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Background: Astroblastoma is a rare tumor of uncertain origin most commonly presenting in the cerebrum of children and young adults. The literature contains only case reports and small series regarding its radiologic features. This systematic review is the largest study of imaging findings of astroblastoma to date and serves to identify features that might differentiate it from other neoplasms., Objective: This study describes the imaging features of astroblastoma based on a systematic review of the literature and two new cases., Materials and Methods: We conducted a PubMed and Google Scholar database search that identified 59 publications containing 125 cases of pathology-confirmed astroblastoma, and we also added two new cases from our own institution. Data collected include patient age, gender, tumor location, morphology, calcifications and calvarial changes. We recorded findings on CT, MRI, diffusion-weighted imaging (DWI), MR spectroscopy, positron emission tomography (PET) and catheter angiography., Results: Age at diagnosis ranged 0-70 years (mean 18 years; median 14 years). Female-to-male ratio was 8:1. Of 127 cases, 66 reported CT, 78 reported MRI and 47 reported both findings. Not all authors reported all features, but the tumor features reported included supratentorial in 96% (122/127), superficial in 72% (48/67), well-demarcated in 96% (79/82), mixed cystic-solid in 93% (79/85), and enhancing in 99% (78/79). On CT, 84% (26/31) of astroblastomas were hyperattenuated, 73% (27/37) had calcifications and 7 cases reported adjacent calvarial erosion. Astroblastomas were hypointense on T1-W in 58% (26/45) and on T2-W in 50% (23/46) of MRI sequences. Peritumoral edema was present in 80% (40/50) of cases but was typically described as slight. Six cases included DWI findings, with 100% showing restricted diffusion. On MR spectroscopy, 100% (5/5) showed nonspecific tumor spectra with elevated choline and decreased N-acetylaspartate (NAA). PET revealed nonspecific reduced uptake of [F-18] 2-fluoro-2-deoxyglucose ((18)F-FDG) and increased uptake of [11C]-Methionine in 100% (3/3) of cases. Catheter angiography findings (n=12) were variable, including hypervascularity in 67%, arteriovenous shunting in 33% and avascular areas in 25%., Conclusion: Astroblastomas occur most often in adolescent girls. Imaging often shows a supratentorial, superficial, well-defined, cystic-solid enhancing mass. On CT, most are hyperattenuated, have calcifications, and may remodel adjacent bone if superficial. MRI characteristically reveals a hypointense mass on T1-W and T2-W sequences with restricted diffusion. MR spectroscopy, PET and catheter angiography findings are nonspecific.

The new interventional radiology (IR) pathways have generated much discussion with articles and editorials pointing out perceived advantages and disadvantages compared to the current pathways. To briefly review, under the new system, there are three pathways to enter IR: the integrated (INT) IR residency, the independent (IND) IR residency, and the early specialization in interventional radiology (ESIR) program. The pathways have been designed to provide maximum flexibility to programs for implementation and to radiology residents for planning their subspecialty training. As a result, there are many potential permutations for these training programs, and understanding the variety of options can be a challenge at first. We offer three potential solutions, based on the different circumstances or requirements a department might face. The first two solutions involve integrated programs created through newly funded and converted diagnostic radiology slots, respectively. The third involves establishing ESIR and IND programs only. Hopefully, the examples provided will be useful for those currently planning for the future of their IR training programs., (Copyright © 2016 The Association of University Radiologists. Published by Elsevier Inc. All rights reserved.)

Recent publications argue that classic metaphyseal fractures are caused by rickets as opposed to trauma. Previous case reports of accidental traumatic classic metaphyseal fractures have been discounted due to lack of identification of the fracture at the time of the traumatic event, and lack of an evaluation for boney metabolic disorders. We report a case of a 20 day old male with a diagnosis of congenital vertical talus who sustained a classic metaphyseal fracture of the distal tibia during manipulation in preparation for intravenous line placement. The mechanics of the event causing the classic metaphyseal fracture were witnessed and accompanied by an audible "pop". Prior x-rays of the tibia demonstrate normal osseous morphology, and an evaluation for boney metabolic disorders was normal. This case identifies a traumatic classic metaphyseal fracture and provides insight into the types of forces necessary to cause such a fracture., (Copyright © 2015 Elsevier Ltd and Faculty of Forensic and Legal Medicine. All rights reserved.)

Childhood primary angiitis of the central nervous system (cPACNS) is a rare and poorly understood immune-mediated vasculitis that preferentially affects blood vessels of the central nervous system (CNS). It must be distinguished from other disorders to initiate prompt treatment and improve the patient's prognosis. The presentation of cPACNS is highly variable, making a clinical diagnosis challenging. However, MRI may be helpful in showing typical findings including perivascular space inflammation and enhancement. Identification of these imaging features allows the radiologist to specifically suggest this rare diagnosis. The purpose of this manuscript is to present a biopsy-confirmed case of cPACNS in a 9-year-old girl who presented uniquely with panuveitis and anisocoria, and emphasize the MRI features that should prompt the radiologist to suggest this rare diagnosis.

