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Purpose This study explored the feasibility of utilizing a deep learning artificial intelligence (AI) model to detect ileocolic intussusception on grayscale ultrasound images. Methods This retrospective observational study incorporated ultrasound images of children who underwent emergency ultrasonography for suspected ileocolic intussusception. After excluding video clips, Doppler images, and annotated images, 40,765 images from two tertiary hospitals were included (positive-to-negative ratio: hospital A, 2,775:35,373; hospital B, 140:2,477). Images from hospital A were split into a training set, a tuning set, and an internal test set (ITS) at a ratio of 7:1.5:1.5. Images from hospital B comprised an external test set (ETS). For each image indicating intussusception, two radiologists provided a bounding box as the ground-truth label. If intussusception was suspected in the input image, the model generated a bounding box with a confidence score (0-1) at the estimated lesion location. Average precision (AP) was used to evaluate overall model performance. The performance of practical thresholds for the model-generated confidence score, as determined from the ITS, was verified using the ETS. Results The AP values for the ITS and ETS were 0.952 and 0.936, respectively. Two confidence thresholds, CTopt and CTprecision, were set at 0.557 and 0.790, respectively. For the ETS, the perimage precision and recall were 95.7% and 80.0% with CTopt, and 98.4% and 44.3% with CTprecision. For per-patient diagnosis, the sensitivity and specificity were 100.0% and 97.1% with CTopt, and 100.0% and 99.0% with CTprecision. The average number of false positives per patient was 0.04 with CTopt and 0.01 for CTprecision. Conclusion The feasibility of using an AI model to diagnose ileocolic intussusception on ultrasonography was demonstrated. However, further study involving bias-free data is warranted for robust clinical validation.

Purpose This study aimed to evaluate the usefulness of two-dimensional shear wave elastography (2D-SWE) in diagnosing hepatic veno-occlusive disease (VOD) in pediatric patients. Methods This study retrospectively included pediatric patients who underwent hematopoietic stem cell transplantation (HSCT) between November 2019 and January 2021. All 34 patients (8.7±5.0 years) were examined using 2D-SWE for an initial diagnosis. A subgroup analysis was performed using the data from follow-up examinations of patients diagnosed with VOD. The characteristics of the initial VOD diagnosis were compared with the longitudinal changes observed in VOD patients who underwent multiple ultrasound examinations. Results In total, 19 patients were diagnosed with VOD at 17.6±9.4 days after HSCT. All VOD patients showed hepatomegaly, ascites, and gallbladder wall thickening. Liver stiffness was higher in VOD patients than in non-VOD patients (12.4±1.1 vs. 6.3±0.8 kPa, P

Purpose This study aimed to assess the feasibility of shear-wave elastography (SWE) for assessing the testicular involvement of hematologic malignancies in children and young adults. Methods Eight patients (mean age, 11.0 years; range, 0.8 to 20 years) with biopsy-confirmed testicular involvement of hematologic malignancy between January 2018 and December 2020 were retrospectively evaluated. Multiparametric ultrasound examinations, including grayscale, color Doppler ultrasonography (CDUS), and SWE, were performed. Stiffness was measured in the involved testicular area and contralateral normal parenchyma. If there was bilateral testicular involvement, the stiffness of the involved area and the adjacent normal echoic parenchyma was measured on one testis. The Mann-Whitney U test was used to compare stiffness values. Results On grayscale, the testicular lesions were noted as a solitary mass in one patient, multiple lesions in four patients, and diffuse involvement in three patients. On CDUS and SWE, all patients demonstrated increased vascularity, and the stiffness of the involved area was higher than the values of normal parenchyma (the involved area vs. normal parenchyma, 11.6 kPa [3.9-20.2 kPa] vs. 2.9 kPa [1.1-3.7 kPa], P=0.003). The ratio of stiffness between the involved area and normal parenchyma was 3.4, ranging from 1.9 to 5.1. One patient showed decreased stiffness on follow-up SWE after treatment (affected testis vs. normal testis: initial, 13.8 vs. 3.2 kPa; 1 year later, 2.2 vs. 2.4 kPa). Conclusion Increased testicular stiffness on SWE in children and young adults with hematologic malignancies suggests the possibility of testicular involvement.

