Portal Imaging Using a CSI (TL) Scintillator Coupled to a Cooled CCD Camera

<p>The purpose of this research was to design a high performance digital portal imaging <br />system, using a transparent x-ray scintillator coupled to a cooled CCD camera. Theoretical <br />analysis using Monte Carlo simulation was performed to calculate the QDE, SNR and DQE of <br />the system. A prototype electronic portal imaging device (EPID) was built, using a 12.7 mm <br />thick, 20.32 cm diameter, CsI (Tl) scintillator, coupled to an Astromed ® liquid nitrogen cooled <br />CCD TV camera. The system geometry of the prototype EPID was optimized to achieve high <br />spatial resolution. Experimental evaluation of the prototype EPID was performed, by <br />determining its spatial resolution, contrast resolution, depth of focus and light scatter. Images of <br />phantoms, animals and human subjects were acquired using the prototype EPID and were <br />compared with those obtained using conventional and high contrast portal film and a commercial <br />EPID. An image processing protocol was developed. The protocol was comprised of <br />preprocessing, noise removal and image enhancement algorithms. An adaptive median filter <br />algorithm for the removal of impulse noise was developed, analyzed and incorporated into the <br />image processing protocol.</p> <p>Results from the theoretical analysis and experimental evaluation have indicated that the performance of the CsI (Tl) - CCD system is comparable or superior to that of current commercial and experimental portal imaging technologies, such as high contrast portal film, commercial TV camera based EPIDs, and amorphous silicon based flat panel EPIDs.</p>

Name thesis:degree_name

Master of Science (MS)

Level thesis:degree_level

Thesis

Discipline thesis:degree_discipline

Biomedical Engineering

Year dc:date.available

1999

Author dc:creator

• Sawant, Amit

Contributors dc:contributor

• Herbert D. Zeman

• digital portal imaging
• treatment verification
• megavoltage x-ray imaging
• transparent scintillator
• CCD camera
• Analytical, Diagnostic and Therapeutic Techniques and Equipment
• Equipment and Supplies
• Medicine and Health Sciences

Repository record dc:identifier

https://dc.uthsc.edu/dissertations/234

OAI identifier oai:identifier

oai:dc.uthsc.edu:dissertations-1231