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To investigate the clinical characteristics and prevalence of paediatric anti-myelin oligodendrocyte glycoprotein (MOG) antibody-associated autoimmune encephalitis.A total of 94 paediatric patients (46 males, 48 females, median age 9 years 5 months, range: 8 months-17 years 8 months) with autoimmune encephalitis were recruited at Seoul National University Children's Hospital. We evaluated autoantibody status and identified patients with anti-MOG antibody-associated autoimmune encephalitis. Retrospective reviews of medical records were performed to describe clinical presentations, laboratory findings, treatments, and outcomes.Eight patients (five males, three females, median age 11 years 9 months) with anti-MOG antibody-associated encephalitis were identified (8.5% of those with autoimmune encephalitis), one of whom was copositive for anti-N-methyl-d-aspartate receptor (NMDAR) antibodies. Anti-NMDAR antibodies were identified in 23 patients (23 out of 94, 24.5%). Unilateral or bilateral cortical involvement was identified in five patients. Focal contrast enhancement was also identified in three of the five patients with cortical lesions. All patients showed favourable response to immunotherapy with a Modified Rankin Scale ≤2 at the last follow-up. Relapse was found in one patient and clinico-radiological remission was achieved with cyclic intravenous immunoglobulin therapy.Anti-MOG antibody-associated encephalitis accounts for a significant proportion of clinically defined paediatric patients with autoimmune encephalitis. Anti-MOG antibody-associated encephalitis should be included in the clinical spectrum of anti-MOG-associated diseases.

Background Cerebral arteriovenous malformation (AVM) can rarely occur in conjunction with moyamoya disease (MMD). There is still no consensus on how to treat AVM when accompanied by MMD. In this study, we assessed the clinical features and suggested appropriate management when AVM was combined with MMD. Methods From August 1994 to December 2020, 7 out of 4004 patients with MMD were found to have AVM. The Karnofsky Performance Scale (KPS) was used to evaluate the clinical outcomes of AVM and MMD. KPS greater than 80 was classified as a good outcome. In addition, the radiologic outcomes of the patients were evaluated. Results The incidence of AVM with MMD was 1.7 per 1000 persons. Five patients underwent bypass surgery for MMD, and 5 patients underwent Gamma Knife surgery (GKS) for concurrent AVM. Postoperative perfusion magnetic resonance imaging and brain single photon emission computerized tomography showed improved cerebral hemodynamics in 4 out of 7 territories. Postoperative cerebral angiography showed good revascularization in 4 out of 8 territories. After GKS, 4 patients showed complete obliteration, and 1 patient showed a significantly decreased AVM size. Six patients showed favorable clinical outcomes (KPS 80–100), and 1 patient with delayed GKS for AVM had a poor outcome (KPS 20) due to AVM rupture. Conclusions In this study, AVM tended to occur where the angiographic stage of MMD was higher. When AVM is combined with MMD, MMD bypass surgery is recommended based on symptoms and cerebral perfusion status. For AVM, less invasive but effective treatments, such as GKS, should be implemented as soon as possible.

Background Pediatric patients with liver disease require noninvasive monitoring to evaluate the risk of fibrosis progression. This study aimed to identify the significant factors affecting liver stiffness values using two-dimensional shear-wave elastography (2D-SWE), and determine whether liver stiffness can predict the fibrosis stage of various childhood liver diseases. Methods This study included 30 children (22 boys and 8 girls; mean age, 5.1 ± 6.1 years; range, 7 days–17.9 years) who had undergone biochemical evaluation, 2D-SWE examination, histopathologic analysis of fibrosis grade (F0 to F3), assessment of necroinflammatory activity, and steatosis grading between August 2016 and March 2020. The liver stiffness from 2D-SWE was compared between fibrosis stages using Kruskal–Wallis analysis. Factors that significantly affected liver stiffness were evaluated using univariate and multivariate linear regression analyses. The diagnostic performance was determined from the area under the receiver operating curve (AUC) values of 2D-SWE liver stiffness. Results Liver stiffness at the F0-1, F2, and F3 stages were 7.9, 13.2, and 21.7 kPa, respectively (P P P = 0.021, respectively). However, in patients with alanine aminotransferase (ALT) levels below 200 IU/L, the only factor affecting liver stiffness was fibrosis stage (P = 0.030). The liver stiffness value could distinguish significant fibrosis (≥ F2) with an AUC of 0.950 (cutoff value, 11.3 kPa) and severe fibrosis (F3 stage) with an AUC of 0.924 (cutoff value, 18.1 kPa). The 2D-SWE values for differentiating significant fibrosis were 10.5 kPa (≥ F2) and 18.1 kPa (F3) in patients with ALT levels below 200 IU/L. Conclusion The liver stiffness values on 2D-SWE can be affected by both fibrosis and necroinflammatory grade and can provide excellent diagnostic performance in evaluating the fibrosis stage in various pediatric liver diseases. However, clinicians should be mindful of potential confounders, such as necroinflammatory activity or transaminase level, when performing 2D-SWE measurements for liver fibrosis staging.

Imatinib is a BCR-ABL tyrosine kinase inhibitor used for the treatment of a variety of diseases including Philadelphia chromosome positive (Ph+) leukemia. We report a 15 year old male patient presenting with symptomatic acute intracerebral hemorrhage (ICH) in midbrain while on imatinib more than three years after completion of therapy for Ph + B-ALL. The patient denied recent trauma history and consumption of other medication. Laboratory findings did not show any signs of relapse, coagulopathy nor thrombocytopenia. Under the impression of imatinib related ICH, imatinib was discontinued and with conservative management the patient recovered without neurologic sequalae. This case demonstrates the first pediatric case of spontaneous ICH as a rare complication of imatinib.

Patients with craniopharyngioma are susceptible to autonomic dysfunction as a result of hypothalamic damage. We evaluated indices of heart rate variability (HRV) in patients with childhood-onset craniopharyngioma to investigate autonomic function and its relationship with components of the metabolic syndrome (MetS). This cross-sectional, case-only study included 53 patients (10–30 years of age). We measured the standard deviation of all normal R-R intervals (SDNN) and total power indicating overall HRV, the root-mean square of the difference of successive R-R intervals (RMSSD) and high frequency indicating parasympathetic modulation, and low frequency. These indices were compared according to the presence of the MetS. During the mean 10.8 years of follow-up, 25% of patients were diagnosed with the MetS. Patients with the MetS showed significantly lower levels of SDNN (29.0 vs. 40.6 ms), total power (416.1 vs. 1129.6 ms2), RMSSD (20.1 vs. 34.5 ms), high frequency (94.7 vs. 338.5 ms2), and low frequency (94.5 vs. 289.4 ms2) than those without (p

To investigate the feasibility and safety of transradial cerebral angiography (TRCA) in comparison to transfemoral cerebral angiography (TFCA) in the pediatric population.We retrospectively reviewed pediatric patients who underwent TRCA between January 2019 and July 2020. Patients with TFCA experience were examined. Pre- and post-procedural Doppler ultrasonography was performed to evaluate TRCA complications. To evaluate differences in radiation exposure between TRCA and TFCA, we investigated the radiation dose, dose area product (DAP), fluoroscopy time, and examination time.Thirty-five patients (mean age, 13.8 years; 22 male) underwent TRCA, with 18 (mean age, 13.0 years; 10 male) experiencing TFCA. TRCA was successful in all cases without technical failure. Radiation exposure including radiation dose and DAP were significantly higher in the TRCA group (474.1 mGy and 8299.6 μGy mAlthough TRCA is a technically feasible and safe method in pediatric patients, high radiation exposure to TFCA must be considered. Therefore, it should be considered as an alternative method in those with unfavorable clinical situations for performing TFCA.Level 4, Case Series.

This study aimed to evaluate a deep learning model for generating synthetic contrast-enhanced CT (sCECT) from non-contrast chest CT (NCCT). A deep learning model was applied to generate sCECT from NCCT. We collected three separate data sets, the development set (n = 25) for model training and tuning, test set 1 (n = 25) for technical evaluation, and test set 2 (n = 12) for clinical utility evaluation. In test set 1, image similarity metrics were calculated. In test set 2, the lesion contrast-to-noise ratio of the mediastinal lymph nodes was measured, and an observer study was conducted to compare lesion conspicuity. Comparisons were performed using the paired t-test or Wilcoxon signed-rank test. In test set 1, sCECT showed a lower mean absolute error (41.72 vs 48.74; P P P P P P ≤ .001). Synthetic CECT generated from NCCT improves the depiction of mediastinal lymph nodes.

