Clinical and Radiological Correlation of Low Flow Vascular Malformation Treated With Percutaneous Sclerotherapy

Objective: To retrospectively correlate imaging findings post-sclerotherapy of low-flow vascular malformations with clinical outcome. Materials and Methods: We retrospectively evaluated 81 pediatric patients who had sclerotherapy in our department over a 14-year period. Patients with a diagnosis of low-flow vascular malformation, pre and post-treatment ultrasound (US) and clinical follow-up evaluation were included in the study. Exclusion criteria were coexisting high-flow vascular malformations, history of additional surgical or medical treatment to their malformation and large infiltrative lesions difficult to measure on US. Pre and post-treatment sonographic volumes of the malformation were assessed. Changes in volume were categorized into 6- increased volume, stable and volume decrease of 1-25%/26-50%/51-75%/75-100%. Clinical outcomes were categorized into 4 - worse, no change, improved and symptom free. In cases where pre-treatment MRI was available, the estimated malformation volumes in both modalities were correlated using Spearman's rank correlation. The change in sonographic volume was correlated with clinical outcome using Spearman's rank correlation. P-values < .05 were considered significant. Results: Twenty-nine patients were included in the study; 13 with venous malformation (VM), and 16 with lymphatic malformation (LM). Nineteen patients had both pre-treatment US and MRI, showing correlation in volume between the 2 modalities (P < .001). Post-treatment change in volume correlated with clinical outcome for combined venous and LMs (rho = .44, P = .02). No correlation was found when venous (rho = .48, P = .09) and lymphatic (rho = .33, P = .21) malformations were considered separately. Conclusion: Ultrasound can potentially be used as an objective tool in evaluating sclerotherapy treatment response of low-flow vascular malformations in the pediatric population.

Is Oral Contrast Beneficial for Visualization of the Appendix in Low-Weight Children?

Purpose: It has been shown that oral contrast does not improve the diagnostic accuracy of Computed Tomography (CT) for appendicitis in pediatric patients; however, the cohorts in these studies were not stratified by weight or body mass index. The purpose of this study is to assess the benefit of oral contrast administration for identifying the appendix in younger children in the lower weight quartile. Materials and Methods: This retrospective study comprised 100 patients (2-10 years) in lower weight quartile who had intravenous contrast-enhanced CT of the abdomen and pelvis, 37 of which with oral contrast, and 63 without. A pediatric radiologist and a pediatric radiology fellow independently assessed whether the appendix was visualized or not. In case of discrepancy, an additional pediatric radiologist was the "tie-breaker." Chi-squared test was used to compare the proportion of visualized appendix between the groups (with and without oral contrast). Inter-rater reliability was determined using Cohen's Kappa coefficient. Results: There was no significant difference in the visualization of the appendix between the group with oral contrast and without (P = 1). The Cohen Kappa coefficients were .33 (.05, .62) and .91 (.73, 1.00) for the "no oral" and "oral" groups, respectively, yielding evidence of a difference (P = .007). Conclusions: There was no significant difference in the visualization of the appendix using CT with or without oral contrast in low-weight pediatric patients. The inter-rater reliability, however, was significantly higher in the group given oral contrast. Additional studies assessing the value of oral contrast for the sole indication of appendicitis may provide clearer results.

The utility of post-biopsy ultrasonography in detecting complications after percutaneous liver biopsy in children

BACKGROUND

Surveillance post image-guided percutaneous liver biopsy in children is variable.

OBJECTIVE

The aim of this study was to assess the value of 4-6-h post-procedure ultrasonography (US) in detecting post-liver-biopsy hemorrhage.

