Pediatric nonalcoholic fatty liver disease (NAFLD) comprises a spectrum of disease that can be si... more Pediatric nonalcoholic fatty liver disease (NAFLD) comprises a spectrum of disease that can be simplified into two categories: (1) isolated/simple steatosis, 70% to 75% of cases, defined by excess liver fat without inflammation or cellular injury; and (2) nonalcoholic steatohepatitis (NASH), 25% to 30% of cases. 1 Unlike isolated steatosis, NASH reflects reactive inflammation and liver damage associated with steatosis and can ultimately progress to hepatic fibrosis and cirrhosis, eventually developing into end-stage liver disease and its related complications, including hepatocellular carcinoma. 2 Historically, the diagnosis, stratification, and management of chronic liver disease, including NAFLD, has relied heavily on liver biopsy, despite its limitations of being costly, subjective, and prone to sampling error. 5,6 The shortcomings of biopsy have meant that imaging studies are often used as surrogates for histology. These noninvasive, nonionizing quantitative imaging methods are reliable, safe, and clinically available with high repeatability and reproducibility. The aim of this article is to review the current status, diagnostic accuracy, limitations, and practical clinical use of ultrasound-and magnetic resonance imaging
ObjectivesTo quantify the bias of shear wave speed (SWS) measurements between different commercia... more ObjectivesTo quantify the bias of shear wave speed (SWS) measurements between different commercial ultrasonic shear elasticity systems and a magnetic resonance elastography (MRE) system in elastic and viscoelastic phantoms.MethodsTwo elastic phantoms, representing healthy through fibrotic liver, were measured with 5 different ultrasound platforms, and 3 viscoelastic phantoms, representing healthy through fibrotic liver tissue, were measured with 12 different ultrasound platforms. Measurements were performed with different systems at different sites, at 3 focal depths, and with different appraisers. The SWS bias across the systems was quantified as a function of the system, site, focal depth, and appraiser. A single MRE research system was also used to characterize these phantoms using discrete frequencies from 60 to 500 Hz.ResultsThe SWS from different systems had mean difference 95% confidence intervals of ±0.145 m/s (±9.6%) across both elastic phantoms and ± 0.340 m/s (±15.3%) acr...
This section is focused on prioritizing unmet clinical needs that will benefit from novel technol... more This section is focused on prioritizing unmet clinical needs that will benefit from novel technologies applied to non-invasive detection and monitoring of active inflammation and assessment of treatment response, mucosal targeted drug delivery systems, and prevention of post-operative septic complications and treatment of fistulizing complications.
This study validates a non-invasive, quantitative technique to diagnose steatosis within tissue. ... more This study validates a non-invasive, quantitative technique to diagnose steatosis within tissue. The proposed method is based on two fundamental concepts: 1) the speed of sound (SOS) in a fatty liver is lower than that in a healthy liver and 2) the quality of an ultrasound image is maximized when the beamformer's speed of sound matches the speed in the medium under examination. The method uses image brightness and sharpness as quantitative image-quality metrics to predict the true sound speed and capture the effects of fat infiltration, while accounting for the transmission through subcutaneous fat. Ex vivo testing on sheep liver, mice livers, and tissue-mimicking phantoms indicated the technique's ability to predict the true speed of sound with errors less than 0.5% and to quantify the inverse correlation between fat content and SOS.
This study presents a method to determine the longitudinal speed of sound in speckle-dominated ul... more This study presents a method to determine the longitudinal speed of sound in speckle-dominated ultrasound images. The method is based on the concept that the quality of an ultrasound image is maximized when the beamformer's speed of sound matches the speed in the medium. The method captures the quality of the ultrasound image using two, quantitative image-quality metrics: image brightness and sharpness around the intended focal zone. The proposed method requires no calibration, is computationally efficient, and is deployable on commercial ultrasound systems without hardware or software modifications. Ex vivo testing on tissue-mimicking phantoms indicates the method's accuracy in predicting the true speed of sound to within 1% of ground truth values.