Currently, the prevention of recurrent immediate hypersensitivity reactions (HSRs) to contrast media (CM) requests premedication and changing the culprit contrast agent. However, strategies for the prevention of immediate HSRs to gadolinium-based magnetic resonance contrast agents (GBCAs) have not yet been established. This study aimed to evaluate the effectiveness of changing the contrast agent and single-dose premedication for HSR recurrence prevention in patients with a history of mild immediate HSR to GBCA.The outcomes of patients with mild immediate HSR to GBCA who subsequently underwent enhanced magnetic resonance imaging between October 2012 and July 2017 were analyzed. The institutional CM monitoring system was retrospectively reviewed, and data on the application of premedication and choice of CM were obtained. Gadolinium-based magnetic resonance contrast agents were classified into 3 classes according to their molecular structure (macrocyclic ionic, macrocyclic nonionic, and linear ionic). Intravenous chlorpheniramine 4 mg, 30 minutes before the GBCA administration, or intravenous methylprednisolone sodium succinate 40 mg plus chlorpheniramine 4 mg, 1 hour before the GBCA administration, was administrated as premedication regimen. Recurrence rates of immediate HSR were compared according to prevention strategies.A total of 185 patients with a history of mild immediate HSR to GBCA were re-exposed to GBCA 397 times during the study period. The overall recurrence rate was 19.6% (78/397). Changing the culprit GBCA significantly reduced the recurrence rate, compared with reusing the culprit GBCA (6.9%, 9/130 and 25.8%, 69/267; P0.001). The recurrence rate was lowest when the GBCA was changed to a different molecular structure class from the culprit agent, followed by changing to CM with the same molecular structure and reusing the culprit GBCA (6.2%, 7/113 vs 11.8%, 2/17 vs 25.8%, 69/267; P0.001 with χ test for trend). Single-dose premedication demonstrated no significant prophylactic effect on recurrence (20.4%, 17/98 vs 17.3%, 61/299 with and without premedication, respectively; P = 0.509). Premedication in addition to changing CM also showed no additional prophylactic effect (7.2%, 7/97 and 6.1%, 2/33, respectively; P = 0.821).Changing the CM from the culprit agent could reduce the chance of HSR recurrence in patients with prior mild immediate HSR to GBCA, especially when the CM was changed to one of a different molecular structure class. However, single-dose premedication administration did not show significant HSR recurrence rate difference.

Objectives The diagnostic role of an ultrasound (US) and plasma renin activity (PRA) combination is unknown, despite the usefulness of Doppler US as a screening tool for renovascular hypertension (RVHT). The purpose of this study was to evaluate the diagnostic usefulness of US for RVHT in children stratified according to PRA. Methods We identified 336 children who underwent renal Doppler US examinations for hypertension and divided them into a high-renin group (n = 177) and a normal-renin group (n = 159) based on PRA and stratified them by age. The Doppler US findings were retrospectively reviewed, and computed tomographic angiography (CTA) for the same children was used as the reference standard. Results In the high-renin group, 36 patients had positive Doppler US findings that were confirmed by CTA in 32 cases. The sensitivity and specificity values for Doppler US in the high-renin group were 84.2% and 93.6%, respectively. In the normal-renin group, 10 patients had positive Doppler US findings; these positive findings were confirmed by CTA in 9 cases. The sensitivity and specificity values for US in the normal-renin group were 100.0% and 100.0%. There were anatomic variations (n = 3) and segmental artery stenosis (n = 2) among the cases with false-negative US findings, which were confirmed by CTA. Conclusions If patients have high PRA, a Doppler US examination should be performed with caution to avoid false-negative detection. If patients have normal PRA, renal Doppler US might be adequate for diagnosis of RVHT to avoid unnecessary CTA.

Background: The guideline for managing pediatric thyroid nodules has not been established. We investigated the appropriateness of the Korean Society of Thyroid Radiology (KSThR) guidelines and the ...

Objective To describe the anatomic locations and imaging features of posterior lung herniation in unilateral pulmonary agenesis and aplasia, focusing on radiograph-CT/MRI correlation. Materials and methods A total of 10 patients (seven with pulmonary agenesis and three with pulmonary aplasia, male: female = 1:9, mean age 7.3 years, age range from 1 month to 20 years) were included. Chest radiographs (n = 9), CT (n = 9), and MRI (n = 1) were reviewed to assess the type of lung underdevelopment, presence of anterior and posterior lung herniation, bronchus origin, supplying artery, and draining vein of the herniated lung. Results Pulmonary agenesis/aplasia more commonly affected the left lung (n = 7) than the right lung (n = 3). Anterior lung herniation was observed in nine of the 10 patients. Posterior lung herniation was observed in seven patients with left pulmonary agenesis/aplasia. Two patients showed posterior lung herniation crossing the midline but not beyond the aorta, and five patients showed the posteriorly herniated right lower lobe crossing the midline to extend into the left hemithorax farther beyond the descending thoracic aorta through the space between the esophagus and the aorta. This anatomical configuration resulted in a characteristic radiographic finding of a radiolucent area with a convex lateral border and a vertical medial border in the left lower lung zone, revealing a tongue-like projection on CT and MRI. Conclusion Posterior lung herniation occurs in unilateral left lung agenesis/aplasia. Approximately 70% of the cases of posterior lung herniation reveal a unique radiolucent tongue-like projection in the left lower lung zone on imaging studies, which is caused by the extension of the posteriorly herniated right lung farther beyond the descending aorta.

Purpose The purpose of this study was to identify imaging risk factors on contrast-enhanced hip MRI after closed reduction of developmental dysplasia of the hip (DDH) that could predict future development of avascular necrosis (AVN) of the femoral head. Materials and methods Fifty-eight infants (F: M = 53: 5, aged 3–18 months) who underwent immediate postoperative contrast-enhanced hip MRI after closed reduction of DDH were included in this study. Quality of reduction (concentric vs eccentric reduction with or without obstacles), abduction angle of the hip, presence of ossific nucleus, and pattern of contrast enhancement of the femoral head were retrospectively evaluated on MRI. Interobserver agreement of contrast enhancement pattern on MRI were evaluated by two radiologists. Development of AVN was determined through radiographic findings at 1 year after reduction. Results AVN of the femoral head developed in 13 (22%) of 58 patients. Excessive abduction of the hip joint (OR 4.65, [95% CI 1.20, 18.06] and global decreased enhancement of the femoral head (OR 71.66, [95% CI 10.54, 487.31]) exhibited statistically significant differences between the AVN and non-AVN groups (P < 0.05). Eccentric reduction (P = 0.320) did not show statistically significant difference between two groups and invisible ossific nucleus (P = 0.05) showed borderline significance. Multi-variable logistic regression indicated that global decreased enhancement of the femoral head was a significant risk factor of AVN (OR 27.92, 95% CI [4.17, 350.18]) (P = 0.0031). Interobserver agreement of contrast enhancement pattern analysis and diagnosis of AVN were good (0.66, 95% CI [0.52, 0.80]). Conclusion Contrast-enhanced hip MRI provides accurate anatomical assessment of the hip after closed reduction of DDH. Global decreased enhancement of the femoral head could be used as a good predictor for future development of AVN after closed reduction of DDH.

Juvenile xanthogranuloma (JXG) is a type of non-Langerhans cell histiocytosis that most commonly manifests as a solitary cutaneous lesion of the head and neck in children. Intracranial JXG is extremely rare. Although it is widely known that JXG skin lesions gradually disappear over time without treatment, treatment guidelines for intracranial JXG have not been established. It is very difficult to predict whether an intracranial lesion is JXG with only a pre-operative imaging work-up without pathologic confirmation. We report a case of the youngest, a 3-month-old male infant with an intracranial extra-axial mass with rapid growth for 2 months. Additionally, we suggest characteristic MRI findings for intracranial extra-axial JXG of a low T2 signal and a kidney bean shape.

