This paper presents a detailed numerical study of specific absorption rate (SAR) and temperature increase calculations within pregnant female models exposed to magnetic resonance imaging (MRI). Nine pregnant female models, representing different pregnant stages, were used for this study. SAR and temperature increase within and around fetuses at different pregnancy stages were calculated for two MRI operating modes (normal mode and first-level controlled mode) at 64 and 128 MHz. Local fetus energy deposition exceeds the International Electrotechnical Commission limit of 10 W/kg in the first-level controlled mode at 64 MHz. Fetus temperature exceeds or approaches 38 C for both frequencies in the first-level controlled mode at later stages of pregnancy. The core temperature limits for both modes and both frequencies are not exceeded. The results show higher maximum SAR and higher temperature at 64 MHz and during later pregnancy stages with a significant increase starting with the fifth month of pregnancy. Based on the results of this study, radiologists can minimize local fetus heating, especially late in pregnancy, by using normal mode sequences, which minimize the whole body SAR in the mother.Index Terms-Electromagnetic heating, finite-difference method, magnetic resonance imaging (MRI), pregnant woman, safety standards.
Introduction. Pott’s puffy tumor is characterized by the osteomyelitis of the frontal bone with underlying subperiosteal abscess, mostly occurring secondary to recurrent sinusitis or head trauma. Though it is a rare clinical entity in this antibiotic era, its occurrence mostly in the adolescent age group has now shown increased reporting lately in all age groups. Case Description. We describe here a case of a 4½-month-old female baby who presented to our hospital’s Emergency Room with clinical features of pyogenic meningitis following aspiration of a midline frontal swelling. The infant presented with high-grade fever, 3-4 episodes of projectile vomiting, increased irritability, and refusal to breastfeeding than usual. This was accompanied by a history of a gradually increasing midline fluctuant erythematous swelling on her forehead extending to the left eye. Aspiration of the swelling was done a day before by a local general practitioner, following which she developed the above-mentioned features of pyogenic meningitis and was brought to the hospital the next day. Examination revealed a conscious, febrile, irritable child with bulging anterior fontanel and 101.4°F axillary temperature. Vital signs were within normal limits. CSF analysis was suggestive of pyogenic meningitis, and appropriate antibiotics were given. MRI showed frontal bone osteomyelitis with erosion of the bony plate and focal cerebritis. The condition turned out to be Pott’s puffy tumor with pyogenic meningitis after detailed investigations. The infant was treated with appropriate antibiotics and other supportive therapeutic measures and discharged with the advice for further management in collaboration with otorhinolaryngologist.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.