Ultra-low-dose chest computed tomography without anesthesia in the assessment of pediatric pulmonary diseases / Tomografia computadorizada de tórax de ultrabaixa dosagem sem anestesia naavaliação de doenças pulmonares pediátricas

Abstract Objective To evaluate the feasibility of using ultra-low-dose computed tomography of the chest with iterative reconstruction without anesthesia for assessment of pulmonary diseases in children. Methods This prospective study enrolled 86 consecutive pediatric patients (ranging from 1 month to 18 years) that underwent ultra-low-dose computed tomography due to suspicion of pulmonary diseases, without anesthesia and contrast. Parameters used were: 80 kVp; 15-30 mA; acquisition time, 0.5 s; and pitch, 1.375. The adaptive statistical iterative reconstruction technique was used. Subjective visual evaluation and quantitative assessment of image quality were done using a 5-point scale in 12 different structures of the chest. Results Mean age was 66 months (interquartile range, 16-147). Final diagnosis was performed in all exams, and 44 (51.2%) were diagnosed with cystic fibrosis, 27 (31.4%) with bronchiolitis obliterans, and 15 (17.4%) with congenital pulmonary airways malformations. Diagnostic quality was achieved in 98.9%, of which 82.6% were considered excellent and 16.3% were slightly blurred but did not interfere with image evaluation. Only one case (1.2%) presented moderate blurring that slightly compromised the image, and previous examinations demonstrated findings compatible with bronchiolitis obliterans. Mean effective radiation dose was 0.39 ± 0.15 mSv. Percentages of images with motion artifacts were 0.3% for cystic fibrosis, 1.3% for bronchiolitis obliterans, and 1.1% for congenital pulmonary airways malformations. Conclusion Chest ultra-low-dose computed tomography without sedation or anesthesia delivering a sub-millisievert dose can provide image quality to allow identification of common pulmonary anatomy and diseases.

Resumo Objetivo Avaliar a viabilidade do uso de tomografia computadorizada com ultrabaixa dose com reconstrução iterativa sem anestesia para avaliação de doenças pulmonares em crianças. Métodos Este estudo prospectivo envolveu 86 pacientes pediátricos consecutivos (um mês a 18 anos) submetidos à tomografia computadorizada com ultrabaixa dose por suspeita de doenças pulmonares, sem anestesia e contraste. Os parâmetros utilizados foram: 80 kVp; 15-30 mA; tempo de aquisição, 0,5 s; e pitch de 1,375. Foi utilizada a técnica de reconstrução estatística adaptativa iterativa. A avaliação visual subjetiva e a avaliação quantitativa da qualidade da imagem foram feitas com uma escala de 5 pontos em 12 estruturas do tórax. Resultados A média de idade foi de 66 meses (intervalo interquartil, 16-147). O diagnóstico final foi feito em todos os exames e 44 (51,2%) foram diagnosticados com fibrose cística, 27 (31,4%) com bronquiolite obliterante e 15 (17,4%) com malformação congênita pulmonar das vias aéreas. A qualidade diagnóstica foi alcançada em 98,9% dos casos, dos quais 82,6% foram considerados excelentes e 16,3% alteração leve na definição, mas isso não interferiu na avaliação da imagem. Apenas um caso (1,2%) apresentou alteração moderada na definição, comprometeu discretamente a imagem, e exames prévios demonstraram achados compatíveis com bronquiolite obliterante. A dose de radiação média efetiva foi de 0,39 ± 0,15 mSv. As porcentagens de imagens com artefatos de movimento foram de 0,3% para fibrose cística, 1,3% para bronquiolite obliterante e 1,1% para malformação congênita pulmonar das vias aéreas. Conclusão É possível realizar a tomografia computadorizada com ultrabaixa dose torácica sem sedação ou anestesia, administrando uma dose de submilisievert, com qualidade de imagem suficiente para a identificação pulmonar anatômica e de doenças pulmonares comuns.

Effects of the addition of quantitative apparent diffusion coefficient data on the diagnostic performance of the PI-RADS v2 scoring system to detect clinically significant prostate cancer.

