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Objective: To evaluate the feasibility of ultrasound shear wave elastography (SWE) for predicting hepatic fibrosis and native liver outcomes in patients with biliary atresia., Materials and Methods: This prospective study included 33 consecutive patients with biliary atresia (median age, 8 weeks [interquartile range, 6-10 weeks]; male:female ratio, 15:18) from Severance Children's Hospital between May 2019 and February 2022. Preoperative (within 1 week from surgery) and immediate postoperative (on postoperative days [PODs] 3, 5, and 7) ultrasonographic findings were obtained and analyzed, including the SWE of the liver and spleen. Hepatic fibrosis, according to the METAVIR score at the time of Kasai portoenterostomy and native liver outcomes during postsurgical follow-up, were compared and correlated with imaging and laboratory findings. Poor outcomes were defined as intractable cholangitis or liver transplantation. The diagnostic performance of SWE in predicting METAVIR F3-F4 and poor hepatic outcomes was analyzed using receiver operating characteristic (ROC) analyses., Results: All patients were analyzed without exclusion. Perioperative advanced hepatic fibrosis (F3-F4) was associated with older age and higher preoperative direct bilirubin and SWE values in the liver and spleen. Preoperative liver SWE showed a ROC area of 0.806 and 63.6% (7/11) sensitivity and 86.4% (19/22) specificity at a cutoff of 17.5 kPa for diagnosing F3-F4. The poor outcome group included five patients with intractable cholangitis and three undergoing liver transplantation who showed high postoperative liver SWE values. Liver SWE on PODs 3-7 showed ROC areas of 0.783-0.891 for predicting poor outcomes, and a cutoff value of 10.3 kPa for SWE on POD 3 had 100% (8/8) sensitivity and 73.9% (17/23) specificity., Conclusion: Preoperative liver SWE can predict advanced hepatic fibrosis, and immediate postoperative liver SWE can predict poor native liver outcomes in patients with biliary atresia., Competing Interests: Kyunghwa Han and Mi-Jung Lee, contributing editors of the Korean Journal of Radiology, were not involved in the editorial evaluation or decision to publish this article. All remaining authors have declared no conflicts of interest., (Copyright © 2023 The Korean Society of Radiology.)

Objective: To determine whether the values of hepatic apparent diffusion coefficient (ADC) can differentiate biliary atresia (BA) from non-BA or be correlated with the grade of hepatic fibrosis in infants with cholestasis., Materials and Methods: This retrospective cohort study included infants who received liver MRI examinations to evaluate cholestasis from July 2009 to October 2017. Liver ADC, ADC ratio of liver/spleen, aspartate aminotransferase to platelet ratio index (APRI), and spleen size were compared between the BA and non-BA groups. The diagnostic performances of all parameters for significant fibrosis (F3-4) were obtained by receiver-operating characteristics (ROCs) curve analysis., Results: Altogether, 227 infants (98 males and 129 females, mean age = 57.2 ± 36.3 days) including 125 BA patients were analyzed. The absolute ADC difference between two reviewers was 0.10 mm²/s for both liver and spleen. Liver ADC value was specific (80.4%) and ADC ratio was sensitive (88.0%) for the diagnosis of BA with comparable performance. There were 33 patients with F0, 15 with F1, 71 with F2, 35 with F3, and 11 with F4. All four parameters of APRI (τ= 0.296), spleen size (τ= 0.312), liver ADC (τ= -0.206), and ADC ratio (τ= -0.288) showed significant correlation with fibrosis grade (all, p < 0.001). The cutoff values for significant fibrosis (F3-4) were 0.783 for APRI (area under the ROC curve [AUC], 0.721), 5.9 cm for spleen size (AUC, 0.719), 1.044 × 10 -3 mm²/s for liver ADC (AUC, 0.673), and 1.22 for ADC ratio (AUC, 0.651)., Conclusion: Liver ADC values and ADC ratio of liver/spleen showed limited additional diagnostic performance for differentiating BA from non-BA and predicting significant hepatic fibrosis in infants with cholestasis., Competing Interests: The authors have no potential conflicts of interest to disclose., (Copyright © 2021 The Korean Society of Radiology.)

