UK audit of analysis of quantitative parameters from renography data generated using a physical phantom.
BACKGROUND
In this second UK audit of quantitative parameters obtained from renography, phantom simulations were used in cases in which the 'true' values could be estimated, allowing the accuracy of the parameters measured to be assessed.


METHODS
A renal physical phantom was used to generate a set of three phantom simulations (six kidney functions) acquired on three different gamma camera systems. A total of nine phantom simulations and three real patient studies were distributed to UK hospitals participating in the audit. Centres were asked to provide results for the following parameters: relative function and time-to-peak (whole kidney and cortical region). As with previous audits, a questionnaire collated information on methodology. Errors were assessed as the root mean square deviation from the true value.


RESULTS
Sixty-one centres responded to the audit, with some hospitals providing multiple sets of results. Twenty-one centres provided a complete set of parameter measurements. Relative function and time-to-peak showed a reasonable degree of accuracy and precision in most UK centres. The overall average root mean squared deviation of the results for (i) the time-to-peak measurement for the whole kidney and (ii) the relative function measurement from the true value was 7.7 and 4.5%, respectively. These results showed a measure of consistency in the relative function and time-to-peak that was similar to the results reported in a previous renogram audit by our group.


CONCLUSIONS
Analysis of audit data suggests a reasonable degree of accuracy in the quantification of renography function using relative function and time-to-peak measurements. However, it is reasonable to conclude that the objectives of the audit could not be fully realized because of the limitations of the mechanical phantom in providing true values for renal parameters.
aRadiological Sciences Unit, Imperial College Healthcare NHS Trust, Hammersmith Hospital, London bDepartment of Psychology, University of Stirling, Stirling cDepartment of Nuclear Medicine, University Hospital Southampton NHS Foundation Trust, Southampton dDepartment of Medical Physics and Clinical Engineering, Cambridge University Hospitals NHS Foundation Trust, Cambridge eDepartment of Nuclear Medicine, Norfolk and Norwich University Hospitals NHS Trust, Norwich, UK fDepartment of Nuclear Medicine, Etelä-Savo Hospital District, Mikkeli Central Hospital, Mikkeli, Finland.
Kuldip S
KS
Nijran
Alex S
AS
Houston
John S
JS
Fleming
Peter H
PH
Jarritt
Jari O
JO
Heikkinen
John V
JV
Skrypniuk
D007668:Kidney / Q000000981:diagnostic imaging; D008485:Medical Audit; D019047:Phantoms, Imaging; D011866:Radioisotope Renography / Q000295:instrumentation*; D013997:Time Factors; D006113:United Kingdom