Background Central nervous system germ cell tumors (CNS GCTs) are a heterogeneous group of brain tumors, which are more common in Asian countries. There have been different therapeutic strategies in treating germinoma and non-germinomatous germ cell tumors (NGGCT), depending on prognosis. Moreover, long-term follow up should be emphasized due to higher late complication rates. Here, we investigated long-term outcomes and complication profiles of 127 CNS GCT patients who received uniform upfront chemotherapy. Methods We retrospectively evaluated outcomes of CNS GCT patients treated in Seoul National University Children’s Hospital from August 2004 to April 2019. Patients were classified as low risk (LR) or high risk (HR) based on pathologic diagnosis and tumor markers. Most patients received upfront systemic chemotherapy with carboplatin, cyclophosphamide, etoposide, and/or bleomycin, followed by either proton or photon radiation therapy according to patients’ choice. Results The median age at diagnosis was 11.9 (range, 3.8–25.1) years, and 54.3% of patients were LR. Photon and proton radiation therapy were administered to 73.2 and 25.2% of patients, respectively. In both LR and HR groups, there were no significant differences in survival between photon and proton radiation therapy. The 10-year relapse incidences were 9.3 and 5.6% in the LR and HR groups, respectively. All recurrences, except one, were local relapse. Six secondary malignancies occurred; the 10-year incidences of secondary malignancy were 2.2 and 7.6% in the LR and HR groups, respectively. The 10-year overall survival rates were 98.3 ± 1.7 and 91.8 ± 3.9% in the LR and HR groups, respectively. In a subgroup analysis of HR group, pathologically diagnosed NGGCT patients (n = 20) showed worse 10-year EFS (65.9 ± 11.9%, p p = 0.024) rates compared to other HR patients who were not pathologically diagnosed or were confirmed as germinoma with elevated tumor markers. All mortalities were related to disease progression or secondary malignancy. Conclusion The strategy of treating CNS GCTs with upfront chemotherapy according to risk groups resulted in good clinical outcomes and acceptable relapse incidence. However, further modification in the definition of the HR group is needed to reduce long-term complications.

We investigated the feasibility of free-breathing modified Look-Locker inversion recovery (MOLLI) sequence for measuring hepatic T1 values in children and young adults. To investigate the accuracy and the reproducibility of the T1 maps, a phantom study was performed with 12 different gadoterate meglumine concentrations and the T1 relaxation times of phantoms measured with the MOLLI sequence were compared against those measured with three different sequences: spin-echo inversion recovery, variable flip angle (VFA), and VFA with B1 correction. To evaluate the feasibility of free-breathing MOLLI sequence, hepatic T1 relaxation times obtained by free-breathing and breath-hold technique in twenty patients were compared. The phantom study revealed the excellent accuracy and reproducibility of MOLLI. In twenty patients, the mean value of hepatic T1 values obtained by free-breathing (606.7 ± 64.5 ms) and breath-hold (609.8 ± 64.0 ms) techniques showed no significant difference (p > 0.05). The Bland–Altman plot between the free-breathing and breath-hold revealed that the mean difference of T1 values was − 3.0 ms (− 0.5%). Therefore, T1 relaxation times obtained by MOLLI were comparable to the values obtained using the standard inversion recovery method. The hepatic T1 relaxation times measured by MOLLI technique with free-breathing were comparable to those obtained with breath-hold in children and young adults.

BACKGROUND. Hippocampal sclerosis (HS) is a leading cause of medically refractory temporal lobe epilepsy in children. The diagnosis is clinically important because most patients with HS have good p...

Posttransplant lymphoproliferative disorder (PTLD) is a heterogeneous group of diseases with abnormal proliferation of lymphoid tissue and classical Hodgkin lymphoma (CHL) type PTLD is a very rare subtype. We describe a successfully diagnosed and treated CHL-PTLD stage IV pediatric patient, 8 years after liver transplantation. The patient was treated with standard CHL (Children's Cancer Group 5942 group 3) chemotherapy, rituximab and reduction of immunosuppressant. The patient remains in complete remission after 3 years with stable graft function. To our best knowledge, this is the first pediatric case report of a successfully treated stage IV CHL-PTLD after a liver transplant.

To evaluate the image quality of low iodine concentration, dual-energy CT (DECT) combined with a deep learning-based noise reduction technique for pediatric abdominal CT, compared with standard iodine concentration single-energy polychromatic CT (SECT).From December 2016 to May 2017, DECT with 300 mg•I/mL contrast medium was performed in 29 pediatric patients (17 boys, 12 girls; age, 2-19 years). The DECT images were reconstructed using a noise-optimized virtual monoenergetic reconstruction image (VMI) with and without a deep learning method. SECT images with 350 mg•I/mL contrast medium, performed within the last 3 months before the DECT, served as reference images. The quantitative and qualitative parameters were compared using paired t tests and Wilcoxon signed-rank tests, and the differences in radiation dose and total iodine administration were assessed.The linearly blended DECT showed lower attenuation and higher noise than SECT. The 60-keV VMI showed an increase in attenuation and higher noise than SECT. The combined 60-keV VMI plus deep learning images showed low noise, no difference in contrast-to-noise ratios, and overall image quality or diagnostic image quality, but showed a higher signal-to-noise ratio in the liver and lower enhancement of lesions than SECT. The overall image and diagnostic quality of lesions were maintained on the combined noise reduction approach. The CT dose index volume and total iodine administration in DECT were respectively 19.6% and 14.3% lower than those in SECT.Low iodine concentration DECT, combined with deep learning in pediatric abdominal CT, can maintain image quality while reducing the radiation dose and iodine load, compared with standard SECT.• An image noise reduction approach combining deep learning and noise-optimized virtual monoenergetic image reconstruction can maintain image quality while reducing radiation dose and iodine load. • The 60-keV virtual monoenergetic image reconstruction plus deep learning images showed low noise, no difference in contrast-to-noise ratio, and overall image quality, but showed a higher signal-to-noise ratio in the liver and a lower enhancement of lesion than single-energy polychromatic CT. • This combination could offer a 19.6% reduction in radiation dose and a 14.3% reduction in iodine load, in comparison with a control group that underwent single-energy polychromatic CT with the standard protocol.

OBJECTIVE. The aim of this study was to develop a low-dose radiography protocol for the neonatal ICU (NICU) using a new mobile digital radiography system with advanced denoising image processing and to evaluate the noninferiority of that protocol. SUBJECTS AND METHODS. In this prospective randomized study, 40 neonates in the NICU underwent radiography of the thorax and abdomen with two different mobile radiography units: conventional technique on one unit (50 kV, 1.6 mAs, and no additional filtration) and a new technique on another unit (54 kV, 0.1-mm Cu filtration). Three low-dose protocols for the second unit were developed in a phantom study: protocol A (100% equivalent dose with conventional protocol), protocol B (80% equivalent dose), and protocol C (64% equivalent dose). The noninferiority of each low-dose protocol was assessed by three independent readers using image quality criteria. RESULTS. Forty patients each underwent three pairs of radiography examinations (protocol A and the conventional protocol, protocol B and the conventional protocol, and protocol C and the conventional protocol), except one pair that did not include one image of the conventional protocol. The interrater reliability among the three readers was 0.91 (p < 0.001). Both of the low-dose protocols (B and C) were statistically noninferior to the conventional protocol with respect to overall image quality. Protocol B better depicted almost all anatomic landmarks and had better overall image quality than the conventional protocol. CONCLUSION. Using appropriate technique and acquisition factors, radiation dose can be lowered on a digital radiography system without significant effect on the image quality by adding filtrations and a new denoising technique.

Background The image quality of abdominal magnetic resonance imaging (MRI) in children who cannot hold their breath has been severely impaired by motion artifacts. Purpose To evaluate the usefulness of T1-weighted (T1W) BLADE MRI for axial abdominal imaging in children who cannot hold their breath. Material and Methods Two different BLADE sequences, with and without an inversion recovery (IR-BLADE), were compared to conventional turbo-spin echo (TSE) with a high number of excitations in 18 consecutive patients who cannot hold their breath. Overall image quality, motion artifact, radial artifact, hepatic vessel sharpness, renal corticomedullary differentiation, and lesion conspicuity were retrospectively assessed by two radiologists, using 4- or 5-point scoring systems. Signal variations of each sequence were measured for a quantitative comparison. The acquisition times of the three sequences were compared. Results IR-BLADE and BLADE showed significantly improved overall image quality and reduced motion artifact compared with TSE. IR-BLADE showed significantly better hepatic vessel sharpness and corticomedullary differentiation compared to both BLADE and TSE. Radial artifacts were only observed on IR-BLADE and BLADE. In nine patients with lesions, there were no significant differences in lesion conspicuity among three sequences. Compared to TSE, both IR-BLADE and BLADE showed decreased signal variations in the liver and muscle, and an increased signal variation through air. The mean acquisition times for IR-BLADE, BLADE, and TSE were comparable. Conclusion Compared to the TSE sequence, T1W IR-BLADE for pediatric abdominal MRI resulted in improved image quality, tissue contrast with a diminished respiratory motion artifact, and a comparable acquisition time.

