The Experts below are selected from a list of 5127 Experts worldwide ranked by ideXlab platform
Mathew D. Sorensen - One of the best experts on this subject based on the ideXlab platform.
-
Innovations in Ultrasound Technology in the Management of Kidney Stones.
Urologic Clinics of North America, 2019Co-Authors: Jessica C. Dai, Michael R. Bailey, Mathew D. Sorensen, Jonathan D. HarperAbstract:: This article reviews new advances in ultrasound technology for urinary stone disease. Recent research to facilitate the diagnosis of nephrolithiasis, including use of the twinkling signal and posterior Acoustic Shadow, have helped to improve the use of ultrasound examination for detecting and sizing renal stones. New therapeutic applications of ultrasound technology for stone disease have emerged, including ultrasonic propulsion to reposition stones and burst wave lithotripsy to fragment stones noninvasively. The safety, efficacy, and evolution of these technologies in phantom, animal, and human studies are reviewed herein. New developments in these rapidly growing areas of ultrasound research are also highlighted.
-
measurement of posterior Acoustic stone Shadow on ultrasound is a learnable skill for inexperienced users to improve accuracy of stone sizing
Journal of Endourology, 2018Co-Authors: Jessica C. Dai, Michael R. Bailey, Jonathan D. Harper, Ziyue Liu, Barbrina Dunmire, Kevan M. Sternberg, Mathew D. SorensenAbstract:Abstract Introduction: Studies suggest that the width of the Acoustic Shadow on ultrasound (US) more accurately reflects true stone size than the stone width in US images. We evaluated the need for...
-
Retrospective comparison of measured stone size and posterior Acoustic Shadow width in clinical ultrasound images.
World journal of urology, 2017Co-Authors: Jessica C. Dai, Michael R. Bailey, Jonathan D. Harper, Ziyue Liu, Barbrina Dunmire, Kevan M. Sternberg, Troy Larson, Jeff Thiel, Helena C. Chang, Mathew D. SorensenAbstract:Purpose Posterior Acoustic Shadow width has been proposed as a more accurate measure of kidney stone size compared to direct measurement of stone width on ultrasound (US). Published data in humans to date have been based on a research using US system. Herein, we compared these two measurements in clinical US images.
-
use of the Acoustic Shadow width to determine kidney stone size with ultrasound
The Journal of Urology, 2016Co-Authors: Barbrina Dunmire, Michael R. Bailey, Jonathan D. Harper, Franklin Lee, Ziyue Liu, Bryan W. Cunitz, Ryan S. Hsi, Mathew D. SorensenAbstract:Purpose: Ultrasound is known to overestimate kidney stone size. We explored measuring the Acoustic Shadow behind kidney stones combined with different ultrasound imaging modalities to improve stone sizing accuracy.Materials and Methods: A total of 45 calcium oxalate monohydrate stones were imaged in vitro at 3 different depths with the 3 different ultrasound imaging modalities of conventional ray line, spatial compound and harmonic imaging. The width of the stone and the width of the Acoustic Shadow were measured by 4 operators blinded to the true size of the stone.Results: Average error between the measured and true stone width was 1.4 ± 0.8 mm, 1.7 ± 0.9 mm, 0.9 ± 0.8 mm for ray line, spatial compound and harmonic imaging, respectively. Average error between the Shadow width and true stone width was 0.2 ± 0.7 mm, 0.4 ± 0.7 mm and 0.0 ± 0.8 mm for ray line, spatial compound and harmonic imaging, respectively. Sizing error based on the stone width worsened with greater depth (p <0.001) while the sizing er...
-
Use of the Acoustic Shadow Width to Determine Kidney Stone Size with Ultrasound.
