Search

Purpose: The aim of this study was to evaluate the usefulness of three-dimensional T1-weighted spoiled gradient-recalled echo (3D T1-GRE) images for the preoperative anatomical evaluation of lumbosacral lipoma, thick filum terminale, and myelomeningocele as a means of compensating for the drawbacks of 3D heavily T2-weighted (3D hT2-W) images., Methods: Nine patients with lumbosacral lipomas, one patient with tight filum terminale, and five patients with myelomeningoceles were included in this study. 3D T1-GRE images were compared with 3D hT2-W images or conventional magnetic resonance images in terms of delineation of lipomas and other structures in the patients with lipomas and tight filum terminale. For patients with myelomeningoceles, 3D T1-GRE images were compared with 3D hT2-W images in terms of artifacts in the cerebrospinal fluid (CSF) space., Results: The 3D T1-GRE images demonstrated lipomas with good contrast to the spinal cord and CSF space and more clearly delineated the anatomical relationship between lipomas and these structures than did the 3D hT2-W images. The 3D T1-GRE images delineated dural defects through which extradural lipomas penetrated into the intradural space. The 3D T1-GRE images also demonstrated the presence or absence of lipomas in the filum terminale and the absence of artifact in the myelomeningoceles. Furthermore, they were useful for differentiating artifacts observed on the 3D hT2-W images from nerve elements., Conclusions: The complementary use of 3D T1-GRE and 3D hT2-W images may compensate for the drawbacks of 3D hT2-W images and may eventually improve lesion visualization and surgical decision making.

Contrast fistulogram (FG) and distal pressure colostogram (DPCG) are standard diagnostic methods for the assessment of anorectal malformations. Pelvic magnetic resonance imaging (MRI) earned a place among essential diagnostic methods in preoperative investigations after the Currarino syndrome and a high incidence of associated spinal dysraphism were described. The aim of our study was to evaluate the possibility of substituting FG and DPCG by a modified pelvic MRI, e.g. MRI fistulogram (MRI-FG) and MRI colostogram (MRI-DPCG). The prospective study involved 29 patients with anorectal malformations who underwent a modified pelvic MRI. The length and course of fistulas and rectum, and the presence of sacral anomalies were studied on MRI images and compared with images obtained by radiologic examinations. Modified MRI brought identical results as contrast studies in 25 patients when related to the fistula and rectum length and course. MRI was more accurate for the detection of sacral anomalies. MRI-FG was the only imaging method used in the four most recent patients. The results support the assumption that conventional contrast examinations for the assessment of anorectal malformations can be replaced by MRI, thus reducing the radiation dose., (© 2013.)

Purpose: To compare two-dimensional ultrasonography (2DUS) and magnetic resonance imaging (MRI) for assessing brain and spine parameters in fetuses with spina bifida., Methods: A cross-sectional study was conducted on 15 fetuses with spina bifida (one with encephalocele, four with rachischisis and 10 with myelomeningocele). The size of the atrium of the lateral ventricle, percentage shortening of the cerebellum, degree of compromising of the first vertebra and total number of vertebras affected by herniation were assessed. The MRI examination was performed not more than 7 days after the 2DUS. To compare and correlate the parameters from the two techniques, the paired Student's t test and intraclass correlation coefficient (ICC) were used. To assess the correlations of atrium measurements from 2DUS and MRI with other parameters, Pearson's correlation coefficient (r) was used., Results: No significant difference was observed in any of the means of the parameters assessed using the two techniques (p > 0.05). Both 2DUS and MRI seemed to present satisfactory reliability in measurements on the size of the atrium of the lateral ventricle and the first vertebra affected (ICC = 0.88 and 0.75, respectively). Measurements on the atrium of the lateral ventricle from 2DUS correlated better with the other parameters than did measurements from MRI., Conclusions: In fetuses with spina bifida, 2DUS and MRI present similar results, but measurements on the atrium of the lateral ventricle from 2DUS correlated better with the other parameters.

Development of spinal canal and its contents occurs in a much regulated fashion. Aberration at any stage of development namely gastrulation, primary neurulation, secondary neurulation, and retrogressive differentiation can result in a specific abnormality. Spinal cord anomalies or spinal dysraphism is a heterogeneous group containing some entities that are obvious at birth and many that are discovered only after imaging for neurological symptoms or signs. Congenital spinal tumors are closely related and present either as an external mass or imaging abnormalities. Radiological imaging plays a crucial role in both diagnosis and postoperative evaluation of these patients. Magnetic resonance imaging is the modality of choice. Computed tomography is used in a limited fashion. Plain radiographs are the initial imaging in patients presenting with abnormal curvatures of spine. No other central nervous system abnormality requires as systematic an approach as spinal dysraphism. The authors present a review of both common and rare anomalies that they encountered for a 3-year period in their institute, a tertiary care level hospital., (Copyright © 2013 Mosby, Inc. All rights reserved.)

