"Optimization of ultrasound settings for better determination of cystolith size in vitro"

Thank you to Lauren Kustasz from Michigan State University for sharing the abstract from her summer research project with Dr. Nathan Nelson DACVR....and CONGRATULATIONS on having it be selected as a winner in the cases and abstracts category.

Accurate estimation of urinary cystolith size is a critical factor in assessing the biological behavior of urocystoliths, their response to dissolution therapy, and their potential for removal by minimally invasive procedures. A previous study found that ultrasound, using a curved array transducer at a frequency of 10 MHz, overestimated cystolith size compared to other imaging techniques. The purpose of this study was to further evaluate ultrasonography as an imaging technique for measuring cystoliths, comparing transducer types, different frequencies, and the use of tissue harmonics imaging and spatial compound imaging using an in vitro bladder phantom model. Thirty cystoliths were imaged using combinations of the ultrasound variables mentioned. The accuracy of cystolith measurement was determined by taking the difference between the measurement obtained from the ultrasound image and the true size of the cystolith determined by a digital caliper. The accuracy of the measurements obtained from the linear transducer was significantly greater than the accuracy of the measurements obtained from the curved array transducer (p < 0.05). Measurements from the linear transducer showed a significant decrease in accuracy of cystolith size estimation when spatial compound imaging was used (p < 0.05 ). Independent of actual cystolith size, the linear transducer tended to overestimate cystolith size by 0.16 cm on average and the curved transducer overestimated by 0.43 cm on average. Subjectively, there were more artifacts seen in the images taken with the curved transducer and, especially with smaller cystoliths, these artifacts superimposed the cystoliths making them difficult to measure.

Dr. Nelson and the author with their ultrasound machine