The DiCoMo (“Direct conversion hybrid-organic X-ray detectors on metal oxide backplane”) Project promises to remove the need for diagnosticians to reconcile the value of high-resolution scanning with the safety concerns associated with exposure to high doses of ionizing radiation through the development of a novel X-ray detector. Their flat panel digital X-ray detector technology draws upon advancements in photonics to improve the specificity and sensitivity of low-radiation scanning systems, thereby enabling low-cost, effective diagnosis and preventive care without endangering patients or radiology staff.
Essential radiographic imaging techniques such as X-ray and X-ray computed tomography (CT) scanning allow for visualization of internal structures by penetrating tissues with high-energy particles that produce harmful ionizing radiation. With traditional radiography systems, higher doses of radiation are required to image at high-resolution. However, additional radiation exposure creates extra risks of health consequences. As such, medical professionals are currently forced to mediate the risk and reward trade off on an application-specific basis, selecting a scanning configuration and detector type that is appropriate for visualizing a given structure or phenomenon.
Some common X-ray scanning techniques require high-resolution imaging to be of value, such as mammograms taken to evaluate or screen breast tissue for irregularities. This type of scan traditionally relies on detectors utilizing direct converters. Direct converters translate absorbed X-rays into electrical signals directly, requiring a heavy dose of X-rays and associated radiation in order to maximize spatial resolution. For other applications, especially those seeking to examine bones or other large structures through radiography or fluoroscopy, low-radiation, lower-resolution imaging is often suitable. Such scans employ detectors with indirect converters. In indirect conversion, scintillators produce light upon absorbing X-rays and the electrical signals are ultimately recorded by a photodetector. However, the scintillators create light in all directions upon X-ray irradiation, causing neighboring photodetector array pixels to register a signal, which, in aggregate, lowers the imaging resolution.
The DiCoMo Project, a consortium of European partner organizations and institutions coordinated in Germany by Siemens Healthineers, is working towards the development of an alternative, hybrid detector technology. Their detector is said to rely on “quasi-direct” conversion that allows for low-dose, high-resolution imaging. In the DiCoMo detector, the scintillator is embedded into the photodetector. This positioning limits light absorption and signal detection to the exact pixel that each X-ray photon irradiates. Additionally, active pixel sensors amplify the detected signals within each pixel via metal-oxide thin-film transistors, creating a stronger signal. Finally, a custom readout chip helps to more than double traditional detection frame rates, from approximately 60 frames per second (fps) to 130 fps. Taken together, the advanced detector technology thereby enables an unprecedented combination of high-resolution and low-radiation X-ray imaging, and is even capable of capturing fast-moving features.
In 2015, DiCoMo received significant research and innovation funding from the Photonics Public Private Partnership and the European Commission’s Horizon 2020 program. The consortium aims to leverage this funding and its existing progress to complete development of the new X-ray detectors within five years.
For additional Medgadget coverage of Photonics21 and Horizon 2020 projects, refer to this week’s story regarding how the COBIOPHAD device promises quicker, more efficient drug allergy diagnosis.
Press Release: High resolution detectors to create safer X-ray diagnosis…
More Information: DiCoMo…