PURPOSE: To evaluate the impact of the addition of quantitative apparent diffusion coefficient (ADC) data into the diagnostic performance of the Prostate Imaging Reporting and Data System version 2 (PI-RADSv2) scoring system to predict clinically significant prostate cancer (CSPCa). METHODS: We retrospectively included 91 consecutive patients who underwent prostate multiparametric magnetic resonance imaging (mp-MRI) and histopathological evaluation. Mp-MRI images were reported by the PI-RADSv2 scoring system and patients were divided into groups considering the likelihood of CSPCa. ADC value and ratio were obtained. Findings were correlated with histopathological data. RESULTS: CSPCa was found in 41.8% of cases (n = 38). PI-RADSv2 score 3-5 yielded a sensitivity of 97.4% (95% confidence intervals 86.5-99.5), a specificity of 50.9% (37.9-63.9), and AUC of 0.74 (0.67-0.81) to predict CSPCa. ADC value < 750 µm2/s and an ADC ratio < 0.62 were the most accurate thresholds for differentiation of CSPCa, with AUC of 0.81 and 0.76, respectively. Combined PI-RADSv2 score 3-5 and ADC value < 750 µm2/s yielded a specificity of 84.9 (72.9-92.2), sensitivity of 70.3 (54.2-82.5), and AUC of 0.77 (0.68-0.86). Combined PI-RADSv2 score 3-5 and ADC ratio < 0.62 yielded a specificity of 86.5 (74.7-93.3), sensitivity of was 64.9 (48.8-78.2), and AUC of 0.75 (0.66-0.84). CONCLUSION: Quantitative ADC data might not be beneficial to be used routinely in mp-MR imaging as criteria to detect clinically significant lesions due to the reduced sensitivity. Instead, when prostate lesions present a PI-RADSv2 score ≥ 3, additional quantitative ADC criteria can be helpful to increase the PI-RADS score specificity.

Ultra-low-dose chest computed tomography without anesthesia in the assessment of pediatric pulmonary diseases.

OBJECTIVE: To evaluate the feasibility of using ultra-low-dose computed tomography of the chest with iterative reconstruction without anesthesia for assessment of pulmonary diseases in children. METHODS: This prospective study enrolled 86 consecutive pediatric patients (ranging from 1 month to 18 years) that underwent ultra-low-dose computed tomography due to suspicion of pulmonary diseases, without anesthesia and contrast. Parameters used were: 80kVp; 15-30mA; acquisition time, 0.5s; and pitch, 1.375. The adaptive statistical iterative reconstruction technique was used. Subjective visual evaluation and quantitative assessment of image quality were done using a 5-point scale in 12 different structures of the chest. RESULTS: Mean age was 66 months (interquartile range, 16-147). Final diagnosis was performed in all exams, and 44 (51.2%) were diagnosed with cystic fibrosis, 27 (31.4%) with bronchiolitis obliterans, and 15 (17.4%) with congenital pulmonary airways malformations. Diagnostic quality was achieved in 98.9%, of which 82.6% were considered excellent and 16.3% were slightly blurred but did not interfere with image evaluation. Only one case (1.2%) presented moderate blurring that slightly compromised the image, and previous examinations demonstrated findings compatible with bronchiolitis obliterans. Mean effective radiation dose was 0.39±0.15mSv. Percentages of images with motion artifacts were 0.3% for cystic fibrosis, 1.3% for bronchiolitis obliterans, and 1.1% for congenital pulmonary airways malformations. CONCLUSION: Chest ultra-low-dose computed tomography without sedation or anesthesia delivering a sub-millisievert dose can provide image quality to allow identification of common pulmonary anatomy and diseases.

Pulmonary Acinus: Understanding the Computed Tomography Findings from an Acinar Perspective.

