title: Ultrasonic contrast agents in transcranial perfusion sonography (TPS) for follow-up of patients with high grade gliomas.
abstract: OBJECTIVE
  The aim of this study was to evaluate brain perfusion differences in patients with high grade gliomas after partial tumor resection and irradiation/chemotherapy between tumor and non-tumor hemisphere by transcranial perfusion sonography (TPS) employing a contrast burst imaging (CBI) technique.
  
  
  METHODS
  Six patients with glioblastoma (WHO Grade IV) in the temporoparietal region within the defined axial diencephalic scanning plane were examined by TPS during follow-up. All subjects had an adequate acoustic temporal bone window. Transtemporal insonation on brain tumor and non-tumor hemisphere was performed with a bolus-injection of sulphur hexafluoride-based contrast agent (10 mg i.v., 5mg/ml--SonoVue, Bracco, Altana, Switzerland). Recorded images were analysed off-line by Quanticon Software (3D-Echotech, Munich, Germany) and time intensity curve parameters [area under the curve (AUC, dB s), peak intensity (PI, dB), time to peak (TTP, s)] in five regions of interest (ROI) [thalamus anterior, thalamus posterior, nucleus lentiformis, white matter, whole hemisphere] were evaluated. Statistical analyses were performed.
  
  
  RESULTS
  Perfusion differences between brain tumor and non-tumor hemispheres were detected with contrast burst imaging (CBI) technique with a significantly greater mean AUC (5343.69 dB s vs. 4625.04 dB s, p<0.028) and a significantly prolonged TTP (32.72 s vs. 28.91 s, p<0.046) in the tumor hemisphere.
  
  
  CONCLUSIONS
  Within our study population, TTP and AUC seem to be the most robust parameters for the evaluation of cerebral perfusion differences assessed by transcranial perfusion sonography with CBI technique. We hypothesize that these results correlate with microvascular changes due to treatment regimens, such as microvessel necrosis after irradiation and chemotherapy. Above that, TPS may be of value for the long-term follow-up of brain tumor therapy concept.
authors.affiliation: Department of Neurology, University of Regensburg, Germany; Department of Neurology, HELIOS General Hospital Aue, Technical University Dresden, Gartenstrasse 6, 08280 Aue, Germany. Electronic address: guntram.ickenstein@helios-kliniken.de.
authors.forename: G W
authors.initials: GW
authors.lastname: Ickenstein
authors.affiliation: Department of Neurology, University of Regensburg, Germany; Department of Neurology, Vilnius University Hospital, Santariskiu Klinikos, Lithuania.
authors.forename: J
authors.initials: J
authors.lastname: Valaikiene
authors.affiliation: Department of Neurology, University of Regensburg, Germany.
authors.forename: H
authors.initials: H
authors.lastname: Koch
authors.affiliation: Department of Neurology, University of Regensburg, Germany.
authors.forename: P
authors.initials: P
authors.lastname: Hau
authors.affiliation: Department of Neurology, University of Regensburg, Germany.
authors.forename: P
authors.initials: P
authors.lastname: Erban
authors.affiliation: Department of Neurology, University of Regensburg, Germany.
authors.forename: F
authors.initials: F
authors.lastname: Schlachetzki
mesh_terms: D000328:Adult; D000368:Aged; D019540:Area Under Curve; D001932:Brain Neoplasms / Q000000981:diagnostic imaging* / Q000628:therapy; D003131:Combined Modality Therapy; D003287:Contrast Media; D005260:Female; D005500:Follow-Up Studies; D005909:Glioblastoma / Q000000981:diagnostic imaging* / Q000628:therapy; D006801:Humans; D008297:Male; D008875:Middle Aged; D010477:Perfusion; D017585:Ultrasonography, Doppler, Transcranial
chemical_list: D003287:Contrast Media