MATERIALS AND METHODS

This prospective study included pediatric patients who underwent US-guided percutaneous liver biopsies. All children had a US study obtained pre-procedure and one obtained 4-6 h post-procedure; US examinations were deemed positive if abnormalities were present. We also reviewed any subsequent imaging that was performed within 7 days (late imaging) at the discretion of the referring team. Changes in US findings (ΔUS) were graded by two radiologists using a descriptive non-validated scale (none, minimal, marked). Hemoglobin (Hb) levels were assessed pre-procedure and 4 h post-procedure. The diagnostic accuracy of US changes for detecting post-procedural hemorrhage was calculated based on a drop in Hb >1.5 g/dL or Hb >15% from baseline (ΔHb). We used a Kruskal-Wallis test to correlate the ΔHb with ΔUS. Association between late-imaging and post-procedure US findings was tested using a chi-square test. We included 224 biopsies.

RESULTS

The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of post-procedure US in detecting post-procedure hemorrhage ranged 26.3-42.1%, 72.4-93.3%, 0.22-0.42, and 0.87-0.88, respectively. No significant association was seen between the ΔHb and sonographic findings (P=0.068). No significant difference was seen in the need for late imaging between children who did and those who did not have positive US findings (P=0.814).

CONCLUSION

The sensitivity and PPV of post-procedure US in detecting post-procedural hemorrhage are low. Our findings do not support routine post-procedure surveillance US.

Whole-Body Diffusion-Weighted MRI Compared to 18 FFDG PET/CT in Initial Staging and Therapy Response Assessment of Hodgkin Lymphoma in Pediatric Patients

PURPOSE

The aim of our study was to compare whole-body diffusion-weighted MRI (WB-DWI-MRI) to fluoro-2-deoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) in the assessment of initial staging and treatment response in pediatric patients with Hodgkin lymphoma.

MATERIALS AND METHODS

This prospective study comprised 11 children with Hodgkin lymphoma. Whole-body DWI-MRI and FDG-PET/CT were obtained at baseline and after 2 cycles of chemotherapy. Two radiologists measured the apparent diffusion coefficient (ADC) values of the sites of involvement agreed upon in consensus and 1 nuclear medicine physician assessed the PET/CT. Reliability of radiologists' ratings was assessed by intraclass correlation coefficients (ICC_2,1). The sensitivity and positive predictive value (PPV) of DW-MRI relative to PET/CT were calculated for nodal and extranodal sites. The patients were staged according to both modalities. Association of treatment responses was assessed through the Pearson correlation between the ADC ratios and the change standardized uptake value (SUV) between baseline and follow-up.

RESULTS

There was good agreement between the raters for nodal and extranodal ADC measurements. The sensitivity and PPV of DW-MRI relative to PET/CT of nodal disease was 0.651 and 1.0, respectively, at baseline, and 0.697 and 0.885 at follow-up. The sensitivity and PPV of extranodal disease were 0.545 and 0.6 at baseline, and 0.167 and 0.333 at follow-up. Diffusion-weighted MRI determined correct tumor stage in 8 of 11 examinations. There was poor correlation between the ADC ratios and the absolute change in SUV between baseline and follow-up (0.348).

CONCLUSION

Our experience showed that WB-DWI-MRI is inferior to PET/CT for initial staging and assessment of treatment response of Hodgkin lymphoma in pediatric patients.

Non-visualization of the ovaries on pediatric transabdominal ultrasound with a non-distended bladder: Can adnexal torsion be excluded?

BACKGROUND

The pediatric reproductive organs are optimally imaged with a full bladder. The filling of the bladder, however, often leads to significant delay in diagnosis and can subject the patient to invasive bladder catheterization. As the key imaging feature in ovarian torsion is unilateral ovarian enlargement, we suspected that a torsed ovary is large enough to be visualized even if the bladder is not well distended.

OBJECTIVE

The purpose of this study was to retrospectively investigate if clinically suspected adnexal torsion can be excluded based on non-visualization of the ovaries on transabdominal ultrasound (US) with a non-distended bladder in pediatric patients.

