Journal of Pediatric Neuroradiology - Volume 1, issue 3

Authors: Huisman, Thierry A.G.M.

Article Type: Other

DOI: 10.3233/PNR-2012-023

Citation: Journal of Pediatric Neuroradiology, vol. 1, no. 3, pp. 145-145, 2012

Authors: Schneider, Jacques F.

Article Type: Review Article

Abstract: Magnetic resonance imaging of the fetus is nowadays routinely used as a complimentary imaging method to ultrasound for the detection of morphological changes of the brain and spine. The advent of fast sequences, which allow high signal-to-noise, high-resolution datasets has facilitated standardized and reliable protocols, enabling fetal Magnetic resonance imaging to be acknowledged as a valuable adjunct in many antenatal clinics. This review covers technical requisites, sequence details, and provides a practical approach for routine diagnosis of fetal brain and spine.

Keywords: Fetal, MRI, brain, spine

DOI: 10.3233/PNR-2012-024

Citation: Journal of Pediatric Neuroradiology, vol. 1, no. 3, pp. 147-153, 2012

Authors: Bekiesinska-Figatowska, Monika

Article Type: Review Article

Abstract: Since the introduction of prenatal magnetic resonance imaging in 1980s, safety issues have been discussed in numerous publications. The examination is contraindicated in certain circumstances, as in the general population. Available fast magnetic resonance imaging (MRI) techniques make sedation of the mother (and fetus) unnecessary. Proper positioning of the patient is important to avoid compression of the inferior vena cava by the pregnant uterus. Static magnetic field, radiofrequency pulses and magnetic field gradients constitute the three hazards to the fetus examined in the MRI scanner. High static magnetic fields are only responsible for sensory effects: vertigo, metallic taste and magnetophosphenes. …Electromagnetic radiofrequency pulses result in energy deposition and are responsible for tissue heating during MRI. Increased temperature is especially harmful to the fetal central nervous system. Temperature rise of 2 °C lasting for 24 h may cause neural tube and cranio-facial abnormalities. The amount of energy deposited in a patient over time is reflected by specific absorption rate (SAR). In a study using SAR of 4.0 W/kg (the upper limit in general clinical MRI imaging) no maternal temperature changes were detected. MRI is unlikely to result in significant temperature changes provided that temperature and humidity in the MRI suite are kept within the recommended limits: of less than 24 degrees °C and below 60%, respectively. MRI generates noise. Water – the main component of the amniotic fluid – reduces sound intensity of approximately 30 dB. It is unlikely that the MRI scan would harm the fetus hearing and such harmful effects have not been observed in follow-up studies. The mother is protected by headphones with music, which also has a calming effect in case of claustrophobia and general anxiety. Harmful influence of MRI on organogenesis in the first trimester of pregnancy has not been described at the clinically used magnetic field strengths. In most centers, gadolinium is not used for fetal imaging. If it is used, it is for maternal reasons, if the benefits outweigh the potential risk. Last but not least, it is important to perform fetal MRI in specialized centers. Staff experience both in performing and interpreting the study is crucial to make the examination as short and conclusive as possible. Show more

Keywords: MRI, fetus, safety

DOI: 10.3233/PNR-2012-025

Citation: Journal of Pediatric Neuroradiology, vol. 1, no. 3, pp. 155-159, 2012

Authors: Brugger, Peter C.

Article Type: Review Article

Abstract: The present paper reviews the normal developmental anatomy of the eyes and orbits and corresponding imaging findings during the period covered by fetal magnetic resonance imaging (MRI), i.e. 20 gestational wk (GW) to birth. Several aspects of orbital and ocular anatomy have to be considered that are peculiar to the fetus. There is normal fetal exophthalmos, since the growth of the eye outpaces that of the orbit. The fetal orbital roof has a typical slanting shape. Eyeball shape changes from elliptic to more circular in axial cross-section between 20 and 25 GW. The vitreous is clearly depicted, while the retina, …choroid, sclera and Tenon's capsule together appear as a hypointense T2-weighted rim lining it. Transient structures like the hyaloid arterial system and primary vitreous are too small or offer insufficient contrast to be depicted with fetal MRI. The initially spherical lens gains its elliptical shape by the end of the second trimester. Although the current resolution of fetal MRI is high, several structures can only be depicted when they reach sufficient size. This applies to the anterior chamber and the cornea both of which can only be demonstrated in the third trimester. Visualization of the optic nerve and extraocular muscles depends on the signal intensity of the intraorbital fat, which changes in the third trimester. Because of frequent fluid filling, the lacrimal sacs can be demonstrated following 25 GW. Show more