Background: Fluoroscopy is an important tool for diagnosis in the pediatric population, but it carries the risk of radiation exposure. Because radiology resident education and experience in the use of fluoroscopy equipment in children vary, we implemented an intervention to standardize fluoroscopy training., Objective: The purpose of this study is to determine the impact of implementing a fluoroscopy competency check-off for radiology resident trainees aimed at decreasing radiation exposure in three common pediatric fluoroscopic studies., Materials and Methods: A fluoroscopy competency check-off form was developed for radiology resident trainees performing pediatric procedures. Techniques used to limit radiation exposure for common pediatric radiologic studies were reviewed as part of the check-off process. Pediatric radiologists supervised each trainee until they demonstrated competence to independently perform three specified procedures. Radiation dose was recorded for the three procedures, upper GI (UGI), voiding cystourethrogram (VCUG) and oropharyngeal (OPM) exams, over 6 months preceding and 6 months following implementation of the competency check-off. The mean cumulative dose for each procedure was compared before and after implementation of competency check-off using a Kruskal-Wallis test., Results: During the 12-month study period doses from 909 fluoroscopic procedures were recorded. In the 6 months preceding competency check-off implementation, procedures were performed by 24 radiology resident trainees including 171 UGI, 176 VCUG and 171 OPM exams. In the 6 months following competency check-off, 23 trainees performed 114 UGI, 145 VCUG and 132 OPM exams. After competency check-off implementation, a statistically significant reduction in average radiation dose was found for all three studies (P < 0.001). Median cumulative doses (mGy) were decreased by 33%, 36% and 13% for UGIs, VCUGs and OPMs, respectively., Conclusion: Implementation of a competency check-off for radiology resident trainees can reduce average radiation doses in pediatric patients undergoing three common fluoroscopic studies.

Objectives: The objectives of the study were to determine the rate of hepatic hemangiomas in infants with cutaneous infantile hemangiomas that were screened by abdominal ultrasound; identify morphological subtypes and number of cutaneous infantile hemangiomas that are likely to suggest the presence of hepatic hemangiomas; and identify clinical history, physical findings, or laboratory abnormalities that may predict hepatic involvement., Methods: A retrospective study was conducted between 2000 and 2007 on 37 infants with cutaneous hemangiomas who underwent abdominal ultrasound for hepatic hemangiomas. Infants were classified into subgroups based upon the morphology of their cutaneous hemangioma(s). Data collected included clinical history, physical examination findings, sonographic findings, laboratory results, treatment(s) rendered, and clinical outcome., Results: Eight of 37 infants (22%) had hepatic hemangiomas. Infants with miliary (30-100 pinpoint/small cutaneous hemangiomas), six or more small cutaneous hemangiomas, and one large with one or more small cutaneous hemangiomas were more likely to have concurrent hepatic hemangiomas. No other clinical findings were associated with hepatic involvement., Conclusions: Similar to other studies, our study found clinically asymptomatic hepatic hemangiomas in 22% of infants with multiple cutaneous infantile hemangiomas. No clinical findings studied were predictive of hepatic involvement.

Rationale and Objectives: Radiology residents must acquire dictation and reporting skills to meet Accreditation Council for Graduate Medical Examination requirements and provide optimal patient care. Historically, these skills have been taught informally and vary between institutions and among radiologists. A structured curriculum improves resident report quality when using a quantitative grading scheme. This study describes the implementation of such a curriculum and evaluates its utility in tracking resident progress., Materials and Methods: We implemented a three-stage reporting curriculum in our diagnostic radiology residency program in 2009. Stages 1 and 2 involve instruction and formative feedback composed of suggestions for improvement in a 360° format from faculty, peers, and others within the resident's sphere of influence. The third stage involves individual, biannual, written feedback with scored reports specifically assessing four categories: succinctness, spelling/grammar, clarity, and responsible referral. Biannual scores were collected from 2009 to 2013, sorted by year of residency training (R1 to R4), and average training level scores were statistically compared., Results: Review of 1500 reports over a 4-year period yielded a total of 153 scores: 54, 36, 29, and 34 from R1, R2, R3, and R4 residents, respectively. The mean (standard deviation) scores for R1, R2, R3, and R4 residents were 10.20 (1.06), 10.25 (0.81), 10.5 (0.74), and 10.75 (0.69), respectively. Post hoc analysis identified significant differences between R1 and R4 residents (P = .012) and R2 and R4 residents (P = .009)., Conclusions: Residents' reporting scores showed significant improvement over the course of their residency training. This indicates that there may be a benefit in using an organized reporting curriculum to track resident progress in producing reports that may improve patient care., (Copyright © 2014 AUR. Published by Elsevier Inc. All rights reserved.)

