MIRA2015 Lecture Notes - Lecture 6: Modified Discrete Cosine Transform, Iterative Reconstruction, Image Noise
3 Aug 2018
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Document Summary
Automatic tube current, automatic tube potential selection. High-pitch acquisition (reduces procedure time but reduces resolution) The tube current (ma) is adjusted in real time during the scanning of a patient on the basis of differences in radiation attenuation in x-y or z-directions. Aec in the x-y axis (in-plane) is referred to as angular modulation, changing the tube current automatically in z-axis (through plane) is referred to as z-axis modulation or longitudinal modulation. When used together, that is angular-longitudinal tube current modulation, and it reduces the dose by 52% compared with use of only angular modulation. Longitudinal (z-axis) tube current modulation is based on differences in attenuation among body parts. The technique is designed to change the ma automatically as the patient scanned from head to toe (along z-axis) while maintaining a constant noise level for different thicknesses of body parts examined p. 44 -47. Automated attenuation-based tube voltage section is available with latest mdct such as.
