Imaging in situ human kidney stones with the color Doppler ultrasound twinkling artifact

Hyperbaric pressures of 3–100 atmospheres absolute (ATA) have been shown to reduce the color Doppler ultrasound twinkling artifact on ex vivo human kidney stones, leading to the hypothesis that surface crevice microbubbles cause twinkling. Similarly supportive for the crevice bubble hypothesis is the suppression of kidney stone twinkling in animals breathing elevated levels of carbon dioxide. However, it is unclear whether stable microbubbles can exist on the surface of kidney stones in the human body. For the first time, we investigate the effect of hyperbaric pressure on in situ human kidney stones to determine whether stable microbubbles exist as measured by the color Doppler ultrasound twinkling artifact.