Comparison between whole-body magnetic resonance imaging and whole-body metaiodobenzylguanidine scintigraphy in the evaluation of primary tumor and metastases in neuroblastoma.

BACKGROUND: Whole-body metaiodobenzylguanidine (131 I-MIBG) scintigraphy is the gold standard method to detect neuroblastoma; however, it depends on radioactive material and is expensive. In contrast, whole-body magnetic resonance imaging (WB-MRI) is affordable in developing countries and has been shown to be effective in the evaluation of solid tumors. This study aimed to compare the sensitivity and specificity of WB-MRI with MIBG in the detection of primary tumors and neuroblastoma metastases. PROCEDURE: This retrospective study enrolled patients with neuroblastoma between 2013 and 2020. All patients underwent WB-MRI and MIBG at intervals of up to 15 days. The results were marked in a table that discriminated anatomical regions for each patient. Two experts evaluated, independently and in anonymity, the WB-MRI images, and two others evaluated MIBG. The results were compared in terms of sensitivity and specificity, for each patient, considering MIBG as the gold standard. This study was approved by the UNIFESP Ethics Committee. RESULTS: Thirty patients with neuroblastoma were enrolled in this study. The age ranged from 1 to 15 years, with a mean of 5.7 years. The interval between exams (WB-MRI and MIBG) ranged from 1 to 13 days, with an average of 6.67 days. Compared to MIBG, WB-MRI presented a sensitivity and specificity greater than or equal to 90% for the detection of primary neuroblastoma in bones and lymph nodes. When we consider the patient without individualizing the anatomical regions, WB-MRI presented sensitivity of 90% and specificity of 73.33%. CONCLUSION: In conclusion, WB-MRI is a sensitive and specific method to detect neuroblastoma in bone and lymph nodes and highly sensible to primary tumor diagnosis, suggesting that this test is a viable alternative in places where MIBG is difficult to access. Studies with a larger number of cases are necessary for definitive conclusions.

Similarities and controversies in imaging of pediatric renal tumors: A SIOP-RTSG and COG collaboration.

Malignant renal tumors are rare in children, and Wilms tumors (WTs) are the most common subtype. Imaging plays an essential role in the diagnosis, staging, and follow-up of these patients. Initial workup for staging is mainly performed by cross-sectional imaging modalities such as computed tomography (CT) and magnetic resonance imaging (MRI). Imaging approach within the two core international groups, the Children's Oncology Group (COG, North America) and the International Society of Pediatric Oncology - Renal Tumor Study Group (SIOP-RTSG, Europe), differs. Whereas abdominal ultrasound (US) is used for the initial diagnosis of a suspected pediatric renal tumor globally, COG protocols support the use of CT or MRI for locoregional staging, contrary to the preference for MRI over CT for abdominopelvic evaluation within the SIOP-RTSG. The purpose of this manuscript is to summarize current imaging approaches, highlighting differences and similarities within these core international groups, while focusing on future innovative efforts and collaboration within the HARMONICA initiative.

MRI Characteristics of Pediatric Renal Tumors: A SIOP-RTSG Radiology Panel Delphi Study.