Objective: The purpose of this article is to review new terminology to diagnose, classify, and refer patients with vascular anomalies for additional imaging, intervention, and treatment., Conclusion: In recent decades, much has been learned regarding the histopathology, cause, and treatment of vascular anomalies. As information has been gleaned, a new classification system has emerged that divides vascular anomalies into neoplasms and malformations. Its utility is based on accurate initial diagnosis that correlates consistently with clinical presentation, disease course, and treatment.

Hepatic neoplasms constitute approximately 5% to 6% of all pediatric intra-abdominal masses, most of which are malignant. When compared with traditional multiphase computed tomography protocols that are often used in adults, magnetic resonance (MR) imaging is particularly desirable for evaluating liver lesions in children because of the lack of ionizing radiation and superb soft tissue contrast resolution. The goal of this article is to discuss common benign and malignant pediatric hepatic lesions and their key MR imaging findings. Particular emphasis is placed on the utility of new hepatocyte-specific contrast agents to narrow the differential diagnosis., (Copyright © 2013 Elsevier Inc. All rights reserved.)

Recent advances in knowledge regarding histopathology, cause, and treatment of pediatric vascular anomalies have led to substantial changes in classification and terminology. Over the past two decades, various subspecialists have adopted a new classification system proposed by the International Society for the Study of Vascular Anomalies (ISSVA). The ISSVA classification of vascular anomalies divides vascular anomalies into two categories: vascular neoplasms and malformations. It has been widely adopted by various pediatric subspecialists, because it reliably correlates patient presentation and disease progression, with more accurate histology, diagnosis, imaging, and treatment., (Copyright © 2013 Elsevier Inc. All rights reserved.)

Objectives: The purpose of this study is to describe the findings and patterns of injury on magnetic resonance imaging (MRI) and magnetic resonance spectroscopy (MRS) after whole-body hypothermia treatment for neonatal hypoxic ischemic encephalopathy., Methods: A retrospective review of consecutive term neonates treated with whole-body hypothermia was performed. Data recorded included demographics and MRI and MRS findings, and day of life (DOL) studies were performed. Injury patterns were classified on MRI as deep, cortical, mixed, or diffuse. The relative apparent diffusion coefficient (rADC) was plotted against DOL scanned and the presence of lactate was recorded., Results: MRI was performed in 44 infants, 34 of whom also underwent MRS. MRI was abnormal in 32% of neonates, 29.5% of whom were imaged at DOL 4 to 8. rADC values were lowest in neonates scanned on DOL 4 and 5 and remained low up to DOL 8. The deep brain nuclei were involved in hypoxic ischemic encephalopathy in 93% of neonates with abnormal MRIs and lactate was identified on MRS in 18% of neonates between DOL 4 and 8., Conclusions: MRI performed after therapeutic cooling was abnormal in 29.5% of neonates scanned on DOL 4 to 8. Deep nuclear injury was identified in 93% of neonates. Lactate was present on MRS in 18% of neonates, and rADC values were most reduced on MRI between DOL 4 and 8.

Cat-scratch disease (CSD) is usually a self-limiting condition that may mimic more serious disorders due to its variable clinical and imaging presentations. Many cases are diagnosed throughout the United States annually, with the majority occurring in children and adolescents who have had contact with a cat, usually in the form of a scratch or bite. This manuscript will discuss the spectrum of radiologic manifestations of CSD emphasising key imaging findings of lymphadenopathy, hepatosplenic lesions, osteomyelitis, discitis, encephalitis, neuroretinitis and cranial neuritis.

Congenital midline nasal masses are uncommon anomalies including nasal dermoids/epidermoids, nasal glial heterotopias and encephaloceles. These lesions can occur at the nasal bridge, extend intranasally and have intracranial extension with communication to the subarachnoid space. Therefore, accurate diagnosis of these lesions is critically important for presurgical planning and prevention of potentially fatal complications. Neuroimaging is essential in the evaluation of congenital midline nasal masses to identify the specific type of lesion, evaluate for the presence of intracranial extension and allow for appropriate presurgical planning.

Purpose: The aim of this study was to assess the impact of new ABR changes on pediatric radiology residency training in terms of the number, timing, availability, and funding of pediatric radiology rotations., Methods: Participants were selected by using the ACGME's list of accredited American radiology residency programs, and data were collected via a survey. Program directors or persons designated by the program directors filled out the surveys., Results: Of 186 programs, 84 (45%) responded. Three months of pediatric radiology were required in 61.0% of programs, with most having their residents complete one pediatric rotation during postgraduate years 2, 3, and 4. In 46% of training programs, pediatric radiology rotations were completed at the home institution. Seven percent of the programs plan to decrease the number of required pediatric rotations, while 75% plan no changes. Additional rotations in areas of interest are planned for 82% of programs. Only 54% could provide additional rotations in all 10 subspecialties, and 57% indicated that it was "very unlikely" or "impossible" that residents could acquire ≥12 months in a single area. Pediatric radiology is among the top 3 most frequent subspecialty areas that cannot be accommodated, along with obstetric and gynecologic (women's) and cardiac imaging. Funding limitations for pediatric rotations were not considered a barrier at 51% of programs., Conclusions: Seven percent of residency programs plan to cut back the overall number of pediatric radiology core rotations and move them to earlier in training (20%). Although 82% of programs said that they plan to provide more time in areas of interest, 57% said that it is very unlikely or impossible that residents could accumulate ≥12 months in an area of interest. It is possible that funding may limit access to additional pediatric rotations in up to 44% of programs. Seventeen of the programs did not know how their institution funded pediatric radiology rotations., (Copyright © 2011 American College of Radiology. Published by Elsevier Inc. All rights reserved.)

