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Glossary Term
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Voxel

Definition

A voxel, short for "volume pixel," is the smallest distinguishable cube-shaped unit in a three-dimensional (3D) imaging dataset. Unlike a pixel, which represents a two-dimensional point in an image, a voxel represents a point in 3D space, including information about its location, intensity, and sometimes additional properties like density or composition.

Relevance to the MedTech Industry

Voxels are fundamental in medical imaging technologies, such as CT, MRI, and PET scans, where 3D representations of anatomical structures or physiological processes are reconstructed from imaging data. They enable detailed analysis of internal body structures and aid in diagnosis, treatment planning, and research.

Additional Information & Related Terms

Key Characteristics of Voxels

  1. Resolution:

    • The size of each voxel determines the resolution of the 3D image. Smaller voxels yield higher resolution and more detailed visualizations.

    • Example: A 1 mm³ voxel offers less detail than a 0.5 mm³ voxel.

  2. Intensity Values:

    • Each voxel stores intensity or density information based on the imaging modality.

    • Example: In CT, voxels represent Hounsfield units (HU), which correspond to tissue density.

  3. 3D Representation:

    • Voxels form a 3D grid or matrix, with each voxel representing a specific volume in the scanned region.


Examples of Applications in Medicine

  1. 3D Imaging:

    • CT or MRI scans generate 3D models of organs and tissues using voxel data.

  2. Radiation Therapy Planning:

    • Voxels represent dose distributions, enabling precise targeting of tumors while sparing healthy tissues.

  3. Functional Imaging:

    • In PET or fMRI, voxel intensity reflects metabolic or neural activity at specific locations.

  4. Surgical Navigation:

    • Voxel-based reconstructions guide surgeons during procedures like brain or spinal surgeries.

  5. Disease Progression Monitoring:

    • Changes in voxel intensity over time help track conditions like cancer or multiple sclerosis.

Related Terms

  • Pixel: The 2D equivalent of a voxel, representing a single point in an image.

  • Resolution: The level of detail in an image, determined by voxel or pixel size.

  • Volume Rendering: A technique for visualizing voxel data as a 3D image.

  • Hounsfield Units (HU): The intensity scale used in CT imaging, mapped to voxel values.

  • Segmentation: The process of isolating specific structures within voxel-based datasets for analysis.

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