Toxicity of carmustine and cyclophosphamide can cause pulmonary injury after hematopoietic stem cell transplantation. To evaluate the radiologic findings of pulmonary injuries following carmustine- and cyclophosphamide-based preparative regimens in children. From 2010 to 2014, 35 children received carmustine- and cyclophosphamide-based preparative regimens. Fourteen of 35 children presented with symptoms and radiologic abnormalities. Eight of 14 children had no evidence of infection, cardiogenic edema, or other explainable causes. We retrospectively analyzed their chest radiographs and CT scans for ground-glass opacity, consolidation, septal thickening and pleural effusion. Major chest radiographic findings were bilateral diffuse ground-glass opacity (n=8) and septal thickening (n=7). CT findings were multifocal patchy (n=4) or inhomogeneously diffuse (n=4) ground-glass opacity, multifocal consolidations (n=7) and septal thickening (n=7). All of these lesions at CT were bilateral, but showed lower lobe predominance in 88, 100, and 63%, respectively. There was no central/peripheral or anterior/posterior predilection. Six children had small pleural effusions, which were bilateral in five children. Bilateral ground-glass opacity with or without consolidation, septal thickening and pleural effusion were common radiologic findings in pulmonary injury following carmustine- and cyclophosphamide-based preparative regimens.

The aim of this study was to identify the signal intensity (SI) changes in the dentate nucleus (DN) and the globus pallidus (GP) on unenhanced T1-weighted magnetic resonance (MR) images after multiple administration of gadolinium-based contrast agents (GBCAs) in children and compare those changes between linear and macrocyclic GBCAs.This retrospective study was approved by the institutional review board and the requirement for informed consent was waived. We identified 92 children who underwent at least 4 consecutive MR examinations exclusively using either linear GBCA (gadodiamide or gadopentetate dimeglumine, n = 41) or macrocyclic GBCA (gadoterate meglumine, n = 51). Signal intensity ratio changes in the DN to pons and GP to thalamus between the first and last MR examinations were calculated.The SI ratios in the linear group increased significantly between the first and last MR examinations (mean difference: DN to pons, 0.0461 ± 0.0480, P0.001; GP to thalamus, 0.0332 ± 0.0385, P0.001), but not in the macrocyclic group (mean difference: DN to pons, -0.0010 ± 0.0371, P = 0.855; GP to thalamus, 0.0007 ± 0.0294, P = 0.867). In the linear regression analysis, the numbers of administrations of gadodiamide and gadopentetate dimeglumine were highly associated with the differences in SI ratios (DN to pons, P0.001 and P = 0.003; GP to thalamus, P0.001 and P = 0.002, respectively).The SIs of the DN and GP on unenhanced T1-weighted images increased after serial administrations of linear GBCA, but not macrocyclic GBCA, in children. The number of linear GBCA administration had a linear association with the SI changes in the DN and GP.

To evaluate the predictive value of ultrasonography in children with clinically suspicious hepatic veno-occlusive disease (VOD) after hematopoietic stem cell transplantation (HSCT). Among 216 children who underwent HSCT, 70 also underwent colour Doppler ultrasonography. Of these, 59 had only one sign/symptom, which did not fulfil the diagnostic criteria (clinical suspicion of VOD) at that time. VOD was confirmed in 20 patients (VOD group), while 39 had other conditions (non-VOD group). The following findings were reviewed and compared between groups: left portal vein (peak velocity, direction), left hepatic artery (peak-systolic/end-diastolic velocities, resistive index), middle hepatic vein (peak velocity, phasicity), hepatomegaly, splenomegaly, gallbladder wall thickness, and ascites. The VOD group showed significantly higher reversed flow in portal vein (P = 0.011), peak systolic velocity of left hepatic artery (P = 0.028), monophasicity of middle hepatic vein (P = 0.015), hepatomegaly (P = 0.001), gallbladder wall thickness (P

This study aimed to evaluate the feasibility and added value of transcatheter dynamic contrast-enhanced magnetic resonance (MR) lymphangiography for nontraumatic lymphatic disorders. Five patients (2 males and 3 females; median age, 16.0 years; range, 3-74 years) who underwent both intranodal and transcatheter dynamic contrast-enhanced MR lymphangiography for suspected nontraumatic lymphatic leakages from June 2017 to January 2020 were included in this retrospective study. The imaging findings of both dynamic contrast-enhanced MR lymphangiography techniques were assessed for the presence of chylolymphatic reflux or direct sign of leakage. Intranodal dynamic contrast-enhanced MR lymphangiography demonstrated chylolymphatic reflux into the thoracic area in 2 patients (40%) but no direct evidence of leakage in any of the 5 patients. Transcatheter dynamic contrast-enhanced MR lymphangiography revealed chylolymphatic reflux and extravasation of the contrast agent in all 5 patients (100%). In conclusion, transcatheter dynamic contrast-enhanced MR lymphangiography may reveal additional signs of reflux and extravasation even when the findings of intranodal dynamic contrast-enhanced MR lymphangiography are negative.

OBJECTIVEThere has been no established animal model of syringomyelia associated with lumbosacral spinal lipoma. The research on the pathophysiology of syringomyelia has been focused on Chiari malformation, trauma, and inflammation. To understand the pathophysiology of syringomyelia associated with occult spinal dysraphism, a novel animal model of syringomyelia induced by chronic mechanical compression of the lumbar spinal cord was created.METHODSThe model was made by epidural injection of highly concentrated paste-like kaolin solution through windows created by partial laminectomy of L-1 and L-5 vertebrae. Behavioral outcome in terms of motor (Basso-Beattie-Bresnahan score) and urinary function was assessed serially for 12 weeks. Magnetic resonance images were obtained in some animals to confirm the formation of a syrinx and to monitor changes in its size. Immunohistochemical studies, including analysis for glial fibrillary acidic protein, NeuN, CC1, ED-1, and caspase-3, were done.RESULTSBy 12 weeks after the epidural compression procedure, syringomyelia formation was confirmed in 85% of the rats (34 of 40) on histology and/or MRI. The syrinx cavities were found rostral to the epidural compression. Motor deficit of varying degrees was seen immediately after the procedure in 28% of the rats (11 of 40). In 13 rats (33%), lower urinary tract dysfunction was seen. Motor deficit improved by 5 weeks after the procedure, whereas urinary dysfunction mostly improved by 2 weeks. Five rats (13%, 5 of 40) died 1 month postoperatively or later, and 3 of the 5 had developed urinary tract infection. At 12 weeks after the operation, IHC showed no inflammatory process, demyelination, or accelerated apoptosis in the spinal cords surrounding the syrinx cavities, similar to sham-operated animals.CONCLUSIONSA novel experimental model for syringomyelia by epidural compression of the lumbar spinal cord has been created. The authors hope that it will serve as an important research tool to elucidate the pathogenesis of this type of syringomyelia, as well as the CSF hydrodynamics of the lumbar spinal cord.

Benign extracerebral fluid collection (bECFC) can be complicated by subdural hematoma (SDH) or subdural fluid collection (SDFC). The etiology, natural history, and management strategy for SDH/SDFC in bECFC are not fully understood. We retrospectively reviewed the cases of bECFC patients complicated with SDH/SDFC and tried (1) to confirm the fact that bECFC children are vulnerable to SDH/SDFC, (2) to investigate the clinical significance of 'trauma history' witnessed by a caregiver, and (3) to determine optimal management for them. Among 213 bECFC patients identified from January 2000 to August 2015, 20 patients (male:female = 14:6; median age, 6.5 months; range 1–16 months) complicated by SDH/SDFC documented with brain imaging were evaluated for their clinical manifestations, radiologic features, and management outcomes. The median follow-up period was 9.5 months. They were divided into two groups (traumatic group versus non-traumatic group) according to whether objective radiologic evidence of head injury was present or not, and the two groups were analyzed for any clinical differences between them. We also evaluated the clinical significance of witnessed traumatic events by caregivers as an additional independent variable in the analysis. The incidence of SDH/SDFC in bECFC patients was 9.4% (20/213) in our data. In a comparative analysis, the traumatic group is more likely to have 'acute' stage SDH, whereas the non-traumatic group is more likely to have 'chronic' stage SDH. The trauma history witnessed by caregivers did not show clinical significance in the data analysis when included as an independent variable. The prognosis of SDH/SDFC in bECFC patients was favorable without surgery in most of patients regardless of whether the patient has evidence of head trauma or not. Benign ECFC is vulnerable to SDH/SDFC development. For the bECFC patients complicated by SDH/SDFC, the trauma history witnessed by a caregiver did not show any clinical significance. A 'wait and watch' strategy is sufficient for the management of SDH/SDFC in bECFC patients.