Background: Untreated neonatal cholestasis can progress to liver cirrhosis and end stage liver disease in infancy due to prolonged hepatocyte and biliary tree injury and may require liver transplantation. Therefore, non-invasive evaluation of hepatic fibrosis is important in infants with cholestasis., Aim: To investigate the usefulness of periportal thickening (PT) measured on liver magnetic resonance imaging (MRI) for the assessment of hepatic fibrosis in infants with cholestasis including biliary atresia (BA)., Methods: This retrospective study included infants less than 6 mo who underwent liver MRI and biopsy for the evaluation of infantile cholestasis. PT and spleen size were measured on MRI. Serologic assessment was based on aspartate transaminase to platelet ratio index (APRI). The grade of histopathologic fibrosis was assessed by the METAVIR grading system. Correlation and diagnostic performance of PT, normalized spleen size ratio (SR, using the upper normal size limit), and APRI for diagnosing hepatic fibrosis were obtained by receiver-operating characteristic (ROC) curve analysis., Results: A total of 155 patients were included, 110 of which were diagnosed with BA. Mean age at the time of MRI was 57.6 ± 34.4 d. There were positive correlations between fibrosis grade and PT and SR, even after adjusting age (all, P < 0.001). For the diagnosis of significant fibrosis (METAVIR grade F2-F4), the area under the ROC curve was 0.899 (95%CI: 0.840-0.941) for PT (cutoff, 4.2 mm), which was higher than 0.741 (95%CI: 0.664-0.808) for SR and 0.712 (95%CI: 0.634-0.782) for APRI (both, P < 0.001). For the diagnosis of cirrhosis (F4), the area under the ROC curve was the highest with SR as 0.790 (95%CI: 0.718-0.852)., Conclusion: Liver MRI findings of PT and SR are useful to assess clinically significant hepatic fibrosis (F2 and higher) in infants with cholestasis including BA., Competing Interests: Conflict-of-interest statement: All authors declare no conflicts-of-interest related to this article., (©The Author(s) 2020. Published by Baishideng Publishing Group Inc. All rights reserved.)

Objectives: To evaluate the implications of hepatic subcapsular and capsular flows using ultrasonography (US) in children after Kasai operation., Methods: Children who underwent liver US including color Doppler US and microvascular imaging (MVI) from May 2017 to October 2017 were retrospectively included. Children who underwent the Kasai operation for biliary atresia were included in the Kasai group and children with normal liver were included in the control group. Using US results, the number of intrahepatic biliary cysts and the maximum diameter of the spleen were evaluated in the Kasai group. Liver stiffness values were included when patients in the Kasai group had transient elastography (TE) or shear wave elastography (SWE) results. Hepatic subcapsular and capsular flows on color Doppler US and MVI were compared between the two groups using the following scores: 0, no flow reaching the hepatic capsule; 1, any flow reaching the hepatic capsule; and 2, contiguous hepatic capsular flow. The logistic regression test was used to identify associations between age, intrahepatic biliary cysts, spleen size, SWV, TE results, and flow scores measured on Doppler US and MVI in the Kasai group using the odds ratio (OR) and 95% confidence interval (CI)., Result: A total of 65 children (mean 7.6 ± 5.3 years), 44 in the Kasai group and 21 in the control group, were included. In the control group, one child had score 1 on MVI and others had score 0 on both Doppler US and MVI. Among the Kasai group, 28 children (63.6%) had score 1, while others had score 0 using Doppler US. Using MVI, 24 children (54.5%) had score 2, 18 children had score 1, and one child had score 0. In the Kasai group, increased liver stiffness on TE was the only factor significantly associated with the presence of subcapsular flow on color Doppler US (OR 1.225, 95% CI 1.020-1.470) and increased spleen size was the only factor significantly associated with increased flow scores on MVI (OR 1.397, 95% CI 1.002-2.724)., Conclusion: Detection of hepatic subcapsular, capsular flows on US would be meaningful for children after receiving the Kasai operation., Key Points: • Hepatic subcapsular or capsular flows can be useful not only for the diagnosis but also for the postoperative follow-up in patients with biliary atresia. • Increased liver stiffness and splenomegaly after the Kasai operation were associated with presence of subcapsular or capsular flow on ultrasonography. • Evaluation of hepatic subcapsular and capsular flows could be needed to assess disease progression after receiving the Kasai operation.