Pediatric pelvic neoplasms, although relatively uncommon, are often difficult to evaluate and characterize with imaging, due to their overlapping appearances. This article discusses key clinical features and imaging findings that help limit the differential diagnosis of pediatric pelvic neoplasms. Testicular, ovarian, uterine, and bladder masses are included in addition to sacrococcygeal teratoma., (Copyright © 2011 Elsevier Inc. All rights reserved.)

This study presents visceral and skeletal imaging findings commonly observed in pediatric patients with type I Gaucher disease. Presented images show methods used for radiologic assessment of pediatric Gaucher patients, and imaging findings are discussed in the context of the underlying pathophysiology of the disease. Routine radiologic surveillance plays a central role in assessing Gaucher disease progression and response to treatment, but monitoring of pediatric patients presents specific challenges with regard to minimizing radiation exposure and interpreting extent of marrow involvement against the backdrop of normal growth-related changes in marrow composition. In addition to highlighting imaging findings in children with type I Gaucher disease, this manuscript discusses alternate modalities, which minimize radiation and may be just as accurate, if not better, than conventional methods exposing the child to radiation.

Objective: In this era of radiation awareness, high-quality ultrasound is more important than ever. Although cranial sonography equipment has advanced greatly, application of modern techniques has not been utilized in a fashion commensurate to other cross-sectional modalities. This article will describe modern cranial sonography techniques, including the utility of linear imaging, use of additional fontanels, and screening Doppler imaging., Conclusion: When modern protocols are used, cranial sonography is highly accurate for the detection of cranial abnormalities.

Objective: In the first part of this article, modern cranial sonography techniques and interpretation were discussed, emphasizing ways in which the application of modern imaging technology and techniques are able to enhance detection of pathologic abnormalities on cranial sonography., Conclusion: In this part of the article, we will describe pitfalls and variants that may be confused with pathologic abnormalities. Emphasis will be placed on recognizing normal variations and distinguishing them from pathologic abnormalities that may require additional imaging or clinical follow-up.

Background: Isolated borderline low conus medullaris is a frequent finding on screening lumbar sonography of unknown significance that often prompts further imaging and clinical follow-up., Objective: To determine the clinical outcome and utility of follow-up neuroimaging in infants with isolated borderline low conus on lumbar sonography., Materials and Methods: We reviewed 748 consecutive spinal sonograms identifying infants with conus terminating between L2-L3 disc space and mid-L3 level without other findings of tethered cord. We excluded infants with conditions associated with developmental delay and those who passed away, and compared the age of gross motor milestone achievement to normal ranges. Follow-up imaging was reviewed., Results: Isolated borderline low conus was found in 90 of 748 infants (12%) on sonography. Seventy of those infants met inclusion criteria. Follow-up imaging in 11 children (10 MRI, 1 sonogram), showed change in conus position to "normal" level in 10, no change in 1, and no new findings within lumbar spine. Clinical follow-up was available in 50 of 70 (71%) children meeting inclusion criteria, with normal motor milestones met in all 50 children., Conclusion: Isolated borderline low conus is a common finding in infants who meet normal developmental milestones suggesting that follow-up evaluation has little utility and is likely unwarranted.

We conducted a retrospective study to measure laryngeal descent in human infants and to determine if there is any correlation between the associated anatomic changes and the timing of the peak incidence of sudden infant death syndrome (SIDS), which is 2 to 4 months of age. We performed a computerized search of hospital records at our institution to identify magnetic resonance imaging (MRI) scans of the head and neck and plain radiographs of the lateral neck in patients younger than 1 year of age (range: 1 to 357 days). After unusable images were excluded, 79 head and neck MRI scans and 111 lateral neck x-rays were suitable for study. Two measurements were taken from each image: one from the tip of the epiglottis to the uvula and one from the tip of the epiglottis to the center of the sella turcica. These measurements were then graphed against the subject's age. SPSS statistical software was used to determine growth curves of the various measurements. The first derivative of these curves was calculated to determine the rate of laryngeal descent at a given age. We found that most subjects did not have an overlapping epiglottis and uvula during the first few months of life. The rate of laryngeal descent, based on measurements of the distance between the epiglottis and uvula, gradually increased in a near-linear fashion from as low as 0.005726 mm/day at day 1 of life to as high as 0.028366 mm/day at 300 days of age. We found no sharp increase in the rate of descent at 2 to 4 months of age, and thus no support for our hypothesis that there might be a correlation between anatomic changes and the peak incidence of SIDS.