The lung acinus is the most distal portion of the airway responsible for the gas exchange. The normal acini are not visible on conventional computed tomography (CT), but the advent of micro-CT improved the understanding of the microarchitecture of healthy acini. The comprehension of the acinar architecture is pivotal for the understanding of CT findings of diseases that involve the acini. Centriacinar emphysema, for example, presents as round areas of low attenuation due to the destruction of the most central acini with compensatory enlargement of proximal acini due to alveolar wall destruction. In pulmonary fibrosis, intralobular septal fibrosis manifests as acinar wall thickening with an overlap of acinar collapse and compensatory dilation of surrounding acini constituting the cystic disease typical of the usual interstitial pneumonia pattern. This is a state-of-the-art review to describe the acinar structure from the micro-CT perspective and display how the comprehension of the acinar structure can aid in the interpretation of its microarchitecture disruption on conventional CT.

Diffusion-weighted imaging and apparent diffusion coefficient values for evaluating terminal ileitis in patients with Crohn's disease.

OBJECTIVE: To determine the accuracy of diffusion-weighted imaging (DWI) in identifying terminal ileitis in patients with Crohn's disease. MATERIALS AND METHODS: This was a retrospective study of 38 consecutive patients with Crohn's disease who underwent magnetic resonance enterography with DWI in a 3.0 T scanner. The patients were divided into two groups, on the basis of colonoscopy and biopsy findings: active inflammation; and inactive disease. Apparent diffusion coefficient (ADC) values were determined, as were the magnetic resonance index of activity (MaRIA) and the Clermont score. RESULTS: Of the 38 patients evaluated, 18 (47%) had active inflammation. The patients with active inflammation showed greater restricted diffusion, more pronounced mucosal edema, greater wall thickening, a higher MaRIA, and a higher Clermont score than did those with inactive disease. The level of interobserver agreement (intraclass correlation coefficient) was excellent for the MaRIA and the Clermont score, whereas it was substantial for the ADC values. For identifying colonoscopy-proven inflammation, the best ADC cut-off point was 2.1 × 10-3 mm2/s, which had a sensitivity of 88.8% and a specificity of 95.0%, whereas DWI presented an overall accuracy of 89.4%, with a sensitivity of 88.9% and a specificity of 90.0%. CONCLUSION: Visual analysis of the DWI sequence has good accuracy in detecting terminal ileitis in patients with Crohn's disease. In addition, low ADC values have good sensitivity for detecting colonoscopy-proven inflammation.

How useful is ultrasound guidance for internal jugular venous access in children?

PURPOSE: The aim of this study was to determine whether US reduces number of puncture attempts, procedure time, and complication rate during IJV access in children. METHODS: A prospective study was performed in children (age ≤18years) admitted to our institution, from September 2013 to July 2014, with indications for central venous access. Patients meeting the inclusion criteria were randomized to the US-guided or control groups. The same physician performed all IJV cannulations in both groups. The end-points for comparison were: length of time to venous access, number of attempts, and rate of complications. RESULTS: Fifty-one patients were included: 23 in the US-guided group and 28 in the control group. There were no between-group differences in weight, age, or sex. In the US-guided group, the number of punctures needed to achieve IJV access (median [interquartile range], 3 [2-5] vs. 1 [1, 2]; P<0.001), time to achievement of venous access, and complication rate (39% vs. 4.3%, P<0.009) were significantly lower. CONCLUSION: US guidance is a useful adjunct to central venous access in children, facilitating the procedure, decreasing time to cannulation, and increasing safety. TYPE OF STUDY: Prospective randomized study. LEVEL OF EVIDENCE: 1.

Quantification of Abdominal Fat in Obese and Healthy Adolescents Using 3 Tesla Magnetic Resonance Imaging and Free Software for Image Analysis.