Purpose: To investigate the clinical utility of mono-exponential model diffusion weighted imaging (DWI) using two b-values compared to the bi- or stretched exponential model to differentiate biliary atresia (BA) from non-BA in pediatric liver magnetic resonance imaging (MRI)., Methods: Patients who underwent liver MRI with DWI for suspected BA from November 2017 to September 2018 were retrospectively included and divided into BA and non-BA groups. Laboratory results including γ-glutamyl transferase (γGT) were compared between the two groups using the Mann-Whitney U test and Fisher's exact test. The hepatic apparent diffusion coefficient (ADC) 10 using ten b-values and ADC 2 using two b-values were obtained from the mono-exponential model. The slow diffusion coefficient (D), fast diffusion coefficient (D*), and perfusion fraction (f) were obtained from the bi-exponential model. The distributed diffusion coefficient (DDC) and heterogeneity index (α) were measured from the stretched exponential model. Parameters were compared between the two groups using a linear mixed model and diagnostic performance was assessed using the area under the curve (AUC) analysis., Results: For 12 patients in the BA and five patients in the non-BA group, the ADC 10 (median 0.985 ×10-3 mm2/s vs. 1.332 ×10-3 mm2/s, p = 0.008), ADC 2 (median 0.987 ×10-3 mm2/s vs. 1.335 ×10-3 mm2/s, p = 0.017), D* (median 33.2 ×10-3 mm2/s vs. 55.3 ×10-3 mm2/s, p = 0.021), f (median 13.4%, vs. 22.1%, p = 0.009), and DDC (median 0.889 ×10-3 mm2/s vs. 1.323 ×10-3 mm2/s, p = 0.009) values were lower and the γGT (median 368.0 IU/L vs. 93.5 IU/L, p = 0.02) and α (median 0.699 vs. 0.556, p = 0.023) values were higher in the BA group. The AUC values for γGT (AUC 0.867 95% confidence interval [CI] 0.616-0.984), ADC 10 (AUC 0.963, 95% CI 0.834-0.998), ADC 2 (AUC 0.925, 95% CI 0.781-0.987), f (AUC 0.850, 95% CI 0.686-0.949), and DDC (AUC 0.925, 95% CI 0.781-0.987) were not significantly different, except for the D* and α values., Conclusion: Patients with BA had lower ADC 10, ADC 2, D*, f, and DDC values and higher γGT and α values than those in the non-BA group. The diagnostic performance of ADC 2 using only two b-values showed excellent diagnostic performance and was not significantly different from that of γGT, ADC 10, f, and DDC for diagnosing BA., Competing Interests: The authors have declared that no competing interests exist.

Background: A recent retrospective study confirmed that hepatic stiffness and splenic stiffness measured with magnetic resonance elastography (MRE) are strongly associated with the presence of esophageal varices. In addition, strong correlations have been reported between splenic stiffness values measured with MRE and hepatic venous pressure gradients in animal models. However, most studies have been conducted on adult populations, and previous pediatric MRE studies have only demonstrated the feasibility of MRE in pediatric populations, while the actual clinical application of spleen MRE has been limited., Aim: To assess the utility of splenic stiffness measurements by MRE to predict gastroesophageal varices in children., Methods: We retrospectively reviewed abdominal MRE images taken on a 3T system in pediatric patients. Patients who had undergone Kasai operations for biliary atresia were selected for the Kasai group, and patients with normal livers and spleens were selected for the control group. Two-dimensional spin-echo echo-planar MRE acquisition centered on the liver, with a pneumatic driver at 60 Hz and a low amplitude, was performed to obtain hepatic and splenic stiffness values. Laboratory results for aspartate aminotransferase to platelet ratio index (APRI) were evaluated within six months of MRE, and the normalized spleen size ratio was determined with the upper normal size limit. All Kasai group patients underwent gastroesophageal endoscopy during routine follow-up. The Mann-Whitney U test, Kendall's tau b correlation and diagnostic performance analysis using the area under the curve (AUC) were performed for statistical analysis., Results: The median spleen MRE value was 5.5 kPa in the control group ( n = 9, age 9-18 years, range 4.7-6.4 kPa) and 8.6 kPa in the Kasai group ( n = 22, age 4-18 years, range 5.0-17.8 kPa). In the Kasai group, the APRI, spleen size ratio and spleen MRE values were higher in patients with portal hypertension ( n = 11) than in patients without ( n = 11) (all P < 0.001) and in patients with gastroesophageal varices ( n = 6) than in patients without ( n = 16) (all P < 0.05), even though their liver MRE values were not different. The APRI ( τ = 0.477, P = 0.007), spleen size ratio ( τ = 0.401, P = 0.024) and spleen MRE values ( τ = 0.426, P = 0.016) also correlated with varices grades. The AUC in predicting gastroesophageal varices was 0.844 at a cut-off of 0.65 (100% sensitivity and 75% specificity) for the APRI, and 0.844 at a cut-off of 9.9 kPa (83.3% sensitivity and 81.3% specificity) for spleen MRE values., Conclusion: At a cut-off of 9.9 kPa, spleen MRE values predicted gastroesophageal varices as well as the APRI and spleen size ratio in biliary atresia patients after the Kasai operation. However, liver MRE values were not useful for this purpose., Competing Interests: Conflict-of-interest statement: All authors declare no conflicts-of-interest related to this article.

