![]() ![]() ![]() diffusion tensor imaging and fiber tractography.MRI pulse sequences ( basics | abbreviations | parameters).iodinated contrast-induced thyrotoxicosis.iodinated contrast media adverse reactions.clinical applications of dual-energy CT.as low as reasonably achievable (ALARA).lipomatous hypertrophy of the interatrial septumĪids in the identification of inflammation 3:.ApplicationsĪids in the diagnosis of benign conditions 3: choose TEs close to 4.5 ms, 9 ms, 13.6 msīlack boundary artifact has several other synonyms, including chemical shift artifact of the 2 nd kind, phase cancelation artifact, edging artifact, and black line artifact.This artifact does not occur with spin echo (SE) sequences as the spins are rephased by the 180 o refocusing gradient. At 1.5 T, the 3.5 ppm difference in frequency between water and saturated fat results in cancelation of spins at 4.5 ms multiples, starting at about 2.3 ms for example at 6.8 ms, 11.3 ms, and 15.9 ms. This artifact occurs in gradient echo (GE) sequences as a result of selecting an echo time (TE) in which the fat and water spins (located in the same voxel at an interface) are out of phase, canceling each other. This results in a sharp delineation of the muscle-fat boundary lending the image an appearance as if someone has outlined these interfaces with ink that is sometimes visually appealing but not an anatomical structure. Black boundary artifact, also known as India ink artifact or type 2 chemical shift artifact, is an artificially-created black line located at fat-water interfaces such as those between muscle and fat.
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