Objective: To compare occult brain injuries on neuroimaging in clinically asymptomatic children under 20 months due to abusive versus accidental head trauma., Subjects and Methods: A retrospective review of 58 children under 20 months who underwent neuroimaging for possible abusive trauma was performed. The data collected were demographics, neurological signs/symptoms, imaging findings, and disposition (abusive or accidental)., Results: The disposition of 31 subjects was abusive trauma and 27 were accidental. At presentation, 8/31(25.8%) children with abusive injury and 15/27(55.6%) with accidental injury were neurologically asymptomatic. Neuroimaging was abnormal in 6 of 8 (75.0%) asymptomatic children with abusive injury, and 13/15 (86.7%) children with accidental trauma. No significant (P = 0.59) difference in frequency of abnormal neuroimaging was seen between the asymptomatic abusive and accidental trauma groups., Conclusions: Although victims of abusive trauma under 20 months of age are less often neurologically asymptomatic compared to accidental trauma victims, neuroimaging revealed a high rate of occult traumatic brain injury in both groups.

This article presents an overview of transcranial Doppler, well known for its use as a screening tool in children with sickle cell disease. However, there are many other pediatric applications in which cranial Doppler ultrasound can supply otherwise unavailable information regarding neurovascular flow dynamics. Images illustrate examples of normal anatomy and pathologic conditions that can be evaluated with cranial Doppler ultrasound. Characteristic imaging features of various pediatric applications of cranial Doppler ultrasound are discussed and illustrated. This image presentation discusses cranial Doppler ultrasound technique and normal findings and illustrates various pediatric disorders including benign enlargement of the subarachnoid space versus subdural hematomas, vasospasm, vasculitis, venous sinus thrombosis, vein of Galen varix, hydrocephalus, hypoxic ischemic injury, traumatic brain injury, and brain death.

A variety of lesions occur in the pediatric salivary glands. With modern imaging techniques such as Doppler sonography, helical CT, and MRI, identification of a specific etiology is often possible. Knowledge of clinical information, normal anatomy, and imaging characteristics of salivary gland pathology are essential for appropriate radiologic evaluation. This review illustrates the various congenital, neoplastic, and inflammatory entities that can occur within the parotid, submandibular, and sublingual spaces.

Objective: The pharmacokinetics of gadoversetamide were examined in pediatric patients scheduled to undergo contrast-enhanced MRI of the central nervous system., Materials and Methods: One hundred patients received an intravenous injection of gadoversetamide at a dose of 0.1 mmol/kg for a contrast-enhanced MRI procedure. A subpopulation of 30 patients were enrolled to evaluate the pharmacokinetics of gadoversetamide in patients 2-11 and 12-18 years of age. Serial blood and urine samples were collected before and after the administration of gadoversetamide., Results: The terminal half-life, initial concentration and area under the curve assessments for gadoversetamide showed no significant (P>.05) differences between the age groups or the sexes. Although no sex-related differences occurred in the volume of distribution or clearance, significant (P<.05) age-related differences were found, but once corrected for body mass or surface area the differences were no longer significant., Conclusions: The pharmacokinetic behavior of gadoversetamide was not significantly altered by differences in age or sex in pediatric patients from 2 to 18 years of age. Although significant differences in volumes of distribution, and clearance occurred between the age groups, these differences appeared to depend on body size rather than on age in pediatric patients between 2 and 18 years of age.

Fibropolycystic liver diseases are a group of associated congenital disorders that present most often in childhood. These disorders include congenital hepatic fibrosis, biliary hamartomas, autosomal dominant polycystic liver disease, choledochal cysts and Caroli disease. We present a discussion and illustrations of the embryology, genetics, anatomy, pathology, imaging approach and key imaging features that distinguish fibropolycystic liver disease in children. The pathogenesis of these disorders is believed to be abnormal development of the embryonic ductal plates, which ultimately form the liver and biliary systems. An understanding of the abnormal embryogenesis helps to explain the characteristic imaging features of these disorders.

