/nimg.2001.0870Search in Google Scholar PubMed
[18] Sato K, Nariai T, Sasaki S, et al. Intraoperative intrinsic optical imaging of neuronal activity from subdivisions of the human primary somatosensory cortex. Cereb Cortex 2002; 12: 269–280.10.1093/cercor/12.3.269Search in Google Scholar PubMed
[19] Schiessl I, Stetter M, Mayhew JE, McLoughlin N, Lund JS, Obermayer K. Blind signal separation from optical imaging recordings with extended spatial decorrelation. IEEE Trans Biomed Eng 2000; 47: 573–577.10.1109/10.841327Search in Google Scholar PubMed
[20] Schwartz TH, Chen LM, Friedman RM, Spencer DD, Roe AW. Intraoperative optical imaging of human face cortical topography: a case study. Neuroreport 2004; 15: 1527–1531.10.1097/01.wnr.0000131006.59315.2fSearch in Google Scholar PubMed
[21] Sobottka SB, Meyer T, Kirsch M, et al. Intraoperative optical imaging of blood volume changes can visualize functional activated brain areas during brain surgery. Biomed Tech 2012; 1 [accepted for publication].Search in Google Scholar
[22] Thirion JP. Image matching as a diffusion process: an analogy with Maxwell’s demons. Med Image Anal 1998; 2: 243–260.10.1016/S1361-8415(98)80022-4Search in Google Scholar
[23] Toga AW, Cannestra AF, Black KL. The temporal/spatial evolution of optical signals in human cortex. Cereb Cortex 1995; 5: 561–565.10.1093/cercor/5.6.561Search in Google Scholar PubMed
[24] Yoo TS, Ackerman MJ, Lorensen WE, et al. Engineering and algorithm design for an image processing Api: a technical report on ITK – the Insight Toolkit. Stud Health Technol Inform 2002; 85: 586–592.Search in Google Scholar
[25] Zhao M, Suh M, Ma H, Perry C, Geneslaw A, Schwartz TH. Focal increases in perfusion and decreases in hemoglobin oxygenation precede seizure onset in spontaneous human epilepsy. Epilepsia 2007; 48: 2059–2067.10.1111/j.1528-1167.2007.01229.xSearch in Google Scholar PubMed
©2013 by Walter de Gruyter Berlin Boston
