Advanced X-ray Imaging Laboratory

Focus

The focus of the research is theoretical and experimental methods in medical image formation, analysis, display, and perception, with particular emphasis on factors that impede the early detection and diagnosis of subtle abnormalities in medical images, and on methods and procedures that improve radiological detection of early cancer. More specifically, recent studies have focused on four particular areas:

1. Biplane Correlation Imaging (BCI) as an advanced method for improved early detection of lung cancer. The early detection of lung cancer has been one of the outstanding challenges in radiographic imaging, the significance of which can be discerned only by considering the fact that lung cancer remains the leading cause of cancer death in the U.S., surpassing breast, prostate, colon, and cervix cancers combined. Prior research has shown that the anatomical structure is the dominant factor in the low detection of early lung cancer in radiographic images. Grounded on this basic understanding, BCI aims to develop a more sensitive image acquisition and processing approach that minimizes this influence, and thus, improves the early detection of lung cancer.

2. The methods for the assessment of image quality in digital imaging, and substantiating the relevance of image quality to diagnostic accuracy. While image quality is often spoken about in radiology circles, its quantification has proven to be complex as many factors contribute to the overall degradation of a medical image. My research and prior publications have provided a framework for assessing the performance of digital radiography systems, as recently reflected in the new IEC international standard. I currently pursue methods to further streamline the assessment methodologies and include other important contributing yet ignored factors such as scattered radiation. Furthermore, the connection between the scientific metrics of image quality and diagnostic accuracy is not straightforward. Two studies are now in progress to substantiate the relevance of these quantities in radiographic (chest and breast imaging), and computed tomography (pediatric CT).

3. The impact of display quality on diagnostic accuracy. The way in which medical image data are displayed has a direct influence on diagnosis. This dependency is task-specific, and for many tasks in medical imaging, including the early detection and classification of cancer, has not been fully substantiated in quantitative terms. I am currently investigating the influence of display characteristics on the diagnostic interpretation of breast cancer in digital mammograms and of lung cancer in chest radiographs.

4. Methods for the objective assessment of display quality. As the medical imaging practice is gradually transitioning from analog media (film) to electronic ones (computer monitors), it is vitally important to understand the tradeoffs in that transition, and to provide the best image quality possible on the display medium. In the last six years, I have led a national task force of the American Association of Physicists in Medicine (AAPM) to define standard testing methodologies for medical display devices. The report is expected to be released in 2004. I have also recently joined an IEC international committee focused on this issue as the US representative. My research in this area is currently focused on fine-tuning of the new methodologies, and to establish new testing paradigms fore remote medical displays.

Personnel

Faculty:

Ehsan Samei, PhD

Post-doctoral Fellow:

Nariman Majdi-Nasab, PhD

Graduate Students:

Sarah Boyce, MS

Amarpreet S. Chawla, MS

Chee Liang Hoe, BS

Robert Saunders, MS

Undergraduate Students:

Anahita Fashchi

Last updated 9/8/04