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The role of post-mortem fetal conventional autopsy (CA) is undisputed but poses challenges with small, macerated bodies, and increasing parental refusal. Fetal post-mortem magnetic resonance imaging (PMMRI) is a less invasive alternative that can be used for assessment of the brain, including the posterior fossa (PF) structures. The purpose of this study was to evaluate the imaging characteristics of the PF in PMMRI compared to antenatal MRI (ANMRI), using CA as the gold standard. A retrospective, single-center study of ten fetuses who underwent ANMRI, PMMRI, and CA from August 2010 to May 2018. The PF structures were evaluated qualitatively for imaging findings, and quantitatively by obtaining the transcerebellar diameter, vermian length, brainstem thickness, width of the fourth ventricle and cisterna magna, skull base angles, and PF volume. Twenty MRI exams were included. The median gestational age of ANMRI was 21.7 weeks. The median age at termination of pregnancy (TOP) and PMMRI was 23.7 weeks. There was good congruence between PMMRI, ANMRI, and CA, with 60% complete congruence and 40% partial congruence between ANMRI and PMMRI. PMMRI and CA showed 70% complete congruence, and 20% partial congruence. No incongruence was noted. PF evaluation on CA was not possible in 1 case due to maceration. Quantitative evaluation in PMMRI showed significant enlargement of most PF structures compared to ANMRI and smaller CSF-filled spaces (p value < 0.05). PMMRI is an acceptable imaging modality for the macroscopic evaluation of PF structures. Smaller CSF-filled spaces and enlargement of the brain are expected findings when evaluating PMMRI.

Pediatric thyroid cancer is rare in children, however incidence is increasing. Papillary thyroid cancer and follicular thyroid cancer are the most common subtypes, comprising about 90% and 10% of cases respectively. This manuscript provides consensus imaging recommendations for evaluation of pediatric patients with thyroid cancer at diagnosis and during follow-up.

The petrous apex (PA) is involved in a myriad of pathological conditions, some of which are exclusive in children. Diagnosis may be difficult due to vague clinical presentation, and local examination is challenging owing to its inaccessible location. This is further complicated by multiple unfused sutures and ongoing PA pneumatization in children. Cross-sectional imaging is vital for the evaluation of the PA lesions, due to their precarious location and proximity to the major neurovascular structures. Several classification systems have been proposed for these lesions based on their site of origin, solid or cystic appearance, surgical or non-surgical (no touch lesions) management, and benign or malignant nature. In this article, we emphasize the distinctive role of different cross-sectional imaging modalities in the diagnosis of pediatric PA lesions, with special attention to normal variants that should not be mistaken for pathology. We also propose a radiological classification and algorithmic approach to aid in the precise diagnosis and facilitate appropriate management of the various PA lesions in children.

Idiopathic intracranial hypertension, or pseudotumor cerebri, is an increase in cerebrospinal fluid pressure of unknown etiology. It is mostly seen in adults, less frequently in adolescents, rarely in younger children. Only 5 infants meeting idiopathic intracranial hypertension criteria have been mentioned in the literature. We report a case of a previously healthy 9-month-old boy who presented with irritability, decreased appetite, and a bulging fontanelle. Computed tomography (CT) head imaging and cerebrospinal fluid studies revealed normal results. The patient’s symptoms transiently resolved after the initial lumbar puncture, but 11 days later, his fontanelle bulged again. A second lumbar puncture revealed an elevated opening pressure of 35 cmH2O and led to a diagnosis of idiopathic intracranial hypertension in accordance with the modified Dandy Criteria. Treatment with acetazolamide at a dose of 25 mg/kg/d was initiated and the patient remained symptom-free for 6 weeks, followed by another relapse. His acetazolamide dose was increased to 37 mg/kg/d, with no further relapses to date. A diagnosis of idiopathic intracranial hypertension is challenging in infants, because the patients cannot yet verbalize typical idiopathic intracranial hypertension–related symptoms such as positional headaches, diplopia, or pulsatile tinnitus. Furthermore, it is more difficult to assess papilledema in that age group. If undetected and untreated, idiopathic intracranial hypertension may result in permanent visual deficits. Little is known about idiopathic intracranial hypertension in infants, and age-specific treatment guidelines are lacking. We discuss this rare case of infantile idiopathic intracranial hypertension and provide a review of the literature, including an overview of disease characteristics and outcomes of idiopathic intracranial hypertension in this very young age group.