BACKGROUND: The SIOP-Renal Tumor Study Group (RTSG) does not advocate invasive procedures to determine histology before the start of therapy. This may induce misdiagnosis-based treatment initiation, but only for a relatively small percentage of approximately 10% of non-Wilms tumors (non-WTs). MRI could be useful for reducing misdiagnosis, but there is no global consensus on differentiating characteristics. PURPOSE: To identify MRI characteristics that may be used for discrimination of newly diagnosed pediatric renal tumors. STUDY TYPE: Consensus process using a Delphi method. POPULATION: Not applicable. FIELD STRENGTH/SEQUENCE: Abdominal MRI including T1- and T2-weighted imaging, contrast-enhanced MRI, and diffusion-weighted imaging at 1.5 or 3 T. ASSESSMENT: Twenty-three radiologists from the SIOP-RTSG radiology panel with ≥5 years of experience in MRI of pediatric renal tumors and/or who had assessed ≥50 MRI scans of pediatric renal tumors in the past 5 years identified potentially discriminatory characteristics in the first questionnaire. These characteristics were scored in the subsequent second round, consisting of 5-point Likert scales, ranking- and multiple choice questions. STATISTICAL TESTS: The cut-off value for consensus and agreement among the majority was ≥75% and ≥60%, respectively, with a median of ≥4 on the Likert scale. RESULTS: Consensus on specific characteristics mainly concerned the discrimination between WTs and non-WTs, and WTs and nephrogenic rest(s) (NR)/nephroblastomatosis. The presence of bilateral lesions (75.0%) and NR/nephroblastomatosis (65.0%) were MRI characteristics indicated as specific for the diagnosis of a WT, and 91.3% of the participants agreed that MRI is useful to distinguish NR/nephroblastomatosis from WT. Furthermore, all participants agreed that age influenced their prediction in the discrimination of pediatric renal tumors. DATA CONCLUSION: Although the discrimination of pediatric renal tumors based on MRI remains challenging, this study identified some specific characteristics for tumor subtypes, based on the shared opinion of experts. These results may guide future validation studies and innovative efforts. LEVEL OF EVIDENCE: 3 Technical Efficacy Stage: 3.

The Role of Whole-Body MRI in Pediatric Musculoskeletal Oncology: Current Concepts and Clinical Applications.

Whole-body magnetic resonance imaging (WB-MRI) has gained importance in the field of musculoskeletal oncology over the last decades, consisting in a one-stop imaging method that allows a wide coverage assessment of both bone and soft tissue involvement. WB-MRI is valuable for diagnosis, staging, and follow-up in many oncologic diseases and is especially advantageous for the pediatric population since it avoids redundant examinations and exposure to ionizing radiation in patients who often undergo long-term surveillance. Its clinical application has been studied in many pediatric neoplasms, such as cancer predisposition syndromes, Langerhans cell histiocytosis, lymphoma, sarcomas, and neuroblastoma. The addition of diffusion-weighted sequences allows functional evaluation of neoplastic lesions, which is helpful in the assessment of viable tumor and response to treatment after neoadjuvant or adjuvant therapy. WB-MRI is an excellent alternative to fluorodeoxyglucose-positron emission tomography/computed tomography in oncologic children, with comparable accuracy and the convenience of being radiation-free, fast to perform, and available at a similar cost. The development of new techniques and protocols makes WB-MRI increasingly faster, safer, and more accessible, and it is important for referring physicians and radiologists to recognize the role of this imaging method in pediatric oncology. LEVEL OF EVIDENCE: 4 TECHNICAL EFFICACY STAGE: 2.

Ultrasound as a Valuable Imaging Modality in Sclerosing Lymphocytic Lobulitis: Imaging Features Based on a Retrospective Cohort Analysis of 51 Cases.

PURPOSE: Sclerosing lymphocytic lobulitis (SLL) is a rare benign breast condition usually associated with diabetes mellitus and whose imaging features have been assessed in few studies, limiting the adoption of diagnostic guidelines. We aimed to identify the main morphological features associated with SLL on imaging examinations (mainly ultrasound and mammography) and to retrospectively evaluate the role that each method played in the diagnostic workup (detection and indication for biopsy). METHODS: A retrospective study was conducted in a high-volume single center, encompassing 51 consecutive patients (100% female; 26-78 y; 43.7 ± 15.5 y) with histopathologically proven SLL (59 lesions; 0.5-6.1 cm). RESULTS: Most lesions (31/59; 53%) were found in asymptomatic individuals. Ultrasound detected 91.1% (51 out of 56 lesions assessed by this modality), of which 94.1% were non-circumscribed masses (BI-RADS® 4). Mammography detected 41.6% (15 out of 36 lesions assessed by this modality), with a predominance (80%) of non-calcified ones (masses, asymmetries and distortion). Two-year follow-up was achieved in 29 lesions (49%), showing complete remission (45%) or stability (41%) in most cases. CONCLUSIONS: Most lesions in this retrospective sample have been detected by means of ultrasound and had their need for biopsy indicated by this modality. Female diabetic patients younger than 40 years presenting with a palpable lesion and a non-circumscribed mass on ultrasound could be submitted to core biopsy; histopathologic findings suggestive of SLL should be considered concordant in this scenario, with subsequent conservative treatment.