The Journal of urology, 2015Co-Authors: Barbrina Dunmire, Michael R. Bailey, Jonathan D. Harper, Franklin Lee, Ziyue Liu, Bryan W. Cunitz, Ryan S. Hsi, Mathew D. SorensenAbstract:Purpose: Ultrasound is known to overestimate kidney stone size. We explored measuring the Acoustic Shadow behind kidney stones combined with different ultrasound imaging modalities to improve stone sizing accuracy.Materials and Methods: A total of 45 calcium oxalate monohydrate stones were imaged in vitro at 3 different depths with the 3 different ultrasound imaging modalities of conventional ray line, spatial compound and harmonic imaging. The width of the stone and the width of the Acoustic Shadow were measured by 4 operators blinded to the true size of the stone.Results: Average error between the measured and true stone width was 1.4 ± 0.8 mm, 1.7 ± 0.9 mm, 0.9 ± 0.8 mm for ray line, spatial compound and harmonic imaging, respectively. Average error between the Shadow width and true stone width was 0.2 ± 0.7 mm, 0.4 ± 0.7 mm and 0.0 ± 0.8 mm for ray line, spatial compound and harmonic imaging, respectively. Sizing error based on the stone width worsened with greater depth (p
Barbrina Dunmire - One of the best experts on this subject based on the ideXlab platform.
-
measurement of posterior Acoustic stone Shadow on ultrasound is a learnable skill for inexperienced users to improve accuracy of stone sizing
Journal of Endourology, 2018Co-Authors: Jessica C. Dai, Michael R. Bailey, Jonathan D. Harper, Ziyue Liu, Barbrina Dunmire, Kevan M. Sternberg, Mathew D. SorensenAbstract:Abstract Introduction: Studies suggest that the width of the Acoustic Shadow on ultrasound (US) more accurately reflects true stone size than the stone width in US images. We evaluated the need for...
-
Retrospective comparison of measured stone size and posterior Acoustic Shadow width in clinical ultrasound images.
World journal of urology, 2017Co-Authors: Jessica C. Dai, Michael R. Bailey, Jonathan D. Harper, Ziyue Liu, Barbrina Dunmire, Kevan M. Sternberg, Troy Larson, Jeff Thiel, Helena C. Chang, Mathew D. SorensenAbstract:Purpose Posterior Acoustic Shadow width has been proposed as a more accurate measure of kidney stone size compared to direct measurement of stone width on ultrasound (US). Published data in humans to date have been based on a research using US system. Herein, we compared these two measurements in clinical US images.
-
use of the Acoustic Shadow width to determine kidney stone size with ultrasound
The Journal of Urology, 2016Co-Authors: Barbrina Dunmire, Michael R. Bailey, Jonathan D. Harper, Franklin Lee, Ziyue Liu, Bryan W. Cunitz, Ryan S. Hsi, Mathew D. SorensenAbstract:Purpose: Ultrasound is known to overestimate kidney stone size. We explored measuring the Acoustic Shadow behind kidney stones combined with different ultrasound imaging modalities to improve stone sizing accuracy.Materials and Methods: A total of 45 calcium oxalate monohydrate stones were imaged in vitro at 3 different depths with the 3 different ultrasound imaging modalities of conventional ray line, spatial compound and harmonic imaging. The width of the stone and the width of the Acoustic Shadow were measured by 4 operators blinded to the true size of the stone.Results: Average error between the measured and true stone width was 1.4 ± 0.8 mm, 1.7 ± 0.9 mm, 0.9 ± 0.8 mm for ray line, spatial compound and harmonic imaging, respectively. Average error between the Shadow width and true stone width was 0.2 ± 0.7 mm, 0.4 ± 0.7 mm and 0.0 ± 0.8 mm for ray line, spatial compound and harmonic imaging, respectively. Sizing error based on the stone width worsened with greater depth (p <0.001) while the sizing er...
-
Use of the Acoustic Shadow Width to Determine Kidney Stone Size with Ultrasound.