Objectives To evaluate the benefits and clinical significance of retrospectively generated spectral image-datasets with the novel detector-based Spectral CT (SDCT). Methods A total of 118 body CTs from the SDCT prototype were included. Based on the clinical indication, two radiologists were asked if they would have opted for a dual-energy mode/scan if the patient was scanned in one of the other commercially-available dual-energy scanners, which need prospective selection of dual energy mode. They also reviewed the scans, identified cases that would benefit from spectral images and evaluated these images for clinical utility and significance on a five-point scale, with 1 being the least and 5 being the highest. Results Dual-energy mode would have been prospectively selected in 20 cases (17%) for Reader 1 and 25 cases (21%) for Reader 2. Additional spectral images were requested for 94 cases (80%) and 96 cases (81%) respectively. A total of 196 and 206 spectral image-sets were utilized respectively with 97% and 96% of these image-sets useful retrospectively. The distribution of scores on the five-point scale for Readers 1 and 2 were, 1 –7% & 6%; 2 –26% & 30%; 3 –36% & 36%; 4 –27% & 21% and; 5 –4% & 7%. Clinically significant score (≥4) was noted in 31% and 28% respectively. Conclusions Additional spectral datasets retrospectively reconstructed from SDCT enhanced the diagnostic capabilities by reducing artifacts, improving contrast and allowing lesion characterization.

Individual ultrasound (US) features have limited ability to distinguish benign from malignant thyroid nodules. Adult-based systems have been developed to integrate the sonographic features in an effort to improve diagnostic accuracy. None, however, has been validated in children, in whom the likelihood of malignancy is 2–5 times higher than adults. To assess the performance of two adult-based sonographic (US) stratification methods for assessment of thyroid nodules in children. This retrospective study comprised 124 children who underwent thyroid US. Three radiologists reviewed the US data using the American Thyroid Association (ATA) and the Thyroid Image Reporting and Data System (TI-RADS). Radiologists’ accuracy and agreement was assessed. The reference standard was histopathology/cytology or 2-year follow-up of clinical outcome for nonoperative cases. We assessed 71 benign and 52 malignant nodules and excluded 1 nodule. Using the ATA pattern descriptions, 80% of malignant nodules were classified as “high” 36/52 (69%) or “intermediate” 6/52 (11%) likelihood of malignancy. A total of 20/71 (28%) benign nodules were also classified within these two categories. Using the TI-RADS, malignant nodules were classified as 2, 3, 4a, 4b, 4c and 5, with rate of malignancy of 0%, 0%, 7/52 (13.5%), 7/52 (13.5%), 32/52 (61.5%) and 6/52 (11.5%), respectively. Benign nodules were also classified in the 4a (26/71; 36.6%), 4b (17/71; 24%), 4c (14/71; 19.7%) and 5 (1/71; 1.4%) categories. The positive and negative predictive values were 68.0% and 87.5% for ATA, and 71.7% and 80.0% for TI-RADS. We validated the use of ATA and TI-RADS methods in children and showed that they have test characteristics similar to those in adults, although neither is independently sufficient to discriminate nodules’ likelihood of malignancy.

This article covers the MRI evaluation of patients with epilepsy, with a focus on neuroimaging in those with localization-related epilepsy who may be potential epilepsy surgery candidates. The article includes structural MRI to identify a lesion, functional MRI to identify the eloquent cortex and diffusion tensor imaging to identify the eloquent white matter tracts. We consider the equipment, protocol or procedures, and reporting of MRI in patients with epilepsy. Recommendations for both adult and pediatric patients are described for protocols and procedures. The authors hope that this article will provide a standardized approach for clinical imaging of patients with suspected localization-related epilepsy who may be evaluated for epilepsy surgery. J. Magn. Reson. Imaging 2016.