Adiponectin is Increased in Pediatric Patients With Autoimmune Hepatitis Independent of Body Weight.

OBJECTIVE: A high prevalence of obesity is reported in children and adolescents with autoimmune hepatitis (AIH). Adipokines participate in inflammatory processes. The objective of this study was to examine the relationship between excess weight and systemic inflammation, adipokines, and ghrelin in adolescents with AIH. METHOD: This case-controlled study included 27 adolescents with AIH (13 with excess weight and 14 with normal weight) and a control group. Excess weight was defined by a body mass index/age Z score >+1 standard deviation. Adipokines (adiponectin, leptin, tumor necrosis factor alpha, interleukin 6 [IL-6], and IL-10) and ghrelin were measured with Luminex technology. RESULTS: Adiponectin (µg/mL) was higher (P < 0.001) in AIH adolescents with and without excess weight (median: 35.0 and 42.1, respectively) than in normal-weight (17.5) and excess-weight (17.0) controls. Leptin was higher (P < 0.001) in excess-weight AIH patients (18.0 ng/mL) and controls (19.8 ng/mL) than in normal-weight AIH (7.7 ng/mL) and control (7.0 ng/mL) adolescents. IL-6 levels were higher in excess-weight (3.8 pg/mL) and normal-weight (3.8 pg/mL) AIH patients than in excess-weight (1.1 pg/mL) and normal-weight (0.5 pg/mL) controls. IL-10 levels were higher (5.2 pg/mL) in normal-weight AIH patients than in excess-weight (1.8 pg/mL) and normal-weight (2.1 pg/mL) controls. Ferritin levels were lower in patients with AIH than in controls. CONCLUSIONS: Independent of body weight, AIH patients had higher levels of adipokines, especially adiponectin and IL-6. Leptin levels were associated with body weight and were not influenced by AIH. IL-10 levels were associated with lean tissue in AIH.

Temporal and Sequential Analysis of the Pharyngeal Phase of Swallowing in Poststroke Patients.

The purpose of this study was to conduct a quantitative analysis of the temporal and sequential events of the pharyngeal phase of swallowing in 45 poststroke patients who presented or did not present with supraglottic penetration and/or laryngotracheal aspiration and to compare the groups with each other and to a group of 46 patients with normal swallowing. All individuals were assessed by videofluoroscopy and the temporal and sequential measures for the swallowing of 3 mL and 5 mL of thickened liquid, 3 mL of liquid, and 3 mL and 5 mL of pasty were obtained by analyzing the recorded exams on Virtual Dub software. The following events were measured: time of maximal displacement and sustaining of the hyoid and larynx, duration of velopharyngeal sphincter (VS) and supraglottic closure, total inversion time of the epiglottis, duration of pharyngeal constriction, and duration of upper esophageal sphincter (UES) opening. For the analysis of the temporal sequence, the initial time of larynx and hyoid elevation, VS closure, epiglottic inversion, supraglottic closure, pharyngeal constriction, and opening of the UES were obtained. For 5 mL of thickened liquid, the maximum hyoid elevation time was greater for patients with normal swallowing and the time the supraglottis remained closed was higher in the aspirators group. The time of pharyngeal constriction during swallowing of 3 mL of thickened liquid was lower in the aspirators group. During the swallowing of 3 mL of thin liquid, it was observed that in the aspirators group, the larynx took longer to reach its maximum elevation and the epiglottis took longer to complete its total inversion. The analysis of the temporal sequence showed that patients in the aspirators group presented greater disorganization with significant alteration of the time interval between the events.

Can diffusion-weighted whole-body MRI replace contrast-enhanced CT for initial staging of Hodgkin lymphoma in children and adolescents?