Purpose: Brain MR imaging is essential in the assessment of Chiari II malformation in clinical and research settings concerning spina bifida. However, the interpretation of MR images of the malformation is not always straightforward. Morphometric analyses of the extent of Chiari II malformation may improve the assessment. In an attempt to select appropriate morphometric measures for this purpose, we investigated the interobserver reliability and diagnostic performance of several morphometric measures of Chiari II malformation on MR images., Methods: Brain MR images of 79 children [26 with open spinal dysraphism, 17 with closed spinal dysraphism, and 36 without spinal dysraphism; mean age 10.6 (SD 3.2; range, 6-16) years] were evaluated. All children had been assessed for Chiari II malformation (defined as cerebellar herniation in combination with open spinal dysraphism; n = 23). Three observers blindly and independently reviewed the MR images for 21 measures of the cerebellum, brainstem, and posterior fossa in three planes. The interobserver reliability was assessed by an agreement index (AI = 1 - RRE) and the diagnostic performance by receiver operating characteristic analyses., Results: Reliability was good for most measures, except for the degree of herniation of the vermis and tonsil. Most values differed statistically significantly between children with and without Chiari II malformation. The measures mamillopontine distance and cerebellar width showed excellent diagnostic performance., Conclusions: Morphometric measures may reliably quantify the morphological distortions of Chiari II malformation on MR images and provide additional tools to assess the severity of Chiari II malformation in clinical and research settings.

Objective: The purpose of this study is to define the role of foetal magnetic resonance imaging (MRI) in evaluating cerebral ischaemic-haemorrhagic lesions and the extension of parenchymal injuries., Study Design: From September 2006 to September 2010, 271 foetal MRI have been performed on cases referred to us for ultrasound suspect of brain abnormalities or cytomegalovirus infection and Toxoplasma serum conversion. Foetal MRI was performed with a 1.5-T magnet system without mother sedation., Results: Foetal MRI detected ischaemic-haemorrhagic lesions in 14 of 271 foetuses, consisting of 5% incidence. MRI confirmed the diagnosis in three of 14 cases with ultrasonography (US) suspect of ischaemic-haemorrhagic lesions associated with ventriculomegaly. In one of 14 cases with US findings of cerebellar haemorrhage, MRI confirmed the diagnosis and provided additional information regarding the parenchymal ischaemic injury. In eight of 14 cases with US suspect of ventriculomegaly (3), corpus callosum agenesis (2), hypoplasia of cerebellar vermis (1), holoprosencephaly (1) and spina bifida (1), MRI detected ischaemic and haemorrhagic lesions unidentified at US examination. In two of 14 foetuses with US suspect of intracerebral space-occupying lesion, MRI modified the diagnosis to extra-axial haematoma associated with dural sinus malformation. Results were compared with post-mortem findings or afterbirth imaging follow-up., Conclusions: Foetal MRI is an additional imaging modality in the diagnosis of cerebral ischemic-haemorrhagic lesions, and it is useful in providing further information on the extension of the parenchymal injury and associated abnormalities, thus improving delivery management.

Background: Spinal dysraphism is suspected in patients with midline abnormalities, especially in those with lumbosacral cutaneous markings. A recent prospective study demonstrated that isolated cutaneous infantile hemangiomas (IH) of the lumbosacral region have one of the highest risks (relative risk of 438) of associated spinal dysraphism., Objective: The specific types of dysraphism and radiological findings associated with cutaneous IH of the lumbosacral region have not been described in detail, to the best of our knowledge. The aim of this multicenter study is to retrospectively classify types of spinal anomalies associated with the cutaneous lumbosacral IH., Materials and Methods: The radiological images of 20 cases of lumbosacral infantile hemangioma associated with spinal dysraphism were reviewed., Results: Tethered cord was found in 60% of the 20 cases, spinal lipoma was present in 50% and 45% had intraspinal hemangiomas. Sinus tract was found in 40% of the children., Conclusion: A range of spinal anomalies is associated with cutaneous lumbosacral infantile hemangiomas and MRI can be used to characterize these abnormalities.

We present a pictorial review of MRI features of various closed spinal dysraphisms based on previously described clinicoradiological classification of spinal dysraphisms proposed. The defining imaging features of each dysraphism type are highlighted and a diagnostic algorithm for closed spinal dysraphisms is suggested.

Pain is also the main symptom of spinal diseases in children. The younger the child, the more frequently organic causes are to be found, whereas in adolescents functional dorsalgia and lumbalgia are ubiquitous. Apart from the neonatal period, where ultrasound is used as the primary method for investigation of closed spinal dysraphia, radiography is still considered to be the first choice examination, which nevertheless should only be carried out after a thorough anamnesis and clinical examination. For targeted follow-up and especially exclusion of neoplasms, MRI is the method of choice in most cases. Computed tomography (CT) plays an important role preoperatively and postoperatively in corrective spine surgery and together with scintigraphy in the diagnostics of spondylolysis and some tumors such as osteoid osteoma. Important is the care of children with hereditary spinal malformations, especially dysraphias where the entire CNS may be affected as with the common association of myelomeningocele and Chiari II malformation with hydrocephalus and hydromyalia.