We evaluated variation in fibrosis staging caused by depth, pre-load force and measurement off-ax... more We evaluated variation in fibrosis staging caused by depth, pre-load force and measurement off-axis distance on different ultrasound shear wave elastography (SWE) systems prospectively in 20 patients with diffuse liver disease. Shear wave speed (SWS) was measured with transient elastography, acoustic radiation force impulse (ARFI) and 2-D shear wave elastography (SWE). ARFI and 2-D-SWE measurements were obtained at different depths (3, 5 and 7 cm), with different pre-load forces (4, 7 and 10N and variable) and at 0, 2 and 4cm off the central axis of the transducer. A single, blinded pathologist staged fibrosis using the METAVIR system (F0-F4). Area under the receiver operating characteristic curve was charted to differentiate significant fibrosis (F ≥ 2). Depth was the only factor found to influence ARFI-derived values; no acquisition factors were found to affect 2-D-SWE SWS values. ARFI and 2-D-SWE for diagnosis of significant fibrosis at a depth of 7cm along the central axis had g...
Non-alcoholic fatty liver disease (NAFLD) is the most common diffuse liver disease, with a worldw... more Non-alcoholic fatty liver disease (NAFLD) is the most common diffuse liver disease, with a worldwide prevalence of 20% to 46%. NAFLD can be subdivided into simple steatosis and nonalcoholic steatohepatitis. Most cases of simple steatosis are non-progressive, whereas nonalcoholic steatohepatitis may result in chronic liver injury and progressive fibrosis in a significant minority. Effective risk stratification and management of NAFLD requires evaluation of hepatic parenchymal fat, fibrosis, and inflammation. Liver biopsy remains the current gold standard; however, non-invasive imaging methods are rapidly evolving and may replace biopsy in some circumstances. These methods include well-established techniques, such as conventional ultrasonography, computed tomography, and magnetic resonance imaging and newer imaging technologies, such as ultrasound elastography, quantitative ultrasound techniques, magnetic resonance elastography, and magnetic resonance-based fat quantitation techniques...
Tissue stiffness has long been known to be a biomarker of tissue pathology. Ultrasound elastograp... more Tissue stiffness has long been known to be a biomarker of tissue pathology. Ultrasound elastography measures tissue mechanical properties by monitoring the response of tissue to acoustic energy. Different elastographic techniques have been applied to many different tissues and diseases. Depending on the pathology, patient-based factors, and ultrasound operator-based factors, these techniques vary in accuracy and reliability. In this review, we discuss the physical principles of ultrasound elastography, discuss differences between different ultrasound elastographic techniques, and review the advantages and disadvantages of these techniques in clinical practice.
Ultrasound (US) imaging is the most commonly performed cross-sectional diagnostic imaging modalit... more Ultrasound (US) imaging is the most commonly performed cross-sectional diagnostic imaging modality in the practice of medicine. It is low-cost, non-ionizing, portable, and capable of real-time image acquisition and display. US is a rapidly evolving technology with significant challenges and opportunities. Challenges include high inter- and intra-operator variability and limited image quality control. Tremendous opportunities have arisen in the last decade as a result of exponential growth in available computational power coupled with progressive miniaturization of US devices. As US devices become smaller, enhanced computational capability can contribute significantly to decreasing variability through advanced image processing. In this paper, we review leading machine learning (ML) approaches and research directions in US, with an emphasis on recent ML advances. We also present our outlook on future opportunities for ML techniques to further improve clinical workflow and US-based dis...