The Kwak Thyroid Imaging Reporting and Data System (Kwak-TI-RADS) guideline (2011) and American College of Radiology Thyroid Imaging Reporting and Data System (ACR TI-RADS) guideline (2017) were developed as ultrasound (US) risk stratification tools for detecting thyroid malignancy in adults. The purpose of this study was to investigate the inter-rater reliability and diagnostic performance of the ACR TI-RADS guideline in the pediatric population and compare it to the Kwak guideline. This retrospective study comprised 75 children who underwent thyroid US at a tertiary-level pediatric hospital. Three pediatric radiologists and one pediatric radiology fellow graded the US findings using the Kwak-TI-RADS and ACR TI-RADS guidelines. We assessed reliability of radiologists’ ratings using percentage inter-rater agreement, and intra-class correlation coefficients (ICC2,1). We assessed area-under-the-receiver-operating-characteristic curve (AUROCC) to compare the discriminative diagnostic ability of the Kwak-TI-RADS and ACR TI-RADS scoring systems against histopathology/cytology, or stability on US over a 2-year follow-up period for cases without tissue diagnosis. The inter-rater agreement was significantly better for the ACR TI-RADS level compared to the Kwak-TI-RADS level (P

Concern regarding gadolinium deposition in the brain after repeated administration of intravenous gadolinium-based contrast agents has prompted evaluation of imaging alternatives.The study purpose was to determine if magnetic resonance imaging (MRI) using conventional sequences with diffusion-weighted imaging (DWI) instead of gadolinium-based contrast-enhanced MRI is valid for local staging and guiding biopsies in osseous sarcomas.Initial pretreatment MRI with DWI and gadolinium-based contrast-enhanced images in patients ≤ 18 years with histopathologically proven osseous sarcomas were included. Two radiologists blinded to collated demographic and clinical data, independently reviewed conventional/DWI and conventional/gadolinium-based contrast-enhanced MRI then conventional sequences alone, recording tumor size, skip lesions, necrosis, neurovascular invasion, enlarged lymph nodes and diffusion restriction. Discrepancies were resolved by a third reader. A single reader measured apparent diffusion coefficient (ADC) values in non-necrotic tumors, then correlated minimum ADC values -- with and without normalization to skeletal muscle -- with relative enhancement.Twenty-one patients (mean age: 11.3±4.2 years, 15 [71%] females) had 14 osteosarcomas and 7 Ewing sarcomas, 50% centered in the femur. Conventional/DWI versus conventional/gadolinium-based contrast-enhanced MRI showed agreement for tumor size estimation with significant associations for necrosis (P=0.021), neurovascular involvement (P0.001) and enlarged lymph nodes (P=0.005). Diagnostic accuracy of conventional/DWI is comparable to conventional/gadolinium-based contrast-enhanced MRI and superior to conventional sequences alone. Comparison between minimum ADC values and relative enhancement showed no correlation (P0.05).Significant associations of key imaging features in the initial assessment of osseous sarcomas support DWI as an alternative to gadolinium-based contrast-enhanced MRI. The lack of association between ADC values and relative enhancement suggests that they measure independent constructs, DWI dependent upon tumor cellularity and perfusion.

OBJECTIVES: To determine parental preferences for diagnostic imaging tests (DITs) for paediatric appendicitis, to rank the attributes impacting the DIT selection and to identify DIT attributes that would cause parents to switch their DIT. METHODS: Parents of children who had an abdominal ultrasound (US) for right lower quadrant pain were interviewed. Two DITs were compared at a time, parents were asked to indicate their preferred test and to rank its attributes according to the impact each attribute had on their selection. The strength of their preference for the chosen DIT was measured by systematically adjusting attributes of the chosen DIT until the parent changed their choice. RESULTS: Fifty parents were interviewed. For US versus CT, more parents preferred US (68%, P=0.02) with higher importance ranks for cancer risk (P

Pyogenic arthritis, pyoderma gangrenosum and acne (PAPA) syndrome is a rare autosomal-dominant autoinflammatory disease of incomplete penetrance and variable expression. PAPA syndrome is the result of a mutation in the proline serine threonine phosphatase-interacting protein 1 (PSTPIP1/CD2BP1) gene located on chromosome 15, which results in an abnormal overproduction of the pro-inflammatory cytokine interleukin-1β (IL-1). This syndrome clinically manifests as early onset of recurrent episodes of acute aseptic inflammation of the joints, generally occurring in the first two decades of life, followed by manifestation of characteristic skin lesions in the third decade, after an obvious decline in the joint symptoms. Although uncommon, the potential clinical implications of PAPA syndrome warrant an appropriate diagnosis in a timely fashion.

