Chance and limit of imaging of articular cartilage in vitro in healthy and arthritic joints: DEI (diffraction enhanced imaging) in comparison with MRI, CT, and ultrasound

Abstract

Description of purpose: Treatment of osteoarthritis in stages of reversible disease requires high resolution visualization of early cartilage damage and of subchondral bone. Here, DEI (Diffraction Enhanced Imaging) is compared to MRI, computed X-ray tomography (CT) and ultrasound (UI) in its ability to detect early degeneration of articular cartilage. In contrast to conventional absorptive X-ray examination where cartilage is poorly visible DEI captures cartilage by detection of selected refraction. Methods: Human femoral heads were investigated by macroscopic inspection, conventional X-ray examination, DEI, MRI, CT, UI and histology. DEI is an imaging technique applying a monochromatic parallel synchrotron X-ray beam. Image features were verified by histology. Results: DEI, MRI and ultrasound lead to interpretable images of cartilage. Of all techniques, DEI provided highest image resolution revealing the structural tissue architecture. MRI needs a very long exposure time (more than 5 hours) to achieve comparable quality. Application of ultrasound is limited because of joint geometry and, at high sound frequency, the necessity of close contact between cartilage and transducer. DEI is an experimental technique which needs synchrotron radiation. Conclusion: DEI is a very promising imaging technique for visualization of cartilage and bone. It may serve as an excellent analytical tool for experimental studies. Our pictures show a part of future of optimised techniques for imaging. Synchrotron based DEI may lead the way towards optimisation of improved techniques for imaging. Upon development of adequate small scale X-ray sources, DEI will also be an important supplementation for medical imaging.

Diffraction Enhanced Imaging

“…Neben knöchernen Strukturen sind auch periartikuläre Weichteile (5) deutlich besser darstellbar als in konventioneller Röntgentechnik. Die Möglichkeit zur Gelenkknorpeldarstellung durch Röntgenstrahlen mittels DEI eröffnet neue Wege der Bildgebung (3,9,(16)(17)(18). Auch die Beurteilung der Knochen-Implantat-Grenze kann durch DEI eine neue Dimension erreichen (3,19).…”

In vivox-ray phase contrast analyzer-based imaging for longitudinal osteoarthritis studies in guinea pigs

“…The cartilage tissue itself is not visible, and focal cartilage defects or structural abnormalities, which are diagnostic of early stages of the degenerative joint disease, are invisible on standard x-ray radiographs or computed tomographs (Wagner et al 2005a(Wagner et al , 2005b.…”

“…Comparative studies of standard imaging data versus phase contrast images for biological applications have been extensively carried out by several groups (Arfelli et al 2000, Bravin et al 2007, Coan et al 2008, Keyriläinen et al 2005, 2008, 2010, Pisano et al 2000, Wagner et al 2005a, 2005b. Pilot in vivo phase contrast experiments have been carried out to visualize cancer implanted in nude mice (Takeda et al 2004) or to study the lung liquid clearance at birth in rabbits (Hooper et al 2009); the interferometry and the propagation phase contrast imaging techniques were used, respectively.…”

X-ray diffraction enhanced imaging study of intraocular tumors in human beings

“…Because of their low contrast differences, most of the medical soft tissues cannot be seen to any extent with the X-ray absorption contrast imaging (XACI) methods mentioned above. Although the other types of modern medical imaging methods can provide important information on human internal structures than XACI, such as ultrasonic and MRI techniques, these methods still suffer from a limited resolution [1].…”