BACKGROUND AND AIMS: Computed tomography, which uses ionizing radiation and expensive software packages for analysis of scans, can be used to quantify abdominal fat. The objective of this study is to measure abdominal fat with 3T MRI using free software for image analysis and to correlate these findings with anthropometric and laboratory parameters in adolescents. METHODS: This prospective observational study included 24 overweight/obese and 33 healthy adolescents (mean age 16.55 years). All participants underwent abdominal MRI exams. Visceral and subcutaneous fat area and percentage were correlated with anthropometric parameters, lipid profile, glucose metabolism, and insulin resistance. Student's t test and Mann-Whitney's test was applied. Pearson's chi-square test was used to compare proportions. To determine associations Pearson's linear correlation or Spearman's correlation were used. RESULTS: In both groups, waist circumference (WC) was associated with visceral fat area (P = 0.001 and P = 0.01 respectively), and triglycerides were associated with fat percentage (P = 0.046 and P = 0.071 respectively). In obese individuals, total cholesterol/HDL ratio was associated with visceral fat area (P = 0.03) and percentage (P = 0.09), and insulin and HOMA-IR were associated with visceral fat area (P = 0.001) and percentage (P = 0.005). CONCLUSIONS: 3T MRI can provide reliable and good quality images for quantification of visceral and subcutaneous fat by using a free software package. The results demonstrate that WC is a good predictor of visceral fat in obese adolescents and visceral fat area is associated with total cholesterol/HDL ratio, insulin and HOMA-IR.

MRI of the knees in asymptomatic adolescent soccer players: A case-control study.

PURPOSE: To determine the range of asymptomatic abnormal findings in adolescent soccer players at 3.0T MRI of the knee. MATERIALS AND METHODS: In all, 87 knees of asymptomatic 14-17-year-old male adolescents were evaluated at 3T, using a standardized examination protocol comprising four sequences: two fat-suppressed T2 -weighted fast spin-echo sequences (T2 FSE), in the sagittal (repetition time / echo time [TR/TE], 5.300/71, echo train length [ETL] 17) and coronal planes (TR/TE, 4234/70, ETL 17), one fat-suppressed proton density (PD) sequence in the axial plane (TR/TE, 2.467/40, ETL 9), and one T1 -weighted spin-echo (T1 SE) sequence in the sagittal plane (TR/TE, 684/12.5). Soccer players (46 knees) were paired with controls (41 knees) by age and weight. Bone marrow, articular cartilage, meniscus, tendons, ligaments, fat pad abnormalities, and joint fluid were assessed. RESULTS: One or more abnormalities were detected in 31 knees (67.4%) in the soccer player group, compared to 20 knees (48.8%) in the control group. The prevalence of bone marrow edema was higher in the soccer group (19 knees, 41.3%) than in the control group (3 knees, 7.3%), P = 0.001. Other abnormalities found in this sample (joint effusion, cartilage lesions, tendinopathy, ganglion cysts, and infrapatellar fat pat edema) were not significantly different between the two study groups. CONCLUSION: Asymptomatic adolescents had a high prevalence of abnormal findings on knee imaging, especially bone marrow edema. This prevalence was higher among soccer players. LEVEL OF EVIDENCE: 4 J. Magn. Reson. Imaging 2017;45:59-65.

Pilot Mechanistic Study of Insulin Modulation of Somatotrophic Hormones, Inflammation, and Lipid Metabolism During Critical Illness in Children.

OBJECTIVES: To evaluate the mechanism of insulin modulation on somatotrophic response, inflammation, and lipid metabolism in critically ill children. DESIGN: Open-label randomized mechanistic study. SETTING: Two-center, tertiary PICU study. PATIENTS: Thirty critically ill children between 1 month and 14 years old, requiring mechanical ventilation and with evidence of two or more organ system failures. INTERVENTIONS: Randomized physiologic design of hyperinsulinemic-euglycemic clamp using continuous insulin infusion at 0.1 U/kg/hr versus conventional management. MEASUREMENTS AND MAIN RESULTS: Thirteen children underwent hyperinsulinemic-euglycemic clamp. Blood samples for somatotrophic, inflammatory, and metabolic evaluation were obtained before randomization, and 24 and 72 hours later. A growth hormone oscillation profile was obtained during the first night. There was no difference between groups at baseline. Growth hormone resistance, increased proinflammatory cytokines, and increased lipolysis with low lipoprotein levels were present in all patients. Hyperinsulinemic-euglycemic clamp did not affect growth hormone, insulin-like growth factor-1 or insulin-like growth factor binding protein-3 levels. By day 2, insulin reduced insulin-like growth factor binding protein-1 levels. Tumor necrosis factor-α and interleukin-1ß were similar in both groups, whereas interleukin-6 levels reduced over time only in children receiving hyperinsulinemic-euglycemic clamp. Hyperinsulinemic-euglycemic clamp also decreased free fatty acid levels, which was accompanied by increased low-density lipoprotein cholesterol and relative increase in high-density lipoprotein levels. Total cholesterol and triglycerides were unchanged. CONCLUSIONS: Insulin does not reverse most of the somatotrophic changes induced by the stress of critical illness. Rather, it may improve lipid metabolism and down-regulate some markers of the inflammatory response.