BACKGROUND: Although positron emission tomography with 18F-fluoro-2-deoxyglucose (FDG-PET/CT) has been recommended as the method of choice for lymphoma staging, it has limited availability in several countries, therefore, studies comparing whole-body magnetic resonance imaging (MRI) to conventional staging methods or to FDG-PET/CT are an important tool to establish whole-body MRI as an alternative to these methods. OBJECTIVE: To compare whole-body MRI versus conventional imaging methods for staging of Hodgkin lymphoma in children and adolescents. MATERIALS AND METHODS: The study included 22 patients ages 5 to 21 years. Staging was performed using conventional imaging methods and whole-body MRI. Conventional imaging methods were defined as computed tomography (CT) of the neck, chest, abdomen and pelvis and ultrasonography of the neck and/or abdomen. We calculated the sensitivity of these methods for Hodgkin lymphoma staging and their sensitivity and specificity for detecting sites of nodal and extranodal involvement. RESULTS: The sensitivity of whole-body MRI for Hodgkin lymphoma staging was superior to that of conventional imaging methods (95.5% vs. 86.4%, respectively), but both methods had similar sensitivity and specificity for detecting involvement of nodal sites (99.1% and 100% vs. 97.3% and 100%, respectively) and extranodal sites (90.5% and 98.7% vs. 90.5% and 99.4%, respectively). CONCLUSION: Whole-body MRI has excellent sensitivity for staging of Hodgkin lymphoma in children and adolescents. It can thus be considered an alternative for this purpose, particularly because it does not expose patients to ionizing radiation.

Preliminary report from the World Health Organisation Chest Radiography in Epidemiological Studies project.

Childhood pneumonia is among the leading infectious causes of mortality in children younger than 5 years of age globally. Streptococcus pneumoniae (pneumococcus) is the leading infectious cause of childhood bacterial pneumonia. The diagnosis of childhood pneumonia remains a critical epidemiological task for monitoring vaccine and treatment program effectiveness. The chest radiograph remains the most readily available and common imaging modality to assess childhood pneumonia. In 1997, the World Health Organization Radiology Working Group was established to provide a consensus method for the standardized definition for the interpretation of pediatric frontal chest radiographs, for use in bacterial vaccine efficacy trials in children. The definition was not designed for use in individual patient clinical management because of its emphasis on specificity at the expense of sensitivity. These definitions and endpoint conclusions were published in 2001 and an analysis of observer variation for these conclusions using a reference library of chest radiographs was published in 2005. In response to the technical needs identified through subsequent meetings, the World Health Organization Chest Radiography in Epidemiological Studies (CRES) project was initiated and is designed to be a continuation of the World Health Organization Radiology Working Group. The aims of the World Health Organization CRES project are to clarify the definitions used in the World Health Organization defined standardized interpretation of pediatric chest radiographs in bacterial vaccine impact and pneumonia epidemiological studies, reinforce the focus on reproducible chest radiograph readings, provide training and support with World Health Organization defined standardized interpretation of chest radiographs and develop guidelines and tools for investigators and site staff to assist in obtaining high-quality chest radiographs.

Microcephaly and Zika virus: neonatal neuroradiological aspects.

PURPOSE: The aim of this study is to describe some radiological features in the newborns with microcephaly caused by Zika virus infection during pregnancy. METHODS: We radiologically analyzed 13 cases of newborns with microcephaly born to mothers who were infected by the Zika virus in the early stage of pregnancy. RESULTS: The most frequently observed radiological findings were microcephaly and decreased brain parenchymal volume associated with lissencephaly, ventriculomegaly secondary to the lack of brain tissue (not hypertensive), and coarse and anarchic calcifications mainly involving the subcortical cortical transition, and the basal ganglia. CONCLUSIONS: Although it cannot be concluded that there is a definitive pathognomonic radiographic pattern of microcephaly caused by Zika virus, gross calcifications and anarchic distribution involving the subcortical cortical transition and the basal ganglia, in association with lissencephaly and in the absence of hypertensive ventriculomegaly, are characteristic of this type of infection.

