Imaging tests are among the many diagnostic tools used by physicians to diagnose and even treat disease. Propagation-based phase-contrast X-ray imaging is a term used to describe various diagnostic techniques that use information about changes in the phase of an X-ray beam as it passes through an object to produce images.

Importance of Radiology in Medical Practice

Since their discovery, X-rays have been harnessed for many scientific uses. The ability of X-rays to penetrate matter has been applied to the visualization of inner structures of opaque objects such as the human body.

Radiology is the branch of medicine that uses diagnostic imaging to diagnose and treat patients. Imaging studies include a variety of technologies designed to capture images of body parts. These tests allow physicians to visualize the internal body structures to facilitate diagnosis and treatment of various diseases.

Imaging can be performed using X-rays, computed tomography scans, magnetic resonance imaging, and positron emission tomography. These technologies allow physicians to detect abnormalities in internal organs so that treatment can be provided in a timely manner.

What is Propagation-Based Phase-Contrast X-Ray Imaging?

Traditional imaging modalities (X-rays and computed tomography) use the reduction of X-ray intensity during passage through an object to create images. Propagation-based phase-contrast X-ray imaging is a term used to describe various technical methods that use phase changes of X-ray beams during passage through an object to produce images or photographs.

In phase-contrast X-ray imaging, the coherent X-ray beam’s free space propagation is used to produce contrast. After passing through the sample, the X-ray beam’s wavefront is distorted because of the phase-shift produced by the sample.

Propagation-based phase-contrast X-ray imaging is a new method by which biologic soft tissues, polymers, low-Z materials, and carbon composite materials can be studied. In addition to creating projection images, this technique can be combined with tomographic methods to generate 3-dimensional distributions of the refractive index’s real part of the sample.

Medical Use

Tissue and organ physiology rely on 3-dimensional structure, which may be disrupted in pathologic states. Propagation-based phase-contrast X-ray imaging can be used in cell migration and invasion assays, live cell imaging, immunofluorescence, high-resolution microscopy, histology, and phenotypic assays.

Propagation-based imaging is the most common name for this application of phase-contrast X-ray imaging for medical use, which is also known as refraction-enhanced imaging, in-line holography, and phase-contrast radiography. To use this technique, an X-ray source with an in-line arrangement is used with an X-ray detector and sample. This method can be used to improve contrast of an absorption image when the phase information is lost while retaining image intensity. However, it can also separate the attenuation contrast and phase to improve separation of the imaginary and real parts of the refractive index.

As the technique is based on the weak absorption interaction of X-rays with matter, contrast disappears for poorly absorbing tissues.

Further Reading

• All Radiology Content
• What is Radiology?
• Radiologist Training
• Teleradiology
• Digital Radiology Advantages

Written by

Angela Betsaida B. Laguipo

Angela is a nurse by profession and a writer by heart. She graduated with honors (Cum Laude) for her Bachelor of Nursing degree at the University of Baguio, Philippines. She is currently completing her Master's Degree where she specialized in Maternal and Child Nursing and worked as a clinical instructor and educator in the School of Nursing at the University of Baguio.