ABSTRACT
Photoacoustic tomography is a developing, promising,non-invasive imaging method in the medical clinic diagnosis. It is an ultrasound-mediated biophotonic imaging method based on the intrinsic optical absorption properties of tissue and ultrasonic detection, and combines the merits of both high contrast advantage of pure optical imaging and high resolution advantage of pure ultrasound imaging. Photoacoustic tomography can be performed by detecting photoacoustic waves instead of detecting photons. In photoacoustic tomography, imaging contrast is based primarily on the optical properties of biological tissues, and imaging resolution is based primarily on the ultrasonic waves. It can avoid the influence of optical scattering on imaging resolution in principle, and can provide tomography of tissues with high contrast and high spatial resolution at medium depths. Photoacoustic tomography can provide an effective approach to studying the structures, physiological properties, metabolisms, pathological properties of biological tissues. It has important potential clinical applications in the early non-invasive detection of cancers, structural and functional in vivo imaging. A brief introduction of photoacoustic imaging mechanisms is gives, and the imaging methods, the image reconstruction algorithm and the potential biomedical applications of photoacoustic tomography are reveiewed.
ABSTRACT
<p><b>OBJECTIVE</b>To report a new method of coracoid transposition for the treatment of complete dislocation of acromioclavicular joint and to evaluate its efficacy.</p><p><b>METHODS</b>We modified Dewar's surgical method as follows: (1) Two small incisions, a transversal incision on the acromioclavicular joint and a longitudinal incision on the coracoid, were made instead of a conventional large arc incision from the acromion to coracoid. (2) The foreign body in the acromioclavicular joint was cleared out. The chondral surface at the lateral segment of clavicle was resected to form a pseudarthrosis and meanwhile the residual joint capsule and ligaments were repaired. (3) The coracoid was moved to the anteroinferior edge of the clavicle instead of the anterior margin and (4) the coracoid was moved to the lateral border of the clavicle instead of the superior border of the coracoclavicular ligament.</p><p><b>RESULTS</b>The follow-up duration in 30 patients of the series was from 6 to 72 months (mean 41 months). Functional assessment was carried out by the criteria delineated previously by Karkson, in which Grade A was in 24 cases, Grade B in 4 cases, and C in 2.</p><p><b>CONCLUSIONS</b>This modified technique, having less postoperative complications and less injuries to tissues and according well with the requirement of biomechanics, can achieve a stable reduction of acromioclavicular joint with a good functional and cosmetic result and therefore is preferable to use clinically on a large scale.</p>