Japanese guideline for the oncology FDG-PET/CT data acquisition protocol: synopsis of Version 1.0

Abstract

This synopsis outlines the Japanese guideline Version 1.0 for the data acquisition protocol of oncology FDG-PET/CT scans that was created by a joint task force of the Japanese Society of Nuclear Medicine Technology (JSNMT) and the Japanese Council of PET Imaging, and published in Kakuigaku-Gijutsu 29(2):195–235, 2009, in Japanese. The guideline aims at standardizing the PET image quality among facilities and different PET/CT scanner models by determining and/or evaluating the data acquisition condition in experiments using an IEC body phantom, as well as by proposing the criteria for human image quality evaluation using patient noise equivalent count (NEC), NEC density, and liver signal-to-noise ratio.

This is a preview of subscription content, log in to check access.

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6
Fig. 7
Fig. 8

References

  1. 1.

    Mizuta T, Senda M, Okamura T, Kitamura K, Inaoka Y, Takahashi M, et al. NEC density and liver ROI S/N ratio for image quality control of whole-body FDG-PET scans: comparison with visual assessment. Mol Imaging Biol. 2009;11:480–6.

    Article  PubMed  Google Scholar 

  2. 2.

    National Electrical Manufacturers Association. NEMA Standards Publication NU 2-2007: performance measurement of positron emission tomographs. Rosslyn, VA: National Electrical Manufacturers Association; 2007.

  3. 3.

    Mawlawi O, Podoloff DA, Kohlmyer S, Williams JJ, Stearns CW, Culp RF, et al. Performance characteristics of a newly developed PET/CT scanner using NEMA standards in 2D and 3D modes. J Nucl Med. 2004;45:1734–42.

    PubMed  Google Scholar 

  4. 4.

    Surti S, Karp JS. Imaging characteristics of a 3-dimensional GSO whole-body PET camera. J Nucl Med. 2004;45:1040–9.

    CAS  PubMed  Google Scholar 

  5. 5.

    Erdi YE, Nehmeh SA, Mulnix T, Humm JL, Watson CC. PET performance measurements for an LSO-based combined PET/CT scanner using the National Electrical Manufacturers Association NU 2–2001 standard. J Nucl Med. 2004;45:813–21.

    CAS  PubMed  Google Scholar 

  6. 6.

    Teräs M, Tolvanen T, Johansson JJ, Williams JJ, Knuuti J. Performance of the new generation of whole-body PET/CT scanners: discovery STE and discovery VCT. Eur J Nucl Med Mol Imaging. 2007;34:1683–92.

    Article  PubMed  Google Scholar 

  7. 7.

    Kemp BJ, Kim C, Williams JJ, Ganin A, Lowe VJ. NEMA NU 2–2001 performance measurements of an LYSO-based PET/CT system in 2D and 3D acquisition modes. J Nucl Med. 2006;47:1960–7.

    PubMed  Google Scholar 

  8. 8.

    Mejia AA, Nakamura T, Masatoshi I, Hatazawa J, Masaki M, Watanuki S. Estimation of absorbed doses in humans due to intravenous administration of fluorine-18-fluorodeoxyglucose in PET studies. J Nucl Med. 1991;32:699–706.

    CAS  PubMed  Google Scholar 

  9. 9.

    Hentschel M, Brink I. Lean body mass-based standardized uptake value, derived from a predictive equation, might be misleading in PET studies. Eur J Nucl Med Mol Imaging. 2002;29:1630–8.

    Article  Google Scholar 

  10. 10.

    National Electrical Manufacturers Association. NEMA Standards Publication NU 2-2001: performance measurement of positron emission tomographs. Rosslyn, VA: National Electrical Manufacturers Association; 2001.

Download references

Acknowledgments

This work was supported in part by the Grant-in-Aid for Cancer Research (21-5-2) of the Ministry of Health, Labour and Welfare.

Author information

Affiliations

Authors

Corresponding author

Correspondence to Hiroyoshi Fukukita.

Appendix: Physical indicators of image quality

Appendix: Physical indicators of image quality

Indicators of phantom image quality

In this guideline, NECphantom (noise equivalent count for phantom), percentage of contrast (Q H,10 mm), and percentage of background variability (N 10 mm) are used as indicators of body phantom image quality.

The NECphantom is calculated using the formula in Eq. 1:

$$ {\text{NEC}}\left[ {\text{Mcounts}} \right] = {\frac{{T^{2} }}{{T + S + \left( {1 + k} \right)fR}}} = \left( {1 - {\text{SF}}} \right)^{2} {\frac{{\left( {P - D} \right)^{2} }}{{\left( {P - D} \right) + \left( {1 + k} \right)fD}}}\quad f = {\frac{{S_{a} }}{{\pi r^{2} }}} $$
(1)

where T, S, and R represent true, scatter, and random coincidences acquired within the scanning period, and P and D represent prompt and delayed coincidences. SF, k, and f represent scatter fraction, random scaling factor, and ratio of object size to sinogram. S a and r represent the cross-sectional area of the phantom and the radius of the detector ring diameter, respectively.

The phantom image is reconstructed with all available corrections applied, using the standard reconstruction algorithm and usual parameters for whole-body studies.