The clinical application of the multi-echo, multi-delay technique of synthetic magnetic resonance imaging (MRI) generates multiple sequences in a single acquisition but has mainly been used in adults. To evaluate the image quality of synthetic brain MR in children compared with that of conventional images. Twenty-nine children (median age: 6 years, range: 0–16 years) underwent synthetic and conventional imaging. Synthetic (T2-weighted, T1-weighted and fluid-attenuated inversion recovery [FLAIR]) images with settings matching those of the conventional images were generated. The overall image quality, gray/white matter differentiation, lesion conspicuity and image degradations were rated on a 5-point scale. The relative contrasts were assessed quantitatively and acquisition times for the two imaging techniques were compared. Synthetic images were inferior due to more pronounced image degradations; however, there were no significant differences for T1- and T2-weighted images in children

OBJECTIVESince the entity limited dorsal myeloschisis (LDM) was proposed, numerous confusing clinical cases have been renamed according to the embryopathogenesis. However, clinical application of this label appears to require some clarification with regard to pathology. There have been cases in which all criteria for the diagnosis of LDM were met except for the presence of a neural component in the stalk, an entity the authors call “probable” LDM. The present study was performed to meticulously review these cases and suggest that a modified surgical strategy using limited laminectomy is sufficient to achieve the surgical goal of untethering.METHODSThe authors retrospectively reviewed the imaging findings, operative notes, and pathology reports of spinal dysraphism patients with subcutaneous stalk lesions who had presented to their institution between 2010 and 2014.RESULTSAmong 33 patients with LDM, 13 had the typical nonsaccular lesions with simple subcutaneous stalks connecting the skin opening to the spinal cord. Four cases had “true” LDM meeting all criteria for diagnosis, including pathological confirmation of CNS tissue by immunohistochemical staining with glial fibrillary acidic protein. There were also 9 cases in which all clinical, imaging, and surgical findings were compatible with LDM, but the “neural” component in the resected stalk was not confirmed. For all the cases, limited exposure of the stalk was done and satisfactory untethering was achieved.CONCLUSIONSOne can speculate based on the initial error of embryogenesis that if the entire stalk were traced to the point of insertion on the cord, the neural component would be proven. However, this would require an extended level of laminectomy/laminotomy, which may be unnecessary, at least with regard to the completeness of untethering. Therefore, the authors propose that for some selected cases of LDM, a minimal extent of laminectomy may suffice for untethering, although it may be insufficient for diagnosing a true LDM.

Computed tomography (CT) has generated public concern associated with radiation exposure, especially for children. Lowering the tube voltage is one strategy to reduce radiation dose. To assess the image quality and radiation dose of non-enhanced brain CT scans acquired at 80 kilo-voltage peak (kVp) compared to those at 120 kVp in children. Thirty children who had undergone both 80- and 120-kVp non-enhanced brain CT were enrolled. For quantitative analysis, the mean attenuation of white and gray matter, attenuation difference, noise, signal-to-noise ratio, contrast-to-noise ratio and posterior fossa artifact index were measured. For qualitative analysis, noise, gray-white matter differentiation, artifact and overall image quality were scored. Radiation doses were evaluated by CT dose index, dose-length product and effective dose. The mean attenuations of gray and white matter and contrast-to-noise ratio were significantly increased at 80 kVp, while parameters related to image noise, i.e. noise, signal-to-noise ratio and posterior fossa artifact index were higher at 80 kVp than at 120 kVp. In qualitative analysis, 80-kVp images showed improved gray-white differentiation but more artifacts compared to 120-kVp images. Subjective image noise and overall image quality scores were similar between the two scans. Radiation dose parameters were significantly lower at 80 kVp than at 120 kVp. In pediatric non-enhanced brain CT scans, a decrease in tube voltage from 120 kVp to 80 kVp resulted in improved gray-white matter contrast, comparable image quality and decreased radiation dose.

Purpose Kaposiform hemangioendothelioma (KHE) is a rare, aggressive vascular tumor that typically occurs during infancy or early childhood. Though several case reports have discussed the imaging findings of KHE, larger comprehensive studies are lacking. The purpose of this study was to evaluate the imaging findings of KHE in children. Materials and methods A total of twelve cases of pathologically proven KHE were collected by searching our institution’s pathology database for children diagnosed between January 2004 and April 2016 (6 male, 6 female; median age: 3 months; age range 7 days − 18 years). CT (n = 7) and MRI (n = 9) findings were retrospectively evaluated. The location, morphology, enhancement, and growth pattern were analyzed. Results KHEs involved various locations: superficial or deep soft tissue of the extremities (n = 4); abdomen (n = 3; 2 cases, pancreas; 1 case, small bowel), neck and mediastinum (n = 1); chest wall, diaphragm, and pericardium (n = 1); abdominal wall (n = 1); and head (IAC, CP angle) (n = 2). Eight of 10 cases (80%) with CT/MR findings were locally invasive and involved two or more adjacent organs. Three cases presented as well-defined solid masses, and seven were associated with infiltrative lesions of the surrounding areas with (n = 4) or without definite solid regions (n = 3). In nine patients with MRI, all KHEs were heterogeneous and hyperintense to muscles on T2-weighted images (T2WI), while four KHEs consisted of some regions that were nearly isointense to muscle. Eight of the 10 cases with imaging exhibited heterogeneous intense enhancement, while only one demonstrated mild enhancement. Signal voids (n = 2), engorged vessels (n = 1), calcification (n = 3), hemorrhage (n = 1), or bone changes (n = 4) were infrequently observed. Four patients (33%) had Kasabach-Merritt phenomenon, and recurrence was observed in two cases. Conclusion KHEs occurred in various locations, affected mostly infants, and generally exhibited intense heterogeneous enhancement. In more than half of the included cases, KHEs were highly infiltrative and locally invasive with ill-defined margins. Awareness of these features should prompt radiologists to include KHE in the differential diagnosis for pediatric masses.

To evaluate the clinical usefulness of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) in children and young adults with Crohn's disease.From August 2017 to October 2018, 30 patients with Crohn's disease (21 males and 9 females; mean age 15.1 ± 2.5 years) underwent DCE-MRI with MRI enterography. We assessed the endoscopic finding, pediatric Crohn's disease activity index (PCDAI), C-reactive protein (CRP) level (mg/dL), Crohn's disease MR index (CDMI) score, and the perfusion parameters of DCE-MRI (KThe active Crohn's disease group showed higher PCDAI, CRP, and CDMI scores than the inactive group (22.2 ± 18.8 vs. 6.3 ± 6.4, p = 0.027; 1.32 ± 1.79 vs. 0.10 ± 0.13, p = 0.005; 7.4 ± 3.9 vs. 4.5 ± 3.0, p = 0.047, respectively). The active Crohn's disease group showed a higher KK• With dynamic contrast-enhanced MRI, we can quantitatively monitor the Crohn's disease status in pediatric patients and provide proper management plans to clinicians. • The K

The aim of this study was to evaluate the diagnostic performance of shear wave elastography (SWE) in human meniscus degeneration, with histology serving as the standard of reference. This comparative in vivo and ex vivo study was performed in 15 medial and 15 lateral menisci from 13 patients undergoing total knee arthroplasty (TKA) for primary osteoarthritis with varus deformity. Patients underwent in vivo coronal measurement with SWE for meniscus before surgery. Then, ex vivo assessment of meniscus stiffness with SWE was performed with the tissue obtained after TKA. SWE measurements were made in coronal and sagittal views with respect to the meniscus. Samples were analyzed histologically on a 0-18 scale according to the level of degeneration based on surface integrity, cellularity, fiber organization, collagen alignment and Safranin O staining intensity. The correlation between SWE measurement scale and histology was analyzed using Spearman's correlation. The area under the receiver operating characteristic curve (AUROC) was used to calculate the diagnostic performance of SWE in evaluating meniscus degeneration. Significant increases in stiffness were observed with increasing histologic degeneration in both in vivo and ex vivo coronal SWE. AUROCs were 0.79 (95% confidence interval [CI]: 0.49-1.00) for in vivo coronal SWE, 0.73 (95% CI: 0.53-0.95) for ex vivo coronal SWE and 0.56 (95% CI: 0.27-0.84) for ex vivo sagittal SWE. The medial meniscus, which exhibited more degeneration on histologic analysis, had greater stiffness than the lateral meniscus on ex vivo coronal SWE. The values of meniscus stiffness measured with SWE are correlated with the degree of meniscus degeneration. Further large-scale prospective studies may confirm the diagnostic performance of SWE as a non-invasive tool to assess meniscus degeneration.