MATERIALS AND METHODS

This retrospective study comprised 349 girls (1-19 years old) between Jan. 1, 2013, and July 30, 2018. Three hundred and forty-one of the girls were referred to transabdominal US to assess for adnexal torsion and/or appendicitis, and the ovaries were initially not visualized on US. Their bladders were subsequently filled and rescanned with a distended bladder showing the ovaries. Ovarian volumes and time between US scans were documented. The ratio of the volume of the larger ovary to the smaller one was calculated. Nine girls had surgically proven adnexal torsion and a preoperative transabdominal US with a non-distended bladder. There was an overlap of one girl between the two groups. The negative predictive value (NPV), positive predictive value (PPV), and sensitivity and specificity for exclusion of adnexal torsion based on non-visualization of the ovaries on US with a non-distended bladder were calculated.

RESULTS

One of the girls (1/341) who had a US study done with a non-distended bladder in which the ovaries were not visualized had a positive diagnosis of adnexal torsion. In eight of the nine girls who had surgically proven adnexal torsion, the torted ovary was identified with a non-distended bladder. The NPV and PPV for exclusion of adnexal torsion with a non-distended bladder was 1.0 and 0.8, respectively. The specificity and sensitivity were 99.4% and 88.9%, respectively. The mean and median time difference between the initial scan and the scan after bladder filling was 105.1 min (standard deviation [SD] -65.8) and 89.0 min (interquartile range [IQR]- 59.0, 130.5), respectively.

CONCLUSION

Non-visualization of the ovaries with a non-distended bladder on transabdominal US study can help exclude clinically suspected adnexal torsion, alleviating the need for bladder filling and prolonging the wait time in the emergency department. Inclusion of non-visualization of the ovaries as one of the features in a predictive score for adnexal torsion should be considered.

Comparison of the diagnostic performance of the 2017 ACR TI-RADS guideline to the Kwak guideline in children with thyroid nodules

BACKGROUND

The Kwak Thyroid Imaging Reporting and Data System (Kwak-TI-RADS) guideline (2011) and American College of Radiology Thyroid Imaging Reporting and Data System (ACR TI-RADS) guideline (2017) were developed as ultrasound (US) risk stratification tools for detecting thyroid malignancy in adults.

OBJECTIVE

The purpose of this study was to investigate the inter-rater reliability and diagnostic performance of the ACR TI-RADS guideline in the pediatric population and compare it to the Kwak guideline.

MATERIALS AND METHODS

This retrospective study comprised 75 children who underwent thyroid US at a tertiary-level pediatric hospital. Three pediatric radiologists and one pediatric radiology fellow graded the US findings using the Kwak-TI-RADS and ACR TI-RADS guidelines. We assessed reliability of radiologists' ratings using percentage inter-rater agreement, and intra-class correlation coefficients (ICC_2,1). We assessed area-under-the-receiver-operating-characteristic curve (AUROCC) to compare the discriminative diagnostic ability of the Kwak-TI-RADS and ACR TI-RADS scoring systems against histopathology/cytology, or stability on US over a 2-year follow-up period for cases without tissue diagnosis.

RESULTS

The inter-rater agreement was significantly better for the ACR TI-RADS level compared to the Kwak-TI-RADS level (P<0.001) using the percentage pairwise agreement. The ROC curves for assessing the diagnostic performance of the two methods showed no significant difference between the methods. The AUROCCs for the Kwak-TI-RADS and ACR TI-RADS levels were 0.74 (95% confidence interval [CI] 0.67-0.82) and 0.72 (95% CI 0.61-0.82), respectively.

CONCLUSION

Both the Kwak-TI-RADS and ACR TI-RADS guidelines provide moderate malignancy risk stratification for thyroid nodules in the pediatric population, with better inter-rater agreement for the ACR TI-RADS guideline. Further work to adjust the recommendations for pediatric patients is necessary.