A transverse image centered on the hot sphere(s) is used in the analysis. A circular region of interest (ROI) with a 10-mm diameter is drawn on the 10-mm hot sphere. The ROI analysis tool should take partial pixels into account and also permit movement of the ROI in increments of 1 mm or smaller.

Twelve ROIs of the same size are drawn throughout the background at a distance of 15 mm from the edge of the phantom, but not closer than 15 mm to any sphere. The ROIs are also drawn on the slices as close as possible to ±1 cm and ±2 cm on either side of the central slice, resulting in a total of 60 background ROIs, twelve on each of the five slices. The locations of all ROIs should be fixed between successive measurements. The measured activity in each background ROI is recorded. The percent contrast for the 10-mm hot sphere (Q H,10 mm) is calculated as follows:

$$ Q_{{{\text{H}},10\,{\text{mm}}}} = {\frac{{{\raise0.7ex\hbox{${C_{{{\text{H,10}}\,{\text{mm}}}} }$} \!\mathord{\left/ {\vphantom {{C_{{{\text{H,10}}\,{\text{mm}}}} } {C_{{{\text{B}},10\,{\text{mm}}}} }}}\right.\kern-\nulldelimiterspace} \!\lower0.7ex\hbox{${C_{{{\text{B}},10\,{\text{mm}}}} }$}} - 1}}{{{\raise0.7ex\hbox{${a_{\text{H}} }$} \!\mathord{\left/ {\vphantom {{a_{\text{H}} } {a_{\text{B}} }}}\right.\kern-\nulldelimiterspace} \!\lower0.7ex\hbox{${a_{\text{B}} }$}} - 1}}} \times 100\% $$
(2)

where C H,10 mm and C B,10 mm are the average measured activity in the ROI for the 10-mm sphere and the average measured activity in all the background 10-mm diameter ROIs, respectively. a H /a H is the activity concentration ratio for the hot sphere to the background.

The percentage of background variability N 10 mm for the 10-mm sphere is calculated as follows:

$$ N_{{ 1 0\,{\text{mm}}}} = {\frac{{{\text{SD}}_{{ 1 0\,{\text{mm}}}} }}{{C_{{{\text{B,10}}\,{\text{mm}}}} }}} \times 100\% $$
(3)

where SD10 mm is the standard deviation of the background ROI counts for the 10-mm sphere, calculated as follows:

$$ {\text{SD}}_{{10\,{\text{mm}}}} = \sqrt {{\frac{{\sum\nolimits_{k = 1}^{K} {\left( {C_{{{\text{B,10}}\,{\text{mm, }}k}} - C_{{{\text{B,10}}\,{\text{mm}}}} } \right)^{2} } }}{K - 1}}} ,\quad K = 60 $$
(4)

Indicators of human image quality

Noise equivalent count per patient height (NECpatient) and noise equivalent count per volume (NECdensity) are evaluated as potential physical indicators of image quality.

The NECpatient is defined to allow for patient height normalization. In this guideline, since the axial scanning range is variable, NECpatient is defined as shown in Eq. 5:

$$ {\text{NEC}}_{\text{patient}} \left[ {{\text{Mcounts}}/m} \right] = {\frac{{\sum\nolimits_{i = 1}^{I} {{\text{NEC}}_{i} } }}{{{x \mathord{\left/ {\vphantom {x {100}}} \right. \kern-\nulldelimiterspace} {100}}}}} $$
(5)

where NEC i and x represent NEC for each bed position (i) and the length (cm) of the axial field of view to be evaluated (i = 1–I), which extends from the neck to the abdomen in this guideline, respectively.

NECi is calculated using the formula in Eq. 6,

$$ {\text{NEC}}_{\text{i}} \left[ {\text{Mcounts}} \right] = \left( {1 - {\text{SF}}} \right)^{2} {\frac{{\left( {P_{i} - D_{i} } \right)^{2} }}{{\left( {P_{i} - D_{i} } \right) + \left( {1 + k} \right)D_{i} }}} $$
(6)

where P i and D i represent prompt and delayed coincidences for each bed position. SF represents the scatter fraction measured within the NEMA NU 2-2001 Standard [10], and k is set to 0 or 1 depending on whether you use variance reduction techniques for estimating a smooth random distribution or using direct random subtraction.

NECdensity is defined as shown in Eq. 7:

$$ {\text{NEC}}_{\text{density}} \left[ {{\text{kcounts/cm}}^{ 3} } \right] = {\frac{{\sum\nolimits_{i = 1}^{I} {{\text{NEC}}_{i} } }}{V}}. $$
(7)

The NECdensity reflects normalized effective counts distributed within the subject body and represents count statistics per subject volume including lung area. The NEC i is calculated as shown in Eq. 6, and V (cm3) represents the subject volume within the axial extent to be evaluated (i = 1–I), i.e., from the neck to the abdomen in this guideline.

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Fukukita, H., Senda, M., Terauchi, T. et al. Japanese guideline for the oncology FDG-PET/CT data acquisition protocol: synopsis of Version 1.0. Ann Nucl Med 24, 325–334 (2010). https://doi.org/10.1007/s12149-010-0377-7

Download citation

Keywords

  • Guideline
  • FDG-PET
  • Oncology
  • NEC
  • QC