DICER1 syndrome, arising from a mutation in the DICER1 gene mapped to chromosome 14q32, is associated with an increased risk of a range of benign and malignant neoplasms. To determine the spectrum of abnormalities and imaging characteristics in patients with DICER1 syndrome at a tertiary pediatric hospital. This retrospective analysis evaluated imaging in patients ≤18 years with DICER1 germline variants between January 2004 and July 2016. An imaging database search including keywords pleuropulmonary blastoma, cystic nephroma, pineoblastoma, embryonal rhabdomyosarcoma, ovarian sex cord-stromal tumor, ovarian Sertoli-Leydig cell tumor and DICER1 syndrome, was cross-referenced against the institutional Cancer Genetics Program database, excluding patients with negative/unknown DICER1 gene testing. Sixteen patients were included (12 females; mean age at presentation: 4.2 years, range: 14 days to 17 years), with surveillance imaging encompassing the following modalities: chest X-ray and CT; abdominal, pelvic and neck US; and brain and whole-body MRI. Malignant lesions (68.8% of patients) included pleuropulmonary blastoma (5), pineoblastoma (3), ovarian Sertoli-Leydig cell tumor (1), embryonal rhabdomyosarcoma (1) and renal sarcoma (1); benign lesions (37.5% of patients) included thyroid cysts (2), thyroid nodules (2), cystic nephroma (2), renal cysts (1) and pineal cyst (1). A common lesional appearance observed across modalities and organs was defined as the “cracked windshield” sign. The spectrum of DICER1-related tumors and the young age at presentation suggest early surveillance of at-risk patients is critical, while minimizing exposure to ionizing radiation.

The purpose of this article was to review the spectrum of common and rare malignant neoplasms arising in the epigastric region in children and to illustrate their characteristic computed tomography (CT) imaging features. Understanding the characteristic CT appearance of various malignant neoplasms, which can occur in the epigastric region in children, aids in accurate diagnosis and optimizes pediatric patient care.

The purpose of this study was to determine the prevalence, distribution, risk factors, and clinical outcome associated with the detection of unsuspected pulmonary emboli (PE) in routine thoracic MDCT examinations of pediatric oncology patients.We used our hospital information system to retrospectively identify all consecutively registered pediatric oncology patients 18 years old and younger who underwent contrast-enhanced thoracic MDCT for indications other than PE from July 2004 to May 2008. Two pediatric radiologists in consensus reviewed diagnostic-quality images from consecutive routine thoracic MDCT examinations for the presence and anatomic distribution of PE. The distribution of PE was assessed according to pulmonary arterial level and lobe. Clinical and radiology reports were reviewed for demographic data, type of underlying neoplasm, prospective embolus detection, risk factors, treatment, and outcome. Subgroups of patients with and without PE were compared with respect to type of neoplasm and risk factors.The study sample consisted of 468 children (249 boys, 219 girls; mean age, 9.5 +/- 5.7 years) who underwent a total of 1,002 thoracic MDCT examinations. Nine of the 468 children (1.9%) had PE, including seven with venous thromboembolism and two with tumor emboli. In these nine patients, the pulmonary arterial locations of 17 emboli were nine (53%) segmental, five (29%) lobar, two (12%) central, and one (6%) subsegmental. Classified by lobar location, six of 11 PE (55%) were in the left lower lobe, four (36%) were in the right lower lobe, and one (9%) was in the right upper lobe. PE were not detected prospectively in five of the nine patients (56%). All PE in this subgroup were solitary and located either within the segmental pulmonary arteries (four PE) or a lobar pulmonary artery (one PE). Underlying coagulation disorder (p0.001) and history of deep venous thrombosis or PE (p0.01) were risk factors for unsuspected PE. Two of nine patients (22%) with unsuspected PE died of causes not directly related to PE. The other seven patients survived, four of whom were not treated for PE.PE are unsuspected findings at nearly 2% of routine thoracic MDCT examinations of pediatric oncology patients. More than one half of PE were not detected prospectively at initial CT image interpretation, but lack of diagnosis and treatment did not appear to have a negative influence on patient outcome. Underlying coagulation disorder and a history of deep venous thrombosis or PE were risk factors for unsuspected PE.