The purpose of this study was to determine the validity of previously established ultrasound shea... more The purpose of this study was to determine the validity of previously established ultrasound shear wave elastography (SWE) cut-off values (≥F2 fibrosis) on an independent cohort of patients with chronic liver disease. In this cross-sectional study, approved by the institutional review board and compliant with the Health Insurance Portability and Accountability Act, 338 patients undergoing liver biopsy underwent SWE using an Aixplorer ultrasound machine (SuperSonic Imagine, Aix-en-Provence, France). Median SWE values were calculated from sets of 10 elastograms. A single blinded pathologist evaluated METAVIR fibrosis staging as the gold standard. The study analyzed 277 patients with a mean age of 48 y. On pathologic examination, 212 patients (76.5%) had F0-F1 fibrosis, whereas 65 (23.5%) had ≥F2 fibrosis. Spearman's correlation of fibrosis with SWE was 0.456 (p < 0.001). A cut-off value of 7.29 kPa yielded sensitivity of 95.4% and specificity of 50.5% for the diagnosis of METAV...
The purpose of this study is to determine the reliability of shear-wave elastographic estimates o... more The purpose of this study is to determine the reliability of shear-wave elastographic estimates of the Young modulus in thyroid follicular neoplasms. In this study, 35 adults with follicular nodules diagnosed by fine-needle aspiration (FNA) biopsy were enrolled. A single sonographer examined all nodules in three planes (sagittal, transverse, and transverse center). Two raters independently placed ROIs in each nodule. Intra- and interrater reliability were computed as intraclass correlation coefficients (ICCs) and were reported using the Guidelines for Reporting Reliability and Agreement Studies. Thirty-five subjects with 35 follicular pattern nodules diagnosed by FNA biopsy were enrolled; 23 (65.7%) patients were female, with a mean age of 55.1 years (range, 23-85 years). For rater 1, intrarater agreement showed ICCs for single measurements of 0.87, 0.87, and 0.90 in the sagittal, transverse, and transverse center plans, respectively; ICCs for the median of multiple measurements wer...
Journal of medical imaging and radiation oncology, Jan 27, 2015
The objective of this study was to evaluate the feasibility of shear wave elastography (SWE), as ... more The objective of this study was to evaluate the feasibility of shear wave elastography (SWE), as a non-invasive means of assessing liver fibrosis stage in paediatric and adolescent patients. Consecutive paediatric and adolescent subjects scheduled for liver biopsy (LB) evaluation of known or suspected diffuse liver disease were included after informed guardian consent and subject assent in this IRB-approved single institution study. Elastograms were acquired prior to liver biopsy, from the liver under a breath-hold after normal inspiration when possible. Biopsy specimens underwent blinded pathologist review using the METAVIR scoring system. Twenty-four patients (M : F = 13:11) with a mean age of 17 years (range: 1-21 years) underwent liver biopsy. The distribution of fibrosis on pathological examination was: F0 = 10, F1 = 9, F2 = 1, F3 = 3, and F4 = 1. Subjects with stages F0 and F1 fibrosis had a mean SWE value of 6.93 kPa (95% CI: 6.33-7.44 kPa) and 8.33 kPa (95% CI: 6.83-10.80 kP...
Background: There currently is a need for a non-invasive measure of renal fibrosis. We aim to exp... more Background: There currently is a need for a non-invasive measure of renal fibrosis. We aim to explore whether shear wave elastography (SWE)-derived estimates of tissue stiffness may serve as a non-invasive biomarker that can distinguish normal and abnormal renal parenchymal tissue. Methods: Participants with CKD (by estimated GFR) and healthy volunteers underwent SWE. Renal elasticity was estimated as Young's modulus (YM) in kilopascals (kPa). Univariate Wilcoxon rank-sum tests were used. Results: Twenty-five participants with CKD (median GFR 38 mL/min; quartile 1, quartile 3 28, 42) and 20 healthy controls without CKD underwent SWE performed by a single radiologist. CKD was associated with increased median YM (9.40 [5.55, 22.35] vs. 4.40 [3.68, 5.70] kPa; p = 0.002) and higher median intra-subject inter-measurement estimated YM's variability (4.27 [2.89, 9.90] vs. 1.51 [1.21, 2.05] kPa; p < 0.001). Conclusions: SWE-derived estimates of renal stiffness and intra-subject estimated stiffness variability are higher in patients with CKD than in healthy controls. Renal fibrosis is a plausible explanation for the observed difference in YM. Further studies are required to determine the relationship between YM, estimated renal stiffness, and renal fibrosis severity.