Clinical delineation of GTPBP2-associated neuro-ectodermal syndrome: Report of two new families and review of the literature

The GTPBP2 gene encodes a guanosine triphosphate (GTP)-binding protein of unknown function. Biallelic loss-of-function variants in the GTPBP2 gene have been previously reported in association with a neuro-ectodermal clinical presentation in six individuals from four unrelated families. Here, we provide detailed descriptions of three additional individuals from two unrelated families in the context of the previous literature. Both families carry nonsense variants in GTPBP2: homozygous p.(Arg470*) and compound heterozygous p.(Arg432*)/p.(Arg131*). Key features of this clinically recognizable condition include prenatal onset microcephaly, tone abnormalities, and movement disorders, epilepsy, dysmorphic features, retinal dysfunction, ectodermal dysplasia, and brain iron accumulation. Our findings suggest that some aspects of the clinical presentation appear to be age-related; brain iron accumulation may appear only after childhood, and the ectodermal findings and peripheral neuropathy are most prominent in older individuals. In addition, we present prenatal and neonatal findings as well as the first Caucasian and black African families with GTPBP2 biallelic variants. The individuals described herein provide valuable additional phenotypic information about this rare, novel, and progressive neuroectodermal condition.

MRI features of the placenta in fetuses with and without CNS abnormalities

AIM

To investigate if magnetic resonance imaging (MRI) features of the placenta are different in fetuses with and without central nervous system (CNS) abnormalities.

MATERIAL AND METHODS

Institutional research ethics board approval was obtained. Fetal MRI of 97 singleton pregnancies were analysed retrospectively (19-25 weeks gestation), 65 with CNS morphological abnormalities and 32 controls. Placental T2 signal intensity, placental and fetal volumes, placental-to-fetal volume ratio, and placental apparent diffusion coefficient (ADC) values were assessed. Measurements were compared with the presence or absence of CNS fetal abnormalities using the Mann-Whitney test. Separate slopes models and intercept models were used to check for significant differences in the slopes and intercepts, respectively, among the groups.

RESULTS

Placental ADC values were significantly lower in placentas of fetuses with CNS abnormalities compared to controls (p=0.04). Placental T2 signal intensity, fetal and placental volumes did not differ between the two groups. The rate of increase in fetal-to-placental volume ratio with gestational age (GA) was greater among the controls.

CONCLUSION

The presence of fetal CNS abnormalities is associated with reduced ADC values of the placenta. Moreover, placentas of fetuses with CNS abnormalities show a less rapid increase in fetal to placental volume ratio with GA. Therefore, ADC mapping, as well as different growth kinetics of the placenta relative to the fetus, may potentially serve as early markers of pathological neurodevelopment.

Apparent Diffusion Coefficient of the Placenta in Twin versus Singleton Pregnancies

Previous studies in singleton pregnancies reported conflicting trends in apparent diffusion coefficient (ADC) values with gestational age (GA) and stable relative ADC (rADC; ADC placenta divided by ADC globe) throughout pregnancy. The purpose of our study was to compare the ADC and rADC of placentas of twin and singleton pregnancies.

MATERIALS AND METHODS

Fetal MRI of 11 twin and 23 singleton pregnancies were retrospectively analyzed. Each group was further divided by GA (≤24 and >24 weeks). On ADC, 3 regions of interest were selected in the placenta and 1 in the globe. ADC and rADC measurements were compared between different GA and between singleton and twin placentas.

RESULTS

No significant difference was shown between ADC and rADC values of singleton and twin placentas as well as between ADC and rADC values of singleton and twin placentas at different GA. No significant difference was shown when accounting for both GA and number of fetuses.

CONCLUSION

The diffusion characteristics of twin placentas are similar to those of singleton placentas. ADC and rADC remain stable throughout pregnancy in twin and singleton placentas, reflecting stable extracellular water diffusion, despite changes associated with placental maturation.

Synovial osteochondromatosis in a 14-year-old boy with a history of Legg-Calve-Perthes disease

We describe a case of a 14-year-old boy with a history of Legg–Calve–Perthes disease diagnosed at the age of 6 years and development of synovial osteochondromatosis of the same hip joint 7 years later. Synovial osteochondromatosis is very rare in children, and to the best of our knowledge, only a single case of Legg–Calve–Perthes disease and secondary synovial osteochondromatosis was described in the literature in a 35-year-old male, making this the first reported case of Legg–Calve–Perthes disease with development of synovial osteochondromatosis in a pediatric patient.