New DICOM elements promise better image quality

December 30, 2004

Steps proposed by researchers to strengthen image quality and consistency can bolster medical image presentation acquired using the DICOM gray-scale standard display function.

Steps proposed by researchers to strengthen image quality and consistency can bolster medical image presentation acquired using the DICOM gray-scale standard display function.

In spite of recent refinements, a number of areas remain in which the effectiveness of DICOM GSDF could be improved to ensure high-quality medical image display, according to a study published in the November issue of the Journal of Digital Imaging.

"There are still notable gaps in the effectiveness of DICOM GSDF," said Ehsan Samei, Ph.D., an assistant professor of radiology at Duke University.

Samei proposes three planks that DICOM, the American Association of Physicists in Medicine (AAPM), and the American College of Radiology could add to strengthen the bridge between technical performance and clinical use.

Standardization could also be improved by following guidelines and tools for visual and quantitative assessment of medical display quality provided by AAPM Task Group 18.

DICOM does not provide means and acceptance criteria to evaluate the conformance of a display device to GSDF or to address other image quality characteristics, Samei said. DICOM can expand beyond luminance response, extending the measurable, quantifiable elements of TG18, such as reflection and resolution.

In a large PACS installation, it is critical to continually track the appropriate use and performance of multiple display devices. DICOM may help with this task by adding a device service class to the standard to provide for communication and control of image quality parameters between applications and devices, he said.

The question of clinical significance of image quality metrics has rarely been addressed by prior efforts.

In cooperation with AAPM, ACR, and the Society for Computer Applications in Radiology, DICOM may help to initiate research that will determine the clinical consequence of variations in image quality metrics (such as GSDF conformance) and to define what constitutes image quality from a diagnostic perspective, Samei said.

"We expect that the proposed additional DICOM elements and suggested activities will unleash the creativity of vendors, application developers, and users, providing substantial benefits for PACS users, administrators, and, ultimately, the patients," he said.