PURPOSE/AIM Hepatic resections for tumors may be complicated when biliary leakage from the cut he... more PURPOSE/AIM Hepatic resections for tumors may be complicated when biliary leakage from the cut hepatic surface or from bilio-enteric anastomoses result in the development of a biloma. Drainage of post-hepatectomy bilomas can be challenging due to difficult access (i.e. subdiaphragmatic location) and source of ongoing biliary leakage. This educational exhibit aims to highlight the currently available techniques, tips and tricks to effect optimum drainage for post-hepatectomy bilomas. CONTENT ORGANIZATION 1. Review of hepatic biliary anatomy and types of partial hepatectomy. 2. Recognition of types of post hepatectomy collections with respect to location and cause. 3. Familiarizing techniques of percutaneous drainage, including imaging guided modalities as well as the tailored use drainage techniques in subphrenic collections. 4. Understanding advantages and disadvantages of the various types of catheter drainages and approaches, including the longitudinal care of the patient. SUMMARY...
PURPOSE We undertook this study to determine the negative predictive value of PET for splenic les... more PURPOSE We undertook this study to determine the negative predictive value of PET for splenic lesions. Although PET has been used extensively for evaluation of space-occupying lesions in other organs, the current medical literature is contradictory on the current role of 18F-FDG-PET for characterization of splenic masses. Some studies have demonstrated high accuracy with good sensitivity and specificity when clinical data was used as the gold standard while others have demonstrated poor accuracy when histopathology was used as a gold standard. METHOD AND MATERIALS In this IRB approved single center retrospective study we searched an institutional database and reviewed imaging of all patients with a focal splenic lesion >6mm who had undergone an FDG-PET/CT scan with or without IV contrast. Splenic lesions with at least one-year follow-up and had metabolic activity less than or similar to the remainder of the spleen were identified. Lesions that exhibited >30% increase on the fo...
PURPOSE/AIM UltraFast Doppler is a new Doppler technique that utilizes massive parallel computing... more PURPOSE/AIM UltraFast Doppler is a new Doppler technique that utilizes massive parallel computing to enable frame rate increases by a factor of 5 to 10 compared with conventional color Doppler, without sacrificing field of view or spatial resolution. This provides a more accurate visualization of complex flow dynamics and transient flow events. It also has potential to increase measurement accuracy particularly in stenosis grading and resistance index calculation. This will likely have important implications for the accuracy of stenosis grading. CONTENT ORGANIZATION 1. Doppler Ultrasound: General Principles – color, power and pulsed wave. 2. Terms: Resistive indices, Peak systolic flow velocity. 3. UltraFast Doppler: a. Review of technology b. Current applications c. Potential Applications 4. Advantages over Doppler Ultrasound SUMMARY UltraFast Doppler holds significant potential to enhance measurement accuracy and visualization of flow dynamics. The purpose of this exhibit is to ed...
Ultrasound elastography, also termed sonoelastography, is being used increasingly in clinical pra... more Ultrasound elastography, also termed sonoelastography, is being used increasingly in clinical practice to aid the diagnosis and management of diffuse liver disease. Elastography has been shown to be capable of differentiating advanced and early-stage liver fibrosis, and consequently a major application in clinical liver care includes progression to cirrhosis risk stratification through (1) assessment of liver fibrosis stage in HCV and HBV patients, (2) distinguishing non-alcoholic steatohepatitis from simple steatosis in non-alcoholic fatty liver disease patients, and (3) prognostic evaluation of liver disease is autoimmune liver disease. In addition, elastographic characterization of focal liver lesions and evaluation of clinically significant portal hypertension have the potential to be clinically useful and are areas of active clinical research.
