Diffusion-Weighted Imaging for Differentiation of Biliary Atresia and Grading of Hepatic Fibrosis in Infants with Cholestasis

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 x 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.

Virtual Reality Community Gait Training Using a 360° Image Improves Gait Ability in Chronic Stroke Patients

Purpose@#Gait and cognitive impairment in stroke patients exacerbate fall risk and mobility difficulties during multi-task walking. Virtual reality can provide interesting and challenging training in a community setting. This study evaluated the effect of community-based virtual reality gait training (VRGT) using a 360-degree image on the gait ability of chronic stroke patients. @*Methods@#Forty-five chronic stroke patients who were admitted to a rehabilitation hospital participated in this study. Patients meeting the selection criteria were randomly divided into a VRGT group (n=23) and a control group (n=22). Both these groups received general rehabilitation. The VRGT group was evaluated using a 360-degree image that was recorded for 50 minutes a day, 5 days per week for a total of 6 weeks after their training. The control group received general treadmill training for the same amount of time as that of the VRGT group. The improvement in the spatiotemporal parameters of gait was evaluated using a gait analyzer system before and after training. @*Results@#The spatiotemporal gait parameters showed significant improvements in both groups compare with the baseline measurements (p<0.05), and the VRGT group showed more improvement than the control group (p<0.05). @*Conclusion@#Community-based VRGT has been shown to improve the walking ability of chronic stroke patients and is expected to be used in rehabilitation of stroke patients in the future.

Virtual Reality Community Gait Training Using a 360° Image Improves Gait Ability in Chronic Stroke Patients

Purpose@#Gait and cognitive impairment in stroke patients exacerbate fall risk and mobility difficulties during multi-task walking. Virtual reality can provide interesting and challenging training in a community setting. This study evaluated the effect of community-based virtual reality gait training (VRGT) using a 360-degree image on the gait ability of chronic stroke patients. @*Methods@#Forty-five chronic stroke patients who were admitted to a rehabilitation hospital participated in this study. Patients meeting the selection criteria were randomly divided into a VRGT group (n=23) and a control group (n=22). Both these groups received general rehabilitation. The VRGT group was evaluated using a 360-degree image that was recorded for 50 minutes a day, 5 days per week for a total of 6 weeks after their training. The control group received general treadmill training for the same amount of time as that of the VRGT group. The improvement in the spatiotemporal parameters of gait was evaluated using a gait analyzer system before and after training. @*Results@#The spatiotemporal gait parameters showed significant improvements in both groups compare with the baseline measurements (p<0.05), and the VRGT group showed more improvement than the control group (p<0.05). @*Conclusion@#Community-based VRGT has been shown to improve the walking ability of chronic stroke patients and is expected to be used in rehabilitation of stroke patients in the future.

Determining the optimal timing of screening spinal cord ultrasonography to detect filum terminale lipoma in infants

Purpose@#The purpose of this study was to identify the optimal timing for screening spinal cord ultrasonography (US) to detect filum terminale lipoma in infants. @*Methods@#We retrospectively reviewed infants (<12 months old) who underwent repeated spinal cord US between April 2011 and January 2019. We excluded infants if they only had one US examination, or if they had lesions other than filum terminale lipoma. Infants with filum terminale lipoma on magnetic resonance imaging were included in the lipoma group and the others in the control group. A linear mixed model was used to assess differences in the growth pattern of filum terminale thickness by age and group. The cutoff thickness on US and its diagnostic performance were assessed according to age. @*Results@#Among 442 infants with 901 US examinations, 46 were included in the lipoma group and 58 in the control group. Sixty-seven infants had unmeasurable filum terminale thickness on initial US, including 55 neonates (82.1%) before 1 month of age. The lipoma group had significantly greater filum terminale thickness than the control group (P<0.001). Thickness increased with age in the lipoma group (P=0.027). The sensitivity of US was 87.5% and the area under the receiver operating characteristic curve was 0.949 (95% confidence interval, 0.849 to 0.991) with a cutoff value of 1.1 mm in 4- to 6-month-old infants. @*Conclusion@#Screening spinal cord US could effectively diagnose filum terminale lipoma in 4- to 6-month-old infants with a cutoff thickness of 1.1 mm. Spinal cord US can be used to screen young infants with intraspinal abnormalities.

