High-capacity x-ray tube could be boon for CT

Monday, November 26 | 12:15 p.m.-12:45 p.m. | PH214-SD-MOA5 | Lakeside, PH Community, Station 5

Researchers are developing a new high-capacity x-ray tube designed to increase dose efficiency and improve image quality for low-energy, contrast-enhanced CT scans.

Justin Solomon, PhD, a radiation physicist at Duke University Health System, is scheduled to present the study, which tested the next-generation, high-capacity x-ray tube against a standard-capacity x-ray tube on a multisized phantom (Mercury 4.0,Gammex). A routine 120-kV abdominopelvic protocol compared the performance of the tubes at 70 kV, 80 kV, and 120 kV. The evaluations included the x-ray tubes' noise power spectrum, dose efficiency, spatial frequency, iodine contrast, and detectability index using image quality analysis software.

The results showed promise for the high-capacity x-ray tube, with dose efficiency estimated at 33 mGy, 32 mGy, and 21 mGy for 70 kV, 80 kV, and 120 kV, respectively. This indicates that low-kV imaging is potentially more dose-efficient for detecting 5-mm lesions, for example.

The x-ray tube's higher maximum output capacity also resulted in a 16% and 10% increase in the diameter of the largest patient that could be imaged at 70 kV and 80 kV, respectively. Additional image quality improvements for larger patients may also be possible using further optimizations of current protocol settings, the researchers speculated.

Perhaps most important, the new x-ray tube achieved comparable image resolution in the routine abdominopelvic protocol.