Purpose The purpose of this study was to use shear-wave elastography (SWE) to assess testicular stiffness changes during the Valsalva maneuver in adolescents and young adults with varicocele, to compare these changes according to clinical severity, and to evaluate the role of SWE in the diagnosis of varicocele. Methods This study included patients undergoing testicular ultrasonography for the diagnosis of varicocele or for post-varicocelectomy follow-up between June 2016 and February 2017. Fifty-four testicles of 27 consecutive patients (mean age, 15.9 years) were classified by clinical grade (grade 0-3). Using SWE, mean testicular stiffness (Emean) was measured at rest and during the Valsalva maneuver. The correlations between multiple ultrasonographic parameters (volume asymmetry, Emean at rest, and absolute and percentage changes in Emean during the Valsalva maneuver) and clinical grade were assessed using the Spearman correlation test. Results The Emean at rest was similar across clinical grades. During the Valsalva maneuver, increased testicular stiffness was frequently observed in patients with grade 2 or 3 varicocele but rarely observed in those with grade 0 or 1 varicocele. The changes in Emean were positively correlated with the clinical grade (all P0.05). Conclusion A transient, reversible increase in testicular stiffness during the Valsalva maneuver was observed in adolescents with high-grade varicocele, and the degree of stiffness change was correlated with the clinical grade. Stiffness change identified using SWE during the Valsalva maneuver is a potential surrogate indicator of venous congestion.

Purpose This study evaluated the diagnostic performance of contrast-enhanced voiding urosonography (ce-VUS) using a second-generation ultrasound contrast agent for the diagnosis of vesicoureteral reflux (VUR) and intrarenal reflux (IRR), and compared it with that of standard fluoroscopic voiding cystourethrography (VCUG). Methods Thirty-two consecutive children from April to October 2019 were included in this study. ce-VUS and VCUG were performed simultaneously by two operators with intravesical infusion of a mixture of ultrasound contrast medium, iodinated contrast medium and water. Two pediatric radiologists independently reviewed the ce-VUS and VCUG images and reported the presence and degree of VUR (grades I-V), and the presence and type of IRR. Results Twenty-seven of 63 urinary systems showed VUR. Interobserver agreement for VUR grading was very good for both examinations (κ=0.87; 95% confidence interval [CI], 0.82 to 0.92 for ce-VUS and κ=0.92; 95% CI, 0.87 to 0.96 for VCUG). The detection rate of VUR showed no significant difference between the two examinations (P=0.370). Four cases of VUR were missed on ce-VUS, while one case of VUR was missed on VCUG. All four false-negative cases on ce-VUS were grade 1 VUR. The two examinations showed very good agreement regarding VUR grading (κ =0.89; 95% CI, 0.81 to 0.96). IRR was more frequently detected with ce-VUS than with VCUG (10 cases with ce-VUS vs. 3 cases with VCUG, P=0.016). Conclusion ce-VUS showed very good agreement with VCUG for detecting grade 2 VUR and above, while grade 1 VUR was sometimes missed with ce-VUS. IRR was more frequently detected with ce-VUS than with VCUG.

Purpose The purpose of this study was to evaluate the usefulness of the stability index (SI) in liver stiffness measurements using shear wave elastography (SWE) in children. Methods A total of 29 children and young adults (mean age, 16.1 years; range, 8 to 28 years; 11 boys and 18 girls) who underwent liver stiffness measurements using SWE under free-breathing and breath-holding conditions were included in our study. Ten SWE measurements were acquired in each of four groups: free-breathing and breath-holding, and with and without using the SI. The failure rate of acquisition of SI values over 90% was calculated in each group. To evaluate variability in the SWE measurements, the standard deviation, coefficient of variation, and percentage of unreliable measurements were compared. Intraobserver agreement and the optimal minimal number of measurements were calculated using intraclass correlation coefficients. Results A failure to acquire SI values over 90% was observed in 17% of the scans in the free-breathing group and in 7% of the scans in the breath-holding group. In both groups, utilizing the SI led to a significantly lower standard deviation and coefficient of variation. When using the SI, the percentage of unreliable measurements decreased from 16.7% to 8.3% in the free-breathing group and 14.8% to 0% in the breath-holding group. With the use of the SI, intraobserver agreement increased and the optimal minimal number of repeated measurements decreased in both the free-breathing and breath-holding groups. Conclusion Utilization of the SI in the measurement of liver SWE in children reduced measurement variability and increased reliability in both free-breathing and breath-holding conditions.

