Ureteroscopic ultrasound technology to size kidney stone fragments: proof of principle using a miniaturized probe in a porcine model.
OBJECTIVE
A prototype ultrasound-based probe for use in ureteroscopy was used for in vitro measurements of stone fragments in a porcine kidney.


METHODS
Fifteen human stones consisting of three different compositions were placed deep in the collecting system of a porcine kidney. A 2 MHz, 1.2 mm (3.6F) needle hydrophone was used to send and receive ultrasound pulses for stone sizing. Calculated stone thicknesses were compared with caliper measurements.


RESULTS
Correlation between ultrasound-determined thickness and caliper measurements was excellent in all three stone types (r(2) = 0.90, p < 0.0001). All 15 ultrasound measurements were accurate to within 1 mm, and 10 measurements were accurate within 0.5 mm.


CONCLUSIONS
A 3.6F ultrasound probe can be used to accurately size stone fragments to within 1 mm in a porcine kidney.
Department of Urology, University of Washington School of Medicine, Seattle, Washington 98195, USA. mathews@u.washington.edu
Mathew D
MD
Sorensen
Anup R
AR
Shah
Michael S
MS
Canney
Oleg A
OA
Sapozhnikov
Joel M H
JM
Teichman
Michael R
MR
Bailey
D000818:Animals; D004195:Disease Models, Animal; D006801:Humans; D007669:Kidney Calculi / Q000000981:diagnostic imaging* / Q000473:pathology*; D008904:Miniaturization / Q000295:instrumentation*; D034421:Sus scrofa / Q000601:surgery; D014463:Ultrasonography; D018666:Ureteroscopy / Q000379:methods*