Comparison of static-fluid or excretory magnetic resonance urography with computed tomography urography for visualization of nondilated renal pelvises and ureters in healthy Beagles

OBJECTIVE To assess the usefulness of magnetic resonance urography (MRU) for the visualization of nondilated renal pelvises and ureters in dogs and to compare our findings for MRU versus CT urography (CTU). ANIMALS 9 healthy Beagles. PROCEDURES Dogs underwent CTU, static-fluid MRU, and excretory MRU, with ≥ 7 days between procedures. Contrast medium was administered IV during CTU and excretory MRU, whereas urine in the urinary tract was an intrinsic contrast medium for static-fluid MRU. For each procedure, furosemide (1 mg/kg, IV) was administered, and reconstructed dorsal plane images were acquired 3 minutes (n = 2) and 7 minutes (2) later. Images were scored for visualization of those structures and for image quality, diameters of renal pelvises and ureters were measured, and results were compared across imaging techniques. RESULTS Excretory MRU and CTU allowed good visualization of the renal pelvises and ureters, whereas static-fluid MRU provided lower visualization of the ureters. Distention of the renal pelvises and ureters was good in excretory MRU and CTU. Distention of the ureters in static-fluid MRU was insufficient compared with that in CTU and excretory MRU. Distinct artifacts were not observed in CTU and excretory MRU images. Static-fluid MRU images had several mild motion artifacts. CLINICAL RELEVANCE Our findings indicated that excretory MRU with furosemide administration was useful for visualizing nondilated renal pelvises and ureters of dogs in the present study. When performing MRU for the evaluation of dogs without urinary tract dilation, excretory MRU may be more suitable than static-fluid MRU.

Impact on clinical outcome of segmental vs diffuse parenchymal thinning in infants with prenatal urinary tract dilation

Objective: To determine the difference in renal function and rate of surgical intervention between neonates with diffuse and segmental parenchymal thinning. Materials and Methods: First postnatal ultrasonography images of neonates with prenatal urinary tract dilation were evaluated and measurements taken. Neonates with parenchymal thinning were categorised into segmental and diffuse parenchymal thinning groups using the medullary to intermedullary ratio. A statistical correlation of differential renal function and rate of surgical intervention between the two groups was calculated and evaluated using an independent t-test and Kaplan-Meier curve with Log-rank test, respectively. Results: Of the 20 neonates, 10 had segmental parenchymal thinning, while the other 10 had diffuse parenchymal thinning. Mean differential renal function was 49.3% in the segmental parenchymal thinning group compared to 45.8% in the diffuse group (p = 0.400). Five patients (50%) from the segmental parenchymal thinning group underwent pyeloplasty in comparison to seven patients (70%) from the diffuse group (p = 0.430) Conclusion: There were no significant differences in renal function or rate of surgical intervention between neonates with segmental parenchymal thinning and diffuse parenchymal thinning. Neonates with segmental parenchymal thinning need to be monitored as closely as those with diffuse parenchymal thinning for early detection of renal deterioration and to identify potential need for surgical intervention.

One-shot dilation versus metallic dilation technique for access in percutaneous nephrolithotomy: comparison of efficacy, access time and fluoroscopic time

Objective: The aim of this study was to compare the efficacy, access tract dilation time and fluoroscopic time between the one-shot dilation technique and telescopic metal dilatation technique in patients undergoing percutaneous nephrolithotomy in Nakornping Hospital. Materials and Methods: Sixty-six patients who underwent percutaneous nephrolithotomy from January 2020 to July 2021 were included in the study and they were randomly divided into two groups. In group 1 (32 patients), telescopic metal dilation was used, in group 2 (33 patients), the one-shot technique was used. Success rates of dilation, access tract dilation time and fluoroscopic time were evaluated. Results: The success rate of dilation was 100% in both groups. The access tract dilation time was 835.63 ± 309.68 seconds in group 1 and 569.42 ± 314.75 seconds in group 2 (p = 0.001). The fluoroscopic time was 48.16 ± 22.16 seconds in group 1 and 41.97 ± 23.99 seconds in group 2 (p = 0.29). The access tract dilation time of the one-shot dilation technique was statistically significantly shorter than that in the telescopic metal dilatation group. The mean fluoroscopic time of the one- shot dilation technique was shorter than in telescopic metal dilatation but was not statistically significant. Conclusion: One-shot dilation technique is as effective as telescopic metal dilatation, with a significant reduction in access tract dilation time.

A Safe and Effective Two-Step Tract Dilation Technique in Totally Ultrasound-Guided Percutaneous Nephrolithotomy

Background To evaluate the safety and the efficacy of a radiation-free 2-step tract dilation technique in totally ultrasound-guided percutaneous nephrolithotomy (PCNL). Methods From Oct 2018 to Mar 2020, we prospectively and consecutively enrolled 18 patients with 19 kidney units with urolithiasis. The nephrostomy tract was established by the following four steps: 1) ultrasound-guided renal puncture, 2) first-stage serial dilation to 16 Fr with Amplatz dilators, 3) check and adjustment of the partially dilated tract with a ureteroscope, 4) second-stage dilation with a 24-Fr balloon dilator. Results The median age was 62.0 [IQR 11.0] years, and 11 (61.1%) were male. The median stone size was 3.3 [3.6] cm2, and stone laterality was almost equal over both sides. Successful tract establishment on the first attempt without fluoroscopy was achieved in 18 (94.7%) operations. The median tract establishment time was 10.4 [4.9] mins, and the median operation time was 67.0 [52.2] mins. The median hemoglobin drop was 1.0 [1.1] g/dL, and none required blood transfusion. Three (15.8%) developed fever. Pleural injury occurred in two (10.5%) operations (both had supracostal puncture), and one required drainage with pigtail. Stone-free status was achieved in 15 (77.8%) operations at 3 months postoperatively. Conclusions Herein we present a radiation-free 2-step tract dilation technique, which is characterized by ureteroscopic check of the partially dilated tract in between the first dilation with serial fascial dilators and the second dilation with balloon. Our data suggest that it is a safe and effective method.

Influence of Febrile Urinary Tract Infection on Ultrasonic Measurements of Nonreflux Upper Urinary Tract Dilation in Infants

Background To investigate the changes in ultrasonic measurements of nonreflux upper urinary tract dilation in infants with febrile urinary tract infection (UTI).Methods There were 28 cases of nonreflux upper urinary tract dilatation with febrile UTI: 14 cases of ureteropelvic junction obstruction (UPJO) (14 kidneys) and 14 cases of ureterovesical junction obstruction (UVJO) (16 kidneys). Changes in anteroposterior renal pelvic diameter (APD) and ureteral dilatation during infection and after infection were compared in UPJO and UVJO patients, respectively.Results In the UPJO with febrile UTI group, the APD was 24.1±10.0 mm at the time of UTI and 16.6±7.0 mm 1 week after infection recovery (P<0.001). In the UVJO with febrile UTI group, the APD was 19.3±8.5 mm at the time of UTI and 15.2±7.7 mm 1 week after infection recovery (P<0.001). In the UVJO with febrile UTI group, the ureteric diameter was 11.0±3.2 mm during UTI and 6.8±2.6 mm 1 week after infection recovery (P<0.001).Conclusions In UPJO patients, the APD decreased after febrile UTI treatment compared with that during infection. In UVJO patients, the APD and ureteric diameter decreased after febrile UTI treatment compared with that during infection.