New CR imaging plate reduces radiation dose

November 28, 2005

Computed radiography’s new needle-like phosphor imaging plate technology provides comparable diagnostic performance with only half the radiation exposure required by its predecessor, according to a study presented Sunday. Findings suggest the gap between CR and digital radiography is shrinking as well.

Computed radiography's new needle-like phosphor imaging plate technology provides comparable diagnostic performance with only half the radiation exposure required by its predecessor, according to a study presented Sunday. Findings suggest the gap between CR and digital radiography is shrinking as well.

Concerns about radiation dose have become prominent among radiologists, particularly for patients requiring repeated imaging studies. German researchers found that chest CR using needle-structured phosphor imaging plates (NIP) match the diagnostic performance of conventional powder-based phosphor storage imaging plates (PIP) with a significant reduction in radiation dose.

In a study conducted at the University of Munich, researchers led by Dr. Markus Koerner compared plain chest x-rays obtained with PIP equipment at standard dose with follow-up studies performed with NIP technology in the same patients. The study involved 24 ICU patients. Koerner documented a 50% radiation dose reduction in the NIP studies.

The investigators divided each patient's chest into seven anatomical regions of interest for imaging, including peripheral and central lung, hilum, heart, diaphragm, upper mediastinum, and bone. They performed postprocessing using the same software package and a PACS console with two identical high-resolution softcopy reading displays for image interpretation of NIP and PIP studies, respectively.

Six independent readers found no relevant differences between NIP and PIP images after Mann-Whitney-U inter-observer coefficient tests. The mean image quality rates for NIP and PIP images were 3.47 and 3.46, respectively. Although NIP images proved noisier than PIP's, the difference was not statistically significant.

"This new technology allows a significant dose reduction, especially in patients undergoing multiple follow-up exams," Koerner said.