Objective: To estimate the relationship between fetal magnetic resonance imaging (MRI) findings of ventriculomegaly, cerebellar herniation, extraaxial space effacement and adverse outcomes in children with spina bifida., Methods: This was a review of all pregnancies with spina bifida referred for fetal MRI from 2001 to 2007 and cared for postnatally at our spina bifida referral center. Degree of cerebellar herniation was based on lowest cervical vertebral level reached. Extraaxial space was considered effaced if too small to be measured above or below the tentorium cerebelli. Bladder dysfunction was termed high risk if renal damage was present or urodynamic studies indicated increased risk for renal damage. Ambulation was assessed in children age 3 years or older. Statistical analyses included chi square, Mantel-Haenszel test, and logistic regression., Results: Magnetic resonance imaging was performed in 36 pregnancies with fetal spina bifida at 27+/-6 weeks with subsequent delivery at 38+/-1 weeks. Outcomes were assessed at 3.2 years (range 2.4-5.1); 23 children were age 3 years or older. If the cerebellum was above the foramen magnum or had herniated to C2, C3, or C4, respectively, childhood seizures occurred in 0%, 7%, 21%, and 100%; high-risk bladder dysfunction in 33%, 33%, 71%, and 100%; and inability to ambulate independently in 20%, 70%, and 100% (no C4 cases) all P<.05. Ventriculomegaly, cerebellar herniation, and extraaxial space effacement were significantly associated with the need for ventriculoperitoneal shunt; however, 94% of children required shunt placement., Conclusion: In fetuses with spina bifida, worsening cerebellar herniation on MRI was significantly associated with childhood seizure activity, high-risk bladder dysfunction, and lack of independent ambulation., Level of Evidence: II.

Purpose: We evaluated the prevalence of spinal dysraphism (SD) in patients with anorectal malformation (ARM) by magnetic resonance imaging (MRI)., Methods: From January 2002 to March 2009, 120 patients with ARM who underwent anorectal reconstruction were evaluated for SD with sacral plain film, spinal ultrasonography (US), and lumbosacral MRI. We adopted Krickenbeck international classification of ARM., Results: Spinal dysraphism was present in 41 (34.2%) of 120 patients with ARM, 3 (13.0%) of 23 patients with perineal fistula, 7 (29.2%) of 24 patients with vestibular fistula, 4 (36.4%) of 11 patients with rectovesical fistula, 18 (40.9%) of 44 patients with rectourethral fistula, and 9 (60.0%) of 15 patients with cloacal anomaly (P = .04). Among 41 patients having SD detected by MR, 26 patients (26/41; 63.4%) underwent detethering surgery for tethered spinal cord. The mean sacral ratio (SR) in patients who underwent detethering surgery (0.54 +/- 0.19) was significantly lower than in patients who did not undergo detethering surgery (0.69 +/- 0.13; P < .001). The optimal cutoff for the SR value predicting SD requiring detethering surgery was 0.605, with sensitivity of 65.4% and specificity of 77.7%., Conclusions: Spinal dysraphism is common in patients with ARM, and its prevalence is higher in patients with complex ARM. Spinal anomalies can occur even with benign types of ARM and, therefore, that all patients should be screened. Magnetic resonance imaging is useful in detecting occult SD that may be missed by conventional radiologic evaluation, physical examination, and spinal US. We further recommend a lumbosacral MRI examination in those whose SR is lower than 0.6., (Copyright 2010 Elsevier Inc. All rights reserved.)

Objective: To determine the prevalence of lumbosacral spine (LSS) abnormalities in children with defecation disorders, intractable constipation, or non-retentive fecal incontinence (NRFI) and evaluate whether LSS abnormalities on magnetic resonance imaging (MRI) are clinically detected by neurologic examination., Study Design: MRI of the LSS and complete neurologic examination by a pediatric neurologist blinded to the MRI results were performed in patients with intractable defecation disorders., Results: Patients with intractable constipation (n = 130; 76 males; median age, 11 years; range, 6-18 years), and patients with NRFI (n = 28; 18 males; median age, 10 years; range, 7-15 years) participated. One occult spina bifida (OSB) and 3 terminal filum lipomas were found in patients with a normal neurologic examination. One patient had a terminal filum lipoma and neurologic complaints. Gluteal cleft deviation was found in 3 of 4 patients with LSS abnormalities. Neurosurgical treatment was not required in any patient during the 12-week follow-up., Conclusions: MRI showed LSS abnormalities in 3% of patients with defecation disorders and normal neurologic examination, all of whom reported symptom relief at the 12-week follow-up without neurosurgical intervention. Thus, whether or not LSS abnormalities play a role in defecation disorders remains unclear., (Copyright 2010 Mosby, Inc. All rights reserved.)

Improvements in magnetic resonance (MR) imaging now permit diagnostic images of the fetus to be obtained. Ultrasound remains vital in all aspects of fetal imaging but MR provides a useful second line imaging test. Its value is best researched in fetal central nervous system disorders but it can be applied in other areas too. This pictorial review shows many of the commonly encountered problems. The pictures have a powerful impact on parental understanding. Future research must involve determination of the prognosis of abnormalities found at MR.

We report a case of vertebral malformation associated with diplomyelia believed to be a type II split cord malformation. Cervicothoracic level cases are exceptional. This article reports the case of an 11-year-old boy with no neurological symptoms who had not undergone surgery. The diagnosis was made during pregnancy by prenatal screening with ultrasound and MRI. Several embryological theories have been offered to provide an explanation for this syndrome. Close follow-up is mandatory. Surgery must only be considered if neurological deterioration occurs., (2009 Published by Elsevier Masson SAS.)