Pediatric nonalcoholic fatty liver disease (NAFLD) comprises a spectrum of disease that can be si... more Pediatric nonalcoholic fatty liver disease (NAFLD) comprises a spectrum of disease that can be simplified into two categories: (1) isolated/simple steatosis, 70% to 75% of cases, defined by excess liver fat without inflammation or cellular injury; and (2) nonalcoholic steatohepatitis (NASH), 25% to 30% of cases. 1 Unlike isolated steatosis, NASH reflects reactive inflammation and liver damage associated with steatosis and can ultimately progress to hepatic fibrosis and cirrhosis, eventually developing into end-stage liver disease and its related complications, including hepatocellular carcinoma. 2 Historically, the diagnosis, stratification, and management of chronic liver disease, including NAFLD, has relied heavily on liver biopsy, despite its limitations of being costly, subjective, and prone to sampling error. 5,6 The shortcomings of biopsy have meant that imaging studies are often used as surrogates for histology. These noninvasive, nonionizing quantitative imaging methods are reliable, safe, and clinically available with high repeatability and reproducibility. The aim of this article is to review the current status, diagnostic accuracy, limitations, and practical clinical use of ultrasound-and magnetic resonance imaging
ObjectivesTo quantify the bias of shear wave speed (SWS) measurements between different commercia... more ObjectivesTo quantify the bias of shear wave speed (SWS) measurements between different commercial ultrasonic shear elasticity systems and a magnetic resonance elastography (MRE) system in elastic and viscoelastic phantoms.MethodsTwo elastic phantoms, representing healthy through fibrotic liver, were measured with 5 different ultrasound platforms, and 3 viscoelastic phantoms, representing healthy through fibrotic liver tissue, were measured with 12 different ultrasound platforms. Measurements were performed with different systems at different sites, at 3 focal depths, and with different appraisers. The SWS bias across the systems was quantified as a function of the system, site, focal depth, and appraiser. A single MRE research system was also used to characterize these phantoms using discrete frequencies from 60 to 500 Hz.ResultsThe SWS from different systems had mean difference 95% confidence intervals of ±0.145 m/s (±9.6%) across both elastic phantoms and ± 0.340 m/s (±15.3%) acr...
This section is focused on prioritizing unmet clinical needs that will benefit from novel technol... more This section is focused on prioritizing unmet clinical needs that will benefit from novel technologies applied to non-invasive detection and monitoring of active inflammation and assessment of treatment response, mucosal targeted drug delivery systems, and prevention of post-operative septic complications and treatment of fistulizing complications.
This study validates a non-invasive, quantitative technique to diagnose steatosis within tissue. ... more This study validates a non-invasive, quantitative technique to diagnose steatosis within tissue. The proposed method is based on two fundamental concepts: 1) the speed of sound (SOS) in a fatty liver is lower than that in a healthy liver and 2) the quality of an ultrasound image is maximized when the beamformer's speed of sound matches the speed in the medium under examination. The method uses image brightness and sharpness as quantitative image-quality metrics to predict the true sound speed and capture the effects of fat infiltration, while accounting for the transmission through subcutaneous fat. Ex vivo testing on sheep liver, mice livers, and tissue-mimicking phantoms indicated the technique's ability to predict the true speed of sound with errors less than 0.5% and to quantify the inverse correlation between fat content and SOS.
This study presents a method to determine the longitudinal speed of sound in speckle-dominated ul... more This study presents a method to determine the longitudinal speed of sound in speckle-dominated ultrasound images. The method is based on the concept that the quality of an ultrasound image is maximized when the beamformer's speed of sound matches the speed in the medium. The method captures the quality of the ultrasound image using two, quantitative image-quality metrics: image brightness and sharpness around the intended focal zone. The proposed method requires no calibration, is computationally efficient, and is deployable on commercial ultrasound systems without hardware or software modifications. Ex vivo testing on tissue-mimicking phantoms indicates the method's accuracy in predicting the true speed of sound to within 1% of ground truth values.
