LOGO ภาควิชาอิเล็กทรอนิกส์ คณะวิศวกรรมศาสตร์ สถาบันเทคโนโลยีพระจอมเกล้าเจ้าคุณทหารลาดกระบัง

5. 6. Conclusion Conclusion 7.

Computed tomography (CT) is a diagnostic procedure that uses special x-ray equipment to obtain cross-sectional pictures of the body. Computed tomography (CT) is a diagnostic procedure that uses special x-ray equipment to obtain cross-sectional pictures of the body. Detector Gantry Rotation X-ray Tube X-ray Beam

Direct detector 1 Indirect detector 2 Direct detector uses a semiconductor material to convert X-ray photons into an electrical charge Indirect detector uses scintillator to transform the radiation into the visible light, and uses photo detector device for measurement

In this paper, the miniature computed tomography system using the indirect X-ray detector panel created from an array of USB cameras coupled with an intensifying screen is presented. In this paper, the miniature computed tomography system using the indirect X-ray detector panel created from an array of USB cameras coupled with an intensifying screen is presented. The aim of this study is carried out to construct the cross sectional images obtained from this system. The aim of this study is carried out to construct the cross sectional images obtained from this system.

Miniature CT system consists of 3 parts USB Web Cameras Lead Glass Intensifying Screen Type Gd 2 O 2 S:Tb Object -Image Sensor Type CMOS - Resolution 640 x 480

USB cameras aligned in 1x3 array Lead Glass

Flow chart described a procedure to achieve the final image Correct an image distortion by a camera calibration Template matching and cross correlation Fuse image by matrix transformation Apply a Lambert-Beer law to the stitched image Image spline by a weighted average technique Achieve the final image Reduce noise by a median filter Capture a projection image

Calibration Phantom Acrylic plate Metal ball

Adjust to align with the same alignment Center ray

Center of X-ray beam (dash line) The projection image of calibration phantom

The center ray point must be shifted to the center of an X-ray detector

Phantom created for using as the object Cement plaster Air

The projection angle is 2 degrees per a projection from 0 to 360 degrees. The projection angle is 2 degrees per a projection from 0 to 360 degrees. The filtered back projection was used to reconstruct cross sectional images. The filtered back projection was used to reconstruct cross sectional images. Phantom 80 kV, 100mA, 0.8s 60 cm

The samples of projection data obtained from 0 to 360 degrees The samples of cross sectional image Cement plaster Air Air bubble

From the result, the miniature computed tomography is capable of constructing a cross sectional image with an ease and cost-effective technique. From the result, the miniature computed tomography is capable of constructing a cross sectional image with an ease and cost-effective technique. Moreover, 3D model reconstructed from these cross sectional images will be performed in the further study. Moreover, 3D model reconstructed from these cross sectional images will be performed in the further study.

LOGO Department of Electronics, Faculty of Engineering King Mongkut’s Institute of Technology Ladkrabang, Thailand

LOGO

Wavelength 540 nm Green Tone

Distance 14 cm Increase distance Close to middle ball

Salt & Paper noise

Edge of image

Overlap

X-ray tube Object Enlarge size Shadow Far Similar size Shadow Near 60 cm

Overlap

Phenomenon Beam Hardening Air bubble