Feasibility of Spin-Echo Echo-Planar Imaging MR Elastography in Livers of Children and Young Adults

PURPOSE: To assess the feasibility of the use of spin-echo echo-planar imaging (SE-EPI) magnetic resonance elastography (MRE) in livers of children and young adults. MATERIALS AND METHODS: Patients (≤ 20 years old) who underwent 3T SE-EPI MRE were included retrospectively. Subjects were divided into three groups according to the purpose of the liver MRI: suspicion of fatty liver or focal fat deposition in the liver (FAT group), liver fibrosis after receiving a Kasai operation from biliary atresia (BA group), and hepatic iron deposition after receiving chemotherapy or transfusions (IRON group). Technical failure of MRE was defined when a stiffness map showed no pixel value with a confidence index higher than 95%, and the patients were divided as success and failure groups accordingly. Clinical findings including age, gender, weight, height, and body mass index and magnetic resonance imaging results including proton density fat fraction (PDFF), T2*, and MRE values were assessed. Factors affecting failure of MRE were evaluated and the image quality in wave propagation image and stiffness map was evaluated using the appropriate scores. RESULTS: Among total 240 patients (median 15 years, 211 patients in the FAT, 21 patients in the BA, and 8 patients in the IRON groups), technical failure was noted in six patients in the IRON group (6/8 patients, 75%), while there were no failures noted in the FAT and BA groups. These six patients had T2* values ranging from 0.9 to 3.8 ms. The image quality scores were not significantly different between the FAT and BA groups (P > 0.999), while the scores were significantly lower in the IRON group (P < 0.001). CONCLUSION: The 3T SE-EPI MRE in children and young adults had a high technical success rate. The technical failure was occurred in children with decreased T2* value (≤ 3.8 ms) from iron deposition.

Quantitative Imaging in Pediatric Hepatobiliary Disease

Pediatric hepatobiliary imaging is important for evaluation of not only congenital or structural disease but also metabolic or diffuse parenchymal disease and tumors. A variety of ultrasonography and magnetic resonance imaging (MRI) techniques can be used for these assessments. In ultrasonography, conventional ultrasound imaging as well as vascular imaging, elastography, and contrast-enhanced ultrasonography can be used, while in MRI, fat quantification, T2/T2* mapping, diffusion-weighted imaging, magnetic resonance elastography, and dynamic contrast-enhanced MRI can be performed. These techniques may be helpful for evaluation of biliary atresia, hepatic fibrosis, nonalcoholic fatty liver disease, sinusoidal obstruction syndrome, and hepatic masses in children. In this review, we discuss each tool in the context of management of hepatobiliary disease in children, and cover various imaging techniques in the context of the relevant physics and their clinical applications for patient care.

Multiple hemangiomas of the urinary bladder in a child with gross hematuria

We report a case of multiple hemangiomas involving the urinary bladder in a 4-year-old boy who presented with recurrent episodes of gross hematuria. On ultrasonography, compared with the bladder wall, the lesions presented as multiple isoechoic polypoid intraluminal masses with mildly increased vascularity on color Doppler exam. Cavernous hemangioma was confirmed by cold-cup biopsy, and the all lesions were coagulated with a Holmium laser. Despite their rarity, bladder hemangiomas should be included in the differential diagnosis of multiple intravesical masses in children with gross hematuria.

Ultrasonographic findings of type IIIa biliary atresia

PURPOSE: To describe the ultrasonographic (US) findings of type IIIa biliary atresia. METHODS: We retrospectively reviewed a medical database of patients pathologically confirmed to have biliary atresia, Kasai type IIIa, between January 2002 and May 2013 (n=18). We evaluated US findings including the visible common bile duct (CBD), triangular cord thickness, gallbladder size and shape, and subcapsular flow on color Doppler US; laboratory data; and pathological hepatic fibrosis grades. We divided them into two groups-those with visible (group A) and invisible (group B) CBD on US-and compared all parameters between the two groups. RESULTS: CBD was visible on US in five cases (27.8%; group A) and invisible in 13 cases (72.2%; group B). US was performed at an earlier age in group A than in group B (median, 27 days vs. 60 days; P=0.027) with the maximal age of 51 days. A comparison of the US findings revealed that the triangular cord thickness was smaller (4.1 mm vs. 4.9 mm; P=0.004) and the gallbladder length was larger (20.0 mm vs. 11.7 mm; P=0.021) in group A. The gallbladder shape did not differ between the two groups, and the subcapsular flow was positive in all cases of both groups. There was no significant difference in the laboratory data between the two groups. Upon pathological analysis, group A showed low-grade and group B showed low- to high-grade hepatic fibrosis. CONCLUSION: When CBD is visible on US in patients diagnosed with type IIIa biliary atresia, other US features could have a false negative status. A subcapsular flow on the color Doppler US would be noted in the type IIIa biliary atresia patients.

