Biomedical Imaging and Emerging Technologies - Lab Report Example

Student Name: Instructor’s Name: Title: Biomedical imaging and technologies Course: Institution: Biomedical imaging and technologies Laboratory report Aim To investigate the biomedical imaging and technologies on different types of materials having varying structures and density Introduction Examination of the internal structures of materials using biomedical imaging technologies has proved to be an important technique in the medical field. Lately, various biomedical imaging technologies have emerged at synchrotron radiation facilities. These technologies mainly focus on investigating the absorption characteristics of the internal structure of an object and they also use several interactions that such technologies such as x-rays go through in order allow visualization of the internal structure of a sample under investigation. The comparatively non-destructive imaging technologies are being investigated to be utilized in areas like cartilage and bone imaging, mammography and also other applications (Mitchell 2010). In normal radiography, a big percentage of the x-ray beam that get to the detector after passing via the sample is a scattering component; X-ray scatter lowers the image contrast as well as sharpness and hence results into a less sensitive measurement. Nonetheless, analyzer-based technologies are nearly entirely free of x-ray scatter due to the location of an analyzer crystal between the sample and the x-ray detector. The narrow acceptance angle of the analyzer crystal lowers the scattering component and thus this enhances the contrast of the image that results. Diffraction enhanced imaging is utilizes refractive index gradient of an object and consists of a mono-chromator, interest object, analyzer crystal in addition to an x-ray detector. Single-crystal materials like aluminum are usually selected for monochromator as well as the analyzer crystal. These materials are placed within a parallel geometry leading within the generation of a greatly parallel monochromatic x-ray beam. Raw images, from a set of set of ultrasound images is then computed are gathered with the analyzer crystal positioned at three positions along the almost triangular curve, the socalled “rocking curve” of reflected intensity as a function of angle particularly, the analyzer crystal is located at the left side and right side of the rocking curve and at the hit the highest point intensity 1-3 image collection at these locations is accomplished through changing the analyzer crystal’s angle to three pre-determined points along the curve. The rocking-curve shape of the analyzer crystal brings in sensitivity to refraction as well as scatter taking place in the object being imaged (Fujimoto 2006). Density, thickness, along with/or material variations in an object will change the direction of the x-rays while they pass through the material, generating small angular variations of the spread x-ray beam. The vertical sides of the reflectivity curve normally change these angle differences into intensity variations, and hence making absorption refraction in addition to scattering outcomes visible within an image. Of late, modifications of biomedical imaging techniques have been explored whereby the number of points gathered along the rocking curve elevated, mostly known as multiple-image radiography through acquiring numerous images with the analyzer set to diffract at various locations (Mitchell 2010). Method The experimental resolution of the imaging technology was determined through imaging different types of materials namely, iron, Aluminum, Zinc, Perspex, wood, rubber and agar. The resulting images were utilized in calculating the line spread of the function (LSF) of the imaging technology. This was achieved through initially measuring the edge spread function, line-by-line, across the whole scatter-rejection image. The measured edge spread functions were then averaged and derivative of the calculation of the averaged edge spread function was done to establish the spread of the function of the imaging technology. The vertical and horizontal directions of LSF were then calculated as well as the spatial resolution. Spatial resolution is projected to hold for single-image as well as multiple-image modalities. The simulations were carried out on 10_10_6 cm3 materials for 5_107 interactions. The field size during imaging is 1_6 cm2 stripe. To image a sample having a bigger surface area as compared to that of x-ray beam filed of view, scanning of the samples was done via mono-energetic beams. In order to induce this procedure, numerous 1_6 cm2 “stripes” adjacent to each other were utilized. Slide scatter from one stripe to the next could probably result into artifacts for instance periodic fluctuations in the calculated field view. MC stimulations were carried out to generate a three-dimensional dose per incident frequency distribution matrix for the equivalent materials. Results Part 1: For this part measured the velocity by using the below equation C = 2d/t Where: c = sound velocity
 d = thickness of test block 
t = time taken for the 1st echo to be received
 eg. Sound velocity of zinc with distance 25.06mm = (2 * 25.06 * 10-3)/ (12.2 * 10-6) = 4108.1967 (m/s) Material Distance (mm) (d) Time (s) Sound velocity (m/s) Aluminium 50 14.6 C=6849.315 Rubber - - - Perspex 51.4 30 3426.667 Iron 50.95 12.2 8352.459 Zinc 25.06 12.2 4108.1967 Wood - - - Agar - - - C= 2d/T Part 2: Material Amplitude Attenuation coefficient Neper/m Attenuation coefficient dB/cm Aluminium 1= 13.6 V 2= 250 mV 39.96 Rubber 1= 2= - - Perspex 1= 60mV 2=13.6 V -52.76 3426.667 Iron 1= 40 mV 2= 20mV 6.80 8352.459 Zinc 1= 40 mV 2= 20mV 13.86 4108.1967 Wood - - - Agar - - - Attenuation coefficient: [log (A2/A1)]/-2 d for Neper/m Read More