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Calibration of Traceable Solid Mock (131)I Phantoms Used in an International SPECT Image Quantification Comparison.

Zimmerman BE, Pibida L, King LE, Bergeron DE, Cessna JT, Mille MM - J Res Natl Inst Stand Technol (2013)

Bottom Line: For this study, we designed a set of solid cylindrical sources so that each site could have a set of phantoms (having nominal volumes of 2 mL, 4 mL, 6 mL, and 23 mL) with traceable activity calibrations so that the results could be properly compared.We also developed a technique using two different detection methods for individually calibrating the sources for (133)Ba activity based on a National standard.This methodology allows for the activity calibration of each (133)Ba source with a standard uncertainty on the activity of 1.4 % for the high-level 2-, 4-, and 6-mL sources and 1.7 % for the lower-level 23 mL cylinders.

View Article: PubMed Central - PubMed

Affiliation: National Institute of Standards and Technology, Gaithersburg, MD 20899.

ABSTRACT
The International Atomic Energy Agency (IAEA) has organized an international comparison to assess Single Photon Emission Computed Tomography (SPECT) image quantification capabilities in 12 countries. Iodine-131 was chosen as the radionuclide for the comparison because of its wide use around the world, but for logistical reasons solid (133)Ba sources were used as a long-lived surrogate for (131)I. For this study, we designed a set of solid cylindrical sources so that each site could have a set of phantoms (having nominal volumes of 2 mL, 4 mL, 6 mL, and 23 mL) with traceable activity calibrations so that the results could be properly compared. We also developed a technique using two different detection methods for individually calibrating the sources for (133)Ba activity based on a National standard. This methodology allows for the activity calibration of each (133)Ba source with a standard uncertainty on the activity of 1.4 % for the high-level 2-, 4-, and 6-mL sources and 1.7 % for the lower-level 23 mL cylinders. This level of uncertainty allows for these sources to be used for the intended comparison exercise, as well as in other SPECT image quantification studies.

No MeSH data available.


Experimentally-determined calibration factors, K, as a function of source volume for the NIST Vinten 671 ionization chamber (VIC) for the solution-filled 133Ba cylinders used in this study. The uncertainty bars correspond to a single uncertainty interval (k = 1) calculated as described in Sec. 3.3. The line through the data is intended only to guide the eye.
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f4-jres.118.017: Experimentally-determined calibration factors, K, as a function of source volume for the NIST Vinten 671 ionization chamber (VIC) for the solution-filled 133Ba cylinders used in this study. The uncertainty bars correspond to a single uncertainty interval (k = 1) calculated as described in Sec. 3.3. The line through the data is intended only to guide the eye.

Mentions: The calibration factors measured for each of the solution sources are shown graphically in Fig. 4. The uncertainty bars on the plot represent standard uncertainties and are equal to the combined standard uncertainties calculated from the quadratic combination of the uncertainty components presented in Table 5. The larger uncertainty on the result for the 2 mL cylinders is due primarily to the much lower current (relative to background) measured for those sources as compared to the others. For those sources, the current was only about 50 times that of background while the signal-to-background ratios for the other volumes were 2 to 5 times higher.


Calibration of Traceable Solid Mock (131)I Phantoms Used in an International SPECT Image Quantification Comparison.

Zimmerman BE, Pibida L, King LE, Bergeron DE, Cessna JT, Mille MM - J Res Natl Inst Stand Technol (2013)

Experimentally-determined calibration factors, K, as a function of source volume for the NIST Vinten 671 ionization chamber (VIC) for the solution-filled 133Ba cylinders used in this study. The uncertainty bars correspond to a single uncertainty interval (k = 1) calculated as described in Sec. 3.3. The line through the data is intended only to guide the eye.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4487311&req=5

f4-jres.118.017: Experimentally-determined calibration factors, K, as a function of source volume for the NIST Vinten 671 ionization chamber (VIC) for the solution-filled 133Ba cylinders used in this study. The uncertainty bars correspond to a single uncertainty interval (k = 1) calculated as described in Sec. 3.3. The line through the data is intended only to guide the eye.
Mentions: The calibration factors measured for each of the solution sources are shown graphically in Fig. 4. The uncertainty bars on the plot represent standard uncertainties and are equal to the combined standard uncertainties calculated from the quadratic combination of the uncertainty components presented in Table 5. The larger uncertainty on the result for the 2 mL cylinders is due primarily to the much lower current (relative to background) measured for those sources as compared to the others. For those sources, the current was only about 50 times that of background while the signal-to-background ratios for the other volumes were 2 to 5 times higher.

Bottom Line: For this study, we designed a set of solid cylindrical sources so that each site could have a set of phantoms (having nominal volumes of 2 mL, 4 mL, 6 mL, and 23 mL) with traceable activity calibrations so that the results could be properly compared.We also developed a technique using two different detection methods for individually calibrating the sources for (133)Ba activity based on a National standard.This methodology allows for the activity calibration of each (133)Ba source with a standard uncertainty on the activity of 1.4 % for the high-level 2-, 4-, and 6-mL sources and 1.7 % for the lower-level 23 mL cylinders.

View Article: PubMed Central - PubMed

Affiliation: National Institute of Standards and Technology, Gaithersburg, MD 20899.

ABSTRACT
The International Atomic Energy Agency (IAEA) has organized an international comparison to assess Single Photon Emission Computed Tomography (SPECT) image quantification capabilities in 12 countries. Iodine-131 was chosen as the radionuclide for the comparison because of its wide use around the world, but for logistical reasons solid (133)Ba sources were used as a long-lived surrogate for (131)I. For this study, we designed a set of solid cylindrical sources so that each site could have a set of phantoms (having nominal volumes of 2 mL, 4 mL, 6 mL, and 23 mL) with traceable activity calibrations so that the results could be properly compared. We also developed a technique using two different detection methods for individually calibrating the sources for (133)Ba activity based on a National standard. This methodology allows for the activity calibration of each (133)Ba source with a standard uncertainty on the activity of 1.4 % for the high-level 2-, 4-, and 6-mL sources and 1.7 % for the lower-level 23 mL cylinders. This level of uncertainty allows for these sources to be used for the intended comparison exercise, as well as in other SPECT image quantification studies.

No MeSH data available.