Shear wave velocity measurements using acoustic radiation force impulse in young children with normal kidneys versus hydronephrotic kidneys

PURPOSE: To measure shear wave velocities (SWVs) by acoustic radiation force impulse (ARFI) ultrasound elastography in normal kidneys and in hydronephrotic kidneys in young children and to compare SWVs between the hydronephrosis grades. METHODS: This study was approved by an institutional review board, and informed consent was obtained from the parents of all the children included. Children under the age of 24 months were prospectively enrolled. Hydronephrosis grade was evaluated on ultrasonography, and three valid ARFI measurements were attempted using a high-frequency transducer for both kidneys. Hydronephrosis was graded from 0 to 4, and high-grade hydronephrosis was defined as grades 3 and 4. RESULTS: Fifty-one children underwent ARFI measurements, and three valid measurements for both kidneys were obtained in 96% (49/51) of the patients. Nineteen children (38.8%) had no hydronephrosis. Twenty-three children (46.9%) had unilateral hydronephrosis, and seven children (14.3%) had bilateral hydronephrosis. Seven children had ureteropelvic junction obstruction (UPJO). Median SWVs in kidneys with high-grade hydronephrosis (2.02 m/sec) were higher than those in normal kidneys (1.75 m/sec; P=0.027). However, the presence of UPJO did not influence the median SWVs in hydronephrotic kidneys (P=0.362). CONCLUSION: Obtaining ARFI measurements of the kidney is feasible in young children with median SWVs of 1.75 m/sec in normal kidneys. Median SWVs increased in high-grade hydronephrotic kidneys but were not different between hydronephrotic kidneys with and without UPJO.

Length and Volume of Morphologically Normal Kidneys in Korean Children: Ultrasound Measurement and Estimation Using Body Size

OBJECTIVE: To evaluate the relationship between anthropometric measurements and renal length and volume measured with ultrasound in Korean children who have morphologically normal kidneys, and to create simple equations to estimate the renal sizes using the anthropometric measurements. MATERIALS AND METHODS: We examined 794 Korean children under 18 years of age including a total of 394 boys and 400 girls without renal problems. The maximum renal length (L) (cm), orthogonal anterior-posterior diameter (D) (cm) and width (W) (cm) of each kidney were measured on ultrasound. Kidney volume was calculated as 0.523 x L x D x W (cm3). Anthropometric indices including height (cm), weight (kg) and body mass index (m2/kg) were collected through a medical record review. We used linear regression analysis to create simple equations to estimate the renal length and the volume with those anthropometric indices that were mostly correlated with the US-measured renal sizes. RESULTS: Renal length showed the strongest significant correlation with patient height (R2, 0.874 and 0.875 for the right and left kidneys, respectively, p < 0.001). Renal volume showed the strongest significant correlation with patient weight (R2, 0.842 and 0.854 for the right and left kidneys, respectively, p < 0.001). The following equations were developed to describe these relationships with an estimated 95% range of renal length and volume (R2, 0.826-0.884, p < 0.001): renal length = 2.383 + 0.045 x Height (+/- 1.135) and = 2.374 + 0.047 x Height (+/- 1.173) for the right and left kidneys, respectively; and renal volume = 7.941 + 1.246 x Weight (+/- 15.920) and = 7.303 + 1.532 x Weight (+/- 18.704) for the right and left kidneys, respectively. CONCLUSION: Scatter plots between height and renal length and between weight and renal volume have been established from Korean children and simple equations between them have been developed for use in clinical practice.