The purpose of this article is to assess radiation dose reduction, image quality, and diagnostic confidence using low tube voltage in combination with hybrid iterative reconstruction in contrast-enhanced pediatric abdominal CT.CT examinations of 133 patients (median age, 10 years) were performed at sequentially reduced doses. The first group (group 1) was scanned using dimension-based protocols at 120 kV for all patient sizes. The optimized group (group 5) was scanned at 80 kV for less than 18 cm in the lateral dimension and 100 kV in the 19-30 cm lateral dimension. CT examinations reconstructed with filtered back projection (FBP) and four levels of hybrid iterative reconstruction were reviewed by four blinded readers for subjective image quality and diagnostic confidence. Objective noise, volume CT dose index (CTDIvol), and size-specific dose estimate (SSDE) were recorded. Data were analyzed using t tests, one and two-way ANOVA, and the intraclass correlation coefficient.Compared with group 1, the radiation dose was reduced for group 5 by 63% measured by SSDE (4.69 vs 10.00 mGy; p0.001). Subjective image noise was increased for FBP images (p0.001) but not was statistically significantly different for all levels of hybrid iterative reconstruction; artifacts were reduced and visibility of small structures was improved (both p0.001). Diagnostic confidence was improved for solid organ injury and metastatic disease (both p0.001) and was not statistically significantly different for appendicitis (p = 0.306).Use of hybrid iterative reconstruction with low-tube-voltage protocols enables substantial radiation dose reduction for pediatric abdominal CT with equivalent to improved subjective image quality and diagnostic confidence.

MR based Attenuation Correction (MRAC) is essential for PET quantitation and image quality assurance in PET/MR. Ultra-short TE (UTE) sequence is promising in generating positive contrast for cortical bone but its further adoption is limited by prohibitively long scan time, lack of soft tissue contrast, and potential ambiguity in a tissue classification due to MR imaging artifacts. In this investigation, we aimed to develop a new MRAC method that consists an optimized under-sampled UTE-mDixon sequence and an iterative voxel-based tissue classification algorithm to generate 4-compartment μ-map, including water, fat, bone and air cavity. In vivo UTE-mDixon images were acquired on 12 human subjects and the developed segmentation method was employed for tissue classification. Diagnostic quality of MR images and the tissue classification accuracy for MRAC was evaluated by three radiologists independently. As a unique advantage over other MRAC sequences, the under-sampled UTE-mDixon of whole brain with retrospective trajectory delay calibration can be finished within less than 3 minutes providing both high quality water/fat separation images for anatomical localization and UTE images for bone segmentation. Robust tissue classification was achieved in all subjects as evaluated by radiologists. The developed MR scan methodology together with tissue classification algorithm may provide a one-scan solution for attenuation correction and anatomical localization in PET/MR.