An Imaging Diagnostic Protocol in Children with Clinically Suspected Acute Appendicitis.

The objective of the present study is to evaluate a new diagnostic strategy using clinical findings followed by ultrasound (US) and, in selected cases, MRI. This study included 166 children presenting signs and symptoms suggesting acute appendicitis. Cases classified as suggesting appendicitis according to clinical exams had to be referred to surgery, whereas the other cases were discharged. Unclear cases were evaluated using US. If the US results were considered inconclusive, patients underwent MRI. Of the 166 patients, 78 (47%) had acute appendicitis and 88 (53%) had other diseases. The strategy under study had a sensitivity of 96 per cent, specificity of 100 per cent, positive predictive value of 100 per cent, negative predictive value of 97 per cent, and accuracy of 98 per cent. Eight patients remained undiagnosed and underwent MRI. After MRI two girls presented normal appendixes and were discharged. One girl had an enlarged appendix on MRI and appendicitis could have been confirmed by surgery. In the other five patients, no other sign of the disease was detected by MRI such as an inflammatory mass, free fluid or an abscess in the right iliac fossa. All of them were discharged after clinical observation. In the vast majority of cases the correct diagnosis was reached by clinical and US examinations. When clinical assessment and US findings were inconclusive, MRI was useful to detect normal and abnormal appendixes and valuable to rule out other abdominal pathologies that mimic appendicitis.

Validation of PI-RADS v.2 for prostate cancer diagnosis with MRI at 3T using an external phased-array coil.

PURPOSE: To date, few studies have validated the Prostate Imaging Reporting and Data System Version 2 (PI-RADS v. 2) for the diagnosis of prostate cancer. Our aim was to validate PI-RADS v.2 using 3 Tesla (T) MRI. MATERIALS AND METHODS: This is a retrospective study of 54 consecutive patients who underwent 3T MRI with a body-array coil for diagnostic confirmation of prostate cancer or cancer staging between June 2013 and June 2015. Sensitivity, specificity, and agreement were calculated based on a criterion of PI-RADS score = 3. Inter-examiner agreement was determined by the weighted kappa statistic. RESULTS: Histological findings were positive for cancer in 33 patients and negative in 21 patients. Considering a PI-RADS score of 3 as positive for cancer, the accuracy of each reader was 85.20% and 70.40%, respectively, and agreement coefficients were κ = 0.69 and κ = 0.35. Considering PI-RADS 3 as absence of cancer, the accuracy of each reader was 77.80% and 77.80%, respectively, and agreement was κ = 0.55 and κ = 0.54. Inter-reader agreement was moderate/good (weighted κ = 0.53; 95% confidence interval: 0.39-0.66; P = 0.038). CONCLUSION: High accuracy was obtained for the diagnosis of prostate cancer using 3T MRI with a body coil and the PI-RADS v.2 score. J. Magn. Reson. Imaging 2016;44:1354-1359.

A prevalência de obesidade na infância e adolescência é maior em escolas públicas no sul do Brasil / The prevalence of obesity in childhood and adolescence is higher in public schools in the South of Brazil

