MEDICAL APPLICATIONS

Photon counting based computed tomography (PC-CT) is the latest implementation of a revolutionary technology, a remarkable advance in the science of X-ray imaging.

Photon counting detectors measure the energy of individual photons after they have passed through the patient’s body, rather than their collective absorption, thereby capturing more detailed information in the resultant X-ray image.

The benefits include better spatial resolution, reduction of artifacts and - in many applications - radiation dose, as well as increased contrast. Photon counting also enables the imaging of separate tissues which when combined can form ‘colour’ images, providing additional diagnostic information.

Patients can be scanned rapidly but with less dose because of the high sensitivity of photon counting X-ray detectors.

Photon counting detectors create X-ray images with increased spatial resolution, bringing high quality information to the task of comprehensive and detailed patient assessment.

Dual energy and multi-energy imaging offer the clinician the opportunity to look more closely at bone composition and density, important parameters for the diagnosis of skeletal diseases.

A single exposure is all that is needed to capture separate images of different tissue types with a photon counting detector.

Three views are generated, including soft tissue, bone structure, as well as the conventional absorption image. These individual views could be of value to a range of investigations, such as lung examinations.

Clinical features that are hard to see with conventional contrast imaging are finally revealed with photon counting X-ray detectors. This is because photons are converted directly into electrical signals using Cadmium Telluride, rather than a scintillator, which avoids smearing or blurring. The images are sharp and patient dose is low.

With dual energy, tissue can be differentiated and analysed which could lead to the discovery of more clinical information. Looking ahead, the technology could be used to estimate composition of a tissue, such as the mineral content of bone, providing quantitative data for patient treatment.

The benefits of photon counting technology extend to specimen imaging, where the high resolution, low noise and tissue separation capabilities of the technology are creating opportunities for more accurate, faster analyses.

Energy separation can be deployed to detect certain structures or classes of tissue, such as tumour tissue, with more clarity and contrast. This information can then be analysed using artificial intelligence (AI) or machine learning approaches.

As photon counting drives new applications in medical imaging, patients will benefit. Increasing spectral imaging (colour X-ray) will open new doors for better healthcare.