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PURPOSE: Gastrointestinal tract (GIT) tumors in children are rare and there is a scarcity of data on their imaging features. The purpose of this study was to determine thefrequency of various GIT tumor types in children and to identify key imaging characteristics. METHODS: This retrospective, single-center study was approved by the local ethics committee. Children with histologically proven GIT tumours (malignantand benign) who had imaging available on the institutional PACS between May 1, 2000 and Dec 31, 2019 were included. Demographic data and available imaging was reviewed by two blinded radiologists. RESULTS: In total, 90 children (45 male, mean age 9.3 ± 4.3 years) with GIT tumours were included. The final diagnoses included polyps (n = 28), lymphomas/PTLD (n = 27), neuroendocrine tumours (n = 16), adenocarcinoma (n = 6), adenoma (n = 5), gastrointestinal stromal tumor (GIST) (n = 3), inflammatory myofibroblastic tumours (n = 2) and lastly leiomyoblastoma, leiomyoma and lipoma (1 each). All GIT segments were affected, but overall the small and large bowel had most lesions. Eighty-one percent children had a single lesion while remaining 19 % had multiple lesions. The neoplastic process manifested as intra-luminal lesion (58 %) or wall thickening (42 %) on imaging. Multiple cystic areas and vascular pedicle for polyps; and hypoechogenecity of the mass or wall thickening and aneurysmal dilatation for lymphomas, were the characteristic imaging features. None of the neuroendocrine tumours affecting appendix were seen on pre-resection imaging. CONCLUSIONS: Variety of benign and malignant tumors are seen throughout the childhood. Polyps, lymphomas and appendiceal neuroendocrine tumors are common lesions. Characteristic imaging features of juvenile polyps and lymphomas on ultrasound may help narrowing the differentials, and guide further work up.
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Neoplasias Gastrointestinais , Humanos , Masculino , Feminino , Criança , Estudos Retrospectivos , Neoplasias Gastrointestinais/diagnóstico por imagem , Neoplasias Gastrointestinais/patologia , Centros de Atenção Terciária , Adolescente , Pré-Escolar , Imageamento por Ressonância Magnética/métodosRESUMO
The imaging evaluation of acute abdominal pain in children with suspected appendicitis has evolved to include rapid abdominopelvic MRI (rMRI) over recent years. Through a collaborative effort between the Magnetic Resonance Imaging (MRI) and Emergency and Trauma Imaging Committees of the Society for Pediatric Radiology (SPR), we conducted a survey on the utilization of rMRI to assess practice specifics and protocols. Subsequently, we present a proposed consensus rMRI protocol derived from the survey results, literature review, and discussion and consensus between committee members.
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Apendicite , Criança , Humanos , Apendicite/diagnóstico por imagem , Consenso , Imageamento por Ressonância Magnética/métodos , Dor Abdominal , Inquéritos e QuestionáriosRESUMO
BACKGROUND: Improving access to magnetic resonance imaging (MRI) in childhood can be facilitated by making it faster and cheaper and reducing need for sedation or general anesthesia (GA) to mitigate motion. Some children achieve diagnostic quality MRI without GA through the use of non- practices fostering their cooperation and/or alleviating anxiety. Employed before and during MRI, these variably educate, distract, and/or desensitize patients to this environment. OBJECTIVE: To assess current utilization of non-sedate practices in pediatric MRI, including variations in practice and outcomes. MATERIALS AND METHODS: A survey-based study was conducted with 1372 surveys emailed to the Society for Pediatric Radiology members in February 2021, inviting one response per institution. RESULTS: Responses from 50 unique institutions in nine countries revealed 49/50 (98%) sites used ≥ 1 non-sedate practice, 48/50 (96%) sites in infants < 6 months, and 11/50 (22%) for children aged 6 months to 3 years. Non-sedate practices per site averaged 4.5 (range 0-10), feed and swaddle used at 47/49 (96%) sites, and child life specialists at 35/49 (71%). Average success rates were moderate (> 50-75%) across all sites and high (> 75-100%) for 20% of sites, varying with specific techniques. Commonest barriers to use were scheduling conflicts and limited knowledge. CONCLUSION: Non-sedate practice utilization in pediatric MRI was near-universal but widely variable across sites, ages, and locales, with room for broader adoption. Although on average non-sedate practice success rates were similar, the range in use and outcomes suggest a need for standardized implementation guidelines, including patient selection and outcome metrics, to optimize utilization and inform educational initiatives.
