Prevalence and evolution of intracranial hemorrhage in asymptomatic term infants.

BACKGROUND AND PURPOSE: Subdural hemorrhage (SDH) is often associated with infants experiencing nonaccidental injury (NAI). A study of the appearance and natural evolution of these birth-related hemorrhages, particularly SDH, is important in the forensic evaluation of NAI. The purpose of this study was to determine the normal incidence, size, distribution, and natural history of SDH in asymptomatic term neonates as detected by sonography (US) and MR imaging within 72 hours of birth. MATERIALS AND METHODS: Birth history, delivery method, duration of each stage of labor, pharmaceutic augmentation, and complications during delivery as well as postnatal physical examination were recorded. Brain MR imaging and US were performed on 101 asymptomatic term infants at 3-7 days, 2 weeks, 1 month, and 3 months. Clinical follow-up at 24 months was recorded. RESULTS: Forty-six neonates had SDH by MR imaging within 72 hours of delivery. SDH was seen in both vaginal and cesarean deliveries. All neonates were asymptomatic, with normal findings on physical examination. All 46 had supratentorial SDH seen in the posterior cranium. Twenty (43%) also had infratentorial SDH. US detected 11 of the 20 (55%) infratentorial SDHs and no supratentorial SDH. Most SDHs present at birth were

Magnetic resonance imaging of stapes prostheses.

OBJECTIVE: To assess the magnetic resonance imaging (MRI) compatibility of stapes prostheses. DATA SOURCES: A comprehensive review of the English literature evaluating MRI compatibility of stapes prostheses. Multiple series of stapes prostheses from different manufactures placed in a 1.5-tesla MRI field to determine ferromagnetic properties. RESULTS: When MRI was first introduced, reports demonstrated the MRI compatibility of stapes prostheses. The testing was performed on single copies of various prostheses from several manufacturers. Although implant manufacturers have indicated MRI compatibility, several reports of variable ferromagnetic properties of aneurysm clips have been reported. This variability has led to rotation of the clips and hemorrhage in patients with supposed MRI-compatible clips. These findings suggest that testing single stapes prostheses from a manufacturer might not completely assess the safety of MRI on patients with stapes prostheses. We performed MRI compatibility testing on several series of stapes prostheses from Xomed Surgical Products and Smith & Nephew Richards. Two series of Xomed stapes prostheses were found to have ferromagnetic properties. CONCLUSION: Manufacturing variability could lead to stapes prostheses being MRI incompatible. Each prosthesis should be tested before implantation for ferromagnetic properties.

MR imaging of patients with carotidynia.

BACKGROUND AND PURPOSE: Carotidynia is an idiopathic neck pain syndrome associated with tenderness to palpation over the carotid bifurcation. Although well known in the otolaryngology and neurology literature, the validity of the entity has recently been questioned, in part because of the almost uniform absence of radiologic or pathologic findings. We report the MR findings in five patients with carotidynia. METHODS: During a period of 44 months, five patients with clinical signs and symptoms consistent with carotidynia were referred for imaging from the otolaryngology service. Each patient underwent MR imaging of the neck on a 1.5-T system. The studies included, as a minimum, pre- and postcontrast axial and postcontrast coronal T1-weighted images. Two patients also had axial T2-weighted imaging and another two patients underwent duplex sonography of the carotids. RESULTS: All five patients had abnormal enhancing tissue surrounding the symptomatic carotid artery centered at the level of the distal common carotid and carotid bifurcation. This tissue had intermediate signal intensity on T1-weighted images and showed marked enhancement. In all patients, the remaining visualized portions of the carotid artery were normal. Normal flow voids were present throughout the vessel, and the caliber of the vessels was always within normal limits. There was no evidence of intramural hematoma, cervical lymphadenopathy, or atherosclerotic disease of the vessel. In one patient, repeat imaging after resolution of symptoms showed an absence of the previous abnormality. CONCLUSION: The MR findings in these patients, along with the lack of any findings to suggest alternative diagnoses, support the existence of carotidynia as a distinct clinical entity.