TITLE:
Effects of Tube Voltage on Phase-Contrast Imaging for Different Microfocus X-Ray Tubes
AUTHORS:
Jianbao Gui, Zhanli Hu, Peter Z. Wu, Hairong Zheng
KEYWORDS:
Phase-Contrast Imaging; Edge Enhancement; X-Ray; Tube Voltage
JOURNAL NAME:
Engineering,
Vol.5 No.10B,
October
28,
2014
ABSTRACT: In the past decade, phase-contrast imaging
(PCI) has become a hot research with an increased improvement of the image
contrast with respect to conventional absorption radiography. In this paper,
effects of tube voltage (kVp) on propagation-based phase-contrast imaging have
been investigated with two types of microfocus x-ray tubes, a conventional
sealed x-ray tube with the focal spot size of 13 - 20 μm and an open x-ray tube
with minimum focal spot size less than 2 μm. A cooled x-ray CCD detector with
the pixel size of 24 μm was used to acquire digital images. Two thin plastic
sheets with different thickness were used as radiography phantoms. Two
different phenomena were observed for the two x-ray tubes. For the open tube,
phase-contrast effect has a slight drop with the increasing of tube voltage,
however, it is opposite for the sealed tube. A further investigation indicates
that the variation of focal spot size causes the abnormal result for the sealed
tube. It also shows that phase-contrast effect is more sensitive to focal spot
size than tube voltage.