Medical Imaging file formats
By Shreya D'Souza
What is a medical image?
A medical image represents the internal structure or function of an anatomic region in the form of pixels or voxels (value on a regular grid in a three-dimensional space).
Analyze .img .hdr
Fixed-length: 348 byte binary format
Fixed-length: 352 byte binary formata (348 byte in the case of data stored as .img and .hdr)
Extensible binary format
Variable length binary format
Medical Imaging Modalities
High-frequency sound waves transmitted from the probe to body via a conducting gel
Waves bounce back when they hit the different structures within the body - used to create an image for diagnosis.
CT (Computed Tomography)
Form of X-ray that creates a 3D picture for diagnosis: produce cross-sectional images of the body
X-ray source and a detector then rotate around the patient producing a narrow ‘fan-shaped’ beam of X-rays that passes through a section of the patient’s body
Different snapshots collated into one or multiple images of the internal organs and issues.
PET (Positron Emission Tomography)
Nuclear medical imaging
Uses small amounts of radioactive materials, a special camera and a computer to evaluate organ and tissue functions
Tracer is given through a vein (IV).
MRI (Magnetic Resonance Imaging)
Uses magnetic field and radio waves to generate images of body
Protons aligned in magnetic field
Scanner uses magnetic field to align proton spins, followed by a radio frequency being applied to flip spins of protons before they return to original alignments
Protons in different body tissues return to normal spins at different rates
MRI can distinguish between different tissue types
X-rays penetrate skin and create image of internal structures