Biomedical Engineering Reference
In-Depth Information
(a)
(b)
Figure 1.
Effects of inhomogeneity in MRI images of brain: (a) images without inhomo-
geneity; (b) with inhomogeneity effects.
Figure 2.
Illustration of streak artifacts in CT images.
from the middle to the outer sides. Figure 2 shows the effect of metal in CT, where
radial streaks are observed from the metal sites (right region in the image).
The resolution of the imaging device also determines image quality. A low-
resolution device suffers from problems of fuzzification and occlusion of bound-
aries, giving rise to blurred and disconnected anatomical edges. But an increase
in image resolution is limited by factors like a low signal-to-noise ratio, expo-
sure to more radiation, extended imaging time, and increasing contrast dosages.
With all these factors affecting image quality, the challenge for the image analysis