The aim of this study was to determine whether a lateral chest radiograph provides additional diagnostic information to a posteroanterior (PA) radiograph in the screening of asymptomatic children with positive purified protein derivative (PPD) skin tests in a nonendemic area.This was an Institutional Review Board-approved, Health Insurance Portability and Accountability Act-compliant, retrospective study of 605 consecutive pediatric patients (294 males, 311 females; mean age, 10.8 ± 5.2 years) with positive PPD skin test results, who underwent PA and lateral chest radiographs between July 2003 and May 2009 at a tertiary care pediatric hospital in a nonendemic area for tuberculosis (TB). Two pediatric radiologists independently reviewed each chest radiograph for evidence of abnormalities that may be indicative of acute or chronic TB infection. The reviewers first analyzed the PA radiograph alone and subsequently evaluated the PA and the lateral radiograph together to determine whether any observed abnormality was identified only on the lateral radiograph. When an abnormality was detected on both PA and lateral radiographs, the reviewers determined whether the abnormality on the lateral radiograph changed the reviewer's decision based on the PA radiograph alone. Assessment of nonconcordance between PA and lateral chest radiographs for each reviewer was evaluated by the McNemar test of matched binary pairs. Agreement between reviewers for detecting abnormalities on radiographs was evaluated by using the kappa (κ) statistic.The frequency of an abnormal chest radiograph related to TB was 1.8% (11/605). The PA radiograph showed abnormalities in all 11 (100%) children with radiographic abnormalities. Lateral radiographs showed abnormalities related to TB in 2 (18.2%) of 11 cases found to be abnormal on PA radiographs. Nine (81.8%) of 11 abnormalities on PA radiographs were not detected on the lateral chest radiographs. There was statistical evidence of nonconcordance between PA and lateral chest radiographs in detecting TB-related abnormalities for reviewer 1 (P.001) and reviewer 2 (P = .004). In cases with abnormalities observed on both PA and lateral radiographs, there were no cases in which information obtained from the lateral chest radiograph resulted in a change in interpretation based on the PA radiograph alone. A high level of agreement was observed between the two independent reviewers in detecting TB-related abnormalities on PA radiographs (κ = 0.84, P.001).A PA radiograph alone is sufficient for TB screening of asymptomatic pediatric patients with positive PPD skin test results in an area non-endemic for TB.

Testicular epidermoid cyst is a rare benign tumor in children. Although this entity is widely described in adults in literature, there are no large series describing the pathological and radiological findings in children. Knowledge of the sonographic features seen in children may alter surgical treatment. To describe the specific US characteristics of testicular epidermoid cyst in children and to correlate these findings with pathology. All children with pathologically proven epidermoid cyst and preoperative sonograms diagnosed at a single children’s hospital between 1978 and 2008 were included. For each child, the medical records, preoperative US and pathological specimens were reviewed and correlated. Eleven patients (ages 1–17 years old) met our criteria. Nine cysts had characteristic target or onion ring appearances, the youngest patient had a simple cyst-like lesion, one cyst had a heterogeneous appearance, and more than 80% of the cysts presented daughter cysts attached along the periphery of the main cyst. In addition to the commonly described findings of the epidermoid cyst (the target and onion ring appearances), simple cysts and the presence of daughter lesions are newly described findings that point to the diagnosis of this benign entity in children.

A potential advantage of pulmonary CT angiography (CTA) is its ability to show alternative diagnoses in patients without evidence of pulmonary embolism (PE), but the frequency and spectrum of alternative diagnoses have yet to be determined in the pediatric population. Our purpose was to determine the frequency and types of alternative diagnoses identified in children with clinically suspected but excluded PE.We used our hospital information system to identify all consecutive pediatric patients (18 years old) with clinically suspected PE who underwent pulmonary CTA from July 2004 to March 2008. Two experienced pediatric radiologists reviewed by consensus a series of 96 consecutive diagnostic-quality pulmonary CTA studies without evidence of PE from 89 patients. Each study was systematically reviewed by consensus for a possible alternative diagnosis in the lungs, mediastinum, central airways, cardiovascular system, pleura, and skeleton.The study population consisted of 89 children (28 boys and 61 girls; mean age 13.4 +/- 4.7 years; range, 2 months-18 years; 34 inpatients, 62 outpatients) who underwent a total of 96 pulmonary CTA studies without evidence of PE. Thirty-nine (41%) of 96 pulmonary CTA studies were normal. Alternative diagnoses were identified for each of the remaining 57 (59%) studies, including: pneumonia (n = 22), atelectasis (n = 22), malignancy (n = 3), congenital heart disease (n = 2), pulmonary hypertension (n = 2), pericardial effusion (n = 2), pulmonary nodules (n = 1), rib fractures (n = 1), right atrial thrombus (n = 1), and fat embolism (n = 1). Seventeen patients showed pleural effusions that were associated with coexisting pneumonia (n = 8), atelectasis (n = 8), or rib fractures (n = 1).Among children with clinically suspected but excluded PE, pulmonary CTA frequently shows positive findings. Although pneumonia and atelectasis are most common, a variety of other alternative diagnoses may be detected throughout the thorax.