Abstract
Pyelonephritis is an infection of the kidneys which is seen more commonly in children than the adults. Technetium-99m-dimercaptosuccinic acid (99mTc-DMSA) scan is a radionuclide imaging study to detect renal scarring after acute pyelonephritis (late DMSA scan) and also helps to diagnose acute pyelonephritis in febrile urinary tract infections (acute DMSA scan). Planar imaging in multiple views (posterior and posterior oblique) is generally used. Pinhole imaging with a high-resolution collimator magnification of each kidney allows detection of smaller cortical defects. Single-photon emission computed tomography (SPECT) is optional. SPECT/Computed tomography (SPECT/CT) is not recommended in children due to higher radiation exposure than routine DMSA scan. The main limitations of DMSA scan includes relatively long waiting time after radiotracer injection, long acquisition time and high radiation dose which is particularly important in repeated studies in children and limited spatial resolution of gamma cameras. 99mTc-glucoheptonate is an alternative radiotracer when 99mTc-DMSA is not available. Dynamic renal functional imaging radiotracers can grossly assess renal cortex in the first few minutes of the dynamic imaging. Gallium‑68 prostate‑specific membrane antigen ligand (68Ga-PSMA ligand) positron emission tomography (PET) has ability to provide images of normal renal cortex and demonstrate renal cortical defects from cysts. In this article, we wanted to assess the current status of renal cortical imaging and present 68Ga-PSMA ligand renal cortical PET images. We would like to further emphasize that 68Ga-PSMA ligand provides excellent renal cortical images and studies should be done to compare 68Ga-PSMA ligand PET to DMSA scan in renal diseases, particularly in pyelonephritis.