Normal pediatric values of carotid artery intima-media thickness measured by B-mode ultrasound and radiofrequency echo tracking respecting the consensus: a systematic review.

BACKGROUND: Carotid artery intima-media thickness (IMT) is a sub-clinical radiologic marker of atherosclerosis in children. It is associated with adult-onset vascular disease. OBJECTIVE: To determine normal pediatric values of IMT from results observed in the literature. METHODS: Our systematic review was conducted according to PRISMA guidelines. We reviewed 2298 English articles from inception to February 2023. Inclusion criteria included studies evaluating B-mode and radiofrequency (RF)-based IMT measurements based on the American Heart Association, the Association for European Pediatric Cardiology, the Mannheim Consensus, and the American Society of Echocardiography recommendations. A meta-analysis of aggregate data was conducted to obtain the confidence interval (CI) for IMT, using a 95% confidence level. RESULTS: We obtained 88 B-mode-based IMT measurement studies with 6184 children and six radiofrequency echo-tracking-based studies with 766 children. Mean IMT in the pediatric population was 0.43 mm, 95% [CI] 0,42 to 0.44, using the B-mode technique, and 0.41 mm, 95% [CI] 0.36 to 0.45 using the radiofrequency technique. No significant relationship was detected between IMT and age (p value = 0.83). Finally, no significant effect of sex on IMT was found (p value = 0.82 for B-mode and p value = 0.62 for RF). CONCLUSION: Based on the studies selected in this literature review, we were unable to conclude that there was a significant difference between the average IMT of boys and girls. No relationship was demonstrated between age and IMT. IMT is technique-specific, and normal values should be interpreted according to recommendations of recognized consensus to counteract the current heterogeneity in literature. CLINICAL RELEVANCE STATEMENT: Technique and children-specific Intima media thickness measurements help clinicians and scientists to assess the risk of atherosclerosis in children. KEY POINTS: • Intima-media thickness (IMT) does not correlate with age in children without risk factors. • According to current literature, there is no difference in IMT between healthy boys and girls. • There is heterogeneity, even with studies abiding by the official consensus.

MR Imaging of Pediatric Neuroblastoma: Is Gadolinium Enhancement Necessary for Evaluation of Image-Defined-Risk Factors?

Background: Pre-treatment stratification and outcomes of neuroblastoma patients often depend on the assessment of image-defined risk factors (IDRFs) on MR Imaging, usually using Gadolinium-contrast materials which are cautioned in pediatrics. We aimed to address whether gadolinium contrast-enhanced sequences are necessary to identify the presence/absence of IDRFs. Methods: Patients with neuroblastoma with MR imaging were retrospectively identified from 2005 to 2021. Ninety confirmed IDRFs were evaluated in 23 patients. Corresponding MR studies were anonymized, randomized, and independently evaluated by 3 fellowship-trained pediatric radiologists. Each radiologist assessed the studies twice. At the first reading, all enhanced sequences were omitted, while in the second reading, the full study with enhanced sequences were included. Consensus reading was obtained among readers. Inter- and intra-rater agreements using Kappa statistics (κ) as well as the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of non-enhanced MR in assessing IDRFs with respect to enhanced MR were calculated. Results: There were substantial (ĸ: 0.64-0.73) intra-reader agreements, and moderate to substantial (ĸ: 0.57-0.62) inter-reader agreements among radiologists in identifying IDRFs using non-enhanced MR. Non-enhanced MR had a sensitivity of 87.8% (95% CI [79-94]), specificity of 93% (89-96), PPV of 82.3 (73-89), NPV of 95.4 (92-98), and accuracy of 91.6 (88-94) in identifying IDRFs. However, 5/23 patients (21.7%) had a change in staging with the inclusion of contrast sequences. Conclusion: Although contrast sequences have a role in IDRF assessment, the majority can be adequately assessed on MR without gadolinium-contrast enhancement. Validation in a larger cohort is an important next step.

Non-Invasive Vascular Elastography as a One-Step Imaging Technique to Evaluate Early Vascular Changes in Children Compared to B-Mode-Based Intima-Media Thickness Technique : A Validation Study Using Inter- and Intra-Rater Reliability.

Background: Childhood obesity is linked to higher adult mortality and morbidity from atherosclerosis. It is primordial to detect at-risk children earlier-on to prevent disease progression. Carotid intima-media thickness (IMT) is a subclinical radiological marker for early atherosclerosis. B-mode ultrasound is a known technique to assess IMT, but no gold standard technique exists in children. Non-invasive vascular elastography (NIVE) using speckle statistics is an innovative alternative to evaluate IMT and adds by providing translation, strain and shear strain measurements. Validation studies for both techniques lack in children. Purpose: Validate the reproducibility of the 2 techniques in Canadian children. Methods: We conducted a prospective study where anthropometry, blood pressure, IMT and elastography were measured. Six operators obtained 2 measurements for both carotid arteries using both techniques, for a total of 720 measurements. Inter- and intra-class correlation coefficients (ICC) were calculated for each measurement technique and elastography parameters. Results: 30 participants (13.0 ± 1.26 years, 17 girls) were recruited. Twelve were overweight. No significant difference was found in mean IMT between weight groups for either technique (P = .15 and P = .60). We found excellent inter- (ICC = .98 [95% Confidence Interval (CI): .97; .99]) and intra- (ICC = .90-.93) operator reliability for the B-mode technique, and good inter (ICC = .70 [95% CI: .47; .85]) and intra- (ICC = .71-.91) operator reliability for the NIVE-based technique. Poor reliability was found between techniques (ICC = .30 [95% CI: -.31; .65). For elastography parameters, translation was the most reliable (ICC = .94-.95). Conclusion: IMT measurement is reproducible in children but not between techniques. NIVE gives the advantage of evaluating elastography.

Experience with Compressed Gelfoam Plugs in Children during Liver Biopsies and Other IR Procedures: A Retrospective Single-Center Case Series.

PURPOSE: To analyze the experience using compressed gelfoam plugs (CGPs) in children during liver biopsies and other interventional procedures. MATERIALS AND METHODS: This was a single-center, retrospective, consecutive case series of 477 various pediatric interventional radiology procedures using CGPs (January 2012 to December 2016) performed on 397 children (209 males, 188 females; median age, 7 years [range, 9 days-17.8 years]; median weight, 18 kg [range, 2.7-141 kg]). Of 477 procedures, most (n = 371) were liver biopsies, 98 were biopsies of other organs, and 8 were non-biopsy procedures. Analysis focused on liver biopsies. RESULTS: Of liver biopsies, a median of 2 CGPs were used per procedure, and the mean drop in hemoglobin was -0.36 g/dl (-3.0% change). Thirty-seven mild, 8 moderate, 2 severe, and 1 life-threatening (an anaphylaxis to CGP) adverse events (AEs) occurred. Analysis of liver biopsies with AEs showed significant association between number of passes, cores, and focal-type lesions (unadjusted logistic regression: P = .007, P = .022, P = .028, respectively) and age, weight, and number of passes (adjusted multiple logistic regression: P = .006, P = .032, P = .046, respectively). Technical problems relating to CGP deployment were noted in 5 (1%), without any AEs. CONCLUSIONS: CGPs were used in a wide variety of procedures and organs in children. There was 1 life-threatening AE resulting from the rare risk of anaphylaxis caused by the gelfoam-containing plug. After liver biopsies, transfusion was required in 2/371 (0.5%) procedures, 1 related to pre-biopsy anemia (0.25%).