The feasibility of diuretic decision after 7 minutes in a 99mTc-MAG3 renography

This study aims to correlate the currently used F+10 99mTc-MAG3 method with the previous established F+20 method which will be used as comparison. The aim is also to validate the current cut-off value of 75 % when deciding whether to administer diuretics or not.

All past F+20 99mTc-MAG3 renographies will be obtained retrospectively from the department’s Picture Archiving and Communication System (PACS). Examination data will be collected from the Radiology Information System (RIS) and from the PACS. The collected data from RIS involves whether diuretic was given, injection time for both the 99mTc-MAG3 and the diuretic, age, gender, examination date and if the Nuclear Medicine physician found an obstruction in any kidney after the performed renography. From PACS, the collected data involves the F+20 time-activity curve, the proportion of remaining activity in each kidney 20 minutes post radiopharmaceutical injection and time-to-peak activity in minutes, in each kidney.