Although certain neuroimaging appearances are highly suggestive of abuse, radiological findings are often nonspecific. The objective of this review is to discuss pitfalls, controversies, and mimics occurring in neuroimaging of nonaccidental head trauma in order to allow the reader to establish an increased level of comfort in distinguishing between nonaccidental and accidental head trauma. Specific topics discussed include risk factors, general biomechanics and imaging strategies in nonaccidental head trauma, followed by the characteristics of skull fractures, normal prominent tentorium and falx versus subdural hematoma, birth trauma versus nonaccidental head trauma, hyperacute versus acute on chronic subdural hematomas, expanded subarachnoid space versus subdural hemorrhage, controversy regarding subdural hematomas associated with benign enlarged subarachnoid spaces, controversy regarding hypoxia as a cause of subdural hematoma and/or retinal hemorrhages without trauma, controversy regarding the significance of retinal hemorrhages related to nonaccidental head trauma, controversy regarding the significance of subdural hematomas in general, and pitfalls of glutaric aciduria type 1 and hemophagocytic lymphohistiocytosis mimicking nonaccidental head trauma.

Pediatric neurodegenerative white matter processes are complex, numerous and result from a vast array of causes ranging from white matter injury or inflammation to congenital metabolic disorders. When faced with a neurodegenerative white matter process on neuroimaging, the first step for the radiologist is to determine whether the findings represent a congenital metabolic leukodystrophy or one of various other white matter processes. In this review we first describe a general approach to neurodegenerative white matter disorders. We will briefly describe a few white matter diseases that mimic metabolic leukodystrophies. In the second half of the review we discuss an approach to distinguishing and classifying white matter leukodystrophies.

Fatal embolic chondroblastic osteosarcoma to the lung is an extremely rare phenomenon. We report a case of a 15-year-old boy who developed bilateral pulmonary embolism shortly after resection of the right distal femur for chondroblastic osteosarcoma. The patient succumbed to right-sided heart failure 8 weeks later. An autopsy revealed extensive intravascular tumor emboli in the bilateral pulmonary arteries and their branches. No metastatic lesions were identified in the lungs. We review the clinical, radiologic, and pathologic findings of this patient and the literature.

Although the association of spinal lumbosacral dysraphism and congenital spinal dermoid tumors is well known, the association of craniocervical spinal anomalies and posterior fossa dermoids has only been recognized recently. Advances in imaging technology and awareness of the association likely contribute to an increase in recently reported cases.

About 80% of cat-scratch disease (CSD) infections occur in children, and CSD neuroretinitis (optic neuropathy with retinal exudates in a "macular star" pattern) mostly occurs in children and young adults. A recent study suggested that CSD optic neuropathy has specific features on MR imaging. However, MR imaging findings in CSD neuroretinitis are not well described in the pediatric literature. We present a patient with CSD neuroretinitis in whom these specific MR imaging features preceded the macular star, a funduscopic finding strongly suggestive of neuroretinitis. This case demonstrates how knowledge of these features is important in the appropriate diagnostic work-up of optic neuropathy. MR imaging also incidentally revealed neuritis of another cranial nerve in the auditory canal-a rare manifestation of CSD.

Objective: The objective of part 2 of this article is to focus on key imaging features of common skin-covered spinal anomalies (spina bifida occulta) and to distinguish them from normal variants (previously discussed in part 1)., Conclusion: Modern imaging technology allows accurate neonatal spinal sonographic screening and the characterization of spinal abnormalities within the first few days of life. It is useful to determine the type of lesion present and to guide the type and timing of therapy.

Objective: Our objective is to discuss neonatal spine sonography with emphasis on imaging pitfalls and normal variants that may simulate disease and to distinguish them from true spinal disorders., Conclusion: Sonography of the neonatal spine is now accepted as a highly sensitive, readily available screening study that can be used to evaluate various anomalies of the lumbar spine in most infants younger than 4 months.

Objective: The safety and efficacy of gadoversetamide injection (OptiMARK) was examined in pediatric patients referred for magnetic resonance imaging (MRI) of the central nervous system (CNS)., Research and Design Methods: This was an open-label, multicenter study in patients aged between 2 and 18 years scheduled for a contrast-enhanced MRI study. Patients received a single injection of gadoversetamide (0.1 mmol/kg). Safety of gadoversetamide was evaluated by physical examinations and monitoring of adverse events, laboratory values, vital signs, and electrocardiogram readings before and after drug administration. Efficacy was assessed by three independent, blinded readers for confidence in diagnosis and level of conspicuity for lesion visualization on precontrast and postcontrast images. The diagnostic accuracy, sensitivity, and specificity of lesion detection were determined for the precontrast images, the postcontrast images, and the precontrast and postcontrast images read together., Results: No drug-related moderate or serious adverse events were observed in this study, according to site investigators. A total of four adverse events in four of 100 patients (4%) were deemed likely related to gadoversetamide injection by the site investigators. All were mild in severity and not clinically significant. The most common adverse events, regardless of relationship to study drug, were injection-site reactions and a small prolongation of the QT interval. The administration of gadoversetamide significantly increased the level of lesion conspicuity and diagnostic confidence (p < 0.05). Compared with the nonenhanced image, gadoversetamide significantly increased the accuracy and sensitivity of lesion detection (p < 0.05). Limitations of the study included a lack of physiological measurements after sedation and prior to contrast administration, a single dose of gadoversetamide administered (0.1 mmol/kg) and patients younger than 2 years of age were excluded., Conclusion: The administration of gadoversetamide injection (0.1 mmol/kg) was safe, well tolerated and produced clinically appropriate contrast enhancement for MRI of the CNS in the pediatric population.

