Hepatic steatosis is common in the general population and is present in 13.25% of donor organs. It can affect graft survival and recovery of the donor after partial hepatectomy. Liver biopsy is the standard method to measure the degree of hepatic steatosis, but it¡¦s also an invasive procedure and may have sampling error. Non-invasive tools, such as computed tomography and magnetic resonance image, are generally utilized and developed. This study was designed to build a standard model for the quantification of the fat content in a fat-water mixed phantom model. Pork fat and pure water were mixed in different ratios by volume (from 0% fraction of fat to 100% fat in steps of 5%), and then measured for fat content in different concentrations of fat-water mixed phantom by using (1) CT number (Hounsfield unit; HU), (2) Dixon method (in-phase & opposed-phase), and (3) 1H spectroscopy (SVS30 & SVS136, without water suppression). The CT number decreased with increasing fat concentration. The Hounsfield units of pure fat were about -122 HU. At Dixon method, the fat image intensity increased to its maximum when the fat concentration reached 25% and then decreased. Fat concentration higher than 25% and lower than 25% both had the same value of the fat image intensity. Combined with SVS30 water/fat peak height ratio, the fat concentration could be estimated. Furthermore, the fat image could be utilized to observe the topographic distribution of hepatic steatosis.
Then a rat fatty liver model fed with a choline deficient and iron supplemented L-amino acid defined (CDAA) diet was established. Fatty liver grade was evaluated by radiological and biochemical assessments. CT and MRS technique displayed the highest fat contents the same with histological examination in CDAA diet rats at 6 weeks.
The results showed that MRS was a suitable method for quantifying fat to water concentration. As a result of this study, model of measurement scale can be established to measure fat concentration both in phanatoms and animal. Further study in human fatty liver was expected.
| Identifer | oai:union.ndltd.org:NSYSU/oai:NSYSU:etd-0808106-011425 |
| Date | 08 August 2006 |
| Creators | Sun, Chin-Chih |
| Contributors | none, none, none |
| Publisher | NSYSU |
| Source Sets | NSYSU Electronic Thesis and Dissertation Archive |
| Language | English |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0808106-011425 |
| Rights | not_available, Copyright information available at source archive |
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