Objective: The width of the photopeak energy window influences the image quality and quantitative accuracy of gamma camera imaging. We compared 20% and 15% energy windows in renal scintigraphy with 99mTc-mercaptoacety...Objective: The width of the photopeak energy window influences the image quality and quantitative accuracy of gamma camera imaging. We compared 20% and 15% energy windows in renal scintigraphy with 99mTc-mercaptoacetyltriglycine (MAG3), especially in terms of camera-based quantitative estimation of renal function. Materials and Methods: Forty patients who underwent dynamic renal scintigraphy with 99mTc-MAG3 were enrolled in this study. Images were acquired simultaneously using two energy windows centered at 140 keV and with widths of 20% and 15%. Fractional renal uptake was calculated as the ratio of initial renal uptake estimated by patient imaging to injected dose estimated by syringe imaging, and was converted to MAG3 clearance using an empirical equation determined previously from data obtained with a 20% energy window. Relative function of the right kidney was also assessed. Visual evaluation was performed to compare image quality between the 20% and 15% energy windows. Results: Both total kidney MAG3 clearance and relative function of the right kidney were identical between the 20% and 15% energy windows. Image quality was also similar irrespective of the energy window width. Conclusions: The camera-based method established using a 20% energy window is applicable for the estimation of renal function using a 15% energy window, and data obtained using 20% and 15% windows are interchangeable.展开更多
Lymphoscintigraphy readily provides confirmation of chylothorax but not detailed localization of the leakage site. A 77-year-old woman developed traumatic chylothorax and underwent lymphoscintigraphy with radiolabeled...Lymphoscintigraphy readily provides confirmation of chylothorax but not detailed localization of the leakage site. A 77-year-old woman developed traumatic chylothorax and underwent lymphoscintigraphy with radiolabeled albumin to identify the site of lymph leakage. Dynamic imaging demonstrated appearance of focal activity presumably in the upper mediastinum, followed by spread to the left hemithorax. Subsequently, SPECT/CT showed that the leakage site was located in the left side of the upper mediastinum, and this location was confirmed during video-assisted thoracoscopic surgery. Dynamic imaging demonstrated the site of first appearance of abnormal activity, and SPECT/CT enabled detailed localization of the abnormal activity with anatomic correlation. The combination of dynamic imaging with SPECT/CT appears to be recommendable for lymphoscintigraphic assessment of chylothorax.展开更多
文摘Objective: The width of the photopeak energy window influences the image quality and quantitative accuracy of gamma camera imaging. We compared 20% and 15% energy windows in renal scintigraphy with 99mTc-mercaptoacetyltriglycine (MAG3), especially in terms of camera-based quantitative estimation of renal function. Materials and Methods: Forty patients who underwent dynamic renal scintigraphy with 99mTc-MAG3 were enrolled in this study. Images were acquired simultaneously using two energy windows centered at 140 keV and with widths of 20% and 15%. Fractional renal uptake was calculated as the ratio of initial renal uptake estimated by patient imaging to injected dose estimated by syringe imaging, and was converted to MAG3 clearance using an empirical equation determined previously from data obtained with a 20% energy window. Relative function of the right kidney was also assessed. Visual evaluation was performed to compare image quality between the 20% and 15% energy windows. Results: Both total kidney MAG3 clearance and relative function of the right kidney were identical between the 20% and 15% energy windows. Image quality was also similar irrespective of the energy window width. Conclusions: The camera-based method established using a 20% energy window is applicable for the estimation of renal function using a 15% energy window, and data obtained using 20% and 15% windows are interchangeable.
文摘Lymphoscintigraphy readily provides confirmation of chylothorax but not detailed localization of the leakage site. A 77-year-old woman developed traumatic chylothorax and underwent lymphoscintigraphy with radiolabeled albumin to identify the site of lymph leakage. Dynamic imaging demonstrated appearance of focal activity presumably in the upper mediastinum, followed by spread to the left hemithorax. Subsequently, SPECT/CT showed that the leakage site was located in the left side of the upper mediastinum, and this location was confirmed during video-assisted thoracoscopic surgery. Dynamic imaging demonstrated the site of first appearance of abnormal activity, and SPECT/CT enabled detailed localization of the abnormal activity with anatomic correlation. The combination of dynamic imaging with SPECT/CT appears to be recommendable for lymphoscintigraphic assessment of chylothorax.