Objetivo: Analisar as medidas antropométricas dos escolares de Veranópolis, Rio Grande do Sul, sul do Brasil, considerando a incidência de obesidade e sobrepeso e a sua relação com o tipo de escola frequentada (pública ou privada). Métodos: Estudo transversal envolvendo todos os escolares da rede pública e privada de Veranópolis-RS a partir de uma coorte iniciada em 2012. As medidas estudadas foram peso, altura e índice de massa corporal. Todos os pais ou responsáveis pelos escolares amostrados responderam a um questionário padronizado sobre antecedentes médicos pessoais e familiares. Para o diagnóstico de sobrepeso e obesidade foram usados os critérios da Organização Mundial da Saúde (OMS) e do Centro de Controle e Prevenção de Doenças (CDC-USA). Na análise dos dados foram usadas a estatística descritiva e inferencial. Resultados: Foram amostrados 2150 escolares entre 6 e 18 anos de idade, sendo 1725 (80%) de escolas públicas e 425 (20%) de escolas privadas. A maioria da população era caucasiana (85,3%) e moradora de zona urbana (89%). Entre os escolares menores de 10 anos, utilizando-se percentil ou escore Z, a prevalência de sobrepeso e obesidade foi de 21% e de baixa estatura de 1,4%. A obesidade medida pelo IMC (percentil) foi mais prevalente em escolares menores de 10 anos (23,8 vs 16,4; p< 0,05). Para essa faixa etá- ria, a distribuição de sobrepeso e obesidade não demonstrou diferença estatisticamente significativa entre escolas públicas e privadas. Entretanto, para os escolares com idade entre 10 e 18 anos, a obesidade foi significativamente mais prevalente nas escolas públicas, tanto utilizando percentil (17,5 vs 6,7%; p< 0,05), quanto escore Z (15,8 vs 5,6%; p< 0,05). Conclusões: O sobrepeso e a obesidade são condições clí- nicas muito frequentes entre escolares de Veranópolis-RS, concordando com estatísticas nacionais e internacionais. A prevalência de obesidade é maior entre escolares menores de 10 anos, sem diferenças na distribuição por escolas públicas ou privadas. Entretanto, na faixa entre 10 e 18 anos, a prevalência de obesidade é mais significativa nas escolas públicas, indicando a participação de um forte componente social, ambiental e educacional na sua origem. Outros fatores de risco para o desenvolvimento da obesidade entre escolares devem ser estudados (AU)

Objective: To analyse the anthropometric measurements of Veranópolis (Rio Grande do Sul, south of Brazil) students, whereas the incidence of obesity and overweight and the association of these clinical conditions with the type of school attended (public or private). Methods: A cross-sectional study involving all students of public and private schools of Veranópolis-RS from a cohort initiated in 2012. Anthropometric measures were weight, height and body mass index. All parents or guardians by the sampled students responded to a standardized questionnaire, involving personal medical and family background. For the diagnosis of overweight and obesity, criteria from the WHO and CDC were used. For data analysis, descriptive and inferential statistics were performed. Results: We sampled 2150 students between 6 and 18 years of age, being 1725 (80%) of public schools and 425 (20%) of private schools. The majority of the population was Caucasians (85.3%) and resident of an urban zone (89%). Among the students under 10 years of age, using percentile or Z-score, the prevalence of overweight and obesity was 21% and short stature was 1.4%. Obesity, as measured by BMI (percentile), was more prevalent in students under 10 years of age (23.8 vs 16.4; p < 0.05). For this age group, the distribution of overweight and obesity did not show statistically significant difference between public and private schools. However, for students aged between 10 and 18 years, obesity was significantly more prevalent in public schools, both using percentile (17.5 vs. 6.7%; p < 0.05) or Z-score (15.8 vs. 5.6%; p < 0.05). Conclusions: Overweight and obesity are very common medical conditions among students of Veranópolis-RS, according to national and international statistics. The prevalence of obesity is higher among students under 10 years of age, without differences in distribution by public or private schools. However, in the range between 10 and 18 years of age, the prevalence of obesity is more significant in the public schools, indicating a strong social, environmental and educational component at its source. Other risk factors for the development of obesity among students between 6 and 18 years of age must be studied (AU)

Accuracy of computer-aided ultrasound as compared with magnetic resonance imaging in the evaluation of nonalcoholic fatty liver disease in obese and eutrophic adolescents.