Purpose The aim of this study was to evaluate impact of 3-dimensional cranial ultrasonography (3DUS) on reinterpretation of cranial ultrasonography images in neonates in comparison with 2-dimensional cranial ultrasonography (2DUS). Methods We retrospectively enrolled 50 young infants who simultaneously underwent both 2DUS and 3DUS scanning from February to March 2015. Two pediatric radiologists independently reviewed both scans for overall image quality on a 5-point scale. Five features were evaluated in both scans: the presence of germinal matrix hemorrhage (GMH), intraventricular hemorrhage (IVH), ventriculomegaly (VM), abnormality of periventricular echogenicity (PVE), and focal parenchymal lesions (FL). The concordance rate between the two scanning modes was calculated. The confidence level for each finding on a 3-point scale and the scanning time were compared between the two scanning modes. Interobserver agreement was evaluated using kappa statistics. Results Both scans demonstrated similar overall image quality in terms of reinterpretation (mean scores for 2DUS and 3DUS, 4.0±0.5 and 4.0±0.7 in reviewer 1, 3.9±0.6 and 4.0±0.8 in reviewer 2, respectively). GMH, IVH, VM, and FL showed perfect concordance, while PVE showed a concordance rate of 91.4% between the two modes by both reviewers. 3DUS was associated with a higher diagnostic confidence in the evaluation of GMH, IVH, and FL than 2DUS (P

Purpose The purpose of this study was to identify ultrasonographic features that can be used to differentiate between thyroglossal duct cysts (TGDCs) and dermoid cysts (DCs). Methods We searched surgical pathology reports completed between January 2004 and October 2015 and identified 66 patients with TGDCs or DCs who had undergone preoperative ultrasonography. The ultrasound images were reviewed by two radiologists who were blinded to the pathological diagnosis. They evaluated the following parameters: dimensions, shape, margin, location in relation to the midline, level in relation to the hyoid bone, attachment to the hyoid bone, the depth of the lesion in relation to the strap muscles, internal echogenicity, internal echogenic dots, multilocularity, the presence of a longitudinal extension into the tongue base, posterior acoustic enhancement, the presence of internal septae, and intralesional vascularity. Results There were 50 TGDCs and 16 DCs. TGDCs were significantly more likely than DCs to have an irregular shape, an ill-defined margin, attachment to the hyoid bone, an intramuscular location, heterogeneous internal echogenicity, multilocularity, and longitudinal extension into the tongue base. Conclusion Ultrasound findings may inform the differential diagnosis between TGDCs and DCs.

Widespread use of fetal ultrasonography is accompanied by more frequent detection of antenatal hydronephrosis. Therefore, sonographic evaluation of neonates with a history of antenatal hydronephrosis is becoming more widespread. As an initial postnatal non-invasive imaging modality, ultrasonography is used to screen for persistence of hydronephrosis, determine the level and severity of obstruction, and contribute to appropriate diagnosis and treatment. This review aims to provide a practical overview of the sonographic evaluation of neonatal hydronephrosis and to describe the sonographic findings of conditions associated with hydronephrosis in the newborn.

Intraoperative ultrasonography (IOUS) is a widely used noninvasive method to evaluate the morphology, vasculature, and pathologies of the brain. The advantages of IOUS include realtime depiction of neuroanatomy, accurate localization and characterization of a lesion, reduced surgical exploration and surgical time, and presumably decreased patient morbidity. IOUS is useful in the intraoperative monitoring of lesion resection as well as intraoperative localization and characterization of focal parenchymal lesions. This review aims to provide an overview of the clinical application of IOUS in pediatric intracranial neurosurgery.