Diagnostic Accuracy of Amino Acid and FDG-PET in Differentiating Brain Metastasis Recurrence from Radionecrosis after Radiotherapy: A Systematic Review and Meta-Analysis.

BACKGROUND: Current studies that analyze the usefulness of amino acid and FDG-PET in distinguishing brain metastasis recurrence and radionecrosis after radiation therapy are limited by small cohort size. PURPOSE: Our aim was to assess the diagnostic accuracy of amino acid and FDG-PET in differentiating brain metastasis recurrence from radionecrosis after radiation therapy. DATA SOURCES: Studies were retrieved from PubMed, Embase, and the Cochrane Library. STUDY SELECTION: Fifteen studies were included from the literature. Each study used PET to differentiate radiation necrosis from tumor recurrence in contrast-enhancing lesions on follow-up brain MR imaging after treating brain metastasis with radiation therapy. DATA ANALYSIS: Data were analyzed with a bivariate random-effects model. Sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, and diagnostic odds ratio were pooled, and a summary receiver operating characteristic curve was fit to the data. DATA SYNTHESIS: The overall pooled sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, and diagnostic odds ratio of PET were 0.85, 0.88, 7.0, 0.17, and 40, respectively. The area under the receiver operating characteristic curve was 0.93. On subgroup analysis of different tracers, amino acid and FDG-PET had similar diagnostic accuracy. Meta-regression analysis demonstrated that the method of quantification based on patient, lesion, or PET scan (based on lesion versus not, P = .07) contributed to the heterogeneity. LIMITATIONS: Our study was limited by small sample size, and 60% of the included studies were of retrospective design. CONCLUSIONS: Amino acid and FDG-PET had good diagnostic accuracy in differentiating brain metastasis recurrence from radionecrosis after radiation therapy.

Imaging of metabolic bone disease and marrow disorders in children.

There are a wide variety of metabolic and infiltrative diseases that involve the bones. Conventional radiography is the primary imaging examination for the initial evaluation of most of these disorders. MR imaging, however, provides detailed information about the bone marrow and is gaining an increasingly important role in the management of disorders of bone marrow infiltration.

Fetal magnetic resonance imaging.

Ultrafast magnetic resonance imaging (MRI) sequences have changed the use of MRI to evaluate fetal abnormalities. Currently, the best application is the evaluation of suspected brain abnormalities found on ultrasound. MRI differentiates the various types of fetal ventriculomegaly. Superior posterior fossa visualization allows differentiation of Dandy-Walker malformation from a large cisterna magna. Anomalies of the corpus callosum can be seen. MRI also is valuable in the evaluation of fetal giant neck masses for planning delivery of the baby and surgery for life-threatening airway obstruction. In the chest, MRI differentiates masses such as diaphragmatic hernia, cystic adenomatoid malformation, and sequestration, and it aids in planning fetal surgery because MRI directly visualizes the position of the lung, liver, and bowel.

A new tool for prenatal diagnosis: ultrafast fetal MRI.

The development of ultrafast magnetic resonance imaging scanners and sequences provides a new tool for the diagnosis of fetal anomalies. Magnetic resonance imaging is a valuable adjunct to prenatal ultrasound especially for the evaluation of suspected fetal brain anomalies, chest masses, abdominal masses, and renal diseases.

Arterial waveforms in the femoral heads of healthy neonates.

OBJECTIVE: The objective of this study was to characterize the Doppler waveform in the cartilaginous capital femoral epiphysis of healthy neonates with the aid of power Doppler and duplex Doppler imaging. SUBJECTS AND METHODS: In this prospective study, both hips were examined in 63 neonates. We used conventional sonographic imaging and power Doppler imaging. Spectral Doppler tracings were obtained when possible. Spectral analysis and resistive index measurements were performed. RESULTS: The examination was completed in 97 hips, revealing pulsatile arterial blood flow with a low-velocity, low-resistance, reproducible waveform. Mean resistive index was 0.48 +/- 0.11. Additional time spent on the Doppler study was documented in all patients and averaged 6 min. CONCLUSION: The arterial blood flow pattern in the femoral chondroepiphysis of healthy neonates has been described. The additional time spent doing the Doppler examination is acceptable. In future studies, this pattern of blood flow can be compared with that of abnormal hips and those undergoing treatment for developmental dysplasia.

Imaging of pediatric central nervous system HIV infection.

With the increasing incidence of pediatric HIV infection, distinct patterns of central nervous system involvement, different from those in adults, are being recognized. This article illustrates the spectrum of neuroimaging findings seen in HIV-infected children with central nervous system involvement. Case examples include HIV encephalitis, basal ganglia calcific vasculopathy, lymphoma, and cerebrovascular complications, such as arterial ectasia and arterial fibrosing sclerosis.

Pseudoprune-Belly syndrome: imaging findings and clinical outcome.

OBJECTIVE: The purpose of this study was to describe the imaging features and clinical outcome of patients with an incomplete form of the prune-belly syndrome, called pseudoprune-belly syndrome. MATERIALS AND METHODS: Imaging and the clinical course of eight boys with pseudoprune-belly syndrome (prune-belly syndrome uropathy, normal abdominal wall examination, and incomplete or absent cryptorchidism) were retrospectively reviewed. RESULTS: Voiding cystourethrography (n = 8) showed a dilated posterior urethra and megacystis in each patient (100%) and vesicoureteral reflux in six (75%). Among the eight patients, IV urography (n = 7) and renal sonography (n = 4) showed dysmorphic kidneys in each patient (100%), with bilateral hydroureteronephrosis in six (75%), and unilateral hydroureteronephrosis with a poorly functioning (or nonfunctioning) contralateral kidney in two (25%). Urologic procedures included vesicostomy (n = 3, 38%), ileal conduit (n = 2, 25%), pyeloplasty (n = 2, 25%), ureteral reimplantation (n = 3, 38%), and nephroureterectomy (n = 3, 38%). Renal failure developed in five patients (63%). CONCLUSION: Uropathy in patients with pseudoprune-belly syndrome is typically moderate to severe. Despite urologic intervention, renal insufficiency develops in most patients.