Ramesh S. Iyer

Comparison of 3 Tesla proton MR spectroscopy, MR perfusion and MR diffusion for distinguishing glioma recurrence from posttreatment effects

To compare 3 Tesla (3T) multi‐voxel and single‐voxel proton MR spectroscopy (MRS), dynamic susceptibility contrast perfusion MRI (DSC), and diffusion‐weighted MRI (DWI) for distinguishing recurrent glioma from postradiation injury.

Pediatric CT: Strategies to Lower Radiation Dose

OBJECTIVE The introduction of MDCT has increased the utilization of CT in pediatric radiology along with concerns for radiation sequelae. This article reviews general principles of lowering radiation dose, the basic physics that impact radiation dose, and specific CT integrated dose-reduction tools focused on the pediatric population. CONCLUSION The goal of this article is to provide a comprehensive review of the recent literature regarding CT dose reduction methods, their limitations, and an outlook on future developments with a focus on the pediatric population. The discussion will initially focus on general considerations that lead to radiation dose reduction, followed by specific technical features that influence the radiation dose.

Usual and unusual causes of pediatric gastric outlet obstruction

Gastric outlet obstruction in children encompasses a spectrum of disorders that extends beyond hypertrophic pyloric stenosis. Each condition can result in the clinical syndrome of persistent nonbilious vomiting, which can progress to dehydration and electrolyte imbalances. This paper reviews the spectrum of both the common and uncommon entities that cause partial or complete gastric outlet obstruction and their imaging appearances. The correct diagnosis of those with gastric outlet obstruction can be achieved by combining clinical presentation with appropriate imaging, leading to optimal and timely patient management.

Pediatric Bone Imaging: Imaging Elbow Trauma in Children???A Review of Acute and Chronic Injuries

OBJECTIVE Pediatric elbow trauma is challenging because of the complex nature of the growing skeleton. The objectives of this article are to review the anatomy and radiographic landmarks and to discuss common acute and chronic injuries sustained. CONCLUSION Radiographic evaluation of elbow trauma in the acute setting requires a firm understanding of developmental anatomy, radiographic landmarks, and the common injury patterns. Both radiography and MRI are vital tools for diagnosing chronic elbow overuse injuries in adolescent athletes.

Craniosynostosis: imaging review and primer on computed tomography

Craniosynostosis is encountered in the pediatric population in isolated or syndromic forms. The resulting deformity depends on the number and type of sutures involved and, in multi-sutural synostosis, the order of suture fusion. Primary craniosynostosis needs to be differentiated from the secondary variety and positional or deformational mimics. Syndromic craniosynostoses are associated with other craniofacial deformities. Evaluation with 3-D CT plays an important role in accurate diagnosis and management; however, implementation of appropriate CT techniques is essential to limit the radiation burden in these children. In this article, the authors briefly review the classification, embryopathogenesis and epidemiology and describe in detail the radiologic appearance and differential diagnoses of craniosynostosis.

Medication neurotoxicity in children

Medication neurotoxicity may have a variety of imaging manifestations in children. In this pictorial essay, we review the two most common brain injury patterns, posterior reversible encephalopathy syndrome (PRES) and acute toxic leukoencephalopathy (ATL). Proposed etiologies, salient features on neurological imaging, and methods for differentiating these entities and their implications will be discussed. Certain agents do not fall into these two broad patterns but instead characteristically involve central structures. We individually review several medications and their respective neurotoxic appearances including methotrexate, cyclosporine A, tacrolimus, metronidazole and vigabatrin. Diagnosis of medication neurotoxicity may be achieved by the combination of new-onset neurological deficits, recent initiation of a new therapy agent and distinctive findings on magnetic resonance imaging. Clinical and radiological improvement and/or resolution are frequently observed after the agent is discontinued.

The Diagnostic Value of CT Myelography, MR Myelography, and Both in Neonatal Brachial Plexus Palsy

BACKGROUND AND PURPOSE: Although most infants with brachial plexus palsy recover function spontaneously, approximately 10–30% benefit from surgical treatment. Pre-operative screening for nerve root avulsions is helpful in planning reconstruction. Our aim was to compare the diagnostic value of CT myelography, MR myelography, and both against a surgical criterion standard for detection of complete nerve root avulsions in birth brachial plexus palsy. MATERIALS AND METHODS: Nineteen patients who underwent a preoperative CT and/or MR myelography and subsequent brachial plexus exploration were included. Imaging studies were analyzed for the presence of abnormalities potentially predictive of nerve root avulsion. Findings of nerve root avulsion on surgical exploration were used as the criterion standard to assess the predictive value of imaging findings. RESULTS: Ninety-five root levels were examined. When the presence of any pseudomeningocele was used as a predictor, the sensitivity was 0.73 for CT and 0.68 for MR imaging and the specificity was 0.96 for CT and 0.97 for MR imaging. When presence of pseudomeningocele with absent rootlets was used as the predictor, the sensitivity was 0.68 for CT and 0.68 for MR imaging and the specificity was 0.96 for CT and 0.97 for MR imaging. The use of both CT and MR imaging did not increase diagnostic accuracy. Rootlet findings in the absence of pseudomeningocele were not helpful in predicting complete nerve root avulsion. CONCLUSIONS: Findings of CT and MR myelography were highly correlated. Given the advantages of MR myelography, it is now the single technique for preoperative evaluation of nerve root avulsion at our institution.

Pictorial essay: The many faces of craniosynostosis.

Craniosynostosis is a common condition in the pediatric age group, which may either be isolated or may present as part of a craniofacial syndrome. This pictorial review illustrates the underlying mechanisms and pathophysiology of craniosynostosis, the various types of craniosynostoses, common craniofacial syndromes and the role of imaging in their diagnosis and management.

Imaging of Pediatric Pancreatic Neoplasms With Radiologic- Histopathologic Correlation

OBJECTIVE The purpose of this article is to describe the imaging features of pediatric pancreatic tumors with pathologic correlation. Epithelial and nonepithelial lesions are described. Pancreatic imaging protocols, clinical presentation, and management are also detailed. CONCLUSION Pancreatic neoplasms are rare in children and vary widely between benign and malignant causes and between cystic and solid lesions. Epithelial tumors are most common and include solid pseudopapillary tumor, pancreatoblastoma, islet cell neoplasms, and cystic lesions.

Imaging of pediatric floor of mouth lesions

There is a vast spectrum of pathology that afflicts the floor of mouth in children. These span inflammatory conditions, vascular malformations, developmental anomalies, benign tumors and malignancies. While this area is readily evaluated on clinical exam, imaging is often performed to better characterize the disorder prior to management. The imaging modalities most frequently utilized are US, CT and MR. The purpose of this article is to describe the primary conditions that occur in this location in children so that radiologists may provide an appropriate differential diagnosis. These include ranula, venolymphatic malformation, dermoid, teratoma, foregut duplication cyst, hairy polyp, thyroglossal duct cyst and rhabdomyosarcoma. For each pathological condition, there will be a focus on describing its imaging manifestation. Floor of mouth anatomy, imaging approach during both prenatal and postnatal life and etiologies will be discussed. Surgical considerations and operative photographs will also be presented.