Objective: To compare prenatal ultrasonography and magnetic resonance imaging (MRI) in the diagnosis of spina bifida with postnatal MRI/surgical findings and to study the postnatal outcome in relation to the level of lesion and head signs on antenatal imaging., Methods: A retrospective study of babies referred to a tertiary neurosurgical unit with a diagnosis of spina bifida in the years 2000-2002 was performed. The levels of lesions and head signs diagnosed using antenatal ultrasonography and MRI were compared with postnatal MRI and operative findings. The levels of lesions and head signs diagnosed pre- and postnatally were used to study the correlation with neurological outcome at a mean follow-up period of 12 months., Results: Twelve antenatally diagnosed and five postnatally diagnosed cases of spina bifida were seen. The level of lesion as identified by antenatal ultrasound correlated with that observed postnatally in 8/12 cases and the antenatal ultrasound diagnosis of ventriculomegaly was confirmed postnatally in all cases. The level of lesion as identified by antenatal MRI correlated with that observed postnatally in 4/8 cases (50%) and the antenatal MRI diagnosis of ventriculomegaly was confirmed postnatally in 5/8 (63%) cases. 12/17 babies were found to have residuals in the immediate postnatal urodynamic studies, of which 83% (n = 10) required intermittent catheterization of the bladder at 12 months of age. Low spinal lesions were associated with increased bladder morbidity when compared to high spinal lesions (8/10 vs. 4/7, P < 0.05) (odds ratio (OR) = 10.0; 95% CI, 1.05-95.01). The level of spinal lesion and the presence of ventriculomegaly did not have any statistically significant correlation with motor functions, morbidity and developmental milestones., Conclusions: Antenatal ultrasonography is a good tool in the diagnosis of spina bifida. We could not demonstrate any advantage of antenatal MRI over ultrasonography. There is better correlation of ultrasonography than MRI with postnatal MRI/operative findings in terms of level of lesion and head signs. Low spinal lesions appear to be associated with increased bladder morbidity., (Copyright 2006 ISUOG)

Recent technical developments led to a change in the significance of the different imaging modalities in the whole spectrum of neuroradiology and thus also in the field of imaging of the cervical spine. The main part in diagnostic imaging of the upper cervical spine is taken by high-resolution multislice CT and MRI. Conventional X-rays serve as an initial screening technique if required.

We describe an infant girl who was referred to us because of a lumbosacral swelling. She was also found to have two nonblanching, erythematous macules, one at the cervical level and one at the lumbosacral level. Occult spinal dysraphism was demonstrated by magnetic resonance imaging.

Background and Purpose: There has been limited description of hydromyelia after surgery for spinal dysraphism. The opportunity to compare pre- and post-operative hydromyelia in patients with spinal dysraphism has been possible in two groups of patients using MRI. Post-operative assessment and possible relationship of hydromyelia to clinical findings has been made during a 7- to 14-year period., Methods: A total of 38 patients with congenital lumbar or sacral lipomas and 20 with diastematomyelia were studied pre-operatively with a 1.5-T MRI. Most patients in each group were examined with surveillance MRI (1.5 T) post-operatively. Clinical correlations were carried out with each examination., Results: Of the 38 dorsal or terminal lipoma post-operative patients, hydromyelia increased in 3 and was a new finding in 4. One symptomatic patient in the latter group had extensive septated lumbar hydromyelia. In 8 of 20 diastematomyelia patients, pre-operative hydromyelia was unchanged post-operatively. Hemicord hydromyelia developed in 1., Conclusion: Hydromyelia of varying degree was found in almost one-third of post-operative dorsal or terminal lipoma patients and nearly one-half of diastematomyelia patients. In five post-operative lipoma and two diastematomyelia patients, significant neurological findings remained. One of the six post-operative lipomas had new extensive lumbar hydromyelia that may have been responsible for the patient's symptoms. In the remaining symptomatic patients, hydromyelia was absent or modest.

Spinal and spinal cord malformations are collectively named spinal dysraphisms. They arise from defects occurring in the early embryological stages of gastrulation (weeks 2-3), primary neurulation (weeks 3-4), and secondary neurulation (weeks 5-6). Spinal dysraphisms are categorized into open spinal dysraphisms (OSDs), in which there is exposure of abnormal nervous tissues through a skin defect, and closed spinal dysraphisms (CSD), in which there is a continuous skin coverage to the underlying malformation. Open spinal dysraphisms basically include myelomeningocele and other rare abnormalities such as myelocele and hemimyelo(meningo)cele. Closed spinal dysraphisms are further categorized based on the association with low-back subcutaneous masses. Closed spinal dysraphisms with mass are represented by lipomyelocele, lipomyelomeningocele, meningocele, and myelocystocele. Closed spinal dysraphisms without mass comprise simple dysraphic states (tight filum terminale, filar and intradural lipomas, persistent terminal ventricle, and dermal sinuses) and complex dysraphic states. The latter category further comprises defects of midline notochordal integration (basically represented by diastematomyelia) and defects of segmental notochordal formation (represented by caudal agenesis and spinal segmental dysgenesis). Magnetic resonance imaging (MRI) is the preferred modality for imaging these complex abnormalities. The use of the aforementioned classification scheme is greatly helpful to make the diagnosis.

