Occupational risk from static magnetic fields of MRI scanners

The health care staff operating magnetic resonance imaging (MRI) scanners are exposed to static magnetic field of significant spatial heterogenity and high level of flux density—usually existing permanently during the shift. The personnel can also be exposed to pulses of magnetic field of high rate of rise/fall, so-called gradient fields, which exist only during examination of patients. The level of workers’ exposure depends both on the type of the magnet and on the ergonomical characteristic of design of the particular MRI scanner. This paper presents the current state of the art on occupational exposure to static magnetic field health effects, gaps in scientific data, MRI workers’ exposure characteristics, research needs, and suggestions for the exposure assessment protocol for future investigations.     

Prenatal diagnosis of neurofibromatosis type 1: sonographic and MRI findings

Prenatal ultrasound and magnetic resonance imaging (MRI) demonstrated a large oropharyngeal tumor, and cardiac and cranial abnormalities consistent with neurofibromatosis type 1 (NF1) in a third-trimester fetus, which were confirmed on postmortem examination. Sonographic features of NF1 are generally nonspecific; MR examination provided significant additional information, facilitating prenatal diagnosis. Copyright © 2006 John Wiley & Sons, Ltd.     

Prenatal evaluation of fetal neck masses in preparation for the EXIT procedure: the value of pulmonary Doppler ultrasonography (PDU)

Sonographic demonstration of normal tracheal diameter and breathing-related lung fluid flow at 30 weeks' gestation in a fetus with a giant neck mass confirmed patent airways, thus avoiding an EXIT procedure. Copyright © 2001 John Wiley & Sons, Ltd.     

Intrauterine brain teratoma: a case report of imaging (US,MRI) with neuropathologic correlations

Fetal brain tumors are rare and teratoma is considered as the most common. Fetal MR Imaging is currently used to evaluate cases of ventricular dilatation. We report a case of cerebral immature teratoma detected by ultrasonography because of ventricular dilatation at 24 gestational weeks. MRI was the more accurate imaging method in depicting the tumor and its consequences on brain development as well as in taking a decision with regard to the management of pregnancy. Copyright © 2003 John Wiley & Sons, Ltd.     

Progressive neuronal degeneration of childhood: prenatal diagnosis by MRI

We report two cases in the same family of progressive neuronal degeneration of childhood—Alpers syndrome—with prenatal MRI findings in one case. The first infant presented at birth with severe microcephaly, then rapidly evolved to progressive encephalopathy with refractory epilepsy, leading to death at 10 months. Biochemical investigations including liver function tests were normal. CT and MRI showed severe diffuse brain atrophy. The diagnosis of progressive neuronal degeneration of childhood was made on the clinical and imaging data. The second pregnancy was marked by gradual decrease of fetal cerebral biometry and a prenatal MRI performed at 32 weeks showed diffuse cortical atrophy, as observed in the sibling. The infant died at 5 months. Neuropathological findings were consistent with Alpers syndrome. Copyright © 2005 John Wiley & Sons, Ltd.     

Intra-abdominal masses: prenatal differential diagnosis and management

Intra-abdominal masses and cystic lesions are not commonly identified during the routine 20-week anomaly scan but are not infrequently seen as incidental findings during a third trimester scan assessing fetal growth and well being. This review looks at the potential differential diagnosis of masses and cysts seen prenatally and aims to define a method of assessment that will help limit the differential diagnosis before delivery. Copyright © 2008 John Wiley & Sons, Ltd.