Photon Factory Activity Report 2005 #23 Part B (2006)
Medical Applications

14C1/2003G319

Depiction of knee joint structure by means of X-ray diffraction
enhanced imaging
Koichi MORI1, Hitoshi SATO1, Daisuke SHIMAO1, Norio SEKINE2, Masahiko MONMA1,Hiroshi OKA3, Kazuyuki HYODO4
1
Ibaraki Prefectural Univ., Ami, Inashiki, Ibaraki 300-0394, Japan
2
Tokyo Metropolitan Univ., Higashi-Ogu, Arakawa-ku, Tokyo 116-8551, Japan
3
St. Marianna Univ., Kawasaki, Miyamae-ku, Kanagawa 216-8512, Japan
4
KEK-PF, Oho, Tsukuba, Ibaraki 305-0801, JapanIntroduction
X-ray refraction contrast imaging with a siliconanalyzer (XDEI) was used to provide a high depiction
image on soft tissues such as mammary tissue, articularcartilage, cruciate ligament and meniscus 1,2). If clinicalimaging with this method is used, the application of Xray image diagnosis will be expanded drastically. In order
to investigate the depiction performance of the XDEI
using a 2D exposure field, an experiment was performed
with a raw knee joint of a Landrace Large White Duroc(LWD-pig) whose soft tissue was formed into a humanlike joint. This sample was chosen because it washomologous to a human knee joint in bone size and finestructures. The Experimental arrangement, preparation of
the sample, image qualities of the sample are described asfollows.
Experiment
The experiment was performed at BL 14C1. The
maximum ring current was 60mA under single bunch
operation. The experimental arrangement is shown in
Fig1. The Si (220) asymmetrical diffraction crystal
extends the size of the horizontal exposure field,
simultaneously improving the angular divergence ofincident X-ray. The Bragg angle at the crystal was 6.18
degrees at an X-ray energy of 30 keV. The crystal surface
had a 5 degree inclination to the Si (220) diffraction
plane; therefore the asymmetric factor was 0.11. Since thelength of the crystal was 180 mm, the horizontal size ofexposure field was about 36 mm. The vertical size of theexposure field was restricted by the present design of thebeam-line, with a maximum value of 30 mm. The Lauetype analyzer with a diffraction plane of (220) waslocated behind the sample. The analyzer crystal wasadjusted near the symmetric Si (220) diffraction conditionin the Laue-geometry. In this configuration, two kinds of
X-ray with almost the same intensity were acquired by
the forward diffracted and diffracted X-rays. Both X-rays
were detected by a high resolution imaging-plate and/or amammography film.
The sample was the right side of the knee joint from apart of the raw LWD-pig without skin. The fat and soft
tissue around the joint was removed adequately to a
thickness of 5 to 10 mm. The remaining main soft tissues
c were the articular cartilage at the distal end of the femur
and the proximal end of the leg, ligaments in the intercondylar fossa, and the meniscuses of both lateral and238

Users' Report

Fig. 1 The experimental arrangement of XDEI at BL14C1.
The exposure time was about 90 sec in case of the film.

Figs. 2 The frontal views of the knee joint. Both (a) and(b) are absorption contrast images, and (c) and (d) basedon the DEI of diffracted images, respectively.
medial sides. The sample images are shown in Figs. 2 (a)to (d). In the absorption contrast images, anatomicalcondylar fossa, and the meniscuses of both lateral andmedial sides. The sample images are shown in Figs. 2 (a)to (d). In the absorption contrast images, anatomicalstructure cannot be observed except for the compact bone.
In the DEI of (c), in addition to the compact bone, thecruciate ligament image with a width of about 10 mm wasclearly delineated. In the DEI of (d), the image of thearticular cartilage with a width of about 2 mm and awedge-shaped organ image of the meniscus were clearlydelineated. Image qualities, image contrast and resolution,of these DEI were better than that of present clinical MRI.
References[1] D. Shimao et al., JJAP. 44 1A 450-451 (2005).
[2] M. Ando et al., NIM. A 548. 1-16 (2005).