Low-dose radiation protocol using 3D mode in a BGO PET/CT.

BACKGROUND: The use of positron emission tomography combined with computed tomography (PET/CT) has brought about significant technological advancement in diagnostic imaging, and a number of PET/CT scanners with bismuth germanate detectors can perform imaging in both 2D and 3D acquisition modes. Nevertheless, certain image acquisition parameters and physical features of patients have to be considered when designing low-dose protocols in the 3D mode. PURPOSE: The aim of this study was to compare images acquired in 2D and 3D modes and establish a low-dose protocol for use in PET/CT imaging, decreasing patient exposure to radiation without compromising results. METHODS: A total of 30 patients, aged 4-72 years, participated in this prospective study, which was conducted at Albert Einstein Hospital, São Paulo, Brazil. Images were evaluated for picture quality, presence/absence of lesions and the number of lesions that were detectable in both acquisition modes. RESULTS: The results consistently showed that the loss in image quality in the 3D mode did not affect exam interpretation and lesion detection when compared with 2D at higher dose and for a longer time. CONCLUSIONS: We therefore conclude that administration of 3.7 MBq [(18)F]-fluorodeoxyglucose (FDG)/kg for an acquisition time of 3 min per FOV (field of view) is optimal for image acquisition in the 3D mode. This protocol, which reduces the acquisition time and radiation dose, is quite beneficial, especially for children.

Takayasu arteritis in a Brazilian multicenter study: children with a longer diagnosis delay than adolescents.

OBJECTIVES: To evaluate and compare demographic, clinical, laboratory and angiographic data of Brazilian children and adolescents with Takayasu's arteritis. METHODS: In this Brazilian multicentre, retrospective study which included 10 paediatric rheumatology centres, we identified 71 children and adolescents with Takayasu's arteritis which were diagnosed before their 19th birthday. The patients' demographic, clinical, laboratorial and angiographic data were recorded. The participants were divided into two groups: children, defined by the WHO as younger than 10 years old (group 1: 36 patients) and adolescents, defined as individuals aged 10 to 19 years old (group 2: 35 patients). Features of both groups concerning disease manifestations were compared. RESULTS: A total of 21 (58.3%) patients in group 1 and 30 (85.7%) patients in group 2 were girls (p=0.01). The mean age at disease onset, the mean time to diagnosis, and the mean follow-up time were 5.7 and 12.7, 1.8 and 0.7, 7.2 and 3.6 years, respectively, in groups 1 and 2 (p<0.001, 0.001 and <0.001). At initial evaluation, constitutional symptoms (77.5%) were the most predominant symptoms and decreased peripheral pulses (85.9%) was the most predominant clinical sign without differences between groups. The main laboratory findings were increased erythrocyte sedimentation rate followed by leukocytosis. Anaemia, thrombocytosis and higher platelet levels were significantly more frequent in group 1 (p=0.031, 0.001 and 0.018). Angiographic data were similar in both groups. CONCLUSIONS: Children presented more laboratory abnormalities but clinical and angiographic characteristics were similar to those presented by the adolescents. Diagnosis delay is longer in younger patients.

Aerobic plus resistance training was more effective in improving the visceral adiposity, metabolic profile and inflammatory markers than aerobic training in obese adolescents.

The purpose of this study was to determine whether aerobic plus resistance training (AT + RT) is more effective than aerobic training (AT) at reducing inflammatory markers and cardiovascular risk in obese adolescents. A total of 139 obese adolescents were enrolled, aged 15-19 years, body mass index (BMI) ≥ 95th percentile and participated in 1 year of interdisciplinary intervention. They were randomised into two groups: AT (n = 55), AT + RT (n = 61). Blood samples were collected to analyse glycaemia, insulin, the lipid profile, leptin and adiponectin concentrations. Insulin resistance was measured by homeostasis model assessment of insulin resistance index (HOMA-IR). The AT + RT group showed better results with regard to decreased body fat mass, low-density lipoprotein concentration (LDL-c) levels, subcutaneous and visceral fat and increased body lean mass. Indeed, a reduction of hyperleptinaemia and an increase in adiponectin concentrations, promoting an improvement in the leptin/adiponectin ratio, was observed. Important clinical parameters were improved in both types of exercise; however, AT + RT was more effective in improving the visceral adiposity, metabolic profile and inflammatory markers than AT alone, suggesting clinical applications for the control of intra-abdominal obesity and cardiovascular risk in the paediatric population.