Keywords: Fetus, eye, orbit, MRI, growth, anatomy

DOI: 10.3233/PNR-2012-026

Citation: Journal of Pediatric Neuroradiology, vol. 1, no. 3, pp. 161-170, 2012

Authors: Senapati, Gunjan Malik | Levine, Deborah

Article Type: Review Article

Abstract: A combination of prenatal ultrasound and magnetic resonance imaging can be used to detect and characterize many primary and secondary central nervous system (CNS) abnormalities in the developing fetus. While this information is useful in prenatal patient counseling, it is important to understand the factors that can influence change in diagnosis and prognosis over time. The etiology of the abnormality, the conspicuity of associated findings, the change in appearance over time, and the opinion of subspecialty experts all can influence the diagnosis. Additionally, technical factors of imaging acquisition may allow the detection of an abnormality in the postnatal period and …not prenatally. Having an understanding of the normal fetal central nervous system anatomy at varying gestational ages will aid in the imaging detection and interpretation of CNS pathology. Understanding how these appearances and diagnoses can change over time will aid in the discussion of prognosis with expectant parents, which is crucial in fetal CNS abnormalities. Show more

Keywords: Central nervous system abnormalities, prenatal, ultrasound, MRI

DOI: 10.3233/PNR-2012-027

Citation: Journal of Pediatric Neuroradiology, vol. 1, no. 3, pp. 171-184, 2012

Authors: Huisman, Thierry A.G.M. | Tekes, Aylin | Poretti, Andrea

Article Type: Review Article

Abstract: Early, sensitive and specific prenatal diagnosis of malformations of the fetal brain and correct identification of the various etiologies of ventriculomegaly are essential for the pre-, peri-, and postnatal management. Prenatal ultrasonography (US) is the primary imaging modality for identification of fetal central nervous system (CNS) pathology. However, prenatal US may not always identify the full spectrum of pathology. Consequently, the final diagnosis may be incorrect or underestimate the CNS anomaly. Fetal magnetic resonance imaging has emerged as a valuable, safe and easy to perform secondary imaging tool for the evaluation of the fetal CNS. The high spatial resolution, good …signal to noise ratio, and high contrast to noise ratio allow the study of various developmental processes of the fetal CNS in detail. Consequently, fetal magnetic resonance imaging may show pathology that remained undetected on prenatal US. The extra information has proven invaluable for managing these high-risk pregnancies and is also important for the counseling of the parents. In the current review we discuss various frequently encountered brain malformations as well as the various etiologies of “ventriculomegaly”. Show more

DOI: 10.3233/PNR-2012-028

Citation: Journal of Pediatric Neuroradiology, vol. 1, no. 3, pp. 185-195, 2012

Authors: Girard, Nadine J. | Dediu, Melania Anca | Dory-Lautrec, Philippe

Article Type: Review Article

Abstract: During the last decade, increasing interest in magnetic resonance imaging (MRI) has emerged for the evaluation of fetal abnormalities detected on ultrasound. The advent of single-shot rapid acquisition sequences has greatly facilitated the ability to obtain detailed imaging information of the fetal brain. To date, fetal MRI has shown to have an important role in the investigation of cerebral abnormalities suspected by sonography, and in the detection of subtle brain anomalies associated with high-risk pregnancies. MRI has proved to be a useful adjunct to sonography during the prenatal period of development, especially for the detection of acquired disorders. Acquired fetal …brain disorders include fetal hypoxia, congenital infections (especially toxoplasmosis and cytomegalovirus infections), brain injury due to malformations, pregnancies at risk of fetal brain damage, inherited metabolic diseases, especially mitochondrial diseases, intrauterine growth retardation, and tumors. Acquired fetal brain disorders represent the third most frequent indication for fetal brain MRI following fetal ventricular dilatation and central nervous system malformations. Show more