Spinal cord development occurs through the three consecutive periods of gastrulation (weeks 2-3), primary neurulation (weeks 3-4), and secondary neurulation (weeks 5-6). Spinal cord malformations derive from defects in these early embryonic stages, and are collectively called spinal dysraphisms. Spinal dysraphisms may be categorized clinically into open and closed, based on whether the abnormal nervous tissue is exposed to the environment or covered by skin. Open spinal dysraphisms include myelomeningocele and other rare abnormalities such as myelocele, hemimyelomeningocele, and hemimyelocele, and are always associated with a Chiari II malformation. Closed spinal dysraphisms are further divided into two subsets based on whether a subcutaneous mass is present in the low back. Closed spinal dysraphisms with mass comprise lipomyelocele, lipomyelomeningocele, meningocele, and myelocystocele. Closed spinal dysraphisms without mass comprise simple dysraphic states (tight filum terminale, filar and intradural lipomas, persistent terminal ventricle, and dermal sinuses) and complex dysraphic states. The latter category involves abnormal notochordal development, either in the form of failed midline integration (ranging from complete dorsal enteric fistula to neurenteric cysts and diastematomyelia) or of segmental agenesis (caudal agenesis and spinal segmental dysgenesis). Magnetic resonance imaging is the imaging modality of choice for evaluation of this complex group of disorders.

Purpose: Neurovesical dysfunction (NVD) is common in children with anorectal malformation (ARM). NVD is mainly related to tethered cord or iatrogenic injury but how to investigate it is still debated. We evaluate the usefulness of routine magnetic resonance imaging (MRI) and urodynamics (UDS) for ARM., Materials and Methods: A total of 89 children were screened for sacral, spinal or urological anomalies using sacrum x-ray, MRI, renal and spinal ultrasound, uroflowmetry and/or 4-hour voiding observation. UDS was performed in 60 patients with suspected NVD. Mean +/- SD followup was 9.8 +/- 5.2 years., Results: Of the 89 patients 29 presented with urinary tract anomalies. The prevalence of sacral (53 cases) and spinal cord (54) anomalies was no different between patients with low, intermediate and high ARM. Spinal cord tethering was present in 13 patients with a normal sacrum x-ray. NVD was found in 31 of the 89 patients (hyperreflexia 21 and hypo-areflexia 10), and was associated with sacral and spinal anomalies in 23, occult spinal dysraphism without bone lesion in 3 and sacral anomalies in 5. The incidence of NVD was 40% of cases with low and 51% with high ARM., Conclusions: Because tethered cord occurs in children without sacral anomalies as well as in those with low ARM, we recommend evaluation of all patients using MRI. When MRI is positive UDS should be performed. We agree with a previous suggestion to evaluate all males with rectourethral fistula and females with cloaca malformations. Finally we recommend a noninvasive evaluation for all other children and UDS when neurogenic dysfunction is suspected.

Magnetic resonance is an excellent modality for imaging the pediatric spine. Its successful use requires understanding both the basic physics and the sedation protocols necessary for acquiring high-resolution images. Interpreting the images accurately depends on appreciating the differences between the normal anatomy of the pediatric and the adult spine. Evaluating the images requires familiarity with the differential diagnosis of pediatric spine disease, including the most common processes (infections, neoplasms, and trauma) as well as spinal dysraphism. Despite the acknowledged usefulness of magnetic resonance imaging of the pediatric spine, controversies remain related to its safety in this age group and its limitations in diagnosing and evaluating scoliosis and tethered cord syndrome.

Spinal cord development occurs through three consecutive periods. Gastrulation (weeks 2-3) is characterized by conversion of the embryonic disk from a bilaminar to a trilaminar arrangement and establishment of a notochord. Primary neurulation (weeks 3-4) produces the uppermost nine tenths of the spinal cord. Secondary neurulation and retrogressive differentiation (weeks 5-6) result in formation of the conus tip and filum terminale. Defects in these early embryonic stages produce spinal dysraphisms, which are characterized by anomalous differentiation and fusion of dorsal midline structures. Spinal dysraphisms may be categorized clinically into two subsets. In open spinal dysraphisms, the placode (non-neurulated neural tissue) is exposed to the environment. These disorders include myelomeningocele, myeloschisis, hemimyelomeningocele, and hemimyelocele, and are always associated with a Chiari II malformation. Closed spinal dysraphisms are covered by intact skin, although cutaneous stigmata usually indicate their presence. Two subsets may be identified based on whether a subcutaneous mass is present in the low back. Closed spinal dysraphisms with mass comprise lipomyeloschisis, lipomyelomeningocele, meningocele, and myelocystocele. Closed spinal dysraphisms without mass comprise complex dysraphic states (ranging from complete dorsal enteric fistula to neurenteric cysts, split cord malformations, dermal sinuses, caudal regression, and spinal segmental dysgenesis), bony spina bifida, tight filum terminale, filar and intradural lipomas, and persistent terminal ventricle. Magnetic resonance imaging is the imaging method of choice for investigation of this complex group of disorders.

Spinal dysraphism is a general term which encompasses a wide variety of anomalies of the spine, all of which result from imperfect midline fusion of the embryonic neural tube. This term refers to large defects that involve the spine and not to small vertical clefts commonly seen within the spinal process of L5 or S1. We present a spectrum of MR imaging findings selected from a retrospective review of 100 patients of spinal dysraphism evaluated at our institution.

