Fetal Intraventricular Hemorrhage in Open Neural Tube Defects: Prenatal Imaging Evaluation and Perinatal Outcomes.

BACKGROUND AND PURPOSE: Fetal imaging is crucial in the evaluation of open neural tube defects. The identification of intraventricular hemorrhage prenatally has unclear clinical implications. We aimed to explore fetal imaging findings in open neural tube defects and evaluate associations between intraventricular hemorrhage with prenatal and postnatal hindbrain herniation, postnatal intraventricular hemorrhage, and ventricular shunt placement. MATERIALS AND METHODS: After institutional review board approval, open neural tube defect cases evaluated by prenatal sonography between January 1, 2013 and April 24, 2018 were enrolled (n = 504). The presence of intraventricular hemorrhage and gray matter heterotopia by both prenatal sonography and MR imaging studies was used for classification. Cases of intraventricular hemorrhage had intraventricular hemorrhage without gray matter heterotopia (n = 33) and controls had neither intraventricular hemorrhage nor gray matter heterotopia (n = 229). A total of 135 subjects with findings of gray matter heterotopia were excluded. Outcomes were compared with regression analyses. RESULTS: Prenatal and postnatal hindbrain herniation and postnatal intraventricular hemorrhage were more frequent in cases of prenatal intraventricular hemorrhage compared with controls (97% versus 79%, 50% versus 25%, and 63% versus 12%, respectively). Increased third ventricular diameter, specifically >1 mm, predicted hindbrain herniation (OR = 3.7 [95% CI, 1.5-11]) independent of lateral ventricular size and prenatal intraventricular hemorrhage. Fetal closure (n = 86) was independently protective against postnatal hindbrain herniation (OR = 0.04 [95% CI, 0.01-0.15]) and postnatal intraventricular hemorrhage (OR = 0.2 [95% CI, 0.02-0.98]). Prenatal intraventricular hemorrhage was not associated with ventricular shunt placement. CONCLUSIONS: Intraventricular hemorrhage is relatively common in the prenatal evaluation of open neural tube defects. Hindbrain herniation is more common in cases of intraventricular hemorrhage, but in association with increased third ventricular size. Fetal closure reverses hindbrain herniation and decreases the rate of intraventricular hemorrhage postnatally, regardless of the presence of prenatal intraventricular hemorrhage.

3T magnetic resonance arteriography in pediatric cerebrovascular disease.

Based on a series of 20 cases, eight with 1.5T and 3T MRA's, 3T MRA provides improvement over 1.5T MRA in imaging the vessels of the circle of Willis in pediatric patients with vascular disease. Dephasing artifact is reduced and laminal stenosis or occlusions become better depicted.

Non-accidental brain trauma in infants: diffusion imaging, contributions to understanding the injury process.

Analysis of MRI diffusion images from 33 infants suffering from non-accidental trauma reveals five patterns of injury. These are diffuse supratentorial hypoxic ischemic, watershed hypoxic ischemic, venous infarction, diffuse axonal injury and contusion.

Evolution of cerebral abscess: correlation of clinical features with computed tomography. A case report.

Computed tomography demonstrated the evolution of a cerebral abscess. Intravenous contrast material was essential for visualization of the abscess capsule. Computed tomography was more specific than technetium 99 brain scanning and cerebral angiography, and is the only diagnostic tool so far capable of differentiating acute focal encephalitis (cerebritis) from a well-developed abscess.

Brainstem tumors in patients with neurofibromatosis type 1: a distinct clinical entity.

