Transient Response Harmonic Imaging

• DOI: 10.1161/01.str.29.9.1901
• Publication Date: 2011-06-17T20:08:03Z
• Authors: Thomas Postert; Andrea Muhs; Saskia Meves; Jens Federlein; Horst Przuntek; Thomas Büttner
• Keywords: Contrast-enhanced ultrasound; Intensity; Second-harmonic imaging microscopy

Background and Purpose —Gray-scale harmonic imaging is the first method to visualize blood perfusion capillary flow with ultrasound after intravenous contrast agent application. The purpose of present study was evaluate potential transient response second (TRsHI) assess normal echo characteristics in different brain areas by transcranial ultrasound. Methods —In 18 patients without cerebrovascular diseases, TRsHI examinations were performed bilaterally use transtemporal approach application 6.5 mL a galactose-based microbubble suspension (400 mg/mL). transmission rate once every 4 cardiac cycles. Regional cerebral visually assessed then quantified off-line time-intensity curves. In regions interest (ROI) (posterior part thalamus [ROIa], anterior [ROIb], lentiform nucleus [ROIc], white matter [ROId]), following parameters evaluated: peak intensity, area under curve (AUC), time intensity. AUC ratios for ROIc/a, d/a, c/b, d/b calculated. Results all parenchymal enhancement detectable. One hundred thirty-one characteristic curves (baseline phase, slow washout phase) demonstrable 144 ROIs. ROIc ROId, could be observed most frequently (68/72 examinations), whereas ROIa ROIb not evaluated because inadequate 9 72 examinations. Time intensity varied between 20 52 cycles; 1 patient it 88 individuals AUCs 16 subjects ROId showed 2- 10-fold increase compared ROIb. no examination did show >2-fold side difference irrespective ROI. Conclusions —The demonstrates that produces accurate represents an ultrasonic tool related perfusion. Absolute values quantitative high variations caused temporal bone thicknesses complex relationship concentrations measurements optic intensities. Ratios ROIs help compare areas. Furthermore, fact attenuation depends strictly on insonation depth, studies cannot directly other techniques such as positron emission tomography.