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Integrated RF coil with stabilization for fMRI human cortex.

Abstract

Functional brain imaging of the human cortex is limited by poor contrast to noise ratio (CNR) and image degradation due to subject motion during the acquisition period. The work described here combines the use of closely coupled phased array receiver coils with a stabilization system to address these needs. Several phased array designs are evaluated and compared with the conventional "birdcage" design. Coil performance is reported in terms of relative SNR and fMRI results. Relative improvements of up to 360% are obtained for the occipital region and 180% in the temporal region. More modest gains of 10-30% were obtained for a "dome"-shaped birdcage volume coil covering the entire cortex.

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BibTeXRIS

J R Fitzsimmons, J D Scott, D M Peterson, B L Wolverton, C S Webster, P J Lang. 1997. Integrated RF coil with stabilization for fMRI human cortex.. https://doi.org/10.1002/mrm.1910380104

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Prenatal diagnosis of malformations of cortical development by dedicated neurosonography.

OBJECTIVE: Malformations of cortical development (MCD) are rarely diagnosed in utero. We describe and compare the ultrasonographic and pathology findings in a cohort of fetuses with MCD. METHODS: Fetuses with MCD were identified among all fetuses evaluated for suspected brain anomalies at the Fetal Neurology Clinic, and the ultrasonographic findings were compared with the results of the pathology examination. RESULTS: We suspected the presence of MCD by ultrasonography in 23 fetuses. The mean gestational age at the time of ultrasound diagnosis was 26.2 (range, 18-40) weeks. The ultrasonographic findings leading to the diagnosis of MCD were abnormally overdeveloped gyri and sulci for gestational age (n = 7), delay in sulcation (n = 5), abnormally thin cortex (n = 5) abnormally wide and broad sulci (n = 3), bulging into the lateral ventricle (n = 1), cortical cleft (n = 1), and multiple intraparenchymal echogenic nodules (n = 1). All fetuses had associated central nervous system (CNS) and/or non-CNS anomalies. Pathology examination (performed in 17 fetuses) confirmed MCD in 16. CONCLUSIONS: Cortical malformations can be diagnosed in utero by ultrasonography based on the presence of specific deviations from the normal pattern of development. The identified cases may represent the more severe forms in the MCD spectrum. The pathology findings do not always conform to the current classification systems of MCD but help in differentiating between possible genetic and acquired etiologies and in some cases provide a definitive syndromic diagnosis.

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