To evaluate the image quality of a double-low protocol (low tube voltage and low iodine concentration) for abdominal CT in children. The double-low protocol was compared to the conventional protocol in pediatric patients weighing less than 40 kg from May 2016 to December 2016. Double-low protocol (Group A, n = 18): tube voltage, 70 kVp; and iodine concentration,: 250 mgI/mL versus Conventional protocol (Group B, n = 13): tube voltage, 80–100 kVp; and iodine concentration, 350 mgI/mL. Mean attenuation, noise, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) were compared between the two groups. Image contrast, noise, beam-hardening artifacts, and overall image quality were subjectively scored. Reader performance for correctly differentiating two groups by visual assessment was evaluated. Radiation dose and total iodine load were recorded. The mean attenuations of the portal vein and liver and the mean image noise in Group A were higher than in Group B (p = 0.04, 0.03, 0.004, respectively). The mean SNR and CNR of the main portal vein and liver were lower in Group A without any statistically significant difference. There were no statistically significant differences between the two groups in qualitative analysis (image contrast, image noise, and overall image quality) with substantial agreement between the reviewers (weighted kappa values; 0.59–0.76). Significantly diminished radiation dose and iodine load were observed in Group A compared with Group B (25.0%, 36.8% reduction; p = 0.007, 0.006, respectively). The double-low protocol was feasible for pediatric abdominal CT and reduced both radiation dose and iodine load, while maintaining image quality.

Background Autonomic nervous system dysfunction is implicated in the development of hypothalamic obesity. We investigated the relationship between hypothalamic involvement (HI), central obesity, and cardiac autonomic dysfunction by assessing heart rate variability (HRV) indices in patients with childhood-onset craniopharyngioma. Methods A cross-sectional study of 48 patients (28 males, 10–30 years old) with hypothalamic damage after childhood-onset craniopharyngioma was performed. Postoperative HI was graded as mild (n = 19) or extensive (n = 29) on magnetic resonance imaging. Anthropometry, body composition and HRV indices including the standard deviation of all normal R-R intervals (SDNN) and total power (TP) as overall variability markers, root-mean square differences of successive R-R intervals (RMSSD) and high frequency (HF) as parasympathetic modulation markers, and low frequency (LF) as a sympathetic/sympathovagal modulation marker were measured. Results Patients with extensive HI had increased means of body mass index, waist circumference, and fat mass than those with mild HI (P < 0.05, for all). Centrally obese patients had a lower mean HF, a parasympathetic modulation marker, than centrally non-obese patients (P < 0.05). The extensive HI group had lower means of overall variability (SDNN and TP), parasympathetic modulation (HF), and sympathetic/sympathovagal modulation (LF) than the mild HI group (P < 0.05, for all). The interaction effect of HI and central obesity on HRV indices was not significant. In models adjusted for age, sex, and family history of cardiometabolic disease, the means of the overall variability indices (P < 0.05 for both SDNN and TP) and a sympathetic/sympathovagal modulation index (P < 0.05 for LF) were lower with extensive HI, without differences according to central obesity. Conclusions The reduced HRV indices with extensive HI suggests that hypothalamic damage may contribute to cardiac autonomic dysfunction, underscoring the importance of minimizing hypothalamic damage in patients with childhood-onset craniopharyngioma.

OBJECTIVE: To assess the role of arterial spin-labeling (ASL) perfusion MRI in identifying cerebral perfusion changes after indirect revascularization in children with moyamoya disease. MATERIALS AND METHODS: We included pre- and postoperative perfusion MRI data of 30 children with moyamoya disease (13 boys and 17 girls; mean age ± standard deviation, 6.3 ± 3.0 years) who underwent indirect revascularization between June 2016 and August 2017. Relative cerebral blood flow (rCBF) and qualitative perfusion scores for arterial transit time (ATT) effects were evaluated in the middle cerebral artery (MCA) territory on ASL perfusion MRI. The rCBF and relative time-to-peak (rTTP) values were also measured using dynamic susceptibility contrast (DSC) perfusion MRI. Each perfusion change on ASL and DSC perfusion MRI was analyzed using the paired t test. We analyzed the correlation between perfusion changes on ASL and DSC images using Spearman's correlation coefficient. RESULTS: The ASL rCBF values improved at both the ganglionic and supraganglionic levels of the MCA territory after surgery (p = 0.040 and p = 0.003, respectively). The ATT perfusion scores also improved at both levels (p < 0.001 and p < 0.001, respectively). The rCBF and rTTP values on DSC MRI showed significant improvement at both levels of the MCA territory of the operated side (all p < 0.05). There was no significant correlation between the improvements in rCBF values on the two perfusion images (r = 0.195, p = 0.303); however, there was a correlation between the change in perfusion scores on ASL and rTTP on DSC MRI (r = 0.701, p < 0.001). CONCLUSION: Recognizing the effects of ATT on ASL perfusion MRI may help monitor cerebral perfusion changes and complement quantitative rCBF assessment using ASL perfusion MRI in patients with moyamoya disease after indirect revascularization.

Purpose To assess the usefulness of the relative position of the superior mesenteric artery (SMA) and superior mesenteric vein (SMV) in diagnosing intestinal malrotation in situs anomaly. Materials and methods From January 2004 to April 2015, 33 patients with situs anomalies were enrolled in this study who underwent abdominal USG, CT or MRI as well as upper gastrointestinal series (UGIS) or surgery: situs inversus (n = 16), left isomerism (n = 10), and right isomerism (n = 7); age 21.2 ± 23.2 years (mean ± standard deviation), range 0–72 years. The intestinal malrotation was confirmed with UGIS and/or operation in 16 patients. Relative positions of the SMV to the SMA were classified into four groups by reviewing abdominal USG, CT, or MRI: right sided, left sided, ventral sided, and dorsal sided. The incidence of malrotation was analyzed for each group. Results In 16 patients with situs inversus, there was reversed SMA-SMV relationship: left sided (n = 11) or ventral sided (n = 5). One situs inversus patient with ventral sided SMV had intestinal malrotation (6.25%). 17 patients with situs ambiguus showed various SMA-SMV relationships (ventral sided, n = 7; left sided, n = 5; right sided, n = 4; dorsal sided, n = 1). Among them, 15 patients (88.2%) had intestinal malrotation. Two patients with normal rotation had either right sided or dorsal sided SMV. Conclusion Situs ambiguus was commonly associated with intestinal malrotation with a variable SMA-SMV relationship. Reversal of the mesenteric vascular relationship was observed in situs inversus with normal rotation, not excluding the possibility of intestinal malrotation.

To evaluate the changes in using patterns of brain magnetic resonance imaging (MRI) in preterm infants after introduction of a MR-compatible incubator coil system.Brain MRIs for preterm infants with the MR-compatible incubator coil from March 2010 to July 2014 (n=154, group A) were compared with MRIs prior to the introduction of the incubator coil, from March 2005 to February 2010 (n=65, group B). Clinical data, MRI findings, acquisition time, and incidence of adverse events during the study were retrospectively reviewed. For the qualitative analysis of the examinations, the presence of motion artefact, spatial resolution, and overall image quality were assessed. Signal uniformity of each sequence was evaluated for a quantitative comparison.Comparing with group B, Group A was significantly younger (36+3 vs. 38+3 weeks, p0.001), had a significantly lower body weight (2006.6 and 2390.3g respectively; p0.001) at the time of MRI, and had shorter time interval (54.3±2.6 vs. 70.5±4.4days, p=0.002) between birth and examination. Abnormal findings were noted more frequently in group A (n=100, 65%) than in B (n=24, 37%. p=0.001) with a significantly higher incidence of diffusion restriction (n=21, 13.6% vs. n=4, 6.2%, p=0.034). Mean image acquisition time was significantly shorter in group A (21.4±4.5 vs. 25.4±5.5min, p0.001) with significant lower adverse events during MRI (n=26, 40 vs. n=6, 3.9%, p0.001). Group A exhibited significantly less motion artefact, better spatial resolution, and better overall image quality with decreased signal variation than group B (all p0.001).Application of the MR-compatible incubator for preterm brain MRI evaluation is safer and provides more timely evaluation of preterm infants with better image quality.

To evaluate the ultrasonography (US) features of Alagille syndrome (ALGS), as compared with biliary atresia (BA) or neonatal hepatitis (NH).Our study included 23 ALGS, 75 BA and 70 NH patients. The initial US images were retrospectively reviewed for gallbladder (GB) morphology with systemic classification, GB length and luminal area, presence of triangular-cord (TC) sign and hypertrophied hepatic-artery. The presence of anomalies associated with ALGS was evaluated. The diagnostic values of each finding and their combinations were evaluated.Both ALGS (57%) and BA (79%) were more frequently associated with abnormal GB shapes than NH (19%, all P0.001). The short and small GBs were more frequently observed in ALGS and BA than in NH (all P0.001). None in the ALGS and NH showed TC sign, while 41% in the BA did (all P0.001). Hypertrophied hepatic-artery was noted less frequently in both ALGS (13%) and NH (14%) than in BA (83%, all P0.001). The combination of US criteria with associated anomalies increased the positive-predictive-value for ALGS.Abnormal shaped GB with absence of the TC sign and hypertrophied hepatic-artery and presence of associated anomalies can be a differential point of ALGS.