Keywords: Brain, human, fetal diseases, MRI, diffusion MRI, MRS

DOI: 10.3233/PNR-2012-029

Citation: Journal of Pediatric Neuroradiology, vol. 1, no. 3, pp. 197-209, 2012

Authors: Huisman, Thierry A.G.M. | Graham, Ernest M. | Tekes, Aylin | Poretti, Andrea

Article Type: Review Article

Abstract: Fetal magnetic resonance imaging is well accepted as secondary image tool for the evaluation of pathologies affecting the fetal brain as detected on prenatal ultrasonography. Significantly, fewer articles have focused on the fetal spinal canal and its contents. Many malformations and pathologies involving the spinal canal and cord may however have a significant impact on the quality of life. In addition, anomalies of the spinal cord may affect the development of the fetal brain or may be part of a more extensive malformation that may also affect the major thoracic and abdominal organs. A thorough knowledge of the normal and …abnormal development of the spinal column and its contents is necessary to diagnose and understand the encountered findings. In the current review the value of fetal magnetic resonance imaging of the spinal column and cord is discussed. The most frequently encountered malformations will be presented and discussed in the context of the most relevant embryological processes. Show more

Keywords: Fetal MRI, spine, malformation, myelomeningoceles, diastematomyelia, dorsal dermal sinus, sacrococcygeal teratoma

DOI: 10.3233/PNR-2012-030

Citation: Journal of Pediatric Neuroradiology, vol. 1, no. 3, pp. 211-223, 2012

Authors: Soman, Salil | Kasprian, Gregor | Schopf, Veronika | Berger-Kulemann, Vanessa | Nemec, Ursula | Mitter, Christian | Prayer, Daniela

Article Type: Research Article

Abstract: Fetal magnetic resonance imaging is playing an increasingly important role in troubleshooting diagnostically uncertain fetal ultrasound examinations. Recent advances in imaging speed and post processing of fetal images have enabled new applications of advanced neural imaging techniques to fetal imaging. This paper reviews recent developments in the topics of fetal diffusion tensor imaging, fetal spectroscopy, fetal dynamic imaging and resting state fetal magnetic resonance imaging.

Keywords: Fetal MRI, fetal diffusion tensor imaging, fetal spectroscopy, dynamic fetal MRI, resting state fetal MRI

DOI: 10.3233/PNR-2012-031

Citation: Journal of Pediatric Neuroradiology, vol. 1, no. 3, pp. 225-251, 2012

Authors: Saadai, Payam | Lee, Hanmin

Article Type: Review Article

Abstract: Fetal intervention is indicated to treat selected neurological anomalies. The introduction of prenatal ultrasound and novel surgical techniques helped advance the use of fetal surgery for neurological disorders, most notably in cases of fetal myelomeningocele. Interventions for hydrocephalus (e.g. serial cephalocentesis, ventriculoamniotic shunts) were among the first treatments attempted by fetal surgeons, but results have been poor. Myelomeningocele is the most widely accepted neurological indication to offer fetal surgery, having recently been studied in a randomized controlled trial. Fetal intervention including prenatal gene and stem cell therapy holds promise for treating other neural tube defects and congenital neurovascular malformations, but …further investigation is needed before new roles for fetal surgery are indicated. Show more

Keywords: Fetal neurosurgery, fetal surgery, hydrocephalus, myelomeningocele, neural tube defect, prenatal surgery, spina bifida, ventriculomegaly

DOI: 10.3233/PNR-2012-021

Citation: Journal of Pediatric Neuroradiology, vol. 1, no. 3, pp. 253-259, 2012