|
KMID : 1151820200140050603
|
|
Journal of the Korean Society of Radiology
2020 Volume.14 No. 5 p.603 ~ p.612
|
|
|
Analysis of Contrast Medium Dilution Rate for changes in Tube Current and SOD, which are Parameters of Lower Limb Angiography Examination
|
|
Kong Chang-Gi
Han Jae-Bok
|
|
|
Abstract
|
|
|
|
This study has a purpose to look into the effect of the relationship between the Tube current (mA) and SOD(Source to Object Distance), which is a parameter of lower limb angiography examination, and the dilution rate of the contrast medium concentration (300, 320, 350) on the image. To that end, using 3 mm vessel model water phantom, a vessel model custom made in the size of peripheral vessel diameter, this study measured relationships between change of parameters, such as tube current (mA), SOD and varying concentrations (300, 320, 350) of contrast medium dilution into SNR and CNR values while analyzing the coefficients of variance(cv< 10). The software used to measure SNR and CNR values was Image J 1.50i from NIH (National Institutes of Health, USA). MPV (mean pixel value) and SD (standard deviation) were used after verifying numerically the image signal for region of interest (ROI) and background on phantom from the DICOM (digital imaging and communications in medicine) 3.0 file transmitted to PACS. As to contrast medium dilution by the change of tube current, when 146 mA and 102 mA were compared, For both SNR and CNR, the coefficient of variation value was less than 10 until the section of CM: N/S dilution (100% ∼ 30% : 70%) but CM: N/S dilution rate (20%: 80% ∼ 10% : 90%) the coefficient of variation was 10 or more. As to contrast medium dilution by concentration for SOD change, when SOD’s (32.5 cm and 22.5 cm) were compared,For both SNR and CNR, the coefficient of variation value was less than 10 until the section of CM: N/S dilution (100% ∼ 30% : 70%) but CM: N/S dilution rate (20%: 80% ∼ 10% : 90%) the coefficient of variation was 10 or more. As to contrast medium dilution by concentration for SOD change, when SOD’s (32.5 cm and 12.5 cm) were compared,For both SNR and CNR, the coefficient of variation value was less than 10 until the section of CM: N/S dilution (100% ∼ 30% : 70%) but CM: N/S dilution rate (20%: 80% ∼ 10% : 90%) the coefficient of variation was 10 or more. As a result, set a low tube current value in other tests or procedures including peripheral angiography of the lower extremities in the intervention, and make the table as close as possible to the image receiver, and adjust the contrast agent concentration (300) to CM: N/S dilution (30%: 70%). ) Is suggested as the most efficient way to obtain images with an appropriate concentration while simultaneously reducing the burden on the kidney and the burden on exposure.
|
|
|
KEYWORD
|
|
|
Tube current (mA), SOD(Source to Object Distance), Coefficient of Variation value
|
|
|
FullTexts / Linksout information
|
|
|
|
|
|
Listed journal information
|
|
|
|