Imaging features of medulloepithelioma: report of four cases and review of the literature.

BACKGROUND: Intraocular medulloepithelioma is a childhood tumor arising from the nonpigmented primitive ciliary neuroepithelium. Although rarer than retinoblastoma, it remains the second most common primary intraocular neoplasm in children. The rarity of intraocular medulloepithelioma creates the challenge in establishing a clinical diagnosis, and radiologically the tumor is often confused with other intraocular masses. OBJECTIVE: To describe the clinical, imaging and pathological features of intraocular medulloepithelioma with emphasis on the role of imaging to enable its differentiation from more common intraocular pathology. MATERIALS AND METHODS: We retrospectively analyzed the clinical, histopathological and imaging data of four children with intraocular medulloepithelioma. RESULTS: All four children had medulloepithelioma arising from the ciliary body. The children were imaged with US (n = 3), MRI (n = 4), whole-body (99m)Tc-MDP scintigraphy (n = 2) and CT (n = 1). All four children had enucleation of the involved eye. One tumor was a malignant teratoid variant, two tumors were malignant nonteratoid variants and one was a nonteratoid variant of uncertain malignant potential. None of the tumors had extraocular extension on histopathology or imaging. Two children had associated retinal detachment on US and MRI examinations. All tumors were iso/hyperintense to vitreous on T1-weighted and hypointense on T2-weighted MRI and showed marked contrast enhancement of the solid components. No calcifications were identified on US or CT examinations. CONCLUSION: Our findings are consistent with previously reported cases of medulloepithelioma. This series emphasizes the roles of various imaging modalities, with pathological correlation, in differentiating the tumor from other ciliary body masses, in detecting tumor extension and in identifying associated ocular complications. In this series we also describe the results of postsurgical follow-up for tumor recurrence.

The effects of propofol on cerebral perfusion MRI in children.

INTRODUCTION: The effects of anesthesia are infrequently considered when interpreting pediatric perfusion magnetic resonance imaging (MRI). The objectives of this study were to test for measurable differences in MR measures of cerebral blood flow (CBF) and cerebral blood volume (CBV) between non-sedated and propofol-sedated children, and to identify influential factors. METHODS: Supratentorial cortical CBF and CBV measured by dynamic susceptibility contrast perfusion MRI in 37 children (1.8-18 years) treated for infratentorial brain tumors receiving propofol (IV, n = 19) or no sedation (NS, n = 18) were compared between groups and correlated with age, hematocrit (Hct), end-tidal CO2 (ETCO2), dose, weight, and history of radiation therapy (RT). The model most predictive of CBF and CBV was identified by multiple linear regression. RESULTS: Anterior cerebral artery (ACA) and middle cerebral artery (MCA) territory CBF were significantly lower, and MCA territory CBV greater (p = 0.03), in IV than NS patients (p = 0.01, 0.04). The usual trend of decreasing CBF with age was reversed with propofol in ACA and MCA territories (r = 0.53, r = 0.47; p < 0.05). ACA and MCA CBF (r = 0.59, 0.49; p < 0.05) and CBV in ACA, MCA, and posterior cerebral artery territories (r = 0.73, 0.80, 0.52; p < 0.05) increased with weight in propofol-sedated children, with no significant additional influence from age, ETCO2, hematocrit, or RT. CONCLUSION: In propofol-sedated children, usual age-related decreases in CBF were reversed, and increases in CBF and CBV were weight-dependent, not previously described. Weight-dependent increases in propofol clearance may diminish suppression of CBF and CBV. Prospective study is required to establish anesthetic-specific models of CBF and CBV in children.

Unique MRI findings as an early predictor of osteonecrosis in pediatric acute lymphoblastic leukemia.