The Journal of urology, 2015Co-Authors: Barbrina Dunmire, Michael R. Bailey, Jonathan D. Harper, Franklin Lee, Ziyue Liu, Bryan W. Cunitz, Ryan S. Hsi, Mathew D. SorensenAbstract:Purpose: Ultrasound is known to overestimate kidney stone size. We explored measuring the Acoustic Shadow behind kidney stones combined with different ultrasound imaging modalities to improve stone sizing accuracy.Materials and Methods: A total of 45 calcium oxalate monohydrate stones were imaged in vitro at 3 different depths with the 3 different ultrasound imaging modalities of conventional ray line, spatial compound and harmonic imaging. The width of the stone and the width of the Acoustic Shadow were measured by 4 operators blinded to the true size of the stone.Results: Average error between the measured and true stone width was 1.4 ± 0.8 mm, 1.7 ± 0.9 mm, 0.9 ± 0.8 mm for ray line, spatial compound and harmonic imaging, respectively. Average error between the Shadow width and true stone width was 0.2 ± 0.7 mm, 0.4 ± 0.7 mm and 0.0 ± 0.8 mm for ray line, spatial compound and harmonic imaging, respectively. Sizing error based on the stone width worsened with greater depth (p
-
MP17-01 THE POSTERIOR Acoustic Shadow: EVALUATING STONE SIZE IN PEDIATRIC STONE FORMERS
The Journal of Urology, 2015Co-Authors: Franklin Lee, Michael R. Bailey, Jonathan D. Harper, Thomas S. Lendvay, Ziyue Liu, Barbrina Dunmire, Manjiri Dighe, Jonathan Swanson, Mathew SorensenAbstract:INTRODUCTION AND OBJECTIVES: Unlike adult stone formers, ultrasound is often exclusively used in both the initial diagnosis and the follow-up of pediatric stone formers. As such, treatment decisions are made based on ultrasound findings alone. Ultrasound has been shown to consistently overestimate stone size, which could lead to surgical intervention for a stone that may spontaneously pass. Our group has previously demonstrated that the posterior Acoustic Shadow is a more accurate predictor of true stone size in an in vitro model. We sought to determine the prevalence and accuracy of the posterior Acoustic Shadow in a pediatric cohort. METHODS: A retrospective analysis was performed of all pediatric stone patient encounters at a children’s hospital over the last 10 years using the ICD-9 code for nephrolithiasis (592.0). All included subjects had a stone present on computed tomography (CT) scan and renal ultrasound, taken within 3 months of each other for an initial stone event. The size of the stone and posterior Acoustic Shadow were measured on ultrasound by two board certified radiologists and compared to stone size as measured on CT. RESULTS: Of 633 charts reviewed, 37 patients with 49 kidney stones were included in this study. Mean age was 13 4 years with a mean BMI of 19 6 kg/m2 and mean stone size of 7.2 2.9 based on CT. A posterior Acoustic Shadow was seen in 85% of stones evaluated and found to be a significantly (p < 0.001) better predictor of true stone size. When compared to CT, measuring the stone directly resulted in an average overestimation of 2.0 1.5 mm, while measuring the Acoustic Shadow resulted in an underestimation of 0.4 2.5 mm. CONCLUSIONS: In this retrospective study, the posterior Acoustic Shadow was seen in the majority of stones. Measuring the Shadow was a more accurate measure of true stone size and may provide valuable prognostic information to help guide clinicians in counseling families about surveillance or surgical management of renal stones. This is particularly relevant to the pediatric population and may reduce unnecessary procedures and further decrease reliance on CT imaging. The results may be improved in a prospective study where the image is optimized for a Shadow measurement.
Jonathan D. Harper - One of the best experts on this subject based on the ideXlab platform.
-
Innovations in Ultrasound Technology in the Management of Kidney Stones.