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Anestesia Geral , Imageamento por Ressonância Magnética , Lactente , Criança , Humanos , Movimento (Física) , Imageamento por Ressonância Magnética/métodos , Inquéritos e Questionários , Exame FísicoRESUMO
The liver is the primary organ for the metabolism of many chemotherapeutic agents. Treatment-induced liver injury is common in children undergoing cancer therapy. Hepatic injury occurs due to various mechanisms, including biochemical cytotoxicity, hepatic vascular injury, radiation-induced cytotoxicity, and direct hepatic injury through minimally invasive and invasive surgical treatments. Treatment-induced liver injury can be seen contemporaneous with therapy and months to years after therapy is complete. Patients can develop a combination of hepatic injuries manifesting during and after treatment. Acute toxic effects of cancer therapy in children include hepatitis, steatosis, steatohepatitis, cholestasis, hemosiderosis, and vascular injury. Longer-term effects of cancer therapy include hepatic fibrosis, chronic liver failure, and development of focal liver lesions. Quantitative imaging techniques can provide useful metrics for disease diagnosis and monitoring, especially in treatment-related diffuse liver injury such as hepatic steatosis and steatohepatitis, hepatic iron deposition, and hepatic fibrosis. Focal liver lesions, including those developing as a result of treatment-related vascular injury such as focal nodular hyperplasia-like lesions and hepatic perfusion anomalies, as well as hepatic infections occurring as a consequence of immune suppression, can be anxiety provoking and confused with recurrent malignancy or hepatic metastases, although there often are imaging features that help elucidate the correct diagnosis. Radiologic evaluation, in conjunction with clinical and biochemical screening, is integral to diagnosing and monitoring hepatic complications of cancer therapy in pediatric patients during therapy and after therapy completion for long-term surveillance. ©RSNA, 2023 Quiz questions for this article are available in the supplemental material See the invited commentary by Ferraciolli and Gee in this issue.
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Carcinoma Hepatocelular , Doença Hepática Crônica Induzida por Substâncias e Drogas , Fígado Gorduroso , Neoplasias Hepáticas , Lesões do Sistema Vascular , Humanos , Criança , Neoplasias Hepáticas/diagnóstico por imagem , Recidiva Local de Neoplasia , Cirrose HepáticaRESUMO
BACKGROUND: Sarcopenia is associated with adverse outcomes following liver transplantation, and at-risk children must be identified and prehabilitated. The gold standard for assessing sarcopenia in end-stage liver disease (ESLD) is CT assessment of the total Psoas Muscle Area (tPMA). However, radiation exposure and sedation requirements make this approach impractical for children. The bilateral anterior thigh thickness (BATT) is the cumulative measurement of the rectus femoris and vastus intermedius muscles by ultrasound and has been used to identify sarcopenia in adults. There are no studies assessing muscle mass in children using ultrasound. We hypothesized that measuring BATT with ultrasound in children with ESLD is feasible and is associated with sarcopenia. METHODS: A prospective pilot feasibility study of patients with ESLD on the liver transplantation waitlist and age-matched healthy controls. BATT was measured by a single operator using ultrasound. tPMA indices were determined by CT imaging, along with clinical and anthropometric data. RESULTS: Thirty children were studied between September 2021 and December 2022, 15 listed patients aged 4-30 months, and 15 controls aged 4-32 months. No major technical challenges or complications were encountered while performing the ultrasounds. Median BATTs of 30.8 mm (interquartile range: 27.9-32.8 mm) versus 32.7 mm (interquartile range: 31.8-36.9 mm) were demonstrated in the ESLD and control groups, respectively, and p = 0.01. A positive correlation (R = 0.603) was demonstrated between BATT and tPMA at the L4-5 level among patients with ESLD. No correlation was observed between BATT and anthropometrics. CONCLUSIONS: This study yields novel data on the feasibility of ultrasound to measure mid-thigh thickness in children with ESLD and suggests a correlation between BATT and tPMA, the gold standard for diagnosing sarcopenia. It sets the stage for ultrasound as a simple, noninvasive, and easily repeatable tool for assessing sarcopenia in children.