The natural history and the clinical and neuroimaging features of brainstem tumors in neurofibromatosis type 1 (NF1) are poorly understood. Magnetic resonance imaging (MRI) has been useful in NF1 in detecting intracranial abnormalities, especially of the brainstem. Brainstem tumors in NF1 have been confused clinically with non-NF1 brainstem tumors and radiographically with the increased T2 signal abnormalities, also known as "unidentified bright objects" (UBOs), which are common in NF1 and often located in the brainstem. This study, which evaluated 17 NF1 patients with brainstem tumors, is the largest series to date. Fifteen of 17 patients (88%) had neurologic signs and symptoms referable to brainstem dysfunction, including dysarthria, cranial neuropathies, and gross motor incoordination. Tumors were located primarily in the medulla in 14 of 17 NF1 patients (82%), in contrast to the pontine tumor location in the non-NF1 population. Seven NF1 patients (41%) required shunt placement for hydrocephalus at initial diagnosis, more frequent than in non-NF1 brainstem tumor patients. Six of 17 patients (35%) had evidence of radiographic tumor progression, but only three of them (18%) had correlative clinical progression. Two patients with progressive symptoms had partial surgical resection, and pathology revealed either fibrillary or anaplastic astrocytomas. Three patients were treated with radiation therapy, chemotherapy, or both, with two deaths. With a median follow-up of 52 months, 15 of 17 patients remain alive; 14 of them did not require adjuvant therapy. In our series, we describe NF1 brainstem tumors as a distinct clinical entity, much less aggressive than non-NF1 pontine tumors but more symptomatic than brainstem UBOs in NF1.

Brainstem gliomas of childhood: magnetic resonance imaging.

We compared magnetic resonance imaging (MRI) and CT on 16 children with brainstem gliomas. MRI demonstrated masses of decreased signal intensity, which enlarged and distorted brainstems in all patients with active disease and showed brainstem abnormalities in 21 of 23 studies (91%). In one-half of the patients, MRI showed more extensive disease than did CT. Exophytic portions of tumors were shown well on MRI. MRI was more sensitive than CT in demonstrating disease relapse.

Comparison of metrizamide computed tomography and magnetic resonance imaging in the evaluation of lesions at the cervicomedullary junction.

We compared intrathecal metrizamide-enhanced CT (metrizamide-CT) and magnetic resonance imaging (MRI) in the evaluation of 17 patients with clinical suspicion of lesions at the cervicomedullary junction. MRI was superior in imaging the position of the cerebellar tonsils and the size and extent of mass lesions. MRI and metrizamide-CT were equal in detecting syringomyelia. CT with and without IV contrast enhancement was necessary to detect calcium or defects in the blood-brain barrier within neoplasms.

Gadolinium-DTPA-enhanced magnetic resonance imaging in childhood brain tumors.

Gadolinium DTPA (Gd-DTPA) is a paramagnetic blood-brain barrier contrast agent for MRI that has been used primarily in adults. During May through October 1987, 17 children between the ages of 3 and 18 years with brain tumors underwent MRI examinations, before and after Gd-DTPA (11 gliomas, 4 medulloblastomas, 1 craniopharyngioma, and 1 child with neurofibromatosis and no pathologic diagnosis). We compared T1 and T2 Gd-DTPA-enhanced MRI with concurrent unenhanced MRI and enhanced CT, and then correlated this with the clinical and pathologic findings. Gd-DTPA enhanced tumors in all 7 patients with newly diagnosed tumors and enhanced tumors in 7 of 10 patients without clinical evidence of progressive disease at the time of the study. In the 7 new patients, Gd-DTPA defined tumor margins in all, and demonstrated internal tumor architecture (vessels, necrosis, and cysts) in 5. Areas believed to represent surgical scars showed varying degrees of enhancement. Leptomeningeal tumor spread, including spinal, not seen on pre-Gd-DTPA MRI or on contrast CT, was evident in 2 patients. Gd-DTPA enhancement obscured hemorrhage within the tumor (methemoglobin) in 2 patients. There were no significant side effects. These results suggest that Gd-DTPA-enhanced MRI (1) is safe in children, (2) demonstrates the extent and character of tumors better than unenhanced MRI and enhanced CT, and (3) may allow for noninvasive imaging of leptomeningeal disease, including the spine, not previously demonstrated by any other noninvasive neuroimaging technique.

Gangliogliomas involving the optic chiasm.