We evaluated variation in fibrosis staging caused by depth, pre-load force and measurement off-ax... more We evaluated variation in fibrosis staging caused by depth, pre-load force and measurement off-axis distance on different ultrasound shear wave elastography (SWE) systems prospectively in 20 patients with diffuse liver disease. Shear wave speed (SWS) was measured with transient elastography, acoustic radiation force impulse (ARFI) and 2-D shear wave elastography (SWE). ARFI and 2-D-SWE measurements were obtained at different depths (3, 5 and 7 cm), with different pre-load forces (4, 7 and 10N and variable) and at 0, 2 and 4cm off the central axis of the transducer. A single, blinded pathologist staged fibrosis using the METAVIR system (F0-F4). Area under the receiver operating characteristic curve was charted to differentiate significant fibrosis (F ≥ 2). Depth was the only factor found to influence ARFI-derived values; no acquisition factors were found to affect 2-D-SWE SWS values. ARFI and 2-D-SWE for diagnosis of significant fibrosis at a depth of 7cm along the central axis had g...
Non-alcoholic fatty liver disease (NAFLD) is the most common diffuse liver disease, with a worldw... more Non-alcoholic fatty liver disease (NAFLD) is the most common diffuse liver disease, with a worldwide prevalence of 20% to 46%. NAFLD can be subdivided into simple steatosis and nonalcoholic steatohepatitis. Most cases of simple steatosis are non-progressive, whereas nonalcoholic steatohepatitis may result in chronic liver injury and progressive fibrosis in a significant minority. Effective risk stratification and management of NAFLD requires evaluation of hepatic parenchymal fat, fibrosis, and inflammation. Liver biopsy remains the current gold standard; however, non-invasive imaging methods are rapidly evolving and may replace biopsy in some circumstances. These methods include well-established techniques, such as conventional ultrasonography, computed tomography, and magnetic resonance imaging and newer imaging technologies, such as ultrasound elastography, quantitative ultrasound techniques, magnetic resonance elastography, and magnetic resonance-based fat quantitation techniques...
Tissue stiffness has long been known to be a biomarker of tissue pathology. Ultrasound elastograp... more Tissue stiffness has long been known to be a biomarker of tissue pathology. Ultrasound elastography measures tissue mechanical properties by monitoring the response of tissue to acoustic energy. Different elastographic techniques have been applied to many different tissues and diseases. Depending on the pathology, patient-based factors, and ultrasound operator-based factors, these techniques vary in accuracy and reliability. In this review, we discuss the physical principles of ultrasound elastography, discuss differences between different ultrasound elastographic techniques, and review the advantages and disadvantages of these techniques in clinical practice.
Ultrasound (US) imaging is the most commonly performed cross-sectional diagnostic imaging modalit... more Ultrasound (US) imaging is the most commonly performed cross-sectional diagnostic imaging modality in the practice of medicine. It is low-cost, non-ionizing, portable, and capable of real-time image acquisition and display. US is a rapidly evolving technology with significant challenges and opportunities. Challenges include high inter- and intra-operator variability and limited image quality control. Tremendous opportunities have arisen in the last decade as a result of exponential growth in available computational power coupled with progressive miniaturization of US devices. As US devices become smaller, enhanced computational capability can contribute significantly to decreasing variability through advanced image processing. In this paper, we review leading machine learning (ML) approaches and research directions in US, with an emphasis on recent ML advances. We also present our outlook on future opportunities for ML techniques to further improve clinical workflow and US-based dis...
