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Hypertension and Correlation to Cerebrovascular Change: A Brief Overview
Published in Ayman El-Baz, Jasjit S. Suri, Cardiovascular Imaging and Image Analysis, 2018
Heba Kandil, Dawn Sosnin, Ali Mahmoud, Ahmed Shalaby, Ahmed Soliman, Adel Elmaghraby, Jasjit S. Suri, Guruprasad Giridharan, Ayman El-Baz
Doppler ultrasonography (handheld, Duplex, Color, and Power) uses high-frequency sound waves generated by a transducer to measure blood flow using the Doppler Effect and blood pressure [47]. The transducer is pressed externally against the patient's skin, with gel between the transducer head and the patient's skin to act as a coupler and eliminate air and to reduce static. This painless noninvasive procedure is generally performed in a hospital radiology department by a sonographer. Intravascular ultrasound is a noninvasive, clean, safe, and inexpensive modality that offers detailed imaging of cardiac arteries [48]. However, it is noisy and cannot image gas-filled and bony structures because they absorb ultrasound waves.
Compression garments and cerebral blood flow: Influence on cognitive and exercise performance
Published in European Journal of Sport Science, 2018
Brittany A. Smale, Joseph M. Northey, Disa J. Smee, Nathan G. Versey, Ben Rattray
During each intervention, MCAv was measured continuously using 2 MHz transcranial Doppler ultrasonography (DWL Doppler, Compumedics Ltd, Germany) by a single trained operator. The MCA was identified through the right temporal window using search techniques described previously (Willie et al., 2011). A Finometer was also placed around the middle finger of the left hand for the entirety of each intervention trial to continually measure finger MAP by photoplethysmography at a 2 Hz frequency (Finapres Medical Systems BV, Amsterdam, The Netherlands) and real time data were captured with the PowerLab (Labchart 7, ADInstruments, Sydney, Australia). To improve the stability of readings, the participants’ left arm was supported at heart level in a relaxed position for 30 s from the 3 min 30 s time point of each increment. A heart rate monitor (Polar Electro, Kempele, Finland) was also fitted with a chest strap to each participant for continuous measurements throughout the trial. The pressure of end-tidal CO2 (PetCO2) was continuously recorded in the intervention trials with a calibrated breath-by-breath K4b2 COSMED system (COSMED, Rome, Italy). Data for MCAv, MAP, PetCO2, and heart rate were averaged over 30 s periods for each time point. Fingertip blood samples were drawn into capillary tubes and analysed immediately to determine lactate concentration with an iStat Radiometer (CD4 + cartridge, Abbott Point of Care, Princeton, NJ, USA).