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Improved reproducibility of simple quantitative indices from ⁹⁹mTc-GSA liver functional imaging.

Ogasawara G, Inoue Y, Itoh Y, Tagami S, Matsunaga K, Miki K - Ann Nucl Med (2013)

Bottom Line: The results of (99m)Tc-GSA scintigraphy in 33 patients were retrospectively analyzed.The use of square ROIs instead of hand-drawn ROIs improved reproducibility.The correlation coefficients for intra- and interoperator comparisons were 0.988 and 0.973 for sHH15, respectively, and 0.989 and 0.975 for FLU15, respectively.

View Article: PubMed Central - PubMed

Affiliation: Department of Diagnostic Radiology, Kitasato University School of Medicine, 1-15-1 Kitasato, Minami-ku, Sagamihara, Kanagawa 252-0374, Japan. r04ogasawa@med.kitasato-u.ac.jp

ABSTRACT

Objective: We evaluated intra- and interoperator reproducibilities in calculating the conventional indices HH15 and LHL15 from (99m)Tc-diethylenetriamine pentaacetic acid galactosyl human serum albumin ((99m)Tc-GSA) scintigraphy, and proposed new, simple methods for the calculation of quantitative indices.

Methods: The results of (99m)Tc-GSA scintigraphy in 33 patients were retrospectively analyzed. Heart and liver ROIs were drawn manually to cover cardiac blood pool and entire liver, respectively, and HH15 and LHL15 were calculated. In addition, square regions of interest (ROIs) of fixed sizes were placed at the highest activity in blood pool and the liver. Using the square heart ROI, sHH15, an equivalent of HH15, was computed. Fractional liver uptake at 15 min (FLU15) was calculated using the square heart and liver ROIs. Intra- and interoperator reproducibilities, as well as correlation with Indocyanine green retention rate at 15 min (ICG R15), were assessed for these four indices by linear regression analysis.

Results: Substantial intra- and interoperator variabilities were found for HH15 and LHL15. The correlation coefficients for intra- and interoperator comparisons were 0.884 and 0.869 for HH15, respectively, and 0.919 and 0.917 for LHL15, respectively. The use of square ROIs instead of hand-drawn ROIs improved reproducibility. The correlation coefficients for intra- and interoperator comparisons were 0.988 and 0.973 for sHH15, respectively, and 0.989 and 0.975 for FLU15, respectively. Correlation with ICG R15 was better for sHH15 (r = 0.619) and FLU15 (r = -0.656) than for HH15 (r = 0.439) and LHL15 (r = -0.490).

Conclusions: HH15 and LHL15 showed substantial intra- and interoperator variabilities, and the use of square ROIs are indicated to provide better reproducibility.

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Related in: MedlinePlus

Hand-drawn (a) and square (b) ROIs set for cardiac blood pool and the heart
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Fig1: Hand-drawn (a) and square (b) ROIs set for cardiac blood pool and the heart

Mentions: ROIs were set using ImageJ 1.46 software. An operator placed four types of ROIs for each image set. Heart and liver ROIs were drawn manually to cover cardiac blood pool and entire liver, respectively (Fig. 1a). In addition, a square ROI of 10 × 10 pixels was set at the highest activity in blood pool, and was defined as a square heart ROI (Fig. 1b). The square heart ROI mainly included cardiac blood pool but was allowed to include activity in the great vessels above cardiac blood pool. A square ROI of 12 × 12 pixels was set at the highest activity in the liver, and was defined as a square liver ROI. Hand-drawn and square heart ROIs were taken on the 2-min image, and hand-drawn and square liver ROIs were taken on the 15-min image. The positions of the square ROIs were determined visually by the operator to maximize the total counts in the ROIs.Fig. 1


Improved reproducibility of simple quantitative indices from ⁹⁹mTc-GSA liver functional imaging.

Ogasawara G, Inoue Y, Itoh Y, Tagami S, Matsunaga K, Miki K - Ann Nucl Med (2013)

Hand-drawn (a) and square (b) ROIs set for cardiac blood pool and the heart
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3672508&req=5

Fig1: Hand-drawn (a) and square (b) ROIs set for cardiac blood pool and the heart
Mentions: ROIs were set using ImageJ 1.46 software. An operator placed four types of ROIs for each image set. Heart and liver ROIs were drawn manually to cover cardiac blood pool and entire liver, respectively (Fig. 1a). In addition, a square ROI of 10 × 10 pixels was set at the highest activity in blood pool, and was defined as a square heart ROI (Fig. 1b). The square heart ROI mainly included cardiac blood pool but was allowed to include activity in the great vessels above cardiac blood pool. A square ROI of 12 × 12 pixels was set at the highest activity in the liver, and was defined as a square liver ROI. Hand-drawn and square heart ROIs were taken on the 2-min image, and hand-drawn and square liver ROIs were taken on the 15-min image. The positions of the square ROIs were determined visually by the operator to maximize the total counts in the ROIs.Fig. 1

Bottom Line: The results of (99m)Tc-GSA scintigraphy in 33 patients were retrospectively analyzed.The use of square ROIs instead of hand-drawn ROIs improved reproducibility.The correlation coefficients for intra- and interoperator comparisons were 0.988 and 0.973 for sHH15, respectively, and 0.989 and 0.975 for FLU15, respectively.

View Article: PubMed Central - PubMed

Affiliation: Department of Diagnostic Radiology, Kitasato University School of Medicine, 1-15-1 Kitasato, Minami-ku, Sagamihara, Kanagawa 252-0374, Japan. r04ogasawa@med.kitasato-u.ac.jp

ABSTRACT

Objective: We evaluated intra- and interoperator reproducibilities in calculating the conventional indices HH15 and LHL15 from (99m)Tc-diethylenetriamine pentaacetic acid galactosyl human serum albumin ((99m)Tc-GSA) scintigraphy, and proposed new, simple methods for the calculation of quantitative indices.

Methods: The results of (99m)Tc-GSA scintigraphy in 33 patients were retrospectively analyzed. Heart and liver ROIs were drawn manually to cover cardiac blood pool and entire liver, respectively, and HH15 and LHL15 were calculated. In addition, square regions of interest (ROIs) of fixed sizes were placed at the highest activity in blood pool and the liver. Using the square heart ROI, sHH15, an equivalent of HH15, was computed. Fractional liver uptake at 15 min (FLU15) was calculated using the square heart and liver ROIs. Intra- and interoperator reproducibilities, as well as correlation with Indocyanine green retention rate at 15 min (ICG R15), were assessed for these four indices by linear regression analysis.

Results: Substantial intra- and interoperator variabilities were found for HH15 and LHL15. The correlation coefficients for intra- and interoperator comparisons were 0.884 and 0.869 for HH15, respectively, and 0.919 and 0.917 for LHL15, respectively. The use of square ROIs instead of hand-drawn ROIs improved reproducibility. The correlation coefficients for intra- and interoperator comparisons were 0.988 and 0.973 for sHH15, respectively, and 0.989 and 0.975 for FLU15, respectively. Correlation with ICG R15 was better for sHH15 (r = 0.619) and FLU15 (r = -0.656) than for HH15 (r = 0.439) and LHL15 (r = -0.490).

Conclusions: HH15 and LHL15 showed substantial intra- and interoperator variabilities, and the use of square ROIs are indicated to provide better reproducibility.

Show MeSH
Related in: MedlinePlus