ایجاد تصویر سه بعدی با استفاده از سیستم های فراصوت دو بعدی معمولی

Ultrasound imaging is one of the common methods in medical diagnostic    systems. There are many artifacts in a two dimentional image. Three dimentional    imaging can be used for better interpretation and perception of an image. Since    1969 many attemps have been made in this regards, and research continues all    over the world. The main goal in our research was to create three - dimentional    images using conventional 2-D ultrasound systems.           To obtain three dimentional data for construction of 3-D images, a conventional    sonography with linear array transducer was used. The 2-D images of an    alominume cylinder, fiber glass sphere, human hand, sheep kidney, human    kidney, and carotid were taken. Using a scanner with three degree of freedom, the    images locations were determined. In one of three directions, the transducer    translations movement was performed. Using a stepping motor the scanner    movements were achieved. High level language programming ‘C’ were written to    control the scanner. Each image slice was obtained with 1mm slice thickness step.    Using appropriate image processing techniques such as filtering and interpolation,    image reconstruction was performed from obtained 2-D images. These image    proccesings were done using MATLAB software.           After reconstruction images in other dimentions, the images were studied from    two aspects. At the first step the size of reconstructed images compared with the    main object. For one dimention of an object 12.5mm,average of images was    12.629 mm. There was not significant difference between them. In next step,    images were compared with the main objects  regard their appearances. For    objects such as fiber glass sphere, alominume cylinder , because of the artifacts,    reconstructed images were not  exactly like main objects. But for human hand,    sheep kidney, and carotid , there was proper accomodation between images    and main objects. For human kidney, the obtained images were not clear.           In vitro ,reconstruction of images for objects which are equal with the organs    like sheep kidney and human hand was done. In vivo for carotid vessel there was    accomodation between carotid  and its images. For human kidney was not done.