Image Fusion Techniques for Different Multimodality Medical Images Based on Various Conventional and Hybrid Algorithms for Disease Analysis

Medical Imaging Modalities

Medical imaging is the technique of creating visual representations of the interior of a body for clinical analysis and medical intervention. It seeks to reveal the internal structures hidden by the skin and bones, as well as to diagnose and treat disease. Medical images are acquired in various bands of the electromagnetic spectrum. The various modalities used in medical imaging are presented in this chapter. The basic principles of CT, MRI, PET and SPECT imaging are described. The background information of the various imaging systems, the physics behind it are presented.

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  Computed Tomography (CT)

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    The drawback of the conventional X-ray is that it is not possible to differentiate soft tissue structures from radiographic images and also unable to resolve spatial structures along the direction of X-ray.

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    The above mentioned drawbacks can be eliminated by using another imaging technology called as computed tomography.

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    In CT a planar slice of the body is defined and x-rays are passed through the slice.

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    The acquisition time is four minutes for a single section which is a time consuming process.

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    But nowadays advanced CT scanners are used with minimum acquisition time of milliseconds.

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    Also provides frozen images for moving organs like heart and lungs.

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    Reconstruction of the image is done by a method called as back projection of each filtered projection into an array of detectors. Figure 1(a) shows the CT scan machine. Neurocyticercosis disease affected CT image is shown in Figure 1(b).