Calculation of the effective atomic number for the iodine contrast agent of the varying concentrations

The author discusses the difficulties that arise with the determination of the concentration of the iodinated contrast agents in the blood stream via the traditional gray-scale computer tomography and searches for the new imaging modalities that would provide for better sensitivity. The topic of the energy-discriminative color CT is discussed as a potential solution and its suitability is evaluated by performing the experiments on the contrast materials phantom and the phantom containing the iohexol solutions of varying concentrations on the original CT system assembled by the author. A method of the effective atomic number mapping is discussed as a viable alternative to the traditional attenuation-based tomography. The dependency of the effective atomic number of the compound on the energy of the x-ray beam is a phenomenon well recorded in the literature, yet no formal study exists to correctly predict the effective atomic number for a given compound. An extensive physical model is developed based on the previously presented models and adaptations unique to the task in order to determine the effective atomic numbers for exact energies experimentally. The method is tested on different materials. The resultant effective atomic numbers for the water, oil, and iohexol-water solutions of varying concentrations are presented in the study. The effects of the k-edge on both the linear attenuation curve and the effective atomic number curve are discussed. The possible future venues of the research are presented in the final part of the thesis.

Name thesis:degree_name

Master of Science

Level thesis:degree_level

masters

Discipline thesis:degree_discipline

Biomedical Engineering

Department dc:contributor.department

Biomedical Engineering

Grantor dc:publisher

Virginia Tech

Year dc:date.issued

2016

Author dc:creator

• Pen, Olga Vladimirovna

Chair dc:contributor.committeechair

• Cao, Guohua

Committee members dc:contributor.committeemember

• Bourland, John Daniel
• LaConte, Stephen M.

• effective atomic number
• color CT
• x-ray imaging
• iodine contrast agent

Statement dc:rights

• In Copyright

Licence dc:rights.uri

• http://rightsstatements.org/vocab/InC/1.0/

Language dc:language.iso

en_US

Dc Identifier Other

etd-08042016-091408
etd-08092016-200555

OAI identifier oai:identifier

oai:vtechworks.lib.vt.edu:10919/78149