The Three-Dimensional Photoacoustic Imaging of Tumor Vascularization on Nude Mice

• Main Authors: Chiung-Tse Hsu, 許瓊澤
• Other Authors: Huihua Kenny Chiang
• Format: Others
• Language: zh-TW
• Published: 2008
• Online Access: http://ndltd.ncl.edu.tw/handle/55565859121077544474

碩士 === 國立陽明大學 === 醫學工程研究所 === 96 === Photoacoustic imaging (PAI) has been shown to have higher spatial resolution and optical contrast than conventional ultrasound imaging due to the high contrast absorption of blood vessels to green and near infrared (NIR) light. Hemoglobin is the most significant optical absorber in human blood; it offers strong optical contrast at 532nm optical wavelengths and makes the photoacoustic technique particularly well suited for imaging blood vessels. The photoacoustic system includes a Nd:YAG laser, operating at 532 nm wavelength, a 20MHz and 45MHz ultrasonic transducer, an X-Y axes piezo ceramic stage, and a computer user interface. We use Matlab software to process the B-mode image and rebuild the 3D image with Amira software. The accumulated evidence show out that angiogenesis plays an important role in tumor cell proliferation. At the early development of the tumor, the tumor cell are often balanced between positive and negative regulators of angiogenesis, and this condition persist for a certain period of time, from months to years in human body, in vascular quiescent status. When the balance was broken, the tumor starts to grow rapidly. Tumor neovacularization relates to the tumor growth, invading, and metastasis. On the other hand, blocking the blood supply of the tumors is one of the most efficient methods for tumor treatment. Therefore, it is an important issue to detect/monitoring tumor neovascularization in clinics, in order to detect the tumor as well as conduct tumor therapy. In addition, the monitoring of tumor neovascularization has been applied for estimating the prognosis of tumors and the diagnosis of cancer therapy in clinics. This study can divide B-mode photoacoustic image and 3D photoacoustic image. In B-mode image, we scanned blood vessel phantom, nude mice brain and tumor vascularization that can differentiable vessels distribution. In 3D image, we detect the blood vessels phantom to test the 3D photoacoustic system, and then detect the back of human’s hand vein, nude mice tail and tumor vascularization. In clinical, we expect photoacoustic technique detected neovascularized in tumor noninvaded.