Developmental symptomatic C1 canal stenosis is very rare. We describe the computed tomography (CT) and magnetic resonance imaging (MRI) appearances in a 8-year-old child who presented with progressive upper and lower limb neurological symptoms and in whom imaging revealed the medial posterior hemiarches of a bifid C1 to be inturned and compressing the cervical cord. This particular configuration of the posterior arch of atlas is frequently associated with other craniocervical bony anomalies and presents with neurological symptoms early in life. Early CT or MRI examination of patients with symptomatic posterior arch of C1 defects is necessary, in order to detect such an appearance, since surgical treatment may prevent neurological deterioration.

Our purpose was to review the neuroradiological features of spinal dysraphism and to correlate them with clinical findings and up-to-date embryological theory. We also aimed to formulate a working classification which might prove useful in clinical practice. We reviewed series of 986 children referred to our Spina Bifida Centre in the past 24 years. There were 353 children with open spinal (OSD) and 633 with closed (skin-covered) spinal (CSD) dysraphism. By far the most common open abnormality was myelomeningocele, and all patients with OSD had a Chiari II malformation. CSD was categorised clinically, depending on the presence of a subcutaneous mass in the back. CSD with a mass mainly consisted of lipomas with dural defects and meningoceles, and accounted for 18.8 % of CSD. CSD without a mass were simple (tight filum terminale, intradural lipoma) or complex (split cord malformations, caudal regression). Our suggested classification is easy to use and to remember and takes into account clinical and MRI features; we have found it useful and reliable when making a preoperative neuroradiological diagnosis in clinical practice.

Background: Accurate fetal imaging is essential to the practice of maternal-fetal medicine. While ultrasonography has been the traditional mainstay of fetal imaging, its ability to resolve critical features of central nervous system (CNS) anatomy remains limited. As interest in intrauterine therapy for myelomeningocele has increased, so has the need for more accurate, noninvasive imaging of the CNS. Fetal magnetic resonance imaging (MRI) promises to fill the gap left by ultrasound., Methods: Thirty-seven MRI scans of fetuses previously diagnosed with myelomeningocele were reviewed by 2 neuroradiologists. The ability of fetal MRI to resolve the commonest CNS stigmata of spina bifida, and the incidence and extent of interobserver error, was assessed. In 4 cases, postnatal MRIs were also available. These were compared to the corresponding fetal studies., Results: The imaging quality with the technique used in this study was excellent, even without the use of maternal or fetal sedation. There were no complications, and the imaging times were minimal. Interobserver error was minimal with respect to the evaluation of ventricular dilatation and hindbrain herniation, but moderate in the description and location of the spinal lesion. As had previously been documented with ultrasonography, a reduction was seen in hindbrain herniation when comparing pre- and postnatal MRIs., Conclusion: It is concluded that fetal MRI is an effective, noninvasive means of assessing fetal CNS anatomy. Its ability to resolve posterior fossa anatomy is superior to ultrasonography while, with respect to the evaluation of hydrocephalus and the level and nature of the spinal lesion, it may be equivalent to inferior. Inclusion of the fetal MRI into the standard diagnostic armamentarium will probably await the next major advance in speed and resolution. It is conceivable that, with further advances, MRI might supplant ultrasonography as the diagnostic tool of choice for evaluation of fetal anomalies including myelomeningocele., (Copyright 2000 S. Karger AG, Basel)

Congenital anomalies of the pediatric spine are ideally evaluated with MR imaging. The wide spectrum of pathology in this category of disease is dramatically displaced for both diagnosis and treatment planning for the neurosurgeon. An understanding of embryology and knowledge of the clinical presentation combined with the MR imaging findings allows the radiologist to play a key role in the evaluation of these complex anomalies.

In summary, MR imaging of CSF and cord motion helps to evaluate diseases affecting cord and CSF motion and to identify the specific pathophysiology involved. A number of significant points have been made. First, MR imaging flow studies can be useful in evaluating CSF spaces and cystic diseases. Second, longitudinal and transverse motions occur in the spinal cord and CSF. Traveling wave motion occurs along the length of the spinal cord. Third, spinal cord tethering is associated with decreased cord velocity and loss of cord displacement at tethering site. Decreased transverse velocities occur with lateral cord tethering to the spinal canal. Fourth, in spinal dysraphism, longitudinal cord velocity is decreased by tethering, and is normal in asymptomatic patients with low conus. Normal cord motion helps to rule out possible tethering in symptomatic dysraphism with hydromyelia. Fifth, in acquired and nonmyelodysplastic symptomatic tethering, spinal cord motion is decreased. Sixth, in symptomatic cord compression, CSF flow and cord motion decrease, but recover after surgical decompression and after compensatory atrophy. Seventh, in asymptomatic spinal stenosis, cord motion is normal or increased. Diffuse spinal stenosis with cord atrophy leads to diffuse cord acceleration and prolonged cord caudal velocity, possibly related to the loss of the transverse mobility of the cord. Finally, focal spinal stenosis leads to focal dynamic cord deformation and can be associated with prominent intramedullary deformations. When compression is severe or symptomatic, cord motion is significantly decreased. Postoperative cases demonstrate good recovery of cord and CSF motion, unless compression or obstruction is still present.

