| Budget Amount *help |
¥1,100,000 (Direct Cost: ¥1,100,000)
Fiscal Year 2006: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 2005: ¥500,000 (Direct Cost: ¥500,000)
|
|---|
| Research Abstract |
We devised a new correction method that combined attenuation correction using a difference of intrinsic dual-energy between lower energy emissions (71keV) and higher energy emissions (167keV) without transmission scan and Compton scatter correction using triple-energy window (TEW) method for 71keV because of enhancing a difference of intrinsic dual-energy in ^<201>TlCl (^<201>Tl), and applied to cardiac phantom and myocardial perfusion SPECT studies.
Attenuation coefficients ratio and counts ratio for 71keV/167keV were calculated from SPECT data acquired by energy window of 71keV and 167keV, respectively. Defects with the same thickness were inserted on the inner surface of a myocardial phantom at 2 difference locations: anterior (ANT) and inferior (INF). The myocardial perfusion SPECT studies was performed with ^<201>Tl using the same protocol that we use for patients. The images reconstructed by non-attenuation-scatter (A(-)S(-)), only scatter (A(-)S(+)) and attenuation-scatter (A(+)S
… More
(+)) correction were compared by visual and quantitative analysis, respectively.
The adequate attenuation coefficients ratio and counts ratio for 71keV/167keV were 2.277 and 5, respectively. In the normal myocardial phantom, the INF wall was improved by attenuation-scatter (A(+)S(+)) correction, and the whole of the myocardial wall was uniform.
In the ANT and INF defect wall phantom, the tracer distribution except defect wall were uniform, and the all defects were clearly detected. In patients with known or suspected CAD, defect regions were clearly discriminated by technique, the detectability for CAD was improved.
It is suggested that a new correction method that combined attenuation correction using a difference of intrinsic dual-energy and Compton scatter correction using triple-energy window (TEW) method for 71keV is useful in ^<201>Tl myocardial perfusion SPECT studies. This may reduce both of attenuation and scatter artifacts, and allow the more accurate assessment of patients with known or suspected CAD. Less
|