The purpose of this study was to determine the validity of previously established ultrasound shea... more The purpose of this study was to determine the validity of previously established ultrasound shear wave elastography (SWE) cut-off values (≥F2 fibrosis) on an independent cohort of patients with chronic liver disease. In this cross-sectional study, approved by the institutional review board and compliant with the Health Insurance Portability and Accountability Act, 338 patients undergoing liver biopsy underwent SWE using an Aixplorer ultrasound machine (SuperSonic Imagine, Aix-en-Provence, France). Median SWE values were calculated from sets of 10 elastograms. A single blinded pathologist evaluated METAVIR fibrosis staging as the gold standard. The study analyzed 277 patients with a mean age of 48 y. On pathologic examination, 212 patients (76.5%) had F0-F1 fibrosis, whereas 65 (23.5%) had ≥F2 fibrosis. Spearman's correlation of fibrosis with SWE was 0.456 (p < 0.001). A cut-off value of 7.29 kPa yielded sensitivity of 95.4% and specificity of 50.5% for the diagnosis of METAV...
The purpose of this study is to determine the reliability of shear-wave elastographic estimates o... more The purpose of this study is to determine the reliability of shear-wave elastographic estimates of the Young modulus in thyroid follicular neoplasms. In this study, 35 adults with follicular nodules diagnosed by fine-needle aspiration (FNA) biopsy were enrolled. A single sonographer examined all nodules in three planes (sagittal, transverse, and transverse center). Two raters independently placed ROIs in each nodule. Intra- and interrater reliability were computed as intraclass correlation coefficients (ICCs) and were reported using the Guidelines for Reporting Reliability and Agreement Studies. Thirty-five subjects with 35 follicular pattern nodules diagnosed by FNA biopsy were enrolled; 23 (65.7%) patients were female, with a mean age of 55.1 years (range, 23-85 years). For rater 1, intrarater agreement showed ICCs for single measurements of 0.87, 0.87, and 0.90 in the sagittal, transverse, and transverse center plans, respectively; ICCs for the median of multiple measurements wer...
Journal of medical imaging and radiation oncology, Jan 27, 2015
The objective of this study was to evaluate the feasibility of shear wave elastography (SWE), as ... more The objective of this study was to evaluate the feasibility of shear wave elastography (SWE), as a non-invasive means of assessing liver fibrosis stage in paediatric and adolescent patients. Consecutive paediatric and adolescent subjects scheduled for liver biopsy (LB) evaluation of known or suspected diffuse liver disease were included after informed guardian consent and subject assent in this IRB-approved single institution study. Elastograms were acquired prior to liver biopsy, from the liver under a breath-hold after normal inspiration when possible. Biopsy specimens underwent blinded pathologist review using the METAVIR scoring system. Twenty-four patients (M : F = 13:11) with a mean age of 17 years (range: 1-21 years) underwent liver biopsy. The distribution of fibrosis on pathological examination was: F0 = 10, F1 = 9, F2 = 1, F3 = 3, and F4 = 1. Subjects with stages F0 and F1 fibrosis had a mean SWE value of 6.93 kPa (95% CI: 6.33-7.44 kPa) and 8.33 kPa (95% CI: 6.83-10.80 kP...
Background: There currently is a need for a non-invasive measure of renal fibrosis. We aim to exp... more Background: There currently is a need for a non-invasive measure of renal fibrosis. We aim to explore whether shear wave elastography (SWE)-derived estimates of tissue stiffness may serve as a non-invasive biomarker that can distinguish normal and abnormal renal parenchymal tissue. Methods: Participants with CKD (by estimated GFR) and healthy volunteers underwent SWE. Renal elasticity was estimated as Young's modulus (YM) in kilopascals (kPa). Univariate Wilcoxon rank-sum tests were used. Results: Twenty-five participants with CKD (median GFR 38 mL/min; quartile 1, quartile 3 28, 42) and 20 healthy controls without CKD underwent SWE performed by a single radiologist. CKD was associated with increased median YM (9.40 [5.55, 22.35] vs. 4.40 [3.68, 5.70] kPa; p = 0.002) and higher median intra-subject inter-measurement estimated YM's variability (4.27 [2.89, 9.90] vs. 1.51 [1.21, 2.05] kPa; p < 0.001). Conclusions: SWE-derived estimates of renal stiffness and intra-subject estimated stiffness variability are higher in patients with CKD than in healthy controls. Renal fibrosis is a plausible explanation for the observed difference in YM. Further studies are required to determine the relationship between YM, estimated renal stiffness, and renal fibrosis severity.