In order to determine the impact of magnetic resonance imaging (MRI) in the management of spinal cord retethering, we retrospectively reviewed case and imaging records of 51 patients who underwent MRI examination in supine and prone positions. Group 1 included 8 control patients without cord tethering. They exhibited a normal level of the conus medullaris with normal surrounding subarachnoid space, and consistent anterior migration of the conus within the dural sac on MRI in prone position. Group 2 included 17 patients with tethered cord secondary to occult spinal dysraphism (spinal cord lipoma in 6 patients, thick filum terminale in 4, diastematomyelia in 4, myelomeningocele manqué in 2, and dermoid tumour in 1). Supine and prone MRI performed at a median period of time of 6 months after untethering showed resolution of posterior tethering in 5 out of the 7 patients who exhibited pre-operatively dorsal attachment of the spinal cord to the dura. Anterior migration of the conus or of the cord/filum complex in prone position was observed in only 24% of the cases. Group 3 included 26 patients with secondary tethered cord following prior myelomeningocele closure. Their MRI performed at a median interval of time of 11 months following untethering demonstrated resolution of the posterior cord tethering in only 8 out of the 24 patients who exhibited this feature pre-operatively. Anterior migration within the expanded dural sac was never noted in this group. We conclude that spine MRI is of limited value and that prone-positioned MRI is of no additional use in the evaluation of spinal cord retethering.

An overview of MR imaging of the pediatric spine is presented with a systematic approach to the analysis of spinal dysraphic disorders. An introduction to the most commonly used MR imaging techniques, with an emphasis on the newer pulse sequence of cine MR flow of the cerebrospinal fluid and embryogenesis of the spine and spinal cord, provides the orientation for diagnosis of this common pediatric disorder.

Spinal dysraphism is easily recognized in the overt form as a meningocele or myelomeningocele. The closed form or occult spinal dysraphism (OSD) can be overlooked. It occurs predominantly at the lumbosacral level, but OSD at the cervical level, although very rare, also occurs. The value of magnetic resonance imaging investigations in preparation for surgical treatment is emphasized. We discuss the value of various midline posterior skin anomalies as indicators of an underlying developmental defect in the neural axis. Hallmarks for OSD in the inferior third of the back are well known. They can also occur at the cervical level. Among these warning cutaneous midline changes, a vascular stain alone is rarely a clue for OSD whatever the spinal level involved, and specifically in the nuchal area.

Purpose: To delineate the clinical and MR findings in children with an unusual type of spinal dysraphism, the terminal myelocystocele. Infants with a terminal myelocystocele carry a favorable neurologic prognosis if the entity is diagnosed early. Understanding the MR characteristics of this entity will allow for earlier and more accurate diagnosis., Method: Analysis of the medical charts and MR studies in 15 children with surgically and histologically proven myelocystocele., Results: In all 15 children, MR demonstrated the primary findings of a terminal cyst of the central canal of the spinal cord which is tethered and herniated with arachnoid and cerebrospinal fluid through an area of spinal dysraphia onto the back as a mass. Of these children, 10 had additional findings (one or more) on MR of Chiari I (five cases), Chiari II (one case), cervicothoracic hydromyelia (two cases), lumbar hydromyelia (two cases), hydrocephalus (2 cases) segmentation anomalies of vertebrae (3 cases) and partial agenesis of sacrum (six cases). Of the clinical findings, all 15 children had a back mass, 10 also had cloacal exstrophy. One had imperforate anus, 10 were girls, five had ambiguous genitalia and all were neurologically intact., Conclusion: Children with a terminal myelocystocele present with a back mass and there is a high association with cloacal exstrophy. MR is the best noninvasive modality to diagnose all of the components of a terminal myelocystocele and the associated central nervous system findings.

Clinical and radiological data of 48 patients with scoliosis who underwent routine MRI were reviewed to elicit the value of MRI in the preoperative assessment of complex spine deformities. Because of its high diagnostic sensitivity MRI gives a new insight into the true incidence of spinal cord pathology in scoliosis. Moreover, it identifies clinically unsuspected dysraphia in a surprisingly high percentage of neurologically asymptomatic patients with left-sided scoliosis. Exact planning of operative interventions is facilitated by the comprehensive diagnostic information gained through MRI. Furthermore, MRI generally allows one to refrain from invasive, high-irradiation techniques such as myelography and contrast-enhanced CT. On the basis of the presented investigational data, routine use of MRI is conclusively recommended in patients with congenital or idiopathic left-sided scoliosis.

The tethered cord syndrome is considered a trouble complex that is caused by fixation of the spinal cord by intra- or extradural components. Clinically it is characterized by motor and sensory dysfunction of the lower extremities, muscle atrophy, decreased or hyperactive reflexes, urinary and bowel incontinence, spastic gait, or orthopedic deformities. Traditionally, positive-contrast myelography has been the diagnostic procedure of choice, often supported by CT (post myelo-CT). With the improvement of surface-coil technology, MR imaging has become a useful diagnostic tool for the assessment of the spinal cord and canal without ionizing radiation. MR examinations of 80 patients with the clinical diagnosis of tethered spinal cord were reviewed retrospectively in order to define normal anatomy and pathological findings as well as to establish MR strategies in the diagnosis of tethered cord syndrome in children. In order to evaluate intraspinal lipomas, the width of the spinal canal and dysraphic lesions, T1-weighed sagittal and transverse images are useful. In case of deformities of the spinal column the corona slice orientation should be used. The filum terminale and its thickness is best seen in T2-weighed transverse and sagittal images. The extension of fat within the spinal canal over more then 6 vertebral bodies and more then 1.2 cm width could be an indication of a lipomatous malformation in the sacral spinal canal.