Background: Simple cysts found within the filum terminale of infants on lumbar spine sonography are relatively common, but no study has established their clinical significance., Objective: To obtain information on the sonographic features of isolated filar cysts and determine their clinical significance in comparison with age- and sex-matched controls., Materials and Methods: We performed a retrospective review of 644 consecutive spine sonograms in patients younger than 8 months. Gestational age- and sex-matched controls with normal lumbar sonograms were taken from the same period. We obtained short-term clinical follow-up of motor milestones for each group., Results: The incidence of filar cyst was 78 of the 644 (11.8%) and was inversely related to age. Developmental follow-up of the study patients compared with control population showed no statistically significant difference in the ages at which the infants were able to turn over, crawl and walk. Follow-up MR imaging of 13 study patients (19%) failed to demonstrate filar cysts previously identified on sonography., Conclusion: No significant difference was found in the short-term outcome of infants with isolated filar cysts on lumbar sonography compared with that of a control population. Filar cysts should be considered a normal variant when found in isolation on lumbar sonography.

We describe the use of serial transcranial Doppler studies to evaluate neurovascular disease in three girls presenting with acute stroke due to primary cerebral vasculitis (n = 2) and West Nile vasculitis (n = 1). Correlation of abnormal findings on transcranial Doppler sonography was compared with those of MR angiography and conventional angiography in each child. All three girls had left middle cerebral artery infarcts on MR imaging, with an abnormal left middle cerebral artery detected by MR angiography, conventional angiography, and transcranial Doppler sonography in each child. In all three cases, findings of the transcranial Doppler sonography, MR imaging, and catheter angiography were concordant.

Post-transplant lymphoproliferative disorder complicates approximately 1% of all renal transplants. The usual site of occurrence is within the abdomen, thorax, allograft, or head and neck. Central nervous system involvement is uncommon but, when present, occurs in isolation, sparing other organ systems. Few articles in the radiology literature have focused on the acute and follow-up central nervous system findings of the disease, especially in children. Because the clinical and imaging characteristics of central nervous system post-transplant lymphoproliferative disorder overlap those of infection and primary central nervous system lymphoma and the fact that untreated posttransplant lymphoproliferative disorder has a poor prognosis, it is important to maintain a high index of suspicion for this disorder so that appropriate treatment can be instituted.

Transcranial Doppler (TCD) is widely accepted as the modality of choice for screening intracranial vessels in children with sickle cell disease. Its advantages are that it is noninvasive (no need for sedation, contrast material, or radiation), portable, easily repeated, and it provides information about the intracranial vessels that is otherwise unavailable. These positive attributes explain why in recent years the applications for TCD have grown beyond sickle cell screening to almost any disease process that involves the major intracranial vessels. The objective of this manuscript is to discuss key points on how to perform and interpret TCD, and discuss imaging features of various pathological processes such as sickle cell, asphyxia, brain trauma, brain death, hydrocephalus, enlarged subarachnoid spaces, vasospasm, vasculitis, venous sinus thrombosis, and vein of Galen malformation.

Objective: The purpose of this study was to determine the value of follow-up renal sonography in children who presented with urinary tract infection and were found to have a voiding cystogram diagnosis of vesicoureteral reflux while having a normal initial renal sonogram., Methods: We retrospectively reviewed the medical records of 64 consecutive children who presented for follow-up renal sonography with a voiding cystogram diagnosis of vesicoureteral reflux and a normal initial sonogram conducted as part of the routine evaluation after urinary tract infection. Data recorded included gender, age, initial grade of reflux, time to follow-up sonogram, and abnormalities on follow-up sonogram. Children with conditions that may predispose to vesicoureteral reflux were excluded., Results: Children who were studied (7 boys, 57 girls) ranged in age from 1 month to 10 years, 10 months (mean: 35.6 months; median: 24 months). Ninety-four (73.4%) of 128 renal units demonstrated vesicoureteral reflux on voiding cystogram; 89 (94.7%) of 94 of them were grade 1 to 3. The mean time to follow-up was 22 months (range: 4 months to 5 years, 2 months; median: 18 months). All 128 (95% confidence interval: 0%-2.8%) renal units were normal on follow-up sonography., Conclusion: Routine performance of repeat sonography seems unnecessary among children, particularly girls, with low- to medium-grade vesicoureteral reflux, who have had a previous normal sonogram and no conditions that predispose to vesicoureteral reflux.