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Doença Hepática Terminal , Sarcopenia , Adulto , Humanos , Criança , Sarcopenia/diagnóstico por imagem , Sarcopenia/complicações , Estudos de Viabilidade , Estudos Prospectivos , MúsculosRESUMO
BACKGROUND. Contrast-enhanced MRI is commonly used to evaluate thoracic central venous patency in children and young adults. A flow-independent noncontrast non-ECG-gated 3D MRA-MR venography (MRV) technique described in 2019 as "relaxation-enhanced angiography without contrast and triggering (REACT)" may facilitate such evaluation. OBJECTIVE. The purpose of our study was to compare image quality, diagnostic confidence, and interreader agreement between respiratory-triggered REACT and 3D Dixon-based contrast-enhanced MRV (CE-MRV) for evaluating thoracic central venous patency in children and young adults. METHODS. This retrospective study included 42 consecutive children and young adults who underwent MRI of the neck and chest to evaluate central venous patency between August 2019 and January 2021 (median age, 5.2 years; IQR, 1.4-15.1 years; 22 female patients and 20 male patients). Examinations included respiratory-triggered REACT and navigator-gated CE-MRV sequences based on the institution's standard-of-care protocol. Six pediatric radiologists from four different institutions independently reviewed REACT and CE-MRV sequences; they assessed overall image quality (scale, 1-5; 5 = excellent), diagnostic confidence (scale, 1-5; 5 = extremely confident), and presence of clinically relevant artifact(s). Readers classified seven major central vessels as normal or abnormal (e.g., narrowing, thrombosis, or occlusion). Analysis used Wilcoxon signed rank and McNemar tests and Fleiss kappa coefficients. RESULTS. The distribution of overall image quality scores was higher (p = .02) for REACT than for CE-MRV for one reader (both sequences: median score, 5). Image quality scores were not significantly different between the sequences for the remaining five readers (all p > .05). Diagnostic confidence scores and frequency of clinically relevant artifact(s) were not significantly different between sequences for any reader (all p > .05). Interreader agreement for vessel classification as normal or abnormal was similar between sequences for all seven vessels (REACT: κ = 0.37-0.81; CE-MRV: κ = 0.34-0.81). Pooling readers and vessels, 65.4% of vessels were normal by both sequences; 18.7%, abnormal by both sequences; 9.8%, abnormal by REACT only; and 6.1%, abnormal by CE-MRV only. CONCLUSION. Respiratory-triggered REACT, in comparison with CE-MRV, showed no significant difference in image quality (aside from for one of six readers), diagnostic confidence, or frequency of artifact(s), with similar interreader agreement for vessel classification as normal or abnormal. CLINICAL IMPACT. High-resolution 3D MRV performed without IV contrast material can be used to assess central venous patency in children and young adults.