Spondylodiscitis (SD) is a rare disease in children and diagnosis can be delayed because of the scarcity in incidence and lack of awareness. The purpose of this study was to evaluate and report the microbiologic epidemiology and clinical features of pediatric SD in South Korea.This was a retrospective study of children19 years old admitted for the treatment of SD between 2000 and 2014. Electronic medical records were reviewed for clinical parameters and etiologic agents.During the 15-year period, 25 patients were diagnosed with SD. The median age was 13.8 years, and 60% were male. Back pain was the most common presenting symptom (n = 17; 68%), and only 52% (n = 13) of the patients had a history of fever (≥38.0°C). In patients younger than 3 years, irritability (n = 5; 62.5%) was the most predominant symptom. Microorganisms were isolated in 22 cases, the most common being Staphylococcus aureus (40%) and Mycobacterium tuberculosis (32%). Of the 25 patients, 64% (n = 16) had blood cultures taken, 56% (n = 14) underwent percutaneous fluoroscopy-guided biopsy, and 48% (n = 12) underwent open surgical biopsy. The positive rate for microbiologic diagnosis of each method was 18.8% (n = 3) for blood culture, 71.4% (n = 10) for percutaneous biopsy and 100% (n = 12) for surgical biopsy. Overall, 52% (n = 13) needed surgical treatment along with antibiotic therapy. Patients who needed surgery had a significant delay in diagnosis compared with those that did not (median, 60 vs. 31 days; P = 0.014).S. aureus and M. tuberculosis are the predominant causes of SD in children in South Korea. Obtaining tissue culture is important to confirm the bacterial etiology of the infection and appropriately guide antibiotic therapy in a community in which the endemic organisms require treatment pathways that are widely divergent.

It is difficult to diagnosis early stage germ cell tumors originating in the basal ganglia, but early recognition is important for better outcome. To evaluate serial MR images of basal ganglia germ cell tumors, with emphasis on the features of early stage tumors. We retrospectively reviewed serial MR images of 15 tumors in 14 children and young adults. We categorized MR images of the tumors as follows: type I, ill-defined patchy lesions (

Objective To evaluate the incidence and risk factors of emetic complications associated with the intravenous administration of low-osmolality iodinated contrast media (ICM) in children undergoing computed tomography (CT). Materials and methods All children who underwent contrast-enhanced CT between April 2017 and July 2019 were included. Pediatric patients were instructed on the preparative dietary protocol at our institution. Experienced nurses in the radiology department monitored the children during the CT scans and recorded any emetic complications in their electronic medical records. These data were used to calculate the incidence of emetic complications. Various patient factors and technical factors, including fasting duration, the type and volume of ICM, and ongoing chemotherapy, were evaluated to identify risk factors for emetic complications using univariate and multivariate logistic regression analyses. Results Among the 864 children (mean age, 8.4 ± 5.7 years) evaluated, 18 (2.1%) experienced emetic complications (6 experienced nausea only and 12 experienced nausea and vomiting). None of the children developed aspiration pneumonia. The mean fasting duration of patients with emesis was 7.9 ± 5.7 hours (range, 3-21 hours), whereas that of patients without nausea was 8.7 ± 5.7 hours (range, 0-24 hours). Fasting duration was not associated with the development of nausea and vomiting (p = 0.634). Multivariate logistic regression analysis revealed that ongoing chemotherapy (odds ratio [OR] = 4.323; 95% confidence interval [CI] = 1.430-13.064; p = 0.009), iomeprol use (OR = 7.219; 95% CI = 1.442-36.146; p = 0.016), and iohexol use (OR = 5.241; 95% CI = 1.350-20.346; p = 0.017) were independent risk factors for emetic complications. Conclusion Only a small proportion (2.1%) of children experienced nausea or vomiting after exposure to low-osmolality ICM. Many children underwent excessive fasting; however, fasting duration was not associated with nausea and vomiting. Moreover, ongoing chemotherapy and the use of iomeprol or iohexol were identified as potential risk factors for emetic complications in children.

High-dose chemotherapy (HDC) and autologous stem-cell transplantation (auto-SCT) are used to improve the survival of children with high-risk brain tumors who have a poor outcome with the standard treatment. This study aims to evaluate the outcome of HDC/auto-SCT with topotecan–thiotepa–carboplatin and melphalan–etoposide–carboplatin (TTC/MEC) regimens in pediatric brain tumors. We retrospectively analyzed the data of 33 children (median age 6 years) who underwent HDC/auto-SCT (18 tandem and 15 single) with uniform conditioning regimens. Eleven patients aged

The purpose of this study is to compare DWI for pediatric brain evaluation using single-shot echo-planar imaging (EPI), periodically rotated overlapping parallel lines with enhanced reconstruction (Blade), and readout-segmented EPI (Resolve).Blade, Resolve, and single-shot EPI were performed for 27 pediatric patients (median age, 9 years), and three datasets were independently reviewed by two radiologists. Qualitative analyses were performed for perceptive coarseness, image distortion, susceptibility-related changes, motion artifacts, and lesion conspicuity using a 5-point Likert scale. Quantitative analyses were conducted for spatial distortion and signal uniformity of each sequence.Mean scores were 2.13, 3.17, and 3.76 for perceptive coarseness; 4.85, 3.96, and 2.19 for image distortion; 4.76, 3.96, and 2.30 for susceptibility-related change; 4.96, 3.83, and 4.69 for motion artifacts; and 2.71, 3.75, and 1.92 for lesion conspicuity, for Blade, Resolve, and single-shot EPI, respectively. Blade and Resolve showed better quality than did single-shot EPI for image distortion, susceptibility-related changes, and lesion conspicuity. Blade showed less image distortion, fewer susceptibility-related changes, and fewer motion artifacts than did Resolve, whereas lesion conspicuity was better with Resolve. Blade showed increased signal variation compared with Resolve and single-shot EPI (coefficients of variation were 0.10, 0.08, and 0.05 for lateral ventricle; 0.13, 0.09, and 0.05 for centrum semiovale; and 0.16, 0.09, and 0.06 for pons in Blade, Resolve, and single-shot EPI, respectively).DWI with Resolve or Blade yields better quality regarding distortion, susceptibility-related changes, and lesion conspicuity, compared with single-shot EPI. Blade is less susceptible to motion artifacts than is Resolve, whereas Resolve yields less noise and better lesion conspicuity than does Blade.

The purpose of this study was to evaluate the usefulness of radially sampled 3D fat-suppressed T1-weighted gradient-echo sequences (radial volumetric interpolated breath-hold examination [radial VIBE]) for contrast-enhanced brain MRI of children through comparison with a magnetization-prepared rapid-acquisition gradient-echo (MP-RAGE) sequence.Sixty-five consecutive contrast-enhanced brain MRI examinations performed with axial MP-RAGE and radial VIBE sequences were included. For quantitative analysis, coefficients of variation of gray matter and white matter and CSF and relative contrast between tissue types (gray matter and white matter, gray matter and CSF, and white matter and CSF) for each sequence were calculated. For qualitative assessment, motion, pulsation artifacts, overall image quality, and lesion conspicuity were retrospectively scored on a 5-point scale. Quantitative and qualitative subgroup analyses were performed for patients with serious motion artifacts.Images obtained with the radial VIBE sequence had fewer motion and pulsation artifacts than those obtained with the MP-RAGE sequence (MP-RAGE vs radial VIBE motion score, 3.57 ± 1.00 vs 4.52 ± 0.51; pulsation score, 3.57 ± 0.60 vs 4.91 ± 0.21; all p0.001). Among 25 images with serious motion artifacts, radial VIBE images had significantly higher scores for all qualitative parameters, including overall image quality, than did MP-RAGE images (overall image quality for MP-RAGE vs radial VIBE, 2.63 ± 0.82 vs 3.42 ± 0.55, p0.001).The study showed that a radial fat-suppressed T1-weighted gradient-echo sequence is a viable alternative to conventional cartesian acquisition for contrast-enhanced brain imaging of restless children.

