MR Imaging and Cochlear Implants with Retained Internal Magnets: Reducing Artifacts near Highly Inhomogeneous Magnetic Fields.

The number of patients receiving cochlear implants and auditory brainstem implants for severe to profound sensorineural hearing loss has rapidly increased. These implants consist of an internal component implanted between the skull and the temporal scalp and an external removable speech processor unit. A small magnet within the internal component is commonly used to hold the external speech processor unit in place.

Double Inversion Recovery Magnetic Resonance Imaging in Identifying Focal Cortical Dysplasia.

Background: Focal cortical dysplasia is commonly recognized in pediatric epilepsy surgery. Despite characteristic radiographic features, focal cortical dysplasia can be subtle on magnetic resonance imaging. Double inversion recovery acquisition suppresses the white matter signal, which may enhance visualization of abnormal features at the gray-white matter interface.

Congenital mydriasis and prune belly syndrome in a child with an ACTA2 mutation.

We report the association of congenital mydriasis with prune belly syndrome and cerebrovascular anomalies in a 9-year-old boy who was found to have an ACTA2 mutation. This case illustrates the spectrum of systemic malformations that are attributable to mutations in ACTA2 and expands the spectrum of cerebrovascular anomalies that are now known to accompany congenital mydriasis.

"Ocular moyamoya" syndrome in a patient with features of microcephalic osteodysplastic primordial dwarfism type II.

Primordial dwarfism refers to severely impaired growth beginning early in fetal life. There are many genetic causes of primordial dwarfism, including disorders classified as microcephalic osteodysplastic primordial dwarfism. Microcephalic osteodysplastic primordial dwarfism type II is an autosomal-recessive disease characterized by small stature, bone and dental anomalies, and characteristic facies.

Assessment of normal myelination with magnetic resonance imaging.

White matter myelination is essential to postnatal neurologic maturation and can be accurately evaluated by magnetic resonance imaging (MRI). Accordingly, MRI pulse sequences should be optimized for detection of myelin in young children. T1-weighted images are most useful during the first year of life.

3 Tesla magnetic resonance imaging with and without corticotropin releasing hormone stimulation for the detection of microadenomas in Cushing's syndrome.

Objective: We sought to determine if higher resolution 3 Tesla (T) magnetic resonance imaging (MRI) with or without ovine corticotropin releasing hormone (o-CRH) stimulation would increase the sensitivity for detection of pituitary microadenomas in ACTH-dependent Cushing's syndrome (CS).

Design And Patients: We prospectively identified 23 patients over a 2-year period with clinical and biochemical evidence of ACTH-dependent CS with no lesion (n = 11) or equivocal lesion (n = 10) on 1.5T MRI.

Neonatal hypoxic-ischemic encephalopathy: multimodality imaging findings.

Diffuse hypoxic-ischemic brain injury in the neonate results in neonatal hypoxic-ischemic encephalopathy (HIE). Because of differences in brain maturity at time of insult, severity of hypotension, and duration of insult, there are four distinct patterns of brain injury. Cranial ultra-sonography and computed tomography reveal periventricular leukomalacia, germinal matrix hemorrhage, and hydrocephalus.

Different patterns of magnetic resonance imaging atrophy for frontotemporal lobar degeneration syndromes.

Background: Frontotemporal lobar degeneration (FTLD) is an uncommon degenerative dementia that presents with focal cognitive and behavioral deficits.

Objective: To determine the correlation of the different presentations of FTLD with structural neuroimaging findings.

Design And Patients: In a blinded study, we retrospectively evaluated the clinical presentations and magnetic resonance imaging (MRI) patterns of atrophy in 59 patients with FTLD and 26 patients with probable Alzheimer disease at a memory disorders clinic.

Frequency of abnormal hand and wrist radiographs at time of diagnosis of polyarticular juvenile rheumatoid arthritis.

Objective: To determine the frequency of radiographic abnormalities in hand/wrist radiographs of children with newly diagnosed polyarticular juvenile rheumatoid arthritis (polyJRA) because radiographs of small joints are an important tool in assessing outcomes in RA and there are clinical similarities between RA and polyJRA.

Methods: A medical record review was performed to identify cases of polyJRA seen at Mayo Clinic from January 1, 1994, to December 31, 2001. Hand/wrist radiographs, obtained at the time of diagnosis, were reviewed by 3 radiologists with attention to periarticular osteopenia, joint space narrowing (JSN), or erosion.