Intracranial epidermoid tumors or cysts are considered benign lesions. Differentiation of epidermoid tumors from arachnoid cysts is important for appropriate patient care because the treatment is different for each lesion. Arachnoid cysts can appear very similar to epidermoid tumors on computed tomography (CT). Epidermoid tumors can grow in the cerebellopontine angle (CPA) cistern, the most common location of these lesions, resulting in trigeminal neuralgia and facial paralysis. Treatment for epidermoid tumors is exclusively surgery. Arachnoid cyst, on the other hand, is a benign condition that rarely produces symptoms. Recent advances in magnetic resonance imaging (MRI) have allowed more accurate imaging diagnosis of epidermoid tumors. This article reviews the recent advances in MRI using conventional T1W, post-contrast T1W, T2W, steady-state free precession imaging, fluid-attenuated inversion recovery (FLAIR), diffusion-weighted imaging (DWI), and proton magnetic resonance spectroscopy (MRS) in the imaging diagnosis of epidermoid tumors.

Purpose: To prospectively compare resident and attending radiologic interpretations of nonenhanced limited computed tomographic (CT) scans obtained in children suspected of having appendicitis., Materials and Methods: Seventy-five consecutive children underwent nonenhanced limited CT for suspected appendicitis. The scans were prospectively interpreted by a resident and an attending radiologist, each unaware of the other's interpretation. The probability that the findings indicated a diagnosis of appendicitis, level of certainty in the interpretation, and presence of an alternate diagnosis were statistically analyzed., Results: Nineteen children (25%) had appendicitis. The area under the receiver operating characteristic curve was not significantly different between residents (0.97 +/- 0.02) and attendings (0.95 +/- 0.04). The percentage agreement between residents and attendings was 91% (kappa = 0.73 +/- 0.095). The average level of certainty tended to be higher for attendings (93% +/- 15) than residents (89% +/- 12). The sensitivity, specificity, and accuracy of resident interpretations were 63%, 96%, and 88%, respectively, compared with those of attending interpretations--95%, 98%, and 97%, respectively. Residents and attendings noted alternate diagnoses in 30% of children without appendicitis., Conclusion: A high level of agreement exists between resident and attending radiologists in the interpretation of nonenhanced limited CT scans in children suspected of having appendicitis. Residents, however, tend to be less confident in their interpretations.

Objective: Infantile hypertrophic pyloric stenosis (IHPS) is a common condition which presents in infants at 2-12 weeks of postnatal life, and whose cause remains obscure. Multiple associated abnormalities have been recognized within the external hypertrophied pyloric muscle layer, but the internal component of the pyloric mucosa has received scant attention in the literature to date. Our purpose in this study was to show that pyloric mucosal redundancy is a constant finding in infants with IHPS, to discuss its possible cause, and to explore the hypothesis of a relationship between pyloric mucosal redundancy and the development of IHPS., Materials and Methods: We identified 102 consecutive infants with surgically confirmed IHPS and determined the thickness of the pyloric mucosa compared with the thickness of the surrounding hypertrophied muscle. Fifty-one infants who did not have pyloric stenosis served as controls., Results: Mean mucosal thickness in patients with IHPS approximated mean muscle thickness, with a ratio of 0.89. In infants with IHPS, the pyloric mucosa constitutes approximately one third of the cross-sectional diameter of the pyloric mass and fills and obstructs the pyloric canal., Conclusion: Mucosal redundancy is a constant associated finding in IHPS. Although the origin of the redundancy and a cause-and-effect relationship are difficult to establish, our findings support the hypothesis that hypergastrinemia may be implicated in the pathogenesis of IHPS, and suggest that mucosal thickening could be implicated as one of the initiating factors in its development.

The pediatric parotid gland and periparotid region are subject to a variety of lesions and are most often evaluated with ultrasonography (US), contrast material-enhanced computed tomography (CT), and magnetic resonance (MR) imaging. US may be used to assess the size of the parotid gland, distinguish diffuse from focal disease, assess vascularity and adjacent vascular structures, distinguish cystic from solid lesions, and guide fine-needle aspiration. However, further evaluation with CT or MR imaging may be needed to better define the nature and extent of disease. CT is the imaging modality of choice for most pediatric parotid disease (including acute inflammation, abscess, calculi, and major salivary duct obstruction) and most solid masses and may obviate sedation. However, a mass associated with facial nerve symptoms should be evaluated with MR imaging because it is the only modality that can consistently demonstrate the facial nerve. Findings at US, CT, and MR imaging allow localization of parotid lesions and may suggest a specific cause. Clinical information, familiarity with normal parotid anatomy at various stages of its development, and knowledge of the imaging characteristics of parotid and periparotid lesions are essential for appropriate radiologic evaluation. This information can be used to guide therapy and plan a surgical approach.

The objective of this manuscript is to review and illustrate the findings of appendicitis, and of alternate diagnoses that may clinically or radiographically simulate appendicitis, on unenhanced limited CT in children. Potential pitfalls in unenhanced limited CT interpretation of pediatric patients will also be discussed.