We report three patients with gangliogliomas involving the optic chiasm via distinct mechanisms. The ganglioglioma in one patient likely originated in the temporal lobe and spread medially to involve the chiasm, and diffuse spinal cord dissemination also occurred. Chiasmal involvement in this manner and dissemination at presentation are unusual for gangliogliomas. The tumor in a second patient was intrinsic to the hypothalmus and chiasm, while in the third patient, it involved both optic tracts, and a cyst compressed the chiasm laterally. Two patients developed severe bilateral visual loss, while the other had a stable bitemporal hemianopsia. Two patients received radiotherapy, but one continued to lose vision. Although gangliogliomas rarely involve chiasm, the mechanisms by which they produce chiasmal visual loss may be diverse, and the long-term visual prognosis is variable.

Magnetic resonance imaging of spinal cord disease of childhood.

Correct diagnosis of spinal cord disease in childhood is often delayed, resulting in irreversible neurologic deficits. A major reason for this delay is the lack of a reliable means to noninvasively visualize the spinal cord. Magnetic resonance imaging (MRI) should be useful in the evaluation of diseases of the spinal cord. A 1.5 Tesla MRI unit with a surface coil was used to study 41 children, including eight patients with intrinsic spinal cord lesions, eight patients with masses compressing the cord, 12 patients with congenital anomalies of the cord or surrounding bony structures, three patients with syrinxes, and three patients with vertebral body abnormalities. Intrinsic lesions of the cord were well seen in all cases as intrinsic irregularly widened, abnormally intense cord regions. MRI was helpful in following the course of disease in patients with primary spinal cord tumors. Areas of tumor were separable from syrinx cavities. Extrinsic lesions compressing the cord and vertebral body disease were also well visualized. Congenital anomalies of the spinal cord, including tethering and lipomatous tissue, were better seen on MRI than by any other radiographic technique. MRI is an excellent noninvasive "screening" technique for children with suspected spinal cord disease and may be the only study needed in many patients with congenital spinal cord anomalies. It is also an excellent means to diagnose and follow patients with other forms of intra- and extraspinal pathology.

Pineal region tumors of childhood.

The incidence, response to treatment, and outcome of children with pineal region neoplasms is poorly characterized. Since 1975, in one institution, 25 consecutive patients with pineal tumors have undergone biopsy prior to further treatment. This constituted 11% (25/234) of all brain neoplasms seen over this time period. Specific tumors diagnosed included pineal parenchymal tumors ( pineoblastomas , pineocytomas ) in eight patients (32%); germ cell tumors (embryonal cell carcinomas, teratomas, germinomas) in eight patients (32%); glial tumors (astrocytoma, ganglioglioma ) in eight patients (32%); and ganglioneuroblastoma in one patient (4%). Clinical parameters, computed tomographic findings and CSF markers (alphafetoprotein and human chorionic gonadotropin) were unreliable in discriminating between specific tumor types. Response to treatment and patterns of disease relapse were dependent on the type of tumor present. Five of eight children with pineal parenchymal tumors had disease recurrence, and in all leptomeningeal dissemination occurred prior to or concurrent with local relapse. Three of eight children with germ cell tumors and two of eight patients with glial tumors suffered a relapse; in all five children recurrence was initially local. Findings suggest that pineal region neoplasms are not infrequent in childhood; that these tumors vary greatly in histologic type; that contrary to other reports germinomas do not constitute the majority of pineal tumors; and that histologic confirmation is necessary prior to treatment for appropriate management.

Computer-assisted tomography: sinus lesions with orbital involvement.

Computer-assisted tomography (CAT) is superior to other roentgenographic modalities in evaluation of paranasal sinus lesions whenever extension into the orbit is suspected. CAT not only demonstrates the orbital involvement, its location, and extent, but also the nature of the sinus lesion. Conclusions based on 43 cases of paranasal sinus lesions with orbital involvement are presented. The entities include sinusitis and orbital cellulitis, mucocele, polyposis, ossifying fibroma, fibrous dysplasia, cylindroma, osteoblastoma, lymphoma, carcinoma, and rhabdomyosarcoma.