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Angiografia por Ressonância Magnética , Imageamento por Ressonância Magnética , Humanos , Masculino , Feminino , Adulto Jovem , Criança , Pré-Escolar , Flebografia/métodos , Angiografia por Ressonância Magnética/métodos , Estudos Retrospectivos , Sensibilidade e Especificidade , Meios de Contraste , Imageamento Tridimensional/métodosRESUMO
OBJECTIVES: To assess abnormal liver enhancement on 15-20 min delayed 3D high-resolution late gadolinium enhancement (3D HR LGE) sequence in patients with Fontan circulation. METHODS: Retrospective study of pediatric Fontan patients (< 18 years old) with combined cardiac-liver MRI from January 2018 to August 2021. Abnormal hepatic enhancement was graded (0-3) for each lobe, summed for a total liver enhancement score (0-6), and compared to repaired tetralogy of Fallot (rTOF) patients. Correlations with other hepatic imaging biomarkers were performed. Temporal relationships of enhancement compared to traditional early portal venous and 5-7-min delayed phase liver imaging were analyzed. RESULTS: The Fontan group (n = 35, 13 ± 3.4 years old, median time from Fontan 10 (9-12) years) had 23/35 (66%) with delayed 3D HR LGE total liver enhancement score > 0 (range 0-5), with greater involvement of the right lobe (1 (0-1) vs 0 (0-1), p < 0.01). The rTOF group (n = 35, 14 ± 2.6 years old) had no abnormal enhancement. In the Fontan group, total liver enhancement was 3 (2-4) in the early portal venous phase, lower at 1 (1-2) in the 5-7-min delayed phase (p < 0.01), and lowest at 1 (0-2) in the 15-20-min delayed phase (p = 0.03). 3D HR LGE enhancement correlated inversely with portal vein flow (rs = - 0.42, p = 0.01) and positively with left lobe stiffness (rs = 0.51, p < 0.01). The enhancement score decreased in 13/35 (37%) between the 5-7- and 15-20-min delayed phases. CONCLUSIONS: Liver fibrosis can be assessed on 3D HR LGE sequences in patients with Fontan circulation, correlates with other imaging biomarkers of Fontan liver disease, and may add information for hepatic surveillance in this population. KEY POINTS: ⢠Abnormal liver enhancement on 3D HR LGE sequences in Fontan patients likely represents liver fibrosis and is seen in up to 66% of children and adolescents with variable distribution and severity. ⢠The degree of 3D HR LGE liver enhancement correlates with decreased portal vein flow and increased left hepatic lobe stiffness.
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Técnica de Fontan , Tetralogia de Fallot , Humanos , Criança , Adolescente , Meios de Contraste , Gadolínio , Estudos Retrospectivos , Cirrose Hepática/diagnóstico por imagem , Tetralogia de Fallot/diagnóstico por imagem , Tetralogia de Fallot/cirurgia , Imageamento por Ressonância Magnética/métodos , BiomarcadoresRESUMO
Primary hepatic malignancies are relatively rare in the pediatric population, accounting for approximately 1%-2% of all pediatric tumors. Hepatoblastoma and hepatocellular carcinoma are the most common primary liver malignancies in children under the age of 5 years and over the age of 10 years, respectively. This paper provides consensus-based imaging recommendations for evaluation of patients with primary hepatic malignancies at diagnosis and follow-up during and after therapy.
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Carcinoma Hepatocelular , Hepatoblastoma , Neoplasias Hepáticas , Criança , Humanos , Pré-Escolar , Ressonância de Plasmônio de Superfície , Neoplasias Hepáticas/diagnóstico por imagem , Neoplasias Hepáticas/patologia , Carcinoma Hepatocelular/diagnóstico por imagem , Carcinoma Hepatocelular/epidemiologia , Hepatoblastoma/diagnóstico por imagem , Hepatoblastoma/patologia , Diagnóstico por ImagemRESUMO
A differential diagnosis based on a patient's age, clinical presentation, and serum α-fetoprotein level will help guide the initial imaging workup in children with a liver lesion. Children vary significantly in size, the ability to stay still, and the ability to breath hold for imaging examinations. Choosing and tailoring imaging techniques and protocols for each indication and age group is important for optimal care with minimal invasiveness. The need for sedation or anesthesia can be obviated by using techniques like feed and bundle, distraction, contrast-enhanced US, and motion-insensitive sequences for MRI. US is often the first imaging modality used in children with a suspected abdominal mass. Once a hepatic lesion is confirmed, multiphasic contrast-enhanced MRI is recommended for most lesions as the next imaging modality allowing full characterization of the lesion and assessment of the liver parenchyma. Contrast-enhanced CT can also be performed for assessment of pediatric focal liver lesions, especially in patients who have a contraindication to MRI. Contrast-enhanced US has shown promise to decrease the need for MRI or CT in some lesions such as hemangioma and focal nodular hyperplasia. Children with a history of malignancy can develop multiple types of hepatic lesions at various stages, including infections during an immunocompromised state, manifesting as focal liver lesions. Based on available limited data in the literature and the collective experiences of the Liver Imaging and Reporting Data System Pediatric Working Group, the authors provide guidelines for the imaging workup of pediatric focal liver lesions with an indication- and age-based approach and discuss the selection and performance of various imaging techniques and modalities. ©RSNA, 2022 See the invited commentary by Chojniak and Boaventura in this issue.
