In the near future, CT may have to make way for a promising new diagnostic imaging modality called photon counting computer tomography (PCCT). Hitachi Medical Corporation and Redlen Technologies, a radiation sensor manufacturer, announced an agreement today to develop a direct conversion semiconductor X-ray detector module to be used with the cutting edge imaging exam.

PCCT is a form of CT, but it extracts tomographic images from the measured amount of X-ray photons. CT measures the summation of the energy of X-ray photons, but PCCT can measure the energy of detected X-ray photons individually, which allows much more information to be acquired.

In addition, conventional CT can’t tell the difference between calcified and adipose tissue and blood, but PCCT can. By generating more detailed information on the targeted organs, the technology may allow clinicians to select medical treatments that are more appropriate for the patients.

The data that is obtained by PCCT tends to be less affected by electric noise and that means that the number of X-ray photons is accurately counted. As a result, the amount of radiation administered to the patient can be reduced without compromising image quality.

Last week, HCB News reported that the Clinical Center at the National Institutes of Health (NIH) in Maryland, has begun investigating the potential of PCCT in a hospital-based research setting.

"Now is an exciting time for us and for our study participants here in the Clinical Center as we help test and develop this CT technology so that it may one day help patients around the world and impact the health care they receive," said Dr. David Bluemke, chief of the Department of Radiology at the NIH Clinical Center, in a statement.

Redlen manufactures high-resolution Cadmium Zinc Telluride (CZT) semiconductor radiation detectors, which are used in the medical imaging, security, and nondestructive testing fields. The company has successfully developed semiconductor radiation sensors that can measure the unique energy of individual X-ray photons, while operating at the high count rates and stability levels that CT requires.

Under the agreement, Hitachi and Redlen will work together to develop the data acquisition technology required to process the high amount of data that is generated from the CZT semiconductor radiation sensors. They will also develop the packaging technology that is required to assemble the sensors into a detector module.

The companies plan to develop the PCCT system equipped with the sensors in the next two years. After that, they will investigate the clinical indications that the modality is best suited for, and then work to compare the new modality with conventional CT.

One of the indications Hitachi expects that PCCT will be useful for is an application for accurate quantitative evaluation of vulnerable plaque.