| Autor: |
D C, Shungu, Z M, Bhujwalla, J P, Wehrle, J D, Glickson |
| Rok vydání: |
1992 |
| Předmět: |
|
| Zdroj: |
NMR in biomedicine. 5(5) |
| ISSN: |
0952-3480 |
| Popis: |
This study evaluates a number of methods for obtaining 1H NMR spectra with adequate suppression of lipid and water resonances in two subcutaneously implanted transplantable tumor models (RIF-1 and EMT6/SF). Spin-echo spectra with long TEs (270 ms; water suppressed by presaturation) eliminated lipid resonances from 1H spectra of RIF-1 and decreased lipid contamination in spectra of EMT6/SF; however, spectral sensitivity was substantially reduced. A shorter TE (135 ms) increased sensitivity but did not result in adequate suppression of the lipid peaks. In RIF-1, but not EMT6/SF, adequate lipid suppression was achieved by: (i) spatially selective presaturation of lipid, which in this tumor (but not in EMT6/SF) was localized in a thin region along the periphery of the tumor, followed by a 1-D spin-echo chemical shift imaging pulse sequence (TE = 135 ms); and (ii) 2-D spin-echo chemical shift imaging (TE = 270 ms; approximately 2 x 2 x 9 mm3 voxels). Preliminary 1H studies of the RIF-1 tumor indicate that: (i) there are no significant changes in metabolite levels relative to tumor water during 4 days of untreated tumor growth; (ii) tumor response to chemotherapy with 5-fluorouracil results in a decrease in intensity of all metabolite 1H resonances relative to tumor water, with total choline decreasing the most and lactate the least; and (iii) acute tumor blood flow reduction induced by administration of hydralazine results in doubling of the lactate intensity relative to water.(ABSTRACT TRUNCATED AT 250 WORDS) |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
|
Plný text