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Carcinoma Hepatocelular , Neoplasias Hepáticas , Humanos , Criança , Carcinoma Hepatocelular/patologia , Meios de Contraste , Neoplasias Hepáticas/diagnóstico por imagem , Neoplasias Hepáticas/patologia , Fígado/patologia , Imageamento por Ressonância MagnéticaRESUMO
Longer examination time, need for anesthesia in smaller children and the inability of most children to hold their breath are major limitations of MRI in pediatric body imaging. Fortunately, with technical advances, many new and upcoming MRI sequences are overcoming these limitations. Advances in data acquisition and k-space sampling methods have enabled sequences with improved temporal and spatial resolution, and minimal artifacts. Sequences to minimize movement artifacts mainly utilize radial k-space filling, and examples include the stack-of-stars method for T1-weighted imaging and the periodically rotated overlapping parallel lines with enhanced reconstruction (PROPELLER)/BLADE method for T2-weighted imaging. Similarly, the sequences with improved temporal resolution and the ability to obtain multiple phases in a single breath-hold in dynamic imaging mainly use some form of partial k-space filling method. New sequences use a variable combination of data sampling methods like compressed sensing, golden-angle radial k-space filling, parallel imaging and partial k-space filling to achieve free-breathing, faster sequences that could be useful for pediatric abdominal and thoracic imaging. Simultaneous multi-slice method has improved diffusion-weighted imaging (DWI) with reduction in scan time and artifacts. In this review, we provide an overview of data sampling methods like parallel imaging, compressed sensing, radial k-space sampling, partial k-space sampling and simultaneous multi-slice. This is followed by newer available and upcoming sequences for T1-, T2- and DWI based on these other advances. We also discuss the Dixon method and newer approaches to reducing metal artifacts.
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Meios de Contraste , Processamento de Imagem Assistida por Computador , Humanos , Criança , Processamento de Imagem Assistida por Computador/métodos , Interpretação de Imagem Assistida por Computador/métodos , Imageamento por Ressonância Magnética/métodos , Respiração , Artefatos , Imageamento Tridimensional , Aumento da Imagem/métodosRESUMO
BACKGROUND. Pediatric hepatocellular carcinoma (HCC) is an aggressive malignancy for which imaging findings remain poorly described. In comparison with adult HCC, pediatric HCC more commonly occurs without underlying risk factors, and standardized surveillance guidelines for those with predispositions are lacking. OBJECTIVE. The purpose of this article was to evaluate imaging findings of nonfibrolamellar pediatric HCC and to identify associations between these imaging findings and the presence of predisposing factors. METHODS. This retrospective study included children (≤ 18 years) with histologically confirmed nonfibrolamellar HCC who underwent multiphase CT or MRI at one of four academic children's hospitals between July 2009 and April 2019. Surveillance regimens in children with predispositions were at the discretion of treating physicians. Clinical characteristics were recorded. Scan indications were classified as surveillance versus clinical signs and symptoms. Images from all sites were submitted to a cloud-based server. Two radiologists independently assessed imaging features of HCC, including tumor size, tumor in vein, Pre-Treatment Extent of Tumor (PRETEXT) stage, and LI-RADS major features of adult HCC. Imaging findings were compared between patients with and without predispositions. RESULTS. The study included 39 patients: 17 with predispositions (mean age, 10.5 ± 4.5 years; nine boys, eight girls) and 22 without predispositions (mean age, 11.3 ± 5.1 years; 12 boys, 10 girls). Scan indication was surveillance in 14/17 patients with predispositions versus 0/22 patients without predispositions (p < .001). Patients with versus those without predispositions had smaller tumor size (reader 1: 6.0 vs 11.9 cm [p = .003]; reader 2: 6.0 vs 12.9 cm [p < .001]) and less frequent tumor in vein (reader 1: 0% vs 41% [p = .002]; reader 2: 0% vs 36% [p = .006]). PRETEXT stage IV disease was observed in 18% (both readers) of patients with predispositions versus 50-55% of patients without predispositions. No LI-RADS major feature of adult HCC showed a significant difference in frequency between patients with and without predispositions for either reader (all p > .05). CONCLUSION. Among children with HCC, those with predispositions exhibited smaller and lower-stage tumors and less frequent tumor in vein, likely because of surveillance imaging. CLINICAL IMPACT. The study supports the role of routine surveillance imaging in children with HCC predispositions to facilitate earlier detection. Standardization of surveillance guidelines remains needed.