Objectives: To evaluate MRI findings and to generate a decision tree model for diagnosis of biliary atresia (BA) in infants with jaundice., Methods: We retrospectively reviewed features of MRI and ultrasonography (US) performed in infants with jaundice between January 2009 and June 2016 under approval of the institutional review board, including the maximum diameter of periportal signal change on MRI (MR triangular cord thickness, MR-TCT) or US (US-TCT), visibility of common bile duct (CBD) and abnormality of gallbladder (GB). Hepatic subcapsular flow was reviewed on Doppler US. We performed conditional inference tree analysis using MRI findings to generate a decision tree model., Results: A total of 208 infants were included, 112 in the BA group and 96 in the non-BA group. Mean age at the time of MRI was 58.7 ± 36.6 days. Visibility of CBD, abnormality of GB and MR-TCT were good discriminators for the diagnosis of BA and the MRI-based decision tree using these findings with MR-TCT cut-off 5.1 mm showed 97.3 % sensitivity, 94.8 % specificity and 96.2 % accuracy., Conclusions: MRI-based decision tree model reliably differentiates BA in infants with jaundice. MRI can be an objective imaging modality for the diagnosis of BA., Key Points: • MRI-based decision tree model reliably differentiates biliary atresia in neonatal cholestasis. • Common bile duct, gallbladder and periportal signal changes are the discriminators. • MRI has comparable performance to ultrasonography for diagnosis of biliary atresia.

Aims: To enable comparison and interconversion of elasticity measurements between two-dimensional (2D) shear wave elastography (SWE) and transient elastography (TE)., Materials and Methods: Elasticities of three phantoms were measured by 2D SWE (supersonic shear imaging) using four probes and TE using two probes. We performed regression analyses to evaluate correlation between the measurements and phantom elasticities, and make converting equations. In pediatric biliary atresia patients who had stiffness measurements by both 2D SWE and TE within 1-year interval, TE measurements were retrospectively converted into correlating 2D SWE values. We compared the calculated values with 2D SWE measurements by intraclass correlation coefficient., Results: Measurements in phantoms varied according to elastography method and probe selection. However, the measurement by both 2D SWE (R2, 0.974-0.985; p<0.001) and TE (R2, 0.996-0.999; p<0.001) showedsignificant linear correlation with phantom elasticity in all probe settings. From 67 biliary atresia patients (age, 2 months-20 years), agreements between the measured and calculated values were excellent in all 88 examinations within 1-year interval(ρ=0.828; p<0.001) and in 63 examinations within 2-month interval (ρ=0.863, p<0.001)., Conclusions: The equations enabledinterconversion of elasticity values among different probes of 2D SWE and TE and provided reliable estimation of elasticityvalues for different probe settings in biliary atresia patients.

