title: Lack of correlation between Xenon133 and near infrared spectroscopy/indocyanine green rCBF measurements.
abstract: In recent literature there are some reports describing cerebral blood flow measurements by a near infrared spectroscopy-based technique with indocyanine-green as an absorbant. To our knowledge there is no systematical study which evaluates this technique in comparison to absolute cerebral blood flow measurements. Ten patients suffering from head injury (n = 9) or subarachnoid hemorrhage (n = 1) were included. Twenty measurements of cerebral blood flow were performed, employing a Xenon133 clearance technique. Near-infrared spectroscopy measurements were performed with the Somanetics 4100 System. Indocyanine-green was given at a total dose of 0.2 mg kg-1 bodyweight intravenously. The indocyanine-green curve was compared to cerebral blood flow measurements according to rising time and area under the curve as suggested in the literature. No correlation between the indocyanine-green clearance curve and the Xenon133 cerebral blood flow measurements could be found. Neither the area under the curve (p = 0.93) nor the rising time (p = 0.75) showed a statistically significant correlation. The near-infrared spectroscopy based indocyanine-green clearance curve measurement method of cerebral blood flow seems not to give reliable results using simple mathematical models (area under the curve and rising time). In view of our findings, we have serious reservations in the potential of this technique.
authors.affiliation: Klinik und Poliklinik für Neurochirurgie, Klinikum der Universität Regensburg, Franz Josef Strauss-Allee 11, 93053 Regensburg, Deutschland. rolf.rothoerl@klinik.uni-regensburg.de
authors.forename: Ralf Dirk
authors.initials: RD
authors.lastname: Rothoerl
authors.forename: Karl Michael
authors.initials: KM
authors.lastname: Schebesch
authors.forename: Rupert
authors.initials: R
authors.lastname: Faltermeier
authors.forename: Chris
authors.initials: C
authors.lastname: Woertgen
authors.forename: Alexander
authors.initials: A
authors.lastname: Brawanski
mesh_terms: D000328:Adult; D000368:Aged; D019540:Area Under Curve; D002560:Cerebrovascular Circulation; D004396:Coloring Agents; D006259:Craniocerebral Trauma / Q000000981:diagnostic imaging* / Q000503:physiopathology; D005260:Female; D006801:Humans; D007208:Indocyanine Green; D008297:Male; D011877:Radionuclide Imaging; D015203:Reproducibility of Results; D019265:Spectroscopy, Near-Infrared / Q000379:methods* / Q000592:standards; D013345:Subarachnoid Hemorrhage / Q000000981:diagnostic imaging / Q000503:physiopathology; D014057:Tomography, X-Ray Computed; D014980:Xenon Radioisotopes
chemical_list: D004396:Coloring Agents; D014980:Xenon Radioisotopes; D007208:Indocyanine Green