OBJECTIVE: To compare the accuracy of computer-aided ultrasound (US) and magnetic resonance imaging (MRI) by means of hepatorenal gradient analysis in the evaluation of nonalcoholic fatty liver disease (NAFLD) in adolescents. MATERIALS AND METHODS: This prospective, cross-sectional study evaluated 50 adolescents (aged 11-17 years), including 24 obese and 26 eutrophic individuals. All adolescents underwent computer-aided US, MRI, laboratory tests, and anthropometric evaluation. Sensitivity, specificity, positive and negative predictive values and accuracy were evaluated for both imaging methods, with subsequent generation of the receiver operating characteristic (ROC) curve and calculation of the area under the ROC curve to determine the most appropriate cutoff point for the hepatorenal gradient in order to predict the degree of steatosis, utilizing MRI results as the gold-standard. RESULTS: The obese group included 29.2% girls and 70.8% boys, and the eutrophic group, 69.2% girls and 30.8% boys. The prevalence of NAFLD corresponded to 19.2% for the eutrophic group and 83% for the obese group. The ROC curve generated for the hepatorenal gradient with a cutoff point of 13 presented 100% sensitivity and 100% specificity. As the same cutoff point was considered for the eutrophic group, false-positive results were observed in 9.5% of cases (90.5% specificity) and false-negative results in 0% (100% sensitivity). CONCLUSION: Computer-aided US with hepatorenal gradient calculation is a simple and noninvasive technique for semiquantitative evaluation of hepatic echogenicity and could be useful in the follow-up of adolescents with NAFLD, population screening for this disease as well as for clinical studies.

OBJETIVO: Comparar a acurácia do ultrassom (US) com análise computadorizada mediante cálculo do gradiente hepatorrenal na avaliação da doença hepática gordurosa não alcoólica (DHGNA), utilizando a ressonância magnética (RM) como referência. MATERIAIS E MÉTODOS: Este estudo, transversal prospectivo, avaliou 50 adolescentes (idades de 11 a 17 anos), sendo 24 deles obesos e 26 eutróficos. Todos os adolescentes foram submetidos a exames de US com análise computadorizada, RM, exames laboratoriais e avaliação antropométrica. Foram calculados sensibilidade, especificidade, valores preditivos positivos e negativos e acurácia, seguindo a posterior geração de curva ROC (receiver operating characteristic) e cálculo da área sob a curva estabelecida, para determinar o melhor ponto de corte para o gradiente hepatorrenal, para predizer graus de esteatose, utilizando os resultados da RM como padrão ouro. RESULTADOS: Resultados: No grupo de obesos, 29,2% foram meninas e 70,8% foram meninos, e no grupo de eutróficos, 69,2% foram meninas e 30,8% foram meninos. A prevalência de DHGNA foi 19,2% nos eutróficos e 83% nos obesos. A curva ROC gerada para o gradiente hepatorrenal, com ponto de corte de 13, apresentou sensibilidade de 100% e especificidade de 100%. Considerando o mesmo ponto de corte para os eutróficos, haveria 9,5% de falso-positivos (especificidade de 90,5%) e 0% de falso-negativos (sensibilidade de 100%). CONCLUSÃO: O US com análise computadorizada, com o cálculo do gradiente hepatorrenal, é técnica simples e não invasiva para avaliação semiquantitativa da ecogenicidade hepática e poderá vir a ser de ajuda no seguimento de adolescentes com DHGNA, no rastreamento populacional dessa doença e para estudos clínicos.

Accuracy of computer-aided ultrasound as compared with magnetic resonance imaging in the evaluation of nonalcoholic fatty liver disease in obese and eutrophic adolescents / Acurácia do ultrassom, utilizando a técnica computadorizada, na avaliação da doença hepática gordurosa não alcoólica em adolescentes obesos e eutróficos, comparativamente com a ressonância magnética

