gamma-aminobutyric acid (GABA) peak:В resonates at 2.2-2.4 ppm.

2-hydroxyglutarate peak: resonates at 2.25 ppm.

arterial spin labeling (ASL) MR perfusion.

dynamic contrast enhanced (DCE) MR perfusion.

dynamic susceptibility contrast (DSC) MR perfusion.

metal artifact reduction sequence (MARS).

turbo inversion recovery magnitude (TIRM).

fluid attenuation inversion recovery (FLAIR).

diffusion tensor imaging and fiber tractographyвЂ‹.

MRI pulse sequencesВ ( basicsВ | abbreviationsВ | parameters).

iodinated contrast-induced thyrotoxicosis.

iodinated contrast media adverse reactions.

clinical applications of dual-energy CT.

as low as reasonably achievable (ALARA).

Named after Austrian physicist, Christian Andreas DopplerВ (1803-1853) 4. It also allows the generation of unique phenomena such as the fluid color signВ or the twinkling artifactВ and allows the targeting of spectral Doppler for a quantitative assessment of blood flow 2.

Depiction of the general velocity and direction of blood flow within the heart and blood vessels is of primary importance in echocardiography and vascular ultrasound respectively.

Clinical useД¬olor flow Doppler is used frequently in sonography to semiquantitate overall blood flow to a region of interest. The velocity at which flow aliases is further impacted by the transducer used and the depth at which one is insonating flow. When the Nyquist limit is reached, however, aliasing results in apparent flow direction occurring in the opposite direction to actual flow, a limitation shared with pulsed wave Doppler. These colors are user-definable and may be reversed, however this is generally inadvisable as it may confuse later readers of the images. A third color, usually green or yellow, is often used to denote areas of high flow turbulence. Flow that travels away from the transducer (negative Doppler shift) is depicted in blue, and flow that is traveling toward the transducer (positive Doppler shift) is depicted in red, with lighter shades of each color denoting higher velocities. Information regarding the flow velocity and direction is arbitrarily color-coded and rendered onto a grey-scale (or M-mode) image. Pulsed wave Doppler, however, is limited to the interrogation of flow velocity and direction along a single line at a certain depth (defined by the sample volume or gate) В Color flow Doppler simultaneously interrogates multiple sample volumes (with each pixel representing a sample volume)В along an array of scan lines 1. In a manner similar to pulsed wave Doppler (PWD), color flow Doppler utilizes intermittent sampling of ultrasound waves thereby avoiding the range ambiguity characteristic of continuous wave Doppler (CWD).

Ghost hunter vena knife