The role of PET/CT in assessing pulmonary nodules in children with solid malignancies.

OBJECTIVE. The purpose of this article is to assess the feasibility and utility of PET/CT in distinguishing benign from malignant pulmonary nodules in patients with solid childhood malignancies. SUBJECTS AND METHODS. This prospective study was conducted between March 2008 and August 2010. We enrolled 25 subjects 21 years old or younger with solid childhood malignancies and at least one pulmonary nodule measuring 0.5-3.0 cm. PET/CT was performed within 3 weeks of diagnostic chest CT. Three panels of three reviewers each reviewed diagnostic CT only (panel 1), PET/CT only (panel 2), or diagnostic CT and PET/CT concurrently (panel 3) and predicted each nodule's histologic diagnosis as benign, malignant, or indeterminate. Interreviewer agreement was assessed with the kappa statistic. Using nodule biopsy or clinical follow-up as reference standards, the sensitivity, specificity, and accuracy for each panel was assessed. Logistic regression was used to assess the nodule's maximum standardized uptake value (SUVmax) association with its histologic diagnosis. RESULTS. There were 75 nodules with a median size of 0.74 cm (range, 0.18-2.38 cm); 48 nodules were malignant. Sensitivity was 85% (41/48) for panel 1, 60% (29/48) for panel 2, and 67% (32/48) for panel 3. All panels had poor specificities. Interreviewer agreement was moderate for panel 1 (0.43) and poor for panels 2 (0.22) and 3 (0.33). SUVmax was a significant predictor of histologic diagnosis (p = 0.004). CONCLUSION. PET/CT assessment of pulmonary nodules is feasible in children with solid malignancies but may not reliably improve our ability to predict a nodule's histologic diagnosis. The SUVmax may improve the performance of PET/CT in this setting.

MRI Findings of Desmoplastic Infantile Ganglioglioma: A Case Report and Analysis.

Desmoplastic infantile gangliogliomas (DIG) are rare intracranial tumors that predominantly affect children. They are characterized by a mixture of glial and neuronal components interspersed with abundant fibrous stroma and are typically located on the surface of the cerebral hemispheres. In this case report, we present a seven-year-old male child with a late presentation of DIG, which is typically diagnosed between zero and 60 months of age. We discuss the MRI findings, clinical symptoms, and differential diagnosis of DIG in patients with this central nervous system tumor.

Whole-Body MRI in Musculoskeletal Oncology: A Comprehensive Review with Recommendations.

Whole-body (WB) MRI has emerged as an attractive method for oncologic evaluation, potentially replacing conventional imaging modalities and providing a one-step wide-coverage assessment of both the skeleton and soft tissues. In addition to providing anatomic information, WB MRI may also yield a functional analysis with the inclusion of diffusion-weighted imaging (DWI). DWI translates microstructural changes, resulting in an excellent alternative to fluorodeoxyglucose PET/CT. WB MRI (with DWI) offers comparable accuracy to PET/CT and has the advantage of avoiding ionizing radiation. Technological advances and the development of faster protocols have prompted greater accessibility of WB MRI, with growing applications in routine practice for the diagnosis, staging, and follow-up of cancer. This review discusses the technical considerations, clinical applications, and accuracy of WB MRI in musculoskeletal oncology. Keywords: Pediatrics, MR Imaging, Skeletal-Axial, Skeletal-Appendicular, Soft Tissues/Skin, Bone Marrow, Extremities, Oncology, Musculoskeletal Imaging © RSNA, 2023.