Comparison of Quantitative Liver US and MRI in Patients with Liver Disease.

Background Quantitative US techniques can be used to identify changes of liver disease, but data regarding their diagnostic performance and relationship to MRI measures are sparse. Purpose To define associations between quantitative US and MRI measures of the liver in children, adolescents, and young adults with liver disease and to define the predictive ability of quantitative US measures to detect abnormal liver stiffening and steatosis defined with MRI. Materials and Methods In this prospective study, consecutive patients aged 8-21 years and known to have or suspected of having liver disease and body mass index less than 35 kg/m2 underwent 1.5-T MRI and quantitative liver US during the same visit at a pediatric academic medical center between April 2018 and December 2020. Acquired US parameters included shear-wave speed (SWS) and attenuation coefficient, among others. US parameters were compared with liver MR elastography and liver MRI proton density fat fraction (PDFF). Pearson correlation, multiple logistic regression, and receiver operating characteristic curve analyses were performed to assess associations and determine the performance of US relative to that of MRI. Results A total of 44 study participants (mean age, 16 years ± 4 [SD]; age range, 8-21 years; 23 male participants) were evaluated. There was a positive correlation between US SWS and MR elastography stiffness (r = 0.73, P < .001). US attenuation was positively correlated with MRI PDFF (r = 0.45, P = .001). For the prediction of abnormal (>2.8 kPa) liver shear stiffness, SWS (1.56 m/sec [7.3 kPa] cutoff) had an area under the receiver operating characteristic curve (AUC) of 0.95 with 91% sensitivity (95% CI: 71, 99) (20 of 22 participants) and 95% specificity (95% CI: 76, 99) (20 of 21 participants). For the prediction of abnormal (>5%) liver PDFF, US attenuation (0.55 dB/cm/MHz cutoff) had an AUC of 0.75 with a sensitivity of 73% (95% CI: 39, 94) (eight of 11 participants) and a specificity of 73% (95% CI: 55, 86) (24 of 33 participants). Conclusion In children, adolescents, and young adults with known or suspected liver disease, there was moderate to high correlation between US shear-wave speed (SWS) and MR elastography-derived stiffness. US SWS predicted an abnormal liver shear stiffness with high performance. © RSNA, 2022 Online supplemental material is available for this article. See also the editorial by Khanna and Alazraki in this issue.

Pancreas ultrasound two-dimensional shear wave elastography in healthy children.

BACKGROUND: Pancreas shear wave speed might be a biomarker of pancreatic disease in children. OBJECTIVE: This study aimed to measure pancreas shear wave speed by two-dimensional (2-D) ultrasound shear wave elastography (SWE) in a balanced cohort of presumed healthy children. MATERIALS AND METHODS: This was a prospective study of 120 children (<18 years of age) without a known history of pancreatic disease, who underwent ultrasound 2-D SWE of the pancreas. Five shear wave speed measurements in the pancreas body and/or tail were obtained for each participant using a Canon Aplio i800 system, i8CX1 transducer. The Mann-Whitney U test or Kruskal-Wallis test were used to compare continuous distributions. Spearman's correlation was used to assess univariate relationships between continuous variables. Multivariable regression with stepwise selection was used to evaluate independent predictors of pancreas shear wave speed. RESULTS: The median age for the study population was 5.0 years (range: 7 days to 17.8 years) and 61 (50.8%) of the participants were female. The median depth of shear wave speed measurement was 4.7 cm (interquartile range [IQR]: 4.2-5.3). The median pancreas shear wave speed was 1.31 m/s (IQR: 1.21-1.40). On multivariable analysis, female biological sex (P=0.051), the number of hours nil per os (P=0.097), the median depth of measurement (P=0.001) and the median liver shear wave speed (P=0.020) were positively associated with pancreas shear wave speed. CONCLUSION: We report pancreas shear wave speed in a large, balanced cohort of children without a known history of pancreatic disease, providing reference values for normal.

Liver Shear Wave Speed and Other Quantitative Ultrasound Measures of Liver Parenchyma: Prospective Evaluation in Healthy Children and Adults.

OBJECTIVE. The purpose of this study was to use 2D ultrasound shear wave elastography (SWE) to define expected ranges for liver shear wave speed and shear wave dispersion in children and adults without a known history of liver disease. The study also sought to define liver attenuation in adults. SUBJECTS AND METHODS. This was an institutional review board-approved prospective study of 128 children (younger than 18 years old) and 32 adults without liver disease who underwent 2D SWE of the liver with a Canon Aplio i800 ultrasound system (i8CX1 transducer). Ten shear wave speed and shear wave dispersion measurements were obtained. In adults, five attenuation measurements were also obtained. Pearson correlation and t tests were used to define relationships between shear wave speed and dispersion values and predictor variables. Multivariable logistic regression with forward selection was used to generate models. RESULTS. Median age was 5.04 years old for the pediatric participants and 48.92 years old for the adult participants. Mean median shear wave speed and shear wave dispersion were 1.29 ± 0.13 m/s and 11.43 ± 1.75 (m/s)/kHz, respectively, for the pediatric participants and 1.32 ± 0.13 m/s and 10.24 ± 1.65 (m/s)/kHz, respectively, for the adults. Mean median attenuation in adults was 0.52 ± 0.11 dB/cm/MHz. On multivariable modeling, height was the only significant predictor of shear wave speed in children (0.0012 m/s per cm, p < 0.0001) and abdominal wall thickness was the only predictor of shear wave speed in adults (0.12 m/s per cm, p = 0.0008). CONCLUSION. Liver shear wave speed and shear wave dispersion data for children and adults without liver disease provides data against which results from patients with liver disease can be compared. Liver shear wave speed increases during childhood associated with increases in height and shear wave speed increases in adulthood with increasing abdominal wall thickness.