Einführung in die medizinische Bildverarbeitung SS 2013
Einführung in die medizinische Bildverarbeitung SS 2013
Einführung in die medizinische Bildverarbeitung SS 2013
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Grundlagen - Bilderzeugung<br />
Computertomographie Artefakte<br />
FIGURE 1. Examples of CT artifacts: streak artifact (A), motion artifact (B), beam-harden<strong>in</strong>g artifact (C), r<strong>in</strong>g artifacts (D and E),<br />
and bloom<br />
A -<br />
artifact<br />
Streak<br />
(F).<br />
Artifact B - Motion Artifact C - Beam Harden<strong>in</strong>g<br />
D - R<strong>in</strong>g Artifact<br />
to each peak kilovoltage sett<strong>in</strong>g. Beam harden<strong>in</strong>g is a complex<br />
paradigm that <strong>in</strong>volves trade-offs related to patient dose,<br />
image noise, contrast, and CT number uniformity. Therefore,<br />
technologists must carefully consider selection of imag<strong>in</strong>g<br />
parameters, filters, and patient position with<strong>in</strong> the scanner.<br />
Beam harden<strong>in</strong>g presents as dark band<strong>in</strong>g between dense<br />
objects such as bone. Variations of contrast and <strong>in</strong>tensity<br />
across an object can appear like certa<strong>in</strong> pathologic conditions<br />
E - R<strong>in</strong>g Artifact<br />
[Quelle: CT Artifact Recogition for the Nuclear Technologist, Popilock et al.]<br />
F - Bloom Artifact<br />
response for different scann<strong>in</strong>g conditions (kilovoltage, collimator<br />
aperture, etc.) <strong>in</strong> an effort to m<strong>in</strong>imize the aforementioned<br />
effects. It is also important to ma<strong>in</strong>ta<strong>in</strong> the<br />
specified ambient room conditions for the scann<strong>in</strong>g room<br />
to m<strong>in</strong>imize temperature drift over time.<br />
© Stephan Gimbel <strong>E<strong>in</strong>führung</strong> <strong>in</strong> <strong>die</strong> mediz<strong>in</strong>ische BLOOM <strong>Bildverarbeitung</strong><br />
ARTIFACTS<br />
h_da
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