A Radiomic "Warning Sign" of Progression on Brain MRI in Individuals with MS.

BACKGROUND AND PURPOSE: MS is a chronic progressive, idiopathic, demyelinating disorder whose diagnosis is contingent on the interpretation of MR imaging. New MR imaging lesions are an early biomarker of disease progression. We aimed to evaluate a machine learning model based on radiomics features in predicting progression on MR imaging of the brain in individuals with MS. MATERIALS AND METHODS: This retrospective cohort study with external validation on open-access data obtained full ethics approval. Longitudinal MR imaging data for patients with MS were collected and processed for machine learning. Radiomics features were extracted at the future location of a new lesion in the patients' prior MR imaging ("prelesion"). Additionally, "control" samples were obtained from the normal-appearing white matter for each participant. Machine learning models for binary classification were trained and tested and then evaluated the external data of the model. RESULTS: The total number of participants was 167. Of the 147 in the training/test set, 102 were women and 45 were men. The average age was 42 (range, 21-74 years). The best-performing radiomics-based model was XGBoost, with accuracy, precision, recall, and F1-score of 0.91, 0.91, 0.91, and 0.91 on the test set, and 0.74, 0.74, 0.74, and 0.70 on the external validation set. The 5 most important radiomics features to the XGBoost model were associated with the overall heterogeneity and low gray-level emphasis of the segmented regions. Probability maps were produced to illustrate potential future clinical applications. CONCLUSIONS: Our machine learning model based on radiomics features successfully differentiated prelesions from normal-appearing white matter. This outcome suggests that radiomics features from normal-appearing white matter could serve as an imaging biomarker for progression of MS on MR imaging.

Intrarenal pressures during percutaneous nephrolithotomy: a porcine kidney model.

BACKGROUND: Increased intrarenal pressure during endoscopic lithotripsy is associated with increased adverse outcomes. The objective of this study was to evaluate the effect of various devices on IRP during percutaneous intrarenal surgery in ex vivo porcine kidney models. METHODS: Whole intact porcine urinary tracts were harvested. Intrarenal pressure was measured using cystometrometry software. Intrarenal pressure during PCNL was recorded using variations of percutaneous access sheath size, irrigation height of 100 cm and 60 cm, use of a ureteric catheter and use of suction. The primary outcome was absolute IRP measurements. Secondary outcomes were comparisons of IRP between techniques. RESULTS: Using a 30 Fr vs 26 Fr access sheath and 26 Fr nephroscope the mean pressure at an irrigation height of 60 cm was significantly lower than 100 cm (p = 0.0013 vs p < 0.0001, respectively). Pressure's during mini-PCNL were significantly higher than conventional PCNL in all variations. Using the 16.5 Fr access sheath and 12 Fr nephroscope produced a significantly lower pressure at a 60 cm irrigation height than 100 cm (p = 0.0010). IRP was significantly lower with a ureteric catheter in place vs no ureteric catheter at 100 cm (p = 0.0015) and at 60 cm (p = 0.0040). CONCLUSIONS: Using standard PCNL tract sizes intrarenal pressure varied significantly depending on the height of the irrigation fluid. Mini-PCNL is at higher risk of pathological pressure, however, the use of a ureteric catheter significantly decreased pressure. To maintain safe IRP during PCNL urologists should be aware of these significant variations.

Evaluation of a new disposable flexible ureterorenoscope and comparison to an established disposable flexible ureterorenoscope: a prospective, observational study.

PURPOSE: To objectively and subjectively assess the performance and surgical outcomes of the new Innovex EU-scope™ single-use digital flexible ureteroscope (fURS). METHODS: A prospective cohort study was carried out (August 2019 to May 2020). The new single-use fURS (Innovex Medical Devices Co. Shanghai, China) was analysed with regard to visibility, manoeuvrability, laser interference and overall performance using a validated Likert scale. Outcomes are compared to the LithoVue™ (Boston Scientific, Marlborough, MA). RESULTS: One hundred patients were included in this study. 50 cases underwent retrograde fURS using the Innovex EU-scope™ and 50 with the LithoVue™. There were no differences in the patient demographics data, or operative data between the two groups. The Innovex EU-scope™ scored higher visibility scores compared to the LithoVue™, median 4, interquartile range (IQR) (4-4), vs. 3.5, IQR (3-5), p = 0.5086. Both scopes had similar manoeuvrability scores. The Innovex EU-scope™ scored significantly lower with regard to comfort compared to the LithoVue, median 4 IQR (3-4) vs. 4.5 IQR (4-5), p = 0.0445. Whereas, laser interference, affected the Innovex much less than the LithoVue™. Both scopes scored well for overall performance. The median overall performance score for the Innovex was 4 IQR (4-4) vs. 4 IQR (4-5). CONCLUSIONS: This Innovex EU-scope™ has good objective and subjective visibility and manoeuvrability profiles. This single-use flexible ureteroscope may achieve similar clinical outcomes to an established single use instrument.