Ureteral wall thickness and distal ureteral density in patients with residual fragments after Ho:YAG laser semi-rigid ureterolithotripsy.

Recent data suggest that greater ureteral density distal to ureteral stones or increased ureteral wall thickness (UWT) can predict impacted stones. The aim of our study was to evaluate if patients with residual fragments present with greater ureteral density and larger UWT when compared to stone-free patients. From January onward, a consecutive series of patients undergoing semi rigid Ho:YAG laser ureterolithotripsy (ULT) for ureteral stones were enrolled. A non-contrast enhanced computed tomography (CT) scan was performed before the procedure to evaluate distal ureteral density (DUD) and wall ureteral thickness (UWT) at the site of ureteral stones. Patients with residual fragments were compared to stone-free patients using a matched-pair analysis (1:1 scenario). Cases were matched sequentially using the following criteria: age, gender, body mass index (BMI), stone length, hydronephrosis, location of stones, and mean Hounsfield unit (HU) of the stone. Overall, 160 patients were enrolled, mean age was 57.9 ± 14 years, mean BMI was 25.8 ± 4 kg/m2, mean length of the stone was 10.6 ± 4.9 mm, and mean UWT was 1.4 ± 1.6 mm. A total of 150/160 (94%) patients presented hydronephrosis; mean HU stone was 868 ± 327; mean DUD was 54 ± 17.8 HU. Ureteral distal density (51.7 vs 56.6; p = 0.535) and ureteral distal thickness (1.39 vs 1.54; p = 0.078) were similar in both groups of patients. In our study, the evaluation of distal ureteral density does not predict stone-free rate. Further studies should evaluate the role for preoperative computer tomography in predicting surgery outcome.

Synthetic Post-Contrast Imaging through Artificial Intelligence: Clinical Applications of Virtual and Augmented Contrast Media.

Contrast media are widely diffused in biomedical imaging, due to their relevance in the diagnosis of numerous disorders. However, the risk of adverse reactions, the concern of potential damage to sensitive organs, and the recently described brain deposition of gadolinium salts, limit the use of contrast media in clinical practice. In recent years, the application of artificial intelligence (AI) techniques to biomedical imaging has led to the development of 'virtual' and 'augmented' contrasts. The idea behind these applications is to generate synthetic post-contrast images through AI computational modeling starting from the information available on other images acquired during the same scan. In these AI models, non-contrast images (virtual contrast) or low-dose post-contrast images (augmented contrast) are used as input data to generate synthetic post-contrast images, which are often undistinguishable from the native ones. In this review, we discuss the most recent advances of AI applications to biomedical imaging relative to synthetic contrast media.

Endovascular management of giant visceral artery aneurysms.

Endovascular management of small visceral artery aneurysms is an established treatment with satisfactory outcomes. However, when size exceeds 5 cm visceral aneurysms are considered as "giant" (giant visceral artery aneurysms or GVAAs) and management is significantly more complex. Between August 2007 and June 2019 eleven cases of GVAAs that were endovascularly treated were retrospectively reviewed and included in this single center study. Mean size was 80 mm (± 26.3 mm) x 46 mm (+ \-11.8 mm). Nine of the lesions were true aneurysms, and two were pseudoaneurysms. In 8 patients, the lesion was causing compression symptoms in the surrounding organs, one patient developed a contained rupture while 2 patients were completely asymptomatic. However, all patients were hemodynamically stable at the time of treatment. Technical success was defined as immediate complete exclusion of the aneurysmal sac, and clinical success as complete relief from clinical symptoms. Follow-up was performed with CT angiography, ultrasound and clinical examination. Mean follow-up was 45 months (range 6-84). Technical and clinical success were both 91%. Complications were one lack of control of contained rupture that was subsequently operated, one case of self-limiting non-target spleen embolization and one case of splenic abscess. Three patients died, one due to the contained rupture 15 days after procedure, the other two for other causes and occurred during the long-term follow-up. This series suggests that endovascular treatment of giant visceral artery aneurysms and pseudoaneuryms is a valid minimally invasive solution with very satisfactory immediate and long-term outcomes unless the aneurysm is already ruptured. A variety of endovascular tools may be required for successful treatment.

External validation of Imamura nomogram as a tool to predict preoperatively laser semi-rigid ureterolithotripsy outcomes.

BACKGROUND: We aimed to validate Imamura nomogram for prediction of stone free rate in patients undergoing ureterolithotripsy (ULT). METHODS: From January 2013 to June 2016, patients undergoing laser semi-rigid ULT were prospectively enrolled at our center. All patients were preoperatively assessed with clinical history, blood samples, uranalysis and non-contrast enhanced computed tomography (CT). Treatment efficacy was assessed 1 month later by non-contrast enhanced CT. ROC curve was used to evaluate the performance characteristics of Imamura nomogram. RESULTS: Overall, we enrolled 275 patients. Median age was 55 years (IQR: 46/64), median length of stone was 9.8 mm (IQR: 7.5/12). Pyuria was detected in 6/275 (2.1%) patients. Stones were located at ureteropelvic junction in 55/275 (19%) patients, proximal ureter in 74/275 (26%) patients, middle and distal ureter in 66/275 (24%) patients and 82/275 (30%) patients, respectively. At 1-month follow-up, 209/275 (76%) patients were stone free. Imamura nomogram presented an AUC of 0.67 (95% CI: 0.580-0.761) for the prediction of stone free rate. At the best cut-off value of 75%, sensitivity was 76%, specificity was 55%, positive predictive value (PPV) was 83% and negative predictive value was 45%. CONCLUSIONS: We firstly validated Imamura nomogram in a European cohort study. It proved a reasonable accuracy (area under curve: 0.67) and a good PPV (83%). Further studies should confirm our results to support the routine clinical use of Imamura nomogram as a tool to predict ULT outcomes.