Proceedings Article | 6 March 2013
Proc. SPIE. 8668, Medical Imaging 2013: Physics of Medical Imaging
KEYWORDS: Amorphous silicon, Chest, Imaging systems, Sensors, X-rays, Radiography, Diagnostics, Modulation transfer functions, X-ray detectors, Chest imaging
Cost and accessibility are major barriers to x-ray medical diagnostic screening in low- to mid-income countries. The cost
of traditional medical-grade x-ray imaging systems is prohibitively large except to major hospitals in urban centers,
preventing the early diagnosis of many curable diseases. Sputum, blood and urine tests are slower, and difficult to
administer in remote locations, having high associated transportation and storage costs. A low-cost, tuberculosis-specific,
teleradiology-enabled, digital x-ray imaging system is proposed that will make diagnosis fast, accessible and
inexpensive. A system of this type would ideally cost below $10,000 and is achievable today using a combination of
commodity and industrial products, region-of-interest imaging, and an optimization of resolution and sensitivity
requirements for the task of screening pulmonary tuberculosis.
In this research, we report preliminary investigations we have carried out on the x-ray detector, a PerkinElmer (XRD
0820) industrial-grade, 8”x8” flat-panel, amorphous silicon array with 200 micron pixels. Detective quantum efficiency
(DQE), modulation transfer function (MTF) and noise power spectrum (NPS) measurements are taken at a typical chest
radiography exposure that allow a direct comparison with high-end chest x-ray detectors and existing CR systems.