PURPOSE/AIM Hepatic resections for tumors may be complicated when biliary leakage from the cut he... more PURPOSE/AIM Hepatic resections for tumors may be complicated when biliary leakage from the cut hepatic surface or from bilio-enteric anastomoses result in the development of a biloma. Drainage of post-hepatectomy bilomas can be challenging due to difficult access (i.e. subdiaphragmatic location) and source of ongoing biliary leakage. This educational exhibit aims to highlight the currently available techniques, tips and tricks to effect optimum drainage for post-hepatectomy bilomas. CONTENT ORGANIZATION 1. Review of hepatic biliary anatomy and types of partial hepatectomy. 2. Recognition of types of post hepatectomy collections with respect to location and cause. 3. Familiarizing techniques of percutaneous drainage, including imaging guided modalities as well as the tailored use drainage techniques in subphrenic collections. 4. Understanding advantages and disadvantages of the various types of catheter drainages and approaches, including the longitudinal care of the patient. SUMMARY...
PURPOSE We undertook this study to determine the negative predictive value of PET for splenic les... more PURPOSE We undertook this study to determine the negative predictive value of PET for splenic lesions. Although PET has been used extensively for evaluation of space-occupying lesions in other organs, the current medical literature is contradictory on the current role of 18F-FDG-PET for characterization of splenic masses. Some studies have demonstrated high accuracy with good sensitivity and specificity when clinical data was used as the gold standard while others have demonstrated poor accuracy when histopathology was used as a gold standard. METHOD AND MATERIALS In this IRB approved single center retrospective study we searched an institutional database and reviewed imaging of all patients with a focal splenic lesion >6mm who had undergone an FDG-PET/CT scan with or without IV contrast. Splenic lesions with at least one-year follow-up and had metabolic activity less than or similar to the remainder of the spleen were identified. Lesions that exhibited >30% increase on the fo...
PURPOSE/AIM UltraFast Doppler is a new Doppler technique that utilizes massive parallel computing... more PURPOSE/AIM UltraFast Doppler is a new Doppler technique that utilizes massive parallel computing to enable frame rate increases by a factor of 5 to 10 compared with conventional color Doppler, without sacrificing field of view or spatial resolution. This provides a more accurate visualization of complex flow dynamics and transient flow events. It also has potential to increase measurement accuracy particularly in stenosis grading and resistance index calculation. This will likely have important implications for the accuracy of stenosis grading. CONTENT ORGANIZATION 1. Doppler Ultrasound: General Principles – color, power and pulsed wave. 2. Terms: Resistive indices, Peak systolic flow velocity. 3. UltraFast Doppler: a. Review of technology b. Current applications c. Potential Applications 4. Advantages over Doppler Ultrasound SUMMARY UltraFast Doppler holds significant potential to enhance measurement accuracy and visualization of flow dynamics. The purpose of this exhibit is to ed...
Ultrasound elastography, also termed sonoelastography, is being used increasingly in clinical pra... more Ultrasound elastography, also termed sonoelastography, is being used increasingly in clinical practice to aid the diagnosis and management of diffuse liver disease. Elastography has been shown to be capable of differentiating advanced and early-stage liver fibrosis, and consequently a major application in clinical liver care includes progression to cirrhosis risk stratification through (1) assessment of liver fibrosis stage in HCV and HBV patients, (2) distinguishing non-alcoholic steatohepatitis from simple steatosis in non-alcoholic fatty liver disease patients, and (3) prognostic evaluation of liver disease is autoimmune liver disease. In addition, elastographic characterization of focal liver lesions and evaluation of clinically significant portal hypertension have the potential to be clinically useful and are areas of active clinical research.
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Papers by Manish Dhyani