Nancy A. Chauvin

Imaging of pediatric ovarian neoplasms

We review the clinical and imaging characteristics of the most common ovarian neoplasms in children and adolescents. Because of the widespread use of diagnostic imaging, incidental ovarian neoplasms might be encountered during the evaluation of abdominal pain, trauma or other indications and might pose a diagnostic dilemma. Conducting adequate imaging studies under these conditions is important, as management strategies differ according to the size and appearance of the lesion as well as the age of the patient. US dominates in gynecological imaging because of its excellent visualization, absence of ionizing radiation and sedation risks and comparatively low cost. For further examination of indeterminate lesions found using US, MRI is being used more progressively in this field, particularly for the evaluation of complex pelvic masses with the aim of distinguishing benign and malignant conditions and conditions requiring surgical intervention. CT is reserved primarily for tumor staging and follow-up and for emergency situations.

Diagnostic Performance of Whole-Body MRI as a Tool for Cancer Screening in Children With Genetic Cancer-Predisposing Conditions

OBJECTIVE Children with cancer-predisposing conditions are at increased risk to develop and die of cancer. Limited data exist on the utility of whole-body MRI as a cancer screening tool in children. In this study, we examined the diagnostic performance of whole-body MRI as a mechanism of tumor surveillance for children at increased genetic risk for cancer. MATERIALS AND METHODS Twenty-four children (six boys and 18 girls) with a mean age of 11.2 years (range, 2.1-18.2 years) underwent 50 unenhanced whole-body MRI examinations over a 5-year period. Scans were retrospectively reviewed and assessed for image quality; sequences performed; and the presence of osseous, soft-tissue, or solid organ abnormalities. Findings suggestive of a malignancy were stratified by risk as low (< 20% chance for cancer), moderate (20-80%), or high (> 80%). MRI findings were correlated with medical records, biopsy results, or additional follow-up imaging; biopsy and follow-up were considered as the reference standards. RESULTS Forty-eight of 50 (96%) examinations were of very good quality. Nine findings suspicious for malignancy were identified, including two high-risk, two moderate-risk, and five low-risk lesions. One high-risk lesion was proven by biopsy to be a papillary thyroid carcinoma, with the remaining lesions deemed nonmalignant. The sensitivity of whole-body MRI was 100%; specificity, 94%; positive predictive value, 25%; and negative predictive value (NPV), 100%. CONCLUSION Unenhanced whole-body MRI is safe and produces excellent images. The high sensitivity, specificity, and NPV make whole-body MRI a valuable cancer screening tool in children with a genetic predisposition for cancer.

Osteoid osteomas: a pain in the night diagnosis

Osteoid osteoma is a common benign bone-forming lesion that is composed of a nidus of vascular osteoid tissue and woven bone lined by osteoblasts. It is frequently associated with considerable surrounding inflammation. The diagnosis is usually straightforward when imaging reveals a radiolucent nidus surrounded by variable degrees of reactive sclerosis. However, the diagnosis can be elusive when osteoid osteomas occur in atypical locations, as they may have a nonspecific and misleading appearance on different imaging modalities, particularly on MRI. The purpose of this pictorial essay is to review the typical and atypical features of osteoid osteomas on different imaging modalities, and the appearance of osteoid osteomas in different locations. We also review growth disturbances caused by osteoid osteomas and potential mimickers, with imaging characteristics that can aid in diagnosis.

Assessment of Sacroiliitis at Diagnosis of Juvenile Spondyloarthritis by Radiography, Magnetic Resonance Imaging, and Clinical Examination

To evaluate the prevalence of sacroiliitis at diagnosis of juvenile spondyloarthritis (SpA) and the accuracy of physical examination and back pain to detect sacroiliitis, using imaging as the reference standard.

Detection of inflammatory sacroiliitis in children with magnetic resonance imaging: is gadolinium contrast enhancement necessary?

In adults, gadolinium contrast enhancement does not add incremental value to fluid‐sensitive sequences for evaluation of bone marrow edema. This study was undertaken to determine if magnetic resonance imaging (MRI) contrast is necessary to assess lesions consistent with inflammatory sacroiliitis in children.

Complex Genitourinary Abnormalities on Fetal MRI: Imaging Findings and Approach to Diagnosis

OBJECTIVE The objective of this article is to present the fetal MRI patterns of complex genitourinary abnormalities including epispadias-exstrophy complex, cloacal malformation, urogenital sinus anomaly, posterior urethral valves, and other causes that result in lower urinary tract dilatation without oligohydramnios. Relevant embryology will be reviewed, and practical points will be provided that can aid in interpretation. CONCLUSION Complex genitourinary abnormalities have recognizable imaging findings on fetal MRI. Imaging findings may be subtle; a high index of suspicion and a systematic checklist are useful for accurate diagnosis. Familiarity with fetal MRI patterns of complex genitourinary abnormalities is crucial for making more precise diagnoses that will likely impact pregnancy management, counseling, and postnatal treatment.

Sacroiliitis at diagnosis of juvenile spondyloarthritis assessed by radiography, magnetic resonance imaging, and clinical examination

To evaluate the prevalence of sacroiliitis at diagnosis of juvenile spondyloarthritis (SpA) and the accuracy of physical examination and back pain to detect sacroiliitis, using imaging as the reference standard.

MR Imaging of Normal Epiphyseal Development and Common Epiphyseal Disorders

During infancy and childhood, multiple developmental changes occur in the epiphysis. Initially the epiphysis is composed entirely of hyaline cartilage. As skeletal maturation progresses, one or several secondary ossification centers (SOCs) develop within the epiphyseal cartilage. The SOCs enlarge by endochondral ossification and undergo marrow transformation in a process analogous to that of the primary physis and metaphysis. Magnetic resonance (MR) imaging can be used to evaluate vascularity, marrow, and cartilage and plays a critical role in the assessment of epiphyseal disorders in children. In cases of shoulder and hip dysplasia, MR imaging demonstrates unossified structures and helps guide treatment. In cases of trauma, the intracartilaginous pathway of fractures, the degree of physeal involvement, and early bridge formation can be assessed. With the use of intravenous gadolinium-based contrast material, avascular necrosis and reperfusion can be characterized. This article reviews the normal structure of the epiphysis, its appearance at MR imaging, and age-related changes to the epiphysis. Common conditions that lead to epiphyseal damage in children are reviewed, with an emphasis on the role of MR imaging in diagnosis, prognosis, and treatment.

Detection of enthesitis in children with enthesitis-related arthritis: dolorimetry compared to ultrasonography.

To evaluate the distribution of enthesitis and the accuracy of physical examination with a dolorimeter for the detection of enthesitis in children, using ultrasound (US) assessment as the reference standard.

Magnetic Resonance Imaging of the Pediatric Shoulder

Magnetic resonance (MR) imaging is a modality widely used to assess shoulder abnormalities in children. A thorough understanding of the development of the shoulder and adequate MR techniques are crucial in the radiologic evaluation. The immature skeleton is particularly vulnerable to insults such as trauma, infection, and inflammation, and responds in unique ways. The pediatric shoulder can also be affected by complex congenital deformities such as brachial plexus injuries. In addition, certain neoplasms can be seen specifically in the young patient. MR imaging plays a critical role in the initial diagnostic evaluation and in assessing posttreatment responses.