Tonic pupil and orbital glial-neural hamartoma in infancy.

PURPOSE/METHODS: Tonic pupils in early childhood are rare. We studied an otherwise healthy 31/2-month-old girl who had a right pupil that was poorly reactive to light, without other signs of oculomotor nerve palsy. RESULTS/CONCLUSIONS: Constriction of the right pupil after instillation of 0.125% pilocarpine eyedrops confirmed denervation hypersensitivity, consistent with a tonic pupil. There was no strabismus or proptosis. A magnetic resonance imaging scan demonstrated a right orbital mass, interposed between the lateral and inferior recti muscles. Biopsy was consistent with a benign, glial-neural hamartoma. Thus, in this young patient, a tonic pupil was associated with a benign orbital mass.

Orbital magnetic resonance imaging.

Magnetic resonance images of the eye and orbit performed with surface coils at 1.5 tesla showed anatomic details superior to those of conventional third- and fourth-generation computed tomography.

Bruton-type (congenital X-linked) agammaglobulinemia: MR imaging of unusual intracranial complications.

The authors describe two patients with Bruton-type agammaglobulinemia, their purpose being to indicate the spectrum of findings, clinical and imaging. MR in one patient revealed diffuse leptomeningeal enhancement in the brain and spine; in the second patient, a heterogeneous mass was seen that had broken through the basiocciput and displaced a cerebellar hemisphere. Awareness of the common and unusual CNS manifestations of this disease can impact clinical management.

Orbital wall infarction in sickle cell disease: MR evaluation.

Orbital wall infarction in a patient with sickle cell disease can present with periorbital swelling and subperiosteal collection and thus can mimic infection on CT. However, MR not only provides excellent morphologic information but, by characterizing the nature of the collection as containing blood, and by identifying bone marrow abnormality, can lead to the diagnosis of orbital wall infarction.

Tumors of the nasopharynx and adjacent areas: MR imaging with Gd-DTPA.

The purpose of this study was to describe our experience with Gd-DTPA-enhanced MR imaging in the evaluation of the most common nasopharyngeal tumors. Forty-two patients with tumors of the nasopharynx and adjacent spaces had MR imaging before and after IV injection of Gd-DTPA. Images were obtained with a 1.0-T superconducting magnet imaging system in transverse, coronal, and sagittal planes with T1- and T2-weighted sequences. MR images were compared with CT scans and tumor histology. The studies were categorized by using a grading system with grades ranging from unsatisfactory (grade 0) to optimal (grade 3). Contrast-enhanced MR enables better identification of small anatomic details such as both palatini muscles and the pharyngobasilar fascia. MR after Gd-DTPA was superior to CT in all cases except for tumors of the maxillary sinuses. MR with Gd-DTPA is recommended for tumors that are small and difficult to detect on the initial nonenhanced MR examination or that show subtle infiltrations. Because of the increased cost and longer examination time, MR with Gd-DTPA does not need to be done when large tumors are well delineated.

Proton MR spectroscopy of pediatric cerebellar tumors.