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Carcinoma Hepatocelular , Neoplasias Hepáticas , Adolescente , Adulto , Carcinoma Hepatocelular/diagnóstico por imagem , Carcinoma Hepatocelular/patologia , Criança , Meios de Contraste , Feminino , Humanos , Neoplasias Hepáticas/diagnóstico por imagem , Neoplasias Hepáticas/patologia , Imageamento por Ressonância Magnética/métodos , Masculino , Estudos Retrospectivos , Fatores de Risco , Sensibilidade e EspecificidadeRESUMO
Purpose: To assess regional blood flow in fasting pediatric patients with Fontan circulation by using MRI and to explore associations with clinical parameters. Materials and Methods: In this retrospective study, pediatric patients who had undergone the Fontan procedure (<18 years of age) and had undergone clinical cardiac MRI, performed after at least 4 hours of fasting, between 2018 and 2021 were included. Regional blood flow was compared with published healthy volunteer data (n = 19) and assessed in relation to hemodynamic parameters and clinical status. Data are presented as medians, with first to third quartiles in parentheses. Mann-Whitney U, Kruskal-Wallis, χ2, and Spearman rank correlation tests were used. Results: Fifty-five patients (38 boys) with median age at MRI of 14 years (IQR, 11-16 years) and median time from Fontan procedure to MRI of 10 years (IQR, 8-12 years) were included. Patients after Fontan procedure had lower ascending aortic, inferior vena cava, and total systemic blood flow compared with healthy volunteers (3.00 L/min/m2 [IQR, 2.75-3.30 L/min/m2] vs 3.61 L/min/m2 [IQR, 3.29-4.07 L/min/m2]; 1.73 L/min/m2 [IQR, 1.40-1.94 L/min/m2] vs 2.24 L/min/m2 [IQR, 2.06-2.75 L/min/m2]; 2.78 L/min/m2 [IQR, 2.45-3.10 L/min/m2] vs 3.95 L/min/m2 [IQR, 3.20-4.30 L/min/m2], respectively; P < .001). Portal vein flow was greater than hepatic vein flow in 25% of patients. Fontan blood flow was inversely correlated with pre-Fontan mean pulmonary artery pressure (Spearman rank correlation coefficient [rs ]= -0.42, P = .005) and ventricular end diastolic pressure (rs = -0.33, P = .04) and positively correlated with post-Fontan percent predicted oxygen consumption at peak workload (rs = 0.34, P = .02). Conclusion: Reference ranges are provided for regional systemic blood flow derived by using MRI in fasting pediatric patients with Fontan circulation, who had lower systemic blood flow compared with healthy volunteers. Lower fasting Fontan blood flow correlated with lower exercise capacity.Keywords: Pediatrics, Heart, Congenital, MR Imaging, Hemodynamics/Flow Dynamics, Cardiac Supplemental material is available for this article. © RSNA, 2022.