Immunoglobulin G4-Related Systemic Sclerosing Disease: A Case Involving the Ureter and Kidney

Immunoglobulin (Ig) G4-related sclerosing disease is a newly defined clinicopathological entity characterized by lymphoplasmacytic infiltration of IgG4-positive plasma cells and varying degrees of fibrosis within affected tissues. Patients usually exhibit multisystem involvement and often respond well to steroid and immunosuppressive therapy. This report presents a case of IgG4-related sclerosing disease involving the ureter and kidney. We hope to bring IgG4-related sclerosing disease to the attention of urologists, because it is an uncommon disease that commonly responds to systemic corticosteroids.

Imaging Findings of Renal Cell Carcinoma Associated with Xp11.2 Translocation/TFE3 Gene Fusion in a 4-Year-Old Male: Case Report and Review of Literature

We represent a pathologically proven case of a four-year-old male patient with renal cell carcinoma associated with Xp11.2 translocation/TFE3 gene fusion, which is rare but more frequent in children or young adults. Computed tomography showed about 2.5 cm size ill-defined mass in the right kidney. The mass was hyperechoic on ultrasound. Magnetic resonance imaging demonstrated a mass with capsular enhancement and diffusion restriction. We present a case of Xp11.2 renal cell carcinoma and provide review of the literature.

Use of Animated Cartoons with Children's Songs to Increase Compliance with Ultrasonography in Young Children

PURPOSE: To evaluate the effect of animated cartoons with children's songs to increase compliance with ultrasonography (US) examination in young children. MATERIALS AND METHODS: Animated cartoons with children's songs viewed on a cell phone were played just before the start of US examination when pediatric patients were agitated or irritable. The effect of this method was evaluated for initial responses and sustained responses (grade 0, no response; 1, partial response; and 2, good response). Site of US examination, scan duration, and the helpfulness of this method (0, useless; 1, partially helpful; and 2, very helpful) were also recorded. RESULTS: Among 464 pediatric patients who underwent US during the study period, 88 children (19%) needed to be calmed (67 abdominal and 21 other parts of the body). All subjects were less than five years of age (mean 1.5 years), except for four patients with mental retardation. Scan duration was less than 5 minutes in almost all examinations. Five children refused to watch the cartoon. Initial responses were good in 75 and partial in eight children. Sustained responses were good in 70 and partial in 12 children. The cartoons were very helpful in 73 (83%) and partially helpful in nine (10%) children. The effect of watching the cartoon did not change with sex, age (less or more than one year), or site of examination. CONCLUSION: Animated cartoons with children's songs viewed on a cell phone were helpful (93%) in increasing compliance with US examination in young children of both the abdomen and other parts.

Cellular Mesoblastic Nephroma with Liver Metastasis in a Neonate: Prenatal and Postnatal Diffusion-Weighted MR Imaging

Congenital mesoblastic nephroma (CMN) is the most common renal tumor in the first year of life. Here, we present unique findings of cellular variant CMN seen on prenatal and postnatal MRI with diffusion-weighted imaging (DWI).The mass was well-visualized on prenatal MR DWI with diffusion restriction in the solid portions. After excision of the mass, follow-up whole body MRI with DWI helped identify local tumor recurrence with suspicious liver metastasis. This hepatic lesion also showed diffusion restriction.

Significance of Contrast Enema in One-stage Transanal Endorectal Pull-through Operation for Hirschsprung Disease

In one-stage transanal endorectal pull-through operation (TERPT) for Hirschsprung disease, preoperative evaluation by contrast enema (CE) is important tool in aspect of planning of surgical procedure as well as diagnosis. This study was to evaluate the significance of CE for identifying the extent of aganglionic bowel. A retrospective analysis was performed in 40 patients who underwent TERPT between 2003 and 2011. The authors reviewed the CE studies and their correlation with pathologic extent of aganglionosis. Total 66 contrast enemas were performed in 40 patients. Twenty patients underwent single CE, but 20 patients required multiple CEs. In single CE group, 17 had clear radiographic transition zone, but 3 had less definite transition zone. In multiple CE group, 17 patients who had equivocal finding in first or second CE had definite radiographic transition zone, but 3 patients of this group had less definite radiographic transition zones. Overall, 34 patients (85%) had clear radiographic transition zone by single or repeated CE. One (2.9%) out of 34 patients with clear radiographic transition zone had discordance between radiographic and pathologic transition zone. In contrast 4 (66.7%) out of 6 patients with equivocal radiographic transition zone had discordance between radiographic and pathologic transition zone. Observation of clear radiographic transition zone is important in preparation of TERPT, and repeated CE is helpful to reduce the discordance between radiographic and pathologic transition zone. Awareness of the possibility of discordance is also important if radiographic transitional zone is not clear.

