Bildgebende Diagnostik – das Ende des AUG?

Evaluation of patient effective doses in CT urography, intravenous urography and renal scintigraphy

Imaging of the renal system is performed with different techniques depending mainly on clinical symptoms and signs. This study intended to evaluate patient effective doses undergoing renal scintigraphy (technetium-99m-diethylene-triamine-pentaacetic acid), computed tomography urography (CTU) and intravenous urography (IVU). A total of 60 patients were evaluated using Orbiter 37 Gamma camera single head, dual-slice CT scanner and conventional X-ray machine with computed radiography (CR) processing unit. Patients effective dose were estimated using the administered activity, DosCal software and dose length product value for renal scan, IVU and CTU procedures, respectively. Patients' effective doses during renal scan, CTU and IVU procedures were 0.78 ± 0.18, 2.53 ± 0.94 and 1.81 ± 0.20 mSv, in that order. Patients were exposed to a higher effective dose during CTU compared with other two procedures. Patient doses depend on the size of patient, the type of scanner and the imaging protocol used. Effective doses considered low compared with previous studies.

Urinary tract effects after multifocal nonthermal irreversible electroporation of the kidney: acute and chronic monitoring by magnetic resonance imaging, intravenous urography and urinary cytology

PURPOSE

The nonthermal irreversible electroporation (NTIRE) is a novel potential ablation modality for renal masses. The aim of this study was the first evaluation of NTIRE's effects on the renal urine-collecting system using intravenous urography (IVU) and urinary cytology in addition to histology and magnetic resonance imaging (MRI).

METHODS

Eight percutaneous NTIRE ablations of the renal parenchyma, including the calyxes or pelvis, were performed in three male swine. MRI, IVU, histology, and urinary cytology follow-ups were performed within the first 28 days after treatment.

RESULTS

MRI and histological analysis demonstrated a localized necrosis 7 days and a localized scarification of the renal parenchyma with complete destruction 28 days after NTIRE. The urine-collecting system was preserved and showed urothelial regeneration. IVU and MRI showed an unaltered normal morphology of the renal calyxes, pelvis, and ureter. A new urinary cytology phenomenon featured a temporary degeneration by individual vacuolization of detached transitional epithelium cells within the first 3 days after NTIRE.

CONCLUSIONS

This first urographical, urine-cytological, and MRI evaluation after porcine kidney NTIRE shows multifocal parenchyma destruction while protecting the involved urine-collecting system with regenerated urothelial tissue. NTIRE could be used as a targeted ablation method of centrally located renal masses.