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Ultrasound Doppler imaging can be used to obtain basic functional measurements of brain activity using blood flow. In functional transcranial Doppler sonography, a low frequency (1-3 MHz) transducer is used through the temporal bone window with a conventional pulse Doppler mode to estimate blood flow at a single focal location.
Sensitivity varies between 42% for lesions <1 cm and 95% for tumors larger than 1 cm, and specificity can reach 90%. Optimal time interval for ultrasound screening of “at risk” population is 6 months as it results from clinical trials that investigated the tumor size doubling time (Bruix, 2005; Maruyama et al., 2008).
Two methods of recording may be used for this procedure. The first uses "B-mode" imaging, which displays a 2-dimensional image of the skull, brain, and blood vessels as seen by the ultrasound probe. Once the desired blood vessel is found, blood flow velocities may be measured with a pulsed Doppler effect probe, which graphs velocities over time.
In DXA, bone mineral content (measured as the attenuation of the X-ray by the bones being scanned) is divided by the area (also measured by the machine) of the site being scanned. Because DXA calculates BMD using area (aBMD: areal Bone Mineral Density), it is not an accurate measurement of true bone mineral density, which is mass divided by a ...
In the early 2000s, the field of neuroimaging reached the stage where limited practical applications of functional brain imaging have become feasible. The main application area is crude forms of brain–computer interface. The world record for the spatial resolution of a whole-brain MRI image was a 100-micrometer volume (image) achieved in 2019.
However, scientists are able to more thoroughly understand brain function by studying the interaction of distinct brain regions, as a great deal of neural processing is performed by an integrated network of several regions of the brain. An active area of neuroimaging research involves examining the functional connectivity of spatially remote ...
Cranial ultrasound is a technique for scanning the brain using high-frequency sound waves. It is used almost exclusively in babies because their fontanelle (the soft spot on the skull) provides an "acoustic window". A different form of ultrasound-based brain scanning, transcranial Doppler, can be used in any age group.
Technetium (99m Tc) sestamibi (commonly sestamibi; USP: technetium Tc 99m sestamibi; trade name Cardiolite) is a pharmaceutical agent used in nuclear medicine imaging.The drug is a coordination complex consisting of the radioisotope technetium-99m bound to six (sesta=6) methoxyisobutylisonitrile (MIBI) ligands.