Urologic Clinics of North America, 2019Co-Authors: Jessica C. Dai, Michael R. Bailey, Mathew D. Sorensen, Jonathan D. HarperAbstract:: This article reviews new advances in ultrasound technology for urinary stone disease. Recent research to facilitate the diagnosis of nephrolithiasis, including use of the twinkling signal and posterior Acoustic Shadow, have helped to improve the use of ultrasound examination for detecting and sizing renal stones. New therapeutic applications of ultrasound technology for stone disease have emerged, including ultrasonic propulsion to reposition stones and burst wave lithotripsy to fragment stones noninvasively. The safety, efficacy, and evolution of these technologies in phantom, animal, and human studies are reviewed herein. New developments in these rapidly growing areas of ultrasound research are also highlighted.
-
measurement of posterior Acoustic stone Shadow on ultrasound is a learnable skill for inexperienced users to improve accuracy of stone sizing
Journal of Endourology, 2018Co-Authors: Jessica C. Dai, Michael R. Bailey, Jonathan D. Harper, Ziyue Liu, Barbrina Dunmire, Kevan M. Sternberg, Mathew D. SorensenAbstract:Abstract Introduction: Studies suggest that the width of the Acoustic Shadow on ultrasound (US) more accurately reflects true stone size than the stone width in US images. We evaluated the need for...
-
Retrospective comparison of measured stone size and posterior Acoustic Shadow width in clinical ultrasound images.
World journal of urology, 2017Co-Authors: Jessica C. Dai, Michael R. Bailey, Jonathan D. Harper, Ziyue Liu, Barbrina Dunmire, Kevan M. Sternberg, Troy Larson, Jeff Thiel, Helena C. Chang, Mathew D. SorensenAbstract:Purpose Posterior Acoustic Shadow width has been proposed as a more accurate measure of kidney stone size compared to direct measurement of stone width on ultrasound (US). Published data in humans to date have been based on a research using US system. Herein, we compared these two measurements in clinical US images.
-
use of the Acoustic Shadow width to determine kidney stone size with ultrasound
The Journal of Urology, 2016Co-Authors: Barbrina Dunmire, Michael R. Bailey, Jonathan D. Harper, Franklin Lee, Ziyue Liu, Bryan W. Cunitz, Ryan S. Hsi, Mathew D. SorensenAbstract:Purpose: Ultrasound is known to overestimate kidney stone size. We explored measuring the Acoustic Shadow behind kidney stones combined with different ultrasound imaging modalities to improve stone sizing accuracy.Materials and Methods: A total of 45 calcium oxalate monohydrate stones were imaged in vitro at 3 different depths with the 3 different ultrasound imaging modalities of conventional ray line, spatial compound and harmonic imaging. The width of the stone and the width of the Acoustic Shadow were measured by 4 operators blinded to the true size of the stone.Results: Average error between the measured and true stone width was 1.4 ± 0.8 mm, 1.7 ± 0.9 mm, 0.9 ± 0.8 mm for ray line, spatial compound and harmonic imaging, respectively. Average error between the Shadow width and true stone width was 0.2 ± 0.7 mm, 0.4 ± 0.7 mm and 0.0 ± 0.8 mm for ray line, spatial compound and harmonic imaging, respectively. Sizing error based on the stone width worsened with greater depth (p <0.001) while the sizing er...
-
Use of the Acoustic Shadow Width to Determine Kidney Stone Size with Ultrasound.
The Journal of urology, 2015Co-Authors: Barbrina Dunmire, Michael R. Bailey, Jonathan D. Harper, Franklin Lee, Ziyue Liu, Bryan W. Cunitz, Ryan S. Hsi, Mathew D. SorensenAbstract:Purpose: Ultrasound is known to overestimate kidney stone size. We explored measuring the Acoustic Shadow behind kidney stones combined with different ultrasound imaging modalities to improve stone sizing accuracy.Materials and Methods: A total of 45 calcium oxalate monohydrate stones were imaged in vitro at 3 different depths with the 3 different ultrasound imaging modalities of conventional ray line, spatial compound and harmonic imaging. The width of the stone and the width of the Acoustic Shadow were measured by 4 operators blinded to the true size of the stone.Results: Average error between the measured and true stone width was 1.4 ± 0.8 mm, 1.7 ± 0.9 mm, 0.9 ± 0.8 mm for ray line, spatial compound and harmonic imaging, respectively. Average error between the Shadow width and true stone width was 0.2 ± 0.7 mm, 0.4 ± 0.7 mm and 0.0 ± 0.8 mm for ray line, spatial compound and harmonic imaging, respectively. Sizing error based on the stone width worsened with greater depth (p
Michael R. Bailey - One of the best experts on this subject based on the ideXlab platform.
