Fig 6 - uploaded by Andrea Poretti
Content may be subject to copyright.
Sagittal, coronal, axial magnetic resonance images of a fetus with a cystic non-skin covered lumbar myelomeningocele (MMC, a). The MMC is protruding through a wide spinal defect, the neural placode is recognized as a T2-hypointense structure on top of the MMC. Lateral to the neural placode the meninges are seen. The stretched T2-hypointense nerve roots are outlined by the cerebrospinal fluid coursing from the anterior surface of the neural placode towards the widened spinal canal (b). A small posterior fossa is noted consistent with a Chiari II malformation, cerebellar and vermian structures are herniating into the upper cervical canal. In addition a significant supratentorial hydrocephalus is seen on the dedicated brain images (c). Axial ultrasonography study of a fetus with an open lumbar MMC. The MMC is seen protruding outside of the spinal canal, outlined by the hypoechogenic amniotic fluid (arrows) (d).
Source publication
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...
Contexts in source publication
Context 1
... MRI typically shows a widened spinal canal with lack of the soft tissues covering the spinal canal (Figs 6-8). The spinal canal is typically widened in both the anterior-posterior and left-right diameter. ...
Context 2
... degrees of hydromyelia may be encountered in the intact spinal cord superior to the level of dysraphia. Heavily T2-weighted, fetography sequences may directly reveal a sac-like protrusion of the neural tissues through the defect (Figs 6 and 7). The Chiari II malformation is easily identified by a small posterior fossa with cerebellar structures herniating upward and downward, frequently accompanied with a moderate supratentorial hydrocephalus. ...
Similar publications
Congenital malformations of spine and spinal cord are collectively termed as spinal dysraphism. It includes a heterogeneous group of anomalies which result from faulty closure of midline structures during development. Magnetic resonance imaging (MRI) is now considered the imaging modality of choice for diagnosing these conditions. The purpose of th...
Citations
... There is ascent of the conus due to relatively faster growth of the spinal column. At term, the conus is seen above L2 (Fig. 3.14) [20][21][22][23]. The fetal spine is examined in three planes. ...
... Similarly, oligohydramnios and large maternal body habitus may further limit image detail. MRI provides additional information due to its high contrast resolution [23]. ...
Advances in various subspecialities of medicine have made it possible to understand Central nervous system (CNS) development better. Congenital CNS malformations may occur due to spontaneous mutations within the embryo’s genes, inherited genetic defects, or damage to the fetus caused by maternal exposure to infection, toxins, drugs, or trauma. The advent of high-resolution imaging techniques and genetic analysis have revolutionized the diagnosis of malformations and we are able to identify specific gene defects in several congenital anomalies. The CNS anomalies can be classified based on embryological development or on the organ/region involved.
... Spinal disrafizmleri değerlendirirken en temel nokta malformasyonun, hemen her zaman Chiari 2 malformasyonu ile beraber izlenen açık tip spinal disrafizm mi yoksa kapalı tip spinal disrafizmin mi olduğunun tespitidir. Açık tip spinal disrafizmlerin büyük bir kısmını oluşturan myelomeningosel en sık görülen fetal spinal anomali olup gelişimini tamamlayamamış spinal kordun, yani nöral plakodun, subaraknoid boşluğun ekspansiyonu ile birlikte vertebra korpuslarının posteriorundaki defektten cilt dışına doğru uzanımı ile karakterizedir [23] (Resim 4). Myelomeningosel ve normalden küçük posterior fossa ile serebellar tonsillerin foramen magnumdan herniasyonu olarak bilinen Chiari 2 malformasyonu kombine patolojiler olarak izlenir. ...
... On MRI, this spinal cord malformation is usually recognized as a widened spinal canal with two hemicords outlined by T2hyperintense cerebrospinal fluid. The bony spur that divides the spinal canal is generally detected on axial or coronal imaging as a hypointense band on T2-weighted sequences [19]. This finding is important because if DMM is not suspected, the surgical repair of the myelomeningocele will not include the repair of the tethered cord that is nearly always present in DMM [17]. ...
