History of ultrasound in obstetrics and gynaecology from 1971 to 2021 on occasion of the 50 years anniversary of EFSUMB

2D ultrasound thermometry during thermal ablation with high-intensity focused ultrasound

The clinical use of high intensity focused ultrasound (HIFU) therapy for noninvasive tissue ablation has recently gained momentum. Guidance is provided by either magnetic resonance imaging (MRI) or conventional B-mode ultrasound imaging, each with its own advantages and disadvantages. The main limitation of ultrasound imaging is its inability to provide temperature measurements over the ranges corresponding to the target temperatures during ablative thermal therapies (between 55 °C and 70 °C). Here, variations in ultrasound backscattered energy (ΔBSE) were used to monitor temperature increases in liver tissue up to an absolute value of 90 °C during and after HIFU treatment. In vitro experimental measurements were performed in 47 bovine liver samples using a toroidal HIFU transducer operating at 2.5 MHz to increase the temperature of tissues. An ultrasound imaging probe working at 7.5 MHz was placed in the center of the HIFU transducer to monitor the backscattered signals. The free-field acoustic power was set to 9 W, 12 W or 16 W in the different experiments. HIFU sonications were performed for 240 s using a duty cycle of 83 % to allow ultrasound imaging and raw radiofrequency data acquisition during exposures. Measurements showed a linear relationship between ΔBSE (in dB) and temperature (r = 0.94, p < 0.001) over a temperature range from 37 °C to 90 °C, with a high reliability of temperature measurements below 75 °C. Monitoring can be performed at the frame rate of ultrasound imaging scanners with an accuracy within an acceptable threshold of 5 °C, given the temperatures targeted during thermal ablations. If the maximum temperature reached is below 70 °C, ΔBSE is also a reliable approach for estimating the temperature during cooling. Histological analysis shown the impact of the treatment on the spatial arrangement of cells that can explain the observed variation of ΔBSE. These results demonstrate the ability of ΔBSE measurements to estimate temperature in ultrasound images within an effective therapeutic range. This method can be implemented clinically and potentially applied to other thermal-based therapies.

Student Ultrasound Education, Current Views and Controversies; Who Should be Teaching?

Acquiring diagnostic ultrasound competencies and skills is crucial in modern health care, and achieving the practical experience is vital in developing the necessary anatomy interpretation and scan acquisition skills. However, traditional teaching methods may not be sufficient to provide hands-on practice, which is essential for this skill acquisition. This paper explores various modalities and instructors involved in ultrasound education to identify the most effective approaches. The field of ultrasound instruction is enriched by the diverse roles of physicians, anatomists, peer tutors, and sonographers. All these healthcare professionals can inspire and empower the next generation of ultrasound practitioners with continuous training and support. Physicians bring their clinical expertise to the table, while anatomists enhance the understanding of anatomical knowledge through ultrasound integration. Peer tutors, often medical students, provide a layer of social congruence and motivation to the learning process. Sonographers provide intensive practical experience and structured learning plans to students. By combining different instructors and teaching methods, success can be achieved in ultrasound education. An ultrasound curriculum organized by experts in the field can lead to more efficient use of resources and better learning outcomes. Empowering students through peer-assisted learning can also ease the burden on faculty. Every instructor must receive comprehensive didactic training to ensure high-quality education in diagnostic ultrasound.