-
Innovations in Ultrasound Technology in the Management of Kidney Stones.
Urologic Clinics of North America, 2019Co-Authors: Jessica C. Dai, Michael R. Bailey, Mathew D. Sorensen, Jonathan D. HarperAbstract:: This article reviews new advances in ultrasound technology for urinary stone disease. Recent research to facilitate the diagnosis of nephrolithiasis, including use of the twinkling signal and posterior Acoustic Shadow, have helped to improve the use of ultrasound examination for detecting and sizing renal stones. New therapeutic applications of ultrasound technology for stone disease have emerged, including ultrasonic propulsion to reposition stones and burst wave lithotripsy to fragment stones noninvasively. The safety, efficacy, and evolution of these technologies in phantom, animal, and human studies are reviewed herein. New developments in these rapidly growing areas of ultrasound research are also highlighted.
-
measurement of posterior Acoustic stone Shadow on ultrasound is a learnable skill for inexperienced users to improve accuracy of stone sizing
Journal of Endourology, 2018Co-Authors: Jessica C. Dai, Michael R. Bailey, Jonathan D. Harper, Ziyue Liu, Barbrina Dunmire, Kevan M. Sternberg, Mathew D. SorensenAbstract:Abstract Introduction: Studies suggest that the width of the Acoustic Shadow on ultrasound (US) more accurately reflects true stone size than the stone width in US images. We evaluated the need for...
-
Retrospective comparison of measured stone size and posterior Acoustic Shadow width in clinical ultrasound images.
World journal of urology, 2017Co-Authors: Jessica C. Dai, Michael R. Bailey, Jonathan D. Harper, Ziyue Liu, Barbrina Dunmire, Kevan M. Sternberg, Troy Larson, Jeff Thiel, Helena C. Chang, Mathew D. SorensenAbstract:Purpose Posterior Acoustic Shadow width has been proposed as a more accurate measure of kidney stone size compared to direct measurement of stone width on ultrasound (US). Published data in humans to date have been based on a research using US system. Herein, we compared these two measurements in clinical US images.
-
use of the Acoustic Shadow width to determine kidney stone size with ultrasound
The Journal of Urology, 2016Co-Authors: Barbrina Dunmire, Michael R. Bailey, Jonathan D. Harper, Franklin Lee, Ziyue Liu, Bryan W. Cunitz, Ryan S. Hsi, Mathew D. SorensenAbstract:Purpose: Ultrasound is known to overestimate kidney stone size. We explored measuring the Acoustic Shadow behind kidney stones combined with different ultrasound imaging modalities to improve stone sizing accuracy.Materials and Methods: A total of 45 calcium oxalate monohydrate stones were imaged in vitro at 3 different depths with the 3 different ultrasound imaging modalities of conventional ray line, spatial compound and harmonic imaging. The width of the stone and the width of the Acoustic Shadow were measured by 4 operators blinded to the true size of the stone.Results: Average error between the measured and true stone width was 1.4 ± 0.8 mm, 1.7 ± 0.9 mm, 0.9 ± 0.8 mm for ray line, spatial compound and harmonic imaging, respectively. Average error between the Shadow width and true stone width was 0.2 ± 0.7 mm, 0.4 ± 0.7 mm and 0.0 ± 0.8 mm for ray line, spatial compound and harmonic imaging, respectively. Sizing error based on the stone width worsened with greater depth (p <0.001) while the sizing er...