Objectives: With the introduction of smaller probes (S1, S2), the use of transient elastography has been expanded to children. Accordingly, we aimed to address points of consideration in probe choice and interpretation of measured liver stiffness by applying and comparing FibroScan S and M probes in biliary atresia., Methods: Using S1, S2, and M probes, 3 liver stiffness measurements, success rates, and interquartile ranges were obtained from 100 patients. Patients were assigned to 2 groups according to thoracic perimeter (≤ 45 cm vs > 45 cm). In both groups, obtained values were compared and the relation between liver stiffness measurement and aspartate aminotransferase-to-platelet ratio index was analyzed., Results: In the small-thorax group, the success rate was highest with the S1 probe and the intraclass correlation coefficient (ICC) was highest for S1 versus S2 (0.98), compared with that for S1 versus M (0.69) and S2 versus M (0.77). In the large-thorax group, ICC was the highest for S2 versus M (0.88), compared with that for S1 versus S2 (0.69) and S1 versus M (0.51). In the small-thorax group, correlations between aspartate aminotransferase-to-platelet ratio index and liver stiffness measurement were stronger for S1 (0.65) and S2 (0.64) than for M (0.49). In the large-thorax group, all probes showed good correlation, S1 (0.68), S2 (0.62), and M (0.62)., Conclusions: We recommend that the S1 probe is more appropriate for use in small children, especially those with a thorax perimeter of < 45 cm. If no S probe is available, the M probe may be acceptable in children whose thorax perimeter is > 45 cm.

Objectives: The purpose of this study was to assess the diagnostic performance of transient elastography and sonography for noninvasive evaluation of liver fibrosis in infants with biliary atresia., Methods: Forty-seven infants with biliary atresia who underwent both transient elastography and sonography before surgery were included in this study. Two types of transient elastographic probes were used: an M probe, which is used for the general adult population; and an S probe, which is specific to children. Transient elastographic measurements and sonographic findings such as triangular cord thickness and hepatic artery and portal vein diameters were compared with the METAVIR histopathologic fibrosis scoring system., Results: Only transient elastography (ρ = 0.63; P < .001) was significantly correlated with METAVIR fibrosis stages. The areas under the receiver operating characteristic curves for transient elastography were 0.86 and 0.96 for diagnosis of severe fibrosis and cirrhosis, respectively. The cutoff value of transient elastography for diagnosis of severe fibrosis was greater than 9.6 kPa, with sensitivity of 89.5% and specificity of 75%. The cutoff value of transient elastography for diagnosis of cirrhosis was greater than 18.1 kPa, with sensitivity of 100% and specificity of 90.5%. The success rate for the S probe (100%) was significantly higher than that for the M probe (77%; P < .001)., Conclusions: Transient elastography may be a useful noninvasive method for diagnosis of severe fibrosis and cirrhosis and may help predict outcomes before surgery or invasive liver biopsy in infants with biliary atresia. The success rate of transient elastography in infants was improved by using the S probe.

Background: Biliary atresia (BA) is a progressive, obliterative cholangiopathy that occurs in neonates with hepatic portoenterostomy the treatment of choice, but early surgery is important for optimum outcomes. MRI, including MR cholangiopancreatography (MRCP) may be a diagnostically useful alternative to US, but the heavily T2-weighted sequences used include not only bile duct signals, but also other heterogeneously high signal intensities from surrounding structures., Objective: To evaluate the effects of gadolinium when used to decrease background signal intensity on T2-weighted MR cholangiopancreatography (MRCP) in infants and to evaluate the qualitative improvement of the depiction of the common bile duct (CBD) for evaluating neonatal cholestasis., Materials and Methods: Our Institutional Review Board approved this prospective study. MRCP was performed with gadopentetate dimeglumine injection using a 1.5-T scanner. Pre- and postcontrast MRCP images were compared. Forty-nine infants (male:female = 21:28; age 0-12 months, mean 2.3) were included. The final diagnoses were biliary atresia (BA) in 28 cases and non-BA in 21. Quantitative analysis was conducted using region-of-interest measurements of mean signal intensities of the liver, pancreatic head and gallbladder (if defined). Qualitative analysis was performed by four radiologists who subjectively scored image confidence in the presence of CBD on a 4-point scale (0 for definitely absent, 1 for probably absent, 2 for probably present, and 3 for definitely present)., Results: The signal-to-noise ratios were significantly decreased in the liver and pancreatic head after contrast medium enhancement (mean 5.7→4.0 in liver and mean 44.9→12.7 in the pancreatic head; P < 0.0001), and this finding was constant in both the BA and the non-BA group. The mean confidence score in the presence of CBD decreased in the BA group (0.9→0.5; P < 0.0001), but did not change significantly in the non-BA group (2.0→2.1; P = 0.459) after contrast medium enhancement. Both intra- and interobserver agreement was higher after contrast medium enhancement (P = 0.046)., Conclusion: Gadopentetate dimeglumine-enhanced MRCP increased the diagnostic confidence of absence of the CBD in cholestatic infants with increased intra- and interobserver agreement.