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BACKGROUND: Dynamic contrast-enhanced magnetic resonance imaging (MRI) of the liver in pediatric Fontan patients often shows peripheral reticular areas of hypoenhancement, which has not been studied in detail. OBJECTIVE: To semiquantitatively score the hepatic MR perfusion abnormality seen in pediatric Fontan patients, and to correlate the perfusion abnormality with functional clinical and hemodynamic parameters. MATERIALS AND METHODS: All children (< 18 years old) after Fontan palliation with combined clinical cardiac and liver MRI performed between May 2017 and April 2019 were considered for inclusion. A semiquantitative perfusion score was used to assess the severity of the hepatic reticular pattern seen on dynamic contrast-enhanced liver imaging. The liver was divided into four sections: right posterior, right anterior, left medial and left lateral. Each liver section was assigned a score from 0 to 4 depending on the amount of abnormal reticular hypoenhancement. Scoring was assigned for each section of the liver across eight successive dynamic contrast-enhanced modified spoiled gradient echo runs. Scores were correlated with clinical and hemodynamic parameters. RESULTS: All Fontan children showed hepatic reticular hypoenhancement by MRI, most severe in the early portal venous phase with a median maximum total perfusion abnormality score of 12 (range: 9-14). All perfusion abnormalities progressively resolved during the hepatic venous phase. Perfusion abnormality scores were greatest in the right compared to left hepatic lobes (7 range: [6-8] vs. 5 [range: 3-6], P < 0.01). The maximum left hepatic lobe perfusion abnormality scores were greatest in children with versus without imaging signs of portal hypertension (8 [range: 7-8] vs. 4 [range: 3-5], P < 0.01). High unconjugated bilirubin and low platelets correlated with greater perfusion abnormality (R = 0.450, P = 0.024, and R = - 0.458, P < 0.01, respectively). Age at MRI, time from Fontan, focal liver lesions and cardiac MRI hemodynamic parameters did not show significant correlations with the severity of the liver perfusion abnormality. CONCLUSION: All Fontan children have hepatic reticular hypoenhancement abnormalities seen with MRI that are most severe in the right hepatic lobe and universally show gradual resolution through the hepatic venous phase. Perfusion abnormality in the left hepatic lobe is worse in children with portal hypertension.
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Técnica de Fontan , Hipertensão Portal , Adolescente , Criança , Humanos , Fígado/diagnóstico por imagem , Fígado/patologia , Cirrose Hepática/patologia , Imageamento por Ressonância Magnética/métodos , Espectroscopia de Ressonância Magnética , PerfusãoRESUMO
Magnetic resonance imaging is used for evaluating focal liver lesions, hepatic vascular diseases, biliary diseases and diffuse liver diseases in children. MRI examinations take a long time, often requiring sedation or anesthesia in smaller children. This makes it essential to understand the concepts and technique necessary to obtain an optimal examination for answering the clinical question while minimizing the need for sedation/anesthesia. We discuss key concepts including appropriate sequence selection, choice of contrast media, dynamic imaging, phases of contrast enhancement and protocol organization.
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Gadolínio DTPA , Neoplasias Hepáticas , Criança , Meios de Contraste , Humanos , Fígado/diagnóstico por imagem , Imageamento por Ressonância Magnética , Espectroscopia de Ressonância MagnéticaRESUMO
This review introduces the basic principles of contrast-enhanced magnetic resonance (MR) angiography and details four contrast-enhanced MR angiography sequences for body imaging with extracellular gadolinium-based contrast agents in pediatric patients. Specifically, this review covers (1) respiratory-navigated, cardiac-gated MR angiography; (2) time-resolved MR angiography; (3) conventional MR angiography; and (4) modified spoiled gradient echo variants. We present and discuss indications, technical considerations, sequence optimization, advantages and disadvantages, along with practical tips and illustrative case examples for each sequence.
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Meios de Contraste , Angiografia por Ressonância Magnética , Criança , Humanos , Imageamento por Ressonância MagnéticaRESUMO
Neonatal hemochromatosis is a rare condition that causes neonatal liver failure, frequently resulting in fetal loss or neonatal death. It is thought that most cases of neonatal hemochromatosis are caused by gestational alloimmune liver disease (GALD), with neonatal hemochromatosis being a phenotype of GALD rather than a disease process. Extrahepatic siderosis in the pancreas, myocardium, thyroid and minor salivary gland is a characteristic feature of neonatal hemochromatosis. There is also sparing of the reticuloendothelial system with no iron deposition in the spleen. Hepatic and extrahepatic siderosis seen in neonatal hemochromatosis is from iron dysregulation secondary to liver damage rather than iron deposition causing the liver damage. The presence of extrahepatic siderosis in the pancreas and thyroid is diagnostic of neonatal hemochromatosis and can be detected noninvasively by multi-echo gradient recalled echo (GRE) T2*-weighted sequence of MRI within hours of birth. This helps to expedite the treatment in the form of intravenous immunoglobulin and exchange transfusion, which improves the survival in these babies. The finding of hepatic siderosis is nonspecific and does not help in the diagnosis of neonatal hemochromatosis because it is seen with other causes of advanced liver disease.