-
Use of the Acoustic Shadow Width to Determine Kidney Stone Size with Ultrasound.
The Journal of urology, 2015Co-Authors: Barbrina Dunmire, Michael R. Bailey, Jonathan D. Harper, Franklin Lee, Ziyue Liu, Bryan W. Cunitz, Ryan S. Hsi, Mathew D. SorensenAbstract:Purpose: Ultrasound is known to overestimate kidney stone size. We explored measuring the Acoustic Shadow behind kidney stones combined with different ultrasound imaging modalities to improve stone sizing accuracy.Materials and Methods: A total of 45 calcium oxalate monohydrate stones were imaged in vitro at 3 different depths with the 3 different ultrasound imaging modalities of conventional ray line, spatial compound and harmonic imaging. The width of the stone and the width of the Acoustic Shadow were measured by 4 operators blinded to the true size of the stone.Results: Average error between the measured and true stone width was 1.4 ± 0.8 mm, 1.7 ± 0.9 mm, 0.9 ± 0.8 mm for ray line, spatial compound and harmonic imaging, respectively. Average error between the Shadow width and true stone width was 0.2 ± 0.7 mm, 0.4 ± 0.7 mm and 0.0 ± 0.8 mm for ray line, spatial compound and harmonic imaging, respectively. Sizing error based on the stone width worsened with greater depth (p
Ziyue Liu - One of the best experts on this subject based on the ideXlab platform.
-
measurement of posterior Acoustic stone Shadow on ultrasound is a learnable skill for inexperienced users to improve accuracy of stone sizing
Journal of Endourology, 2018Co-Authors: Jessica C. Dai, Michael R. Bailey, Jonathan D. Harper, Ziyue Liu, Barbrina Dunmire, Kevan M. Sternberg, Mathew D. SorensenAbstract:Abstract Introduction: Studies suggest that the width of the Acoustic Shadow on ultrasound (US) more accurately reflects true stone size than the stone width in US images. We evaluated the need for...
-
Retrospective comparison of measured stone size and posterior Acoustic Shadow width in clinical ultrasound images.
World journal of urology, 2017Co-Authors: Jessica C. Dai, Michael R. Bailey, Jonathan D. Harper, Ziyue Liu, Barbrina Dunmire, Kevan M. Sternberg, Troy Larson, Jeff Thiel, Helena C. Chang, Mathew D. SorensenAbstract:Purpose Posterior Acoustic Shadow width has been proposed as a more accurate measure of kidney stone size compared to direct measurement of stone width on ultrasound (US). Published data in humans to date have been based on a research using US system. Herein, we compared these two measurements in clinical US images.
-
use of the Acoustic Shadow width to determine kidney stone size with ultrasound
The Journal of Urology, 2016Co-Authors: Barbrina Dunmire, Michael R. Bailey, Jonathan D. Harper, Franklin Lee, Ziyue Liu, Bryan W. Cunitz, Ryan S. Hsi, Mathew D. SorensenAbstract:Purpose: Ultrasound is known to overestimate kidney stone size. We explored measuring the Acoustic Shadow behind kidney stones combined with different ultrasound imaging modalities to improve stone sizing accuracy.Materials and Methods: A total of 45 calcium oxalate monohydrate stones were imaged in vitro at 3 different depths with the 3 different ultrasound imaging modalities of conventional ray line, spatial compound and harmonic imaging. The width of the stone and the width of the Acoustic Shadow were measured by 4 operators blinded to the true size of the stone.Results: Average error between the measured and true stone width was 1.4 ± 0.8 mm, 1.7 ± 0.9 mm, 0.9 ± 0.8 mm for ray line, spatial compound and harmonic imaging, respectively. Average error between the Shadow width and true stone width was 0.2 ± 0.7 mm, 0.4 ± 0.7 mm and 0.0 ± 0.8 mm for ray line, spatial compound and harmonic imaging, respectively. Sizing error based on the stone width worsened with greater depth (p <0.001) while the sizing er...