Langerhans Cell Histiocytosis with Pancreatic Involvement: Imaging Findings Including Diffusion-Weighted Imaging

Langerhans cell histiocytosis (LCH) can affect many different organs. However, LCH with pancreatic involvement is very rare with a few reports about imaging findings. We present a case of multisystemic LCH with pancreatic involvement in a five-week-old infant. Pancreas lesion showed hypoechoic on ultrasonography, low density with poor enhancement on CT, and restricted diffusion on diffusion-weighted imaging. Although LCH with pancreatic involvement is rare, LCH should be considered in the differential diagnosis of pancreatic mass in children.

Rapidly Evoluting Congenital Cystic Neuroblastoma in a Neonate

Perinatal detection of neonatal suprarenal masses has increased. Here, we report an unusual case of an adrenal cystic neuroblastoma that presented as a purely cystic lesion upon initial postnatal ultrasonography (US) and showed rapid evolution to a mixed cystic and solid mass during follow-up US and MRI. We suggest a short-term (two weeks) follow-up US for neonatal adrenal cystic lesions, even if they appear as purely cystic.

A case Report of a Classic Cystic fibrosis Pediatric Patient in Korea Carrying Very Rare CFTR Gene Mutations (D993Y and Q220X) / 소아알레르기및호흡기학회지

Cystic fibrosis is the most common autosomal recessive disease in Caucasian. Cystic fibrosis is caused by cystic fibrosis transmembrane conductance regulator (CFTR) gene mutations that lead to dysfunction of chloride ion channel regulations in the epithelium. Cystic fibrosis can affect multiple organ functions, resulting in various signs and symptoms. Typically, chronic airway infection, maldigestion, failure to thrive, and male infertility can occur. There are approximately 1800 CFTR gene mutations which have been identified thus far. However, there are only a few types of mutations reported in Korea because the prevalence of the disease is different among ethnicitiess and nations. Despite its rarity, reports of CFTR mutations or diagnosed patients on the rise. Therefore, we have to detect better outcomes as early as possible based on a precise understanding of the disease entity. We report a 9-year-old girl carrying D339Y and Q220X gene mutations, as the first case report of a D339Y mutation in Korea.

Renal Cell Carcinoma in a Right Malrotated Kidney

The authors report a case of renal cell carcinoma in a right malrotated (horizontal axis) kidney. The patient was treated by hand-assisted laparoscopic radical nephrectomy. This is the first report of a horizontal axis malrotated kidney with renal cell carcinoma.

Comparison of Flap Thickness Measured with Ultrasound Subtraction Method, Direct Method, and Optical Coherence Tomography

PURPOSE: To compare the flap thicknesses measured with the ultrasound (US) subtraction method, the direct method, and optical coherence tomography (OCT) in femtosecond laser-assisted LASIK eyes. METHODS: The present study included 65 eyes of 37 patients who underwent femtosecond laser-assisted LASIK surgery. Flap thickness was measured intraoperatively using the direct and subtraction methods with US pachymetry and postoperatively using anterior segment OCT. Flap thickness measurements were compared among the three methods. RESULTS: There was no significant difference between the flap thickness measured using the US subtraction method and OCT (p = 0.511). The flap thickness values obtained by these two different methods also correlated well with each other (gamma = 0.820, p < 0.001). However, flap thickness measured using the US direct method was significantly different (p < 0.001) with a low agreement value compared to the other two methods. Furthermore, the US direct method showed a lower measurement success rate compared to the US subtraction method (54% vs. 95%). CONCLUSIONS: Flap thickness measured using the US subtraction method and OCT showed different values compared to that measured using the US direct method. Because of the lower measurement success rate and agreement value, the US direct method is not capable of being used in substitute for the US subtraction method.