PURPOSE: To investigate the role of proton MR spectroscopy in pediatric cerebellar tumor diagnosis. METHODS: Single voxel pulse sequences with long echo time (135 or 270 milliseconds, voxel size 8 to 19 cm3), were used to obtain proton spectra of primary pediatric cerebellar tumors. Eleven primitive neuroectodermal tumors (patient age, 2 to 12 years; mean, 7 years), 11 low-grade astrocytomas (age, 2 to 16 years; mean, 9 years), 4 ependymomas (age, 1 to 6 years; mean, 4 years), 1 mixed glioma ependymo-astrocytoma (age, 11 years), 1 anaplastic ependymoma (age, 7 years), 1 ganglioglioma (age, 14 years), and 1 malignant teratoma (age, 6 days) were studied. Control cerebellum spectra were acquired from five patients without abnormality in cerebellum (age, 2 to 15 years; mean, 8 years). The signal intensities from choline-containing compounds (Cho), creatine/phosphocreatine (Cr), N-acetyl-aspartate (NAA), and lactate (Lac) were quantified. The mean and standard deviation of metabolite ratios were calculated. RESULTS: The control spectra ratios (NAA:Cho = 1.49 +/- 0.36, Cr:Cho = 1.13 +/- 0.23) were distinct from the tumor spectra (NAA:Cho = 0.41 +/- 0.27 and Cr:Cho = 0.37 +/- 0.23). Most of primitive neuroectodermal tumors had low NAA:Cho (0.17 +/- 0.09) and Cr:Cho (0.32 +/- 0.19). Compared with primitive neuroectodermal tumors, low-grade astrocytomas and ependymomas had higher NAA:Cho ratio (0.63 +/- 0.19 and 0.39 +/- 0.12). The Cr:Cho ratio was higher for ependymomas (0.60 +/- 0.20) than for astrocytomas (0.27 +/- 0.12) and primitive neuroectodermal tumors. No NAA was found in the malignant teratoma. Lac:Cho ratio was 0.66 +/- 0.40, 0.58 +/- 0.30, and 0.08 +/- 0.12 for astrocytoma, ependymoma, and primitive neuroectodermal tumor, respectively. Lactate was elevated in the mixed glioma ependymo-astrocytoma, ganglioglioma, and teratoma. The NAA and lactate signals were sometimes obscured by lipids in the spectra. Discriminant analysis was carried out using NAA:Cho and Cr:Cho ratios to differentiate the three major tumor types. The sensitivity/specificity values for diagnosing astrocytoma, ependymoma, and primitive neuroectodermal tumor were found to be 0.91/0.84, 0.75/0.92, and 0.82/0.89, respectively, based on this study. CONCLUSION: In many cases, proton MR spectroscopy can be used to help differentiate cerebellar primitive neuroectodermal tumor, low-grade astrocytoma, and ependymoma.

MRI of central nervous system: early clinical results.

In patients with central nervous system problems, a comparison of the results obtained with high-field MRI (1.5 T) to those achieved with more conventional imaging studies, primarily CT, reveals significant improvement in the demonstration of various abnormalities by MRI (56.5%), with increased specificity in some (29.5%). High-field MRI provides advantages over CT by providing both multiplanar images and superior contrast resolution. The diagnostic specificity of MRI is increased when acute, subacute, and chronic hematomas are visualized and when flowing blood within vessels is demonstrated in addition to the location and extent of the disease process. In this series, MRI produced a more accurate diagnosis in 8.7% of cases, revealed clinically unexpected abnormalities in 3.9% of cases, and was less invasive or avoided the risk of complications in 17.4% of cases. Despite the success of MRI, CT continues to play an important role in demonstrating calcification and contrast enhancement, and in evaluating patients in whom MRI is contraindicated or impossible because of an unsuitable clinical state.

High-field MRI of hemorrhagic cortical infarction.

High-field MRI is capable of differentiating acute, subacute, and chronic hemorrhagic cortical infarctions. In eight of nine patients, hemorrhage occurred in a vascular watershed zone. Acute hemorrhagic cortical infarction produces mild cortical low intensity on T2-weighted images outlined by subcortical edema (high intensity) and isointensity with normal cortex on T1-weighted images. Subacute hemorrhagic cortical infarction shows cortical high intensity first on T1-weighted images and later on T2-weighted images; it is also associated with subcortical edema. In the chronic stage, there is a marked persistent cortical low intensity on T2-weighted images. This is most prominent in the deeply infolded cortical gyri. The low intensity noted in acute and chronic hemorrhagic cortical infarction with T2 weighting appears to be related to two separate underlying histochemical states. The characteristic cortical low intensity observed on T2-weighted images in acute and chronic hemorrhagic cortical infarction is proportional to the square of the magnetic field strength.