GE debuts next-generation HDCT technologies
GE Healthcare this week rolled out its next-generation HDCT technologies that feature new detector, image reconstruction and x-ray tube technology to create better, crisper images faster and with less x-ray dose.

“HDCT technologies represent a dramatic departure from recent CT industry trends, but one that—at its core—is aligned with the real diagnostic goals that clinicians are demanding for their patients,” said Gene Saragnese, vice president of GE’s CT business. “We’re re-inventing CT to help them clearly see more detail. We’re working with new functional and time-based CT information that might help them know more. And we’re investing to provide them unprecedented diagnostic clarity using considerably less dose.”

Believing that simply adding more slices or x-ray sources does nothing to improve image clarity, GE engineers and scientists are working on completely revamping the entire CT imaging chain—from the x-ray tube through the detector and data acquisition system—even rewriting the way images are reconstructed for the first time since CT was invented.

As a new foundation, GE materials scientists are reformulating new CT detector material, having engineered new scintillator based on a modified garnet gemstone (but the traditional red color is now yellow to increase x-ray scintillator behavior). The “GE Gemstone” CT detector is being designed to significantly improvement x-ray conversion speed and other properties required to support step-function improvements in spatial resolution. It’s also being designed to enable advanced CT applications like material decomposition and monochromatic imaging.

GE engineers are also working to extend the capabilities of the Volara Digital Acquisition System (DAS) by boosting its sampling speed to more than double that of anything currently on the market today, while still maintaining its outstanding low signal performance for dose efficiency, the company said.

GE engineers are also finding a way to acquire helical dual energy data with improved temporal registration, using only a single source and detector. Utilizing a prototype HDCT imaging chain, the kVp of the x-rays can be switched from 80 kVp to 140 kVp and back in less than a blink of an eye (< 1 msec). With HDCT technologies, GE engineers are demonstrating dkVp acquisitions with temporal registration approximately 150 times better than those obtained by current technologies, the company said.

In addition, through the introduction of projection-based dual energy data processing, GE developers have been recently reconstructing monochromatic CT images that show reduced beam-hardening artifacts, and subsequently more accurate CT numbers.  This potentially fulfills a dream of truly quantitative CT exams.

With a clinical eye toward potential support of multiple application dual energy helical studies, HDCT technologies’ single source/detector approach naturally provides a 50 cm scan field of view (SFOV); twice as large as that currently available.

 “The clinical potential of dual-energy CT may finally be unleashed by HDCT technologies’ ability to natively support monochromatic whole body helical exams; potentially providing more quantitative diagnostic content, virtually free of temporal misregistration and beam-hardening effects,” Saragnese said. “Potential clinical applications may include calcium/iodine separation, accurate auto-bone removal in 3D assessments, material decomposition, and artifact-free images in areas previously rendered less diagnostic by beam-hardening.”

GE engineers are also working to dramatically expand coverage of fast-moving cardiovascular events to whole organs through an innovative volume helical shuttle technique. This HDCT technology has been under clinical investigation for over a year, and is recently demonstrating 4D coverage of up to 250 mm of thoracic anatomy. It extends helical scanning with a back-and-forth pattern, modulating energy (mA) levels during acceleration and deceleration to minimize patient dose. 

GE also is changing the way images are reconstructed. The new approach differs from traditional filtered back-projection techniques in that statistical noise profiles are utilized in an iterative manner to extract additional image clarity and suppress noise. When coupled with ongoing industry advances in computing power, these Adaptive Statistical Iterative Reconstruction (ASIR) algorithms are showing considerable promise in providing images of higher clarity and at lower patient dose—while maintaining reasonable diagnostic workflows for the reading physician.