Two patients who postoperatively developed extensive multiseptated hydrosyringomyelia following surgical repair of a lumbal meningomyelocele are reported. Since MRI has been available, an increasing number of reports showed that MRI is useful in the diagnosis of hydrosyringomyelia. Hydrosyringomyelia can be considered as a dysraphic lesion. Etiology and pathogenesis of hydrosyringomyelia are still not fully understood. Probably arachnoidal adhesions and cord tethering in both patients may be potential factors in producing cystic degeneration of the underlying structure secondary to ischemia.

Findings on Magnetic Resonance Imaging (MRI) of 52 children with suspected spinal dysraphism have been reviewed. In 24, no significant spinal abnormality was demonstrated. Seven patients had scoliosis or vertebral segmentation anomalies without demonstrable abnormality of the underlying soft tissues and one had an isolated subcutaneous haemangioma. In 20 children with spinal dysraphism, a low tethered cord was the most frequent finding, occurring in 80%. Other manifestations included myelo- or meningocoele (60%), syringomyelia (30%), lipoma (25%), congenital tumour (20%), diastematomyelia (15%) and thickened filum terminale (5%). The relationship between the clinical reason for requesting MRI and the scan results are discussed.

Somato-sensory evoked potentials (SSEP) were found to be pathological mostly in the lower extremities in 26 out of 45 children suffering from so called idiopathic scoliosis. We examined the vertebral spine and the spinal cord of 8 of them (with controlled SSEP-findings) by use of conventional MR-imaging and (where necessary) 3-dimensional-data-set following the Fournier-procedure. 6 of the 8 children showed alterations as follows: 1. A lipoma spreading partly extra-, partly intraspinally. 2. Subligamentous protrusions of the intervertebral disc (2 patients). 3. Dysraphic processes (2 patients). 4. An abnormally cranial ending myelon surrounded by a widened spinal channel. The findings are demonstrated and discussed concerning the questions whether the pathological SSEP and, furthermore, the deformity of the vertebral spine could be explained thereby. We are at least able to prove that some of the children with so called idiopathic scoliosis show pathological evoked potentials and MRI-findings.

Magnetic resonance (MR) imaging of the spine was performed as the initial imaging technique in 20 children when spinal dysraphism was suspected clinically and plain radiographs showed spina bifida. The correlation with surgical findings indicated that MR provided accurate information preoperatively in all the cases. Some unusual observations in cases with spina bifida cystica and occulta are discussed. It is concluded that plain radiograph and MR complete the preoperative radiologic evaluation of cases with spinal dysraphism.

Three cases of children with spinal dysraphism are reported. Magnetic resonance imaging (MRI) was used as a primary diagnostic examination. The ages of the patients were 2 days, 4 years, and 16 years. In all instances the scan gave a precise diagnosis as well as well as an accurate delineation of the structural abnormalities before surgical treatment. Plain radiographs and ultrasound analysis may not be helpful, and invasive procedures can be associated with morbidity. Technical ease, safety, and anatomic precision suggest that MRI should be performed as a primary radiologic examination in the diagnostic workup of spinal dysraphism.

Magnetic resonance imaging (MRI) was used in the pre-operative assessment of closed spinal dysraphism in 61 paediatric patients. There were 25 cases of tethered cord, 6 of retethering at the site of myelomeningocele repair, 15 cases of diastematomyelia, 12 cases of lipomyelomeningocele, and 1 case each of dermal sinus, dermoid cyst and neurenteric cyst. MRI was found to have accurate correlation with surgical findings in all cases of tethered cord, and diastematomyelia. In cases of re-tethering at the site of previous myelomeningocele repair, while it was a significant advance on previous imaging techniques precise delineation of neural tissue and discrimination from post-operative fibrosis was frequently not possible. Imaging of dorsal lipomyelomeningoceles also correlated with surgical findings and provided accurate pre-operative information. However, the accuracy and pre-operative detail in cases of transitional and terminal lipomyelomeningoceles was disappointing.

Motion of the cerebrospinal fluid (CSF) in and around the brain and spinal cord was examined in healthy subjects and in a number of patients with abnormalities of the CSF circulation. The pulsatile motion of the CSF was determined by spin echo phase (velocity) imaging, sometimes in combination with gradient echo phase contrast cine. Differences in flow patterns across CSF spaces were observed: flow reversal in the cerebellomedullary cistern and lumbar area relative to cervical CSF, and in the posterior versus the anterior subarachnoid space in the spinal canal. Flow communication was demonstrated in known communicating cysts or cavities. Differences in flow were also noted across spinal narrowing or block, and across the walls of a variety of cystic lesions in the brain and spinal cord. MR phase imaging of CSF flow provides pathophysiological information of potential clinical importance for the assessment of diseases affecting the CSF circulation.