Automated Generation of Reliable Blood Velocity Parameter Maps from Contrast-Enhanced Ultrasound Data

Comparison of voiding vesicoureteral urosonography with fluoroscopic voiding cystourethrography in children with vesicoureteral reflux

Objective

To evaluate the value and compliance rate of voiding vesicoureteral urosonography in pediatric vesicoureteral reflux (VUR).

Methods

This is a retrospective study. A total of 80 children with high-risk VUR admitted to Children's Hospital affiliated to Capital Medical University from December 2018 to December 2020 were selected. All patients underwent voiding urosonography (VUS) and fluoroscopic voiding cystourethrography (VCUG). The sensitivity and compliance of voiding vesicoureteral urosonography were compared, and its application value was evaluated.

Results

A total of 160 PUUs were examined, and all cases were normal. Among them, 56 PUUs had reflux (35.00%, 56/160), 46 PUUs had reflux under both examination methods (28.75%, 46/160), and 10 PUUs were only detected under VUS (6.25%, 10/160). Thirty-four cases of VUR (42.50%, 34/80) were diagnosed by VUS, among which 15 cases were bilateral reflux and 4 cases were unilateral reflux. Twenty-five cases (35.00%, 25/80) were diagnosed by VCUG, among which 10 cases were bilateral regurgitation and five cases were unilateral regurgitation. No significant difference was observed in the detection rate of reflux between the two methods (P=0.432). A total of 146 PUUs were found to be consistent between the two methods (91.25%, 160), including 2 Grade-I reflux, 6 Grade-II reflux, 14 Grade-III reflux, 12 Grade-IV reflux, eight Grade-V reflux, and 104 without reflux, demonstrating SATISFACTORY consistency between the two groups (Kappa=0.885).

Conclusion

Voiding vesicoureteral urosonography has a high coincidence rate in the detection of vesicoureteral reflux in children.

Clinical Pilot Application of Super-Resolution US Imaging in Breast Cancer

Recently, we proved in the first measurements of breast carcinomas the feasibility of super-resolution ultrasound (US) imaging by motion-model ultrasound localization microscopy in a clinical setup. Nevertheless, pronounced in-plane and out-of-plane motions, a nonoptimized microbubble injection scheme, the lower frame rate and the larger slice thickness made the processing more complex than in preclinical investigations. Here, we compare the results of state-of-the-art contrast-enhanced to super-resolution US imaging and systematically analyze the measurements to get indications for the improvement of image acquisition and processing in the future clinical studies. In this regard, the application of a saturation model to the reconstructed vessels is shown to be a valuable tool not only to estimate the measurement times necessary to adequately reconstruct the microvasculature but also for the validation of the measurements. The parameters from this model can also serve to optimize contrast agent concentration and injection protocols. Finally, for the measurements of well-perfused tumors, we observed between 28% and 50% filling for 90-s examination times.

Motion model ultrasound localization microscopy for preclinical and clinical multiparametric tumor characterization

Super-resolution imaging methods promote tissue characterization beyond the spatial resolution limits of the devices and bridge the gap between histopathological analysis and non-invasive imaging. Here, we introduce motion model ultrasound localization microscopy (mULM) as an easily applicable and robust new tool to morphologically and functionally characterize fine vascular networks in tumors at super-resolution. In tumor-bearing mice and for the first time in patients, we demonstrate that within less than 1 min scan time mULM can be realized using conventional preclinical and clinical ultrasound devices. In this context, next to highly detailed images of tumor microvascularization and the reliable quantification of relative blood volume and perfusion, mULM provides multiple new functional and morphological parameters that discriminate tumors with different vascular phenotypes. Furthermore, our initial patient data indicate that mULM can be applied in a clinical ultrasound setting opening avenues for the multiparametric characterization of tumors and the assessment of therapy response.

Motion model ultrasound localization microscopy for preclinical and clinical multiparametric tumor characterization

Super-resolution imaging methods promote tissue characterization beyond the spatial resolution limits of the devices and bridge the gap between histopathological analysis and non-invasive imaging. Here, we introduce motion model ultrasound localization microscopy (mULM) as an easily applicable and robust new tool to morphologically and functionally characterize fine vascular networks in tumors at super-resolution. In tumor-bearing mice and for the first time in patients, we demonstrate that within less than 1 min scan time mULM can be realized using conventional preclinical and clinical ultrasound devices. In this context, next to highly detailed images of tumor microvascularization and the reliable quantification of relative blood volume and perfusion, mULM provides multiple new functional and morphological parameters that discriminate tumors with different vascular phenotypes. Furthermore, our initial patient data indicate that mULM can be applied in a clinical ultrasound setting opening avenues for the multiparametric characterization of tumors and the assessment of therapy response.

The vascular structure of tumors impacts diagnosis, prognosis and drug response; however, imaging methods to analyse this important feature have been hindered by spatial resolution limitations. Here the authors present a tool called motion model ultrasound localization microscopy to morphologically and functionally characterize fine vascular networks in tumors at super-resolution.