Haploidentical hematopoietic stem cell transplantation (haplo-HSCT) with post-transplantation cyclophosphamide (PTCy) was performed previously in adults using a nonmyeloablative conditioning regimen and bone marrow as a graft source. In an effort to reduce relapse rates, myeloablative conditioning regimens with higher intensities are now used. We used an intensive daily pharmacokinetic monitoring method for busulfan dosing in children for effective myeloablation and to reduce toxicity. Here, we report the retrospective results of 34 patients (median age 11.1 years) who underwent haplo-HSCT with PTCy using a targeted busulfan-based myeloablative conditioning regimen and peripheral blood as a stem cell source. The donor-type neutrophil engraftment rate was 97.1%, and the cumulative incidence rates of grade II to IV and grade III to IV acute and extensive chronic graft-versus-host disease were 38.2%, 5.9%, and 9.1%, respectively. The overall survival and event-free survival rates, and treatment-related mortality were 85.0%, 79.4%, and 2.9%, respectively. Based on the subgroup analysis of patients with malignancies (n = 23), the relapse incidence rate was 21.7%. Haplo-HSCT using PTCy with targeted busulfan-based myeloablative conditioning and peripheral blood as a stem cell source was a safe and promising therapeutic option for children.

BACKGROUND AND PURPOSE: For the postoperative follow-up in pediatric patients with Moyamoya disease, it is essential to evaluate the degree of neovascularization status. Our aim was to quantitatively assess the neovascularization status after bypass surgery in pediatric Moyamoya disease by using color-coded digital subtraction angiography. MATERIALS AND METHODS: Time-attenuation intensity curves were generated at ROIs corresponding to surgical flap sites from color-coded DSA images of the common carotid artery, internal carotid artery, and external carotid artery angiograms obtained pre- and postoperatively in 32 children with Moyamoya disease. Time-to-peak and area under the curve values were obtained. Postoperative changes in adjusted time-to-peak (ΔTTP) and ratios of adjusted area under the curve changes (ΔAUC ratio) of common carotid artery, ICA, and external carotid artery angiograms were compared across clinical and angiographic outcome groups. To analyze diagnostic performance, we categorized clinical outcomes into favorable and unfavorable groups. RESULTS: The ΔTTP at the common carotid artery increased among clinical and angiographic outcomes, in that order, with significant differences ( P = .003 and .005, respectively). The ΔAUC ratio at the common carotid artery and external carotid artery also increased, in that order, among clinical and angiographic outcomes with a significant difference (all, P = .000). The ΔAUC ratio of ICA showed no significant difference among clinical and angiographic outcomes ( P = .418 and .424, respectively). The ΔTTP for the common carotid artery of >1.27 seconds and the ΔAUC ratio of >33.5% for the common carotid artery and 504% for the external carotid artery are revealed as optimal cutoff values between favorable and unfavorable groups. CONCLUSIONS: Postoperative changes in quantitative values obtained with color-coded DSA software showed a significant correlation with outcome scores and can be used as objective parameters for predicting the outcome in pediatric Moyamoya disease, with an additional cutoff value calculated through the receiver operating characteristic curve.

The purpose of this study was to compare wide-volume and helical pediatric 320-MDCT of the chest with respect to radiation dose and image quality.From November 2012 to September 2013, 59 wide-volume and 47 helical pediatric chest 320-MDCT images were obtained. The same tube potential and effective tube current-time product were applied in the two groups according to patient weight (group A,10 kg, n = 18; group B, 10-19.9 kg, n = 60; group C, 20-39.9 kg, n = 28). To compensate for overranging, adjusted CT dose index (CTDI) was calculated by dividing dose-length product (DLP) by the scan ranges imaged. Adjusted CTDI, DLP, overall image quality, motion artifact, noise, and scan ranges were compared by Mann-Whitney U test or t test.The adjusted CTDI was significantly lower in the group who underwent wide-volume CT than in the group who underwent helical CT (weight group A, p0.001; group B, p0.001; group C, p = 0.003). The DLP was lower in the wide-volume group than in the helical CT group in weight groups A (p0.001) and B (p0.001) but not in group C (p = 0.162). All CT scans were of diagnostic quality, and there was no significant difference between the wide-volume and helical CT groups (p = 0.318). The motion artifact score was significantly higher in the wide-volume group than in the helical CT group in groups B (p0.001) and C (p = 0.010) but not in group A (p = 0.931). The noise was significantly lower in the wide-volume group than in the helical CT group (p0.001).In pediatric chest CT, use of wide-volume CT can decrease radiation exposure while preserving image quality. It is associated with less noise than helical CT but may be subject to more motion artifact.

This study aimed to assess the therapeutic results of ultrasound (US)-guided water-soluble contrast enema in very low birth weight (VLBW) preterm infants (1,500 g) with meconium obstruction and to study factors that affect therapeutic results.This study included a total of 33 consecutive VLBW infants with clinically diagnosed meconium obstruction underwent US-guided water-soluble contrast enema, from April 2007 to March 2014. Patients were classified into two groups based on to procedure outcome: the success group (evacuation of the meconium plug resolution followed by improved bowel distention within 2 days of the procedure, without additional interventions), and the failure group (the contrast enema failed to relieve the obstruction, or other procedure-related complications occurred). Patient- and mother-related clinical factors and procedure-related factors were compared between both groups.Overall success rate was 54.5%, with 18 successful (M:F=10:8), and 15 failure (M:F=7:8) cases. When compared with the failure group, the success group patients showed statistically significant older gestational age (29(+1) vs. 27 weeks; p=0.028), larger birth weight (1023.1g vs. 790.3g; p=0.048), and higher body weight on the day of the procedure (1036.2g vs. 801.6g, p=0.049). However, no statistically significant differences were seen between other patient and maternal factors. Among the procedure-related factors, retrial of contrast injection during the procedure was associated with significantly higher success than the single trial (p=0.027). The presence of refluxed contrast into the distal ileum was the statistically significant predictor for success of the procedure (p=0.038). There were three cases of bowel perforation (9.1% per person).US-guided water-soluble contrast enema in VLBW infants with meconium obstruction showed a 54.5% success rate and a 9.1% perforation rate per person. Among the procedure-related factors, retrial of contrast injection during the procedure and the presence of refluxed contrast into the distal ileum were related to the success of the procedure.

Objectives To analyze the texture features on cranial sonography in preterm neonates with white matter injury quantitatively and to correlate these features with magnetic resonance imaging (MRI). Methods The study included 33 preterm neonates treated in our neonatal intensive care unit who underwent serial cranial sonography and brain MRI near term. Patients were subdivided into 3 groups according to the presence and severity of white matter injury as revealed by MRI: normal (group 1; n = 20), mild (group 2; n = 5), and severe (group 3; n = 8). The periventricular echogenicity on sonography was evaluated quantitatively with second-order gray-level statistics (gray-level co-occurrence matrix [GLCM] method). Four GLCM texture features representing homogeneity were extracted in 12 directions: (1) angular second moment (ASM), (2) inverse differential moment (IDM), (3) contrast, and (4) entropy. Results Thirty of 48 features showed a statistically significant difference between groups 1 and 3 (ASM in 9 directions, IDM in 6 directions, contrast in 3 directions, and entropy in all 12 directions). There were no significant differences observed between groups 1 and 2 or groups 2 and 3. The mean contrast and entropy values were generally lower in group 1 than group 3, whereas the mean ASM and IDM values were higher in group 1. Conclusions Severe white matter injury could be identified by using GLCM texture analysis, whereas mild white matter injury observed on MRI could not be evaluated by GLCM analysis. Quantitative texture analysis using the GLCM may serve as a complementary tool for quantitative assessment of periventricular echogenicity.

Introduction The location of a brain tumor is a fundamental characteristic, because various brain tumors develop in relatively specific locations. An atypical teratoid/rhabdoid tumor (AT/RT) is a highly age-specific tumor that occurs in infants and young children. However, AT/RTs develop in a variety of locations in the brain. This study aimed at uncovering the tumor location pattern of AT/RTs to enhance diagnoses. Material and methods Neuroimages from 27 patients with a pathologically proven AT/RTwere reviewed, and the specific tumor locations were described and categorized. The association of imaging characteristics and tumor location was analyzed. Results The posterior fossa was the most frequent locations accounting for 19 patients (70 %), followed by the diencephalon (four patients; 15 %), cerebrum (three patients; 11 %), and midbrain (one patient; 4 %). In the posterior fossa, the superior medullary velum (SMV) and cerebellopontine angle (CPA) areas were the most common sites (eight patients each) and three patients had a tumor in the inferior medullary velum (IMV) region. AT/RTs in the SMV area had a significantly higher chance of no/minimal enhancement compared with tumors in other locations (P=0.001) and a lower likelihood of leptomeningeal tumor seeding at presentation (P=0.053). Conclusion Thelocationspectrum of AT/RT follows a specific pattern, and some of the locations are linked with intriguing clinical characteristics. This information may not only help make correct preoperative diagnosis but also occasionally aid in postoperative pathological diagnosis.