Accuracy of attenuation coefficient measurement (ACM) for real-time ultrasound hepatic steatometry: Comparison of simulator/phantom data with magnetic resonance imaging proton density fat fraction (MRI-PDFF).

Objectives: To evaluate the accuracy and reproducibility of real time ultrasound (US) steatometry with the Attenuation Coefficient (AC) measurement in comparison with magnetic resonance imaging with proton density software module (MRI-PDFF). Methods: This study was conducted between January 2021 and October 2021. The comparison of instrumental methods for assessing and grading hepatic steatosis using a multimodal phantom simulator of different fat and water ratios was performed. The study involved 3 radiological centers. The steatophantom was simultaneously investigated using three methods: magnetic resonance imaging with proton density software module (MRI-PDFF) and 128-slice multidetector computed tomography, and then by 2 different US scanner for steatosis assessment via Measurement Attenuation Imaging (ATI) ant Attenuation Coefficient Measurement (ACM). Results: Modeling of hepatic steatosis using a series of phantom simulators allows evidence-based medicine to determine the diagnostic accuracy of the latest US techniques for steatosis. The ACM and ATI of both US systems on phantoms correlated well with each other and with MRI-PDFF and, thus, can provide good diagnostic value in the assessment of hepatic steatosis. MDCT was less sensitive to mild steatosis than AC and MRI-PDFF. Conclusion: Measurement of ACs in US studies by devices from different vendors compared to other modalities of radiological imaging (MDCT and MRI-PDFF) by special phantoms is an accurate and promising method for noninvasive quantification of hepatic steatosis.

MXene-Assisted Ablation of Cells with a Pulsed Near-Infrared Laser.

Innovative therapies are urgently needed to combat cancer. Thermal ablation of tumor cells is a promising minimally invasive treatment option. Infrared light can penetrate human tissues and reach superficial malignancies. MXenes are a class of 2D materials that consist of carbides/nitrides of transition metals. The transverse surface plasmons of MXenes allow for efficient light absorption and light-to-heat conversion, making MXenes promising agents for photothermal therapy (PTT). To date, near-infrared (NIR) light lasers have been used in PTT studies explicitly in a continuous mode. We hypothesized that pulsed NIR lasers have certain advantages for the development of tailored PTT treatment targeting tumor cells. The pulsed lasers offer a wide range of controllable parameters, such as power density, duration of pulses, pulse frequency, and so on. Consequently, they can lower the total energy applied and enable the ablation of tumor cells while sparing adjacent healthy tissues. We show for the first time that a pulsed 1064 nm laser could be employed for selective ablation of cells loaded with Ti3C2Tx MXene. We demonstrate both low toxicity and good biocompatibility of this MXene in vitro, as well as a favorable safety profile based on the experiments in vivo. Furthermore, we analyze the interaction of MXene with cells in several cell lines and discuss possible artifacts of commonly used cellular metabolic assays in experiments with MXenes. Overall, these studies provide a basis for the development of efficient and safe protocols for minimally invasive therapies for certain tumors.