Purpose: To describe color Doppler ultrasonographic (US) findings in livers of neonates with biliary atresia (BA) and to compare them with US findings in livers of neonates with non-BA and control subjects., Materials and Methods: Institutional review board approval was obtained; acquisition of informed consent was exempted. US and color Doppler US findings were retrospectively reviewed in 64 patients with neonatal cholestasis and 19 control subjects. BA and non-BA were confirmed in 29 and 35 patients, respectively. Three pediatric radiologists assessed US and color Doppler US images, independently documented their findings, and resolved discrepancies by consensus. Triangular cord (TC) sign, gallbladder length, and hepatic artery and portal vein diameters were evaluated on US images. The presence of hepatic subcapsular flow was evaluated on color Doppler US images. Diagnostic value of TC sign and hepatic subcapsular flow in the diagnosis of BA were evaluated. Significance of hepatic artery and portal vein diameters in each group was assessed., Results: In the diagnosis of BA, sensitivity and specificity of the TC sign on US images were 62% and 100%, respectively. On color Doppler US images, hepatic subcapsular flow was detected in all patients with BA and in five patients with non-BA. At the first review, there was a discrepancy between radiologists in interpretation of hepatic subcapsular flow in patients with non-BA. However, consensus was reached at the second review. There was no hepatic subcapsular flow in control subjects. Sensitivity and specificity of hepatic subcapsular flow on color Doppler US images were 100% and 80%-86%, respectively, on the basis of individual interpretations of reviewers. Sensitivity and specificity of hepatic subcapsular flow on color Doppler US images were 100% and 86%, respectively, on the basis of consensus reading. Mean diameter of the hepatic artery in patients with BA (2.1 mm +/- 0.7 [standard deviation]) was significantly larger than that in patients with non-BA (1.5 mm +/- 0.4, P < .001) and control subjects (1.5 mm +/- 0.4, P = .001)., Conclusion: The presence of hepatic subcapsular flow is useful for differentiating between BA and other causes of neonatal jaundice., ((c) RSNA, 2009.)

Aims: To enable comparison and interconversion of elasticity measurements between two-dimensional (2D) shear wave elastography (SWE) and transient elastography (TE).Materials and Methods: Elasticities of three phantoms were measured by 2D SWE (supersonic shear imaging) using four probes and TE using two probes. We performed regression analyses to evaluate correlation between the measurements and phantom elasticities, and make converting equations. In pediatric biliary atresia patients who had stiffness measurements by both 2D SWE and TE within 1-year interval, TE measurements were retrospectively converted into correlating 2D SWE values. We compared the calculated values with 2D SWE measurements by intraclass correlation coefficient.Results: Measurements in phantoms varied according to elastography method and probe selection. However, the measurement by both 2D SWE (R2, 0.974-0.985; p<0.001) and TE (R2, 0.996-0.999; p<0.001) showedsignificant linear correlation with phantom elasticity in all probe settings. From 67 biliary atresia patients (age, 2 months-20 years), agreements between the measured and calculated values were excellent in all 88 examinations within 1-year interval(ρ=0.828; p<0.001) and in 63 examinations within 2-month interval (ρ=0.863, p<0.001).Conclusions: The equations enabledinterconversion of elasticity values among different probes of 2D SWE and TE and provided reliable estimation of elasticityvalues for different probe settings in biliary atresia patients. [ABSTRACT FROM AUTHOR]