AbstractObjective:To compare the accuracy of computer-aided ultrasound (US) and magnetic resonance imaging (MRI) by means of hepatorenal gradient analysis in the evaluation of nonalcoholic fatty liver disease (NAFLD) in adolescents.Materials and Methods:This prospective, cross-sectional study evaluated 50 adolescents (aged 11–17 years), including 24 obese and 26 eutrophic individuals. All adolescents underwent computer-aided US, MRI, laboratory tests, and anthropometric evaluation. Sensitivity, specificity, positive and negative predictive values and accuracy were evaluated for both imaging methods, with subsequent generation of the receiver operating characteristic (ROC) curve and calculation of the area under the ROC curve to determine the most appropriate cutoff point for the hepatorenal gradient in order to predict the degree of steatosis, utilizing MRI results as the gold-standard.Results:The obese group included 29.2% girls and 70.8% boys, and the eutrophic group, 69.2% girls and 30.8% boys. The prevalence of NAFLD corresponded to 19.2% for the eutrophic group and 83% for the obese group. The ROC curve generated for the hepatorenal gradient with a cutoff point of 13 presented 100% sensitivity and 100% specificity. As the same cutoff point was considered for the eutrophic group, false-positive results were observed in 9.5% of cases (90.5% specificity) and false-negative results in 0% (100% sensitivity).Conclusion:Computer-aided US with hepatorenal gradient calculation is a simple and noninvasive technique for semiquantitative evaluation of hepatic echogenicity and could be useful in the follow-up of adolescents with NAFLD, population screening for this disease as well as for clinical studies.

ResumoObjetivo:Comparar a acurácia do ultrassom (US) com análise computadorizada mediante cálculo do gradiente hepatorrenal na avaliação da doença hepática gordurosa não alcoólica (DHGNA), utilizando a ressonância magnética (RM) como referência.Materiais e Métodos:Este estudo, transversal prospectivo, avaliou 50 adolescentes (idades de 11 a 17 anos), sendo 24 deles obesos e 26 eutróficos. Todos os adolescentes foram submetidos a exames de US com análise computadorizada, RM, exames laboratoriais e avaliação antropométrica. Foram calculados sensibilidade, especificidade, valores preditivos positivos e negativos e acurácia, seguindo a posterior geração de curva ROC (receiver operating characteristic) e cálculo da área sob a curva estabelecida, para determinar o melhor ponto de corte para o gradiente hepatorrenal, para predizer graus de esteatose, utilizando os resultados da RM como padrão ouro.Resultados:Resultados: No grupo de obesos, 29,2% foram meninas e 70,8% foram meninos, e no grupo de eutróficos, 69,2% foram meninas e 30,8% foram meninos. A prevalência de DHGNA foi 19,2% nos eutróficos e 83% nos obesos. A curva ROC gerada para o gradiente hepatorrenal, com ponto de corte de 13, apresentou sensibilidade de 100% e especificidade de 100%. Considerando o mesmo ponto de corte para os eutróficos, haveria 9,5% de falso-positivos (especificidade de 90,5%) e 0% de falso-negativos (sensibilidade de 100%).Conclusão:O US com análise computadorizada, com o cálculo do gradiente hepatorrenal, é técnica simples e não invasiva para avaliação semiquantitativa da ecogenicidade hepática e poderá vir a ser de ajuda no seguimento de adolescentes com DHGNA, no rastreamento populacional dessa doença e para estudos clínicos.

Ultrasound Evaluation of Carotid Intima-Media Thickness in Children.

AIM: The purpose of this study was to assess the association with automated US measurements of carotid artery intima-media thickness (cIMT) with anthropometric, laboratory data and ultrasonographic measurements of fat, in order to identify potential markers that could be used to prevent the development and progression of cardiovascular pathology in adolescents. METHOD: Forty-five patients aged 10 to 17 years were enrolled in this study. Blood samples and anthropometric measurements were obtained from all subjects. All patients underwent an ultrasonic assessment of subcutaneous tissue, pre-peritoneal fat, and intra-abdominal fat. All patients received an US assessment of the common carotid artery intima-media thickness. RESULTS: There was a positive association of minimum beds of pre-peritoneal fat, on both sides, with cIMT. Additionally, cIMT on the right side was positively associated with HOMA-IR. In our multivariate analysis, HOMA-IR remained independently associated with cIMT (left) and measurement of the minimum bed of pre-peritoneal fat was associated with right cIMT. There was no association of cIMT with sex, BMI z-score, demographic variables or laboratory findings. CONCLUSION: Pre-peritoneal fat and HOMA-IR are associated with automated ultrasound measurements of both carotid intima-media thickness. Carotid intima-media thickness was not associated with any other demographic variables nor with other laboratory findings when assessed with our automated US method.