Objective:
To assess the role of magnetic resonance imaging (MRI) in the management of myelomenigocele.
Background:
Spinal dysraphism or neural tube defects (NTD) encompass a heterogeneous group of congenital spinal anomalies that result from the defective closure of the neural tube early in gestation. Myelomeningocele is the most common type of NTD that is compatible with life, with high survival rates but lifelong physical impairments.
Conclusion:
MRI is an important adjunct to ultrasound in assessing NTD, as it pertains to pre-surgical planning and perinatal management. However, it should not be considered a replacement for ultrasonography, which continues to be the gold standard for fetal anatomic evaluation.
... Prenatally, the indication of spine MRI is completely different and includes the identification and characterization of the open spinal dysraphia. 68 Compared with prenatal ultrasound, fetal MRI provides more detailed evaluation of the spinal malformation including determination of the exact level and extent of the dysraphia, exclusion of complications (eg, syringohydromyelia), and identification of additional malformations (eg, diastematomyelia) (Fig. 13). Figure 11 Supratentorial neuroimaging findings in Chiari type 2 malformation. ...
Chiari malformations are a heterogeneous group of disorders with distinct clinical anatomical features all of which involve the hindbrain. Our understanding of Chiari malformations increased tremendously over the past decades, and progress in neuroimaging was instrumental for that. Conventional and advanced neuroimaging of the brain and spine play a key role in the workup of children with suspected Chiari malformations. In addition, neuroimaging studies in Chiari malformations may guide the management, serve as a predictor of outcome, and shed light on the pathogenesis.
... Fetal MR imaging of spinal malformations typically serves as a secondary confirming or complementing imaging modality, after prenatal US has identified a spinal anomaly. It is a valuable additional tool in cases of maternal obesity, oligohydramnion, posterior position of the fetal spine with respect to the mother, in detecting additional intracranial malformations, as well as various uro-genital and gastro-intestinal malformations (45). Com-mon malformations of the spine include open or closed dysraphism, diastematomyelia, tethered cord, scoliosis and sacrococcygeal teratoma (Fig. 10, 11). ...
The purpose of this article is to provide an overview of MR imaging of the fetal central nervous system, and to briefly discuss recent advances. Fetal MRI has been commonly used throughout the world for over 20 years. Compared to US it has better contrast resolution, allows direct visualization of both hemispheres and the additional limitations of sonography do not affect the quality of MRI. There are no known adverse short-term or long-term side effects of MRI in children, who were imaged in the fetal period. The standard protocol for fetal MRI consists of single-shot rapid acquisition T2 weighted sequences in three planes, fast spoiled gradient recalled T1 weighted sequence, T2 gradient echo sequence and diffusion weighted sequence in the axial plane. The clinical applications of advanced MRI techniques are still limited. Fetal MRI is performed to confirm abnormalities detected on US, and to exclude additional pathology. Interpreting fetal MRI images requires understanding of normal fetal CNS development and one should also evaluate other fetal structures, the umbilical cord and placenta. The most common indication for MR imaging of the fetal CNS is mild ventriculomegaly. Other common indications, that are also discussed in the article, include commissural abnormalities, infratentorial abnormalities, cortical malformations, spinal pathology and complications of monochorionic twin pregnancy. Conclusion : Fetal MRI provides important information in prenatal counseling, therefore familiarity with the applications and limitations of fetal MRI, and multidisciplinary collaboration remain essential for the radiologist involved in prenatal imaging.
... Prenatally, the indication of spine MRI is completely different and includes the identification and characterization of the open spinal dysraphia. 68 Compared with prenatal ultrasound, fetal MRI provides more detailed evaluation of the spinal malformation including determination of the exact level and extent of the dysraphia, exclusion of complications (eg, syringohydromyelia), and identification of additional malformations (eg, diastematomyelia) (Fig. 13). Figure 11 Supratentorial neuroimaging findings in Chiari type 2 malformation. ...