OBJECTIVE: Osteonecrosis is a potential complication of glucocorticoid chemotherapy in children surviving leukemia. Early diagnosis may allow effective interventions to minimize or ameliorate joint deterioration and obviate surgical intervention. We investigated the significance of MRI signal changes that precede the currently recognized "double-line" changes, which are considered pathognomic of osteonecrosis. MATERIALS AND METHODS: We retrospectively reviewed MRI scans acquired during prospective screening and follow-up of pediatric patients with leukemia for osteonecrosis. RESULTS: Of 481 patients, we identified 21 cases (4.3%; 12 boys; median age at leukemia diagnosis, 12.8 years) with subtle poorly defined geographically delineated MRI signal abnormalities in knees or hips, or both, that progressed over a median of 4 months (range, 1.6-18.5 months) to florid MRI signs of osteonecrosis. Articular surface collapse developed in three hips (two patients) and three knees (three patients). Three patients subsequently underwent surgical intervention (one bilateral total hip arthroplasty and one bilateral and one unilateral hip core decompression). The median duration of follow-up was 27 months (range, 1.9-90.7 months). CONCLUSION: The MRI signal abnormalities described here appear to herald extensive osteonecrosis and precede the typical MRI findings of osteonecrosis previously reported in the literature.

Topics in perinatal genitourinary system ultrasound evaluation.

Ultrasound is a helpful imaging tool for triaging and in most instances making a definitive diagnosis of abnormalities of the fetal and neonatal genitourinary systems. Ultrasound can define an abnormality found in a fetus or neonate as definitively related to the genitourinary system, guiding further workups. Ultrasound can be used to assuage clinical concern by showing normal anatomic findings or variants that can simulate abnormality. This article discusses necessary information to aid in ultrasound diagnosis in various areas of the perinatal genitourinary system including the kidneys, bladder, and genital system. It discusses some adrenal findings that may help in these diagnoses.

Outcome of fetuses with cerebral ventriculomegaly and septum pellucidum leaflet abnormalities.

OBJECTIVE: The objective of this study was to assess the outcomes of the prenatal diagnosis of septal leaflet abnormalities in fetuses referred for prenatal imaging with a finding of ventriculomegaly. MATERIALS AND METHODS: This study is a retrospective review of fetuses with a diagnostic code of septal leaflet abnormalities from a larger prospective study. Four hundred twenty-five pregnant women with 433 fetuses referred for ventriculomegaly were imaged with ultrasound and MRI between July 1, 2003, and May 15, 2009. Four to six radiologists independently reviewed sonographic and MR images and recorded lateral ventricular diameters at the atrium and frontal horns, ventricular configuration, and the presence of ventriculomegaly and of other CNS abnormalities. Final prenatal ultrasound, MRI, and overall diagnoses were decided by consensus. Fetuses with a diagnostic code of septal leaflet abnormalities were identified, and birth outcome, autopsy findings, postnatal imaging, and postnatal follow-up examinations were obtained. The analysis of covariance, controlling for gestational age, was used to compare ventricular dimensions between fetuses with septal leaflet abnormalities and fetuses with isolated ventriculomegaly. Interrater agreement for the detection of septal leaflet abnormalities was assessed with kappa statistics. Interrater agreement and intrarater agreement for frontal horn measurements were assessed by variance components analysis. RESULTS: Twenty-three fetuses had septal leaflet abnormalities and 229 had isolated ventriculomegaly. Atrial and frontal horn diameters, adjusted for gestational age, were 77% and 98% larger, respectively, in fetuses with septal leaflet abnormalities than in fetuses with isolated ventriculomegaly (p < 0.0001). Before the consensus conference, agreement among ultrasound readers was moderate (κ = 0.54) and among MR readers, good (κ = 0.69). Additional CNS findings were seen on MRI in 12 of 23 fetuses (52%). Eleven pregnancies with septal leaflet abnormalities underwent termination and 12 progressed to livebirth; of the 12 livebirths, three neonates died. Neurodevelopmental follow-up was abnormal in all surviving children. CONCLUSION: A septal leaflet abnormality in the setting of ventriculomegaly is most frequently associated with other CNS abnormalities and is associated with postnatal developmental delay.