1215: Fetal brain and spinal cord by 3D/4D neuroimaging technology

Abstract

Antenatal evaluation of the fetal central nervous system (CNS) plays an important role in the field of perinatology. Transvaginal sonography of the fetal brain opened a new field in medicine, neurosonography. Transvaginal approach to the normal fetal brain during the second and third trimester was introduced in the beginning of 1990s. Transvaginal observation of the fetal brain offers sagittal and coronal views of the brain from fetal parietal direction through the fontanelles and/or the sagittal suture as ultrasound windows. Serial oblique sections via the same ultrasound window reveal the intracranial morphology in detail. This method has contributed to the prenatal sonographic assessment of congenital CNS anomalies and acquired brain damage in utero, especially when compared with conventional transabdominal method. Combination of both transvaginal sonography and 3D ultrasound has been a great diagnostic tool for evaluation of 3D structure of fetal CNS. 3D transvaginal sonography demonstrates bony structure such as cranial os and vertebrae, multiplanar analysis of inside morphology from early till late pregnancy, sono-angiography and volume extraction and calculation of target organ, i.e., lateral ventricle and/or choroids plexus. Recent advanced 3D technology produced tomographic ultrasound imaging, which shows tomographic parallel slices of any cutting sections. Because tomographic images are produced from original 3D dataset, slice distance can be changed, and all tomographic images can be rotated around x, y and z axes. Those 3D technologies have contributed to the CNS neuroassessment during pregnancy. 4D ultrasound has furthermore added the information of fetal functional neurobehavior to static neuroimaging data. Fetal MRI has also produced whole CNS information of fetuses and compensated smartly for the weak points of ultrasound, such as detection of gyri and sulci in late pregnancy By the use of update imaging technologies, it has been possible to clarify natural history of normal development of the brain and spine from very early period, natural history and detailed structure of congenital CNS anomalies and rapid morphological changes of in utero brain damage such as intracranial bleeding. In referral cases with CNS abnormalities, main reasons for referral are enlarged ventricles or intracranial cystic area. However, there are many intracranial morphological changes without ventriculomegaly or cystic area, which might cause neurological deficits. New facts produced from advanced neuroimaging of fetal CNS might be clues for explaining the unknown neurological disorders. Antenatal evaluation of the fetal central nervous system (CNS) plays an important role in the field of perinatology. Transvaginal sonography of the fetal brain opened a new field in medicine, neurosonography. Transvaginal approach to the normal fetal brain during the second and third trimester was introduced in the beginning of 1990s. Transvaginal observation of the fetal brain offers sagittal and coronal views of the brain from fetal parietal direction through the fontanelles and/or the sagittal suture as ultrasound windows. Serial oblique sections via the same ultrasound window reveal the intracranial morphology in detail. This method has contributed to the prenatal sonographic assessment of congenital CNS anomalies and acquired brain damage in utero, especially when compared with conventional transabdominal method. Combination of both transvaginal sonography and 3D ultrasound has been a great diagnostic tool for evaluation of 3D structure of fetal CNS. 3D transvaginal sonography demonstrates bony structure such as cranial os and vertebrae, multiplanar analysis of inside morphology from early till late pregnancy, sono-angiography and volume extraction and calculation of target organ, i.e., lateral ventricle and/or choroids plexus. Recent advanced 3D technology produced tomographic ultrasound imaging, which shows tomographic parallel slices of any cutting sections. Because tomographic images are produced from original 3D dataset, slice distance can be changed, and all tomographic images can be rotated around x, y and z axes. Those 3D technologies have contributed to the CNS neuroassessment during pregnancy. 4D ultrasound has furthermore added the information of fetal functional neurobehavior to static neuroimaging data. Fetal MRI has also produced whole CNS information of fetuses and compensated smartly for the weak points of ultrasound, such as detection of gyri and sulci in late pregnancy By the use of update imaging technologies, it has been possible to clarify natural history of normal development of the brain and spine from very early period, natural history and detailed structure of congenital CNS anomalies and rapid morphological changes of in utero brain damage such as intracranial bleeding. In referral cases with CNS abnormalities, main reasons for referral are enlarged ventricles or intracranial cystic area. However, there are many intracranial morphological changes without ventriculomegaly or cystic area, which might cause neurological deficits. New facts produced from advanced neuroimaging of fetal CNS might be clues for explaining the unknown neurological disorders.