-
Use of the Acoustic Shadow Width to Determine Kidney Stone Size with Ultrasound.
The Journal of urology, 2015Co-Authors: Barbrina Dunmire, Michael R. Bailey, Jonathan D. Harper, Franklin Lee, Ziyue Liu, Bryan W. Cunitz, Ryan S. Hsi, Mathew D. SorensenAbstract:Purpose: Ultrasound is known to overestimate kidney stone size. We explored measuring the Acoustic Shadow behind kidney stones combined with different ultrasound imaging modalities to improve stone sizing accuracy.Materials and Methods: A total of 45 calcium oxalate monohydrate stones were imaged in vitro at 3 different depths with the 3 different ultrasound imaging modalities of conventional ray line, spatial compound and harmonic imaging. The width of the stone and the width of the Acoustic Shadow were measured by 4 operators blinded to the true size of the stone.Results: Average error between the measured and true stone width was 1.4 ± 0.8 mm, 1.7 ± 0.9 mm, 0.9 ± 0.8 mm for ray line, spatial compound and harmonic imaging, respectively. Average error between the Shadow width and true stone width was 0.2 ± 0.7 mm, 0.4 ± 0.7 mm and 0.0 ± 0.8 mm for ray line, spatial compound and harmonic imaging, respectively. Sizing error based on the stone width worsened with greater depth (p
-
MP17-01 THE POSTERIOR Acoustic Shadow: EVALUATING STONE SIZE IN PEDIATRIC STONE FORMERS
The Journal of Urology, 2015Co-Authors: Franklin Lee, Michael R. Bailey, Jonathan D. Harper, Thomas S. Lendvay, Ziyue Liu, Barbrina Dunmire, Manjiri Dighe, Jonathan Swanson, Mathew SorensenAbstract:INTRODUCTION AND OBJECTIVES: Unlike adult stone formers, ultrasound is often exclusively used in both the initial diagnosis and the follow-up of pediatric stone formers. As such, treatment decisions are made based on ultrasound findings alone. Ultrasound has been shown to consistently overestimate stone size, which could lead to surgical intervention for a stone that may spontaneously pass. Our group has previously demonstrated that the posterior Acoustic Shadow is a more accurate predictor of true stone size in an in vitro model. We sought to determine the prevalence and accuracy of the posterior Acoustic Shadow in a pediatric cohort. METHODS: A retrospective analysis was performed of all pediatric stone patient encounters at a children’s hospital over the last 10 years using the ICD-9 code for nephrolithiasis (592.0). All included subjects had a stone present on computed tomography (CT) scan and renal ultrasound, taken within 3 months of each other for an initial stone event. The size of the stone and posterior Acoustic Shadow were measured on ultrasound by two board certified radiologists and compared to stone size as measured on CT. RESULTS: Of 633 charts reviewed, 37 patients with 49 kidney stones were included in this study. Mean age was 13 4 years with a mean BMI of 19 6 kg/m2 and mean stone size of 7.2 2.9 based on CT. A posterior Acoustic Shadow was seen in 85% of stones evaluated and found to be a significantly (p < 0.001) better predictor of true stone size. When compared to CT, measuring the stone directly resulted in an average overestimation of 2.0 1.5 mm, while measuring the Acoustic Shadow resulted in an underestimation of 0.4 2.5 mm. CONCLUSIONS: In this retrospective study, the posterior Acoustic Shadow was seen in the majority of stones. Measuring the Shadow was a more accurate measure of true stone size and may provide valuable prognostic information to help guide clinicians in counseling families about surveillance or surgical management of renal stones. This is particularly relevant to the pediatric population and may reduce unnecessary procedures and further decrease reliance on CT imaging. The results may be improved in a prospective study where the image is optimized for a Shadow measurement.
