Correlation of MRI and CSF cytology in the diagnosis of medulloblastoma spinal metastases

Background. Medulloblastoma frequently spreads to involve the spinal cord, which significantly reduces patient survival and determines whether chemotherapy is utilised and the dose of irradiation to the neuraxis. Staging is usually achieved by MRI of the spine and/or cytology of CSF, both methods having their limitations. Objective. To determine whether there is a correlation between CSF cytology and the demonstration of spinal metastases by MRI and whether CSF cytology is useful when spinal MRI is equivocal. Materials and methods. All cases of medulloblastoma diagnosed at our hospital between 1992 and 1997 were identified. Of 26 cases, 11 presentations (age range 4 months to 12 years) had both CSF cytology (either from the cisterna magna or lumbar puncture) and spinal MRI. The MR studies were reviewed for the presence of metastases and the CSF cytology for the presence of tumour cells. Results. We found 100 % correlation between MRI and CSF cytology for samples taken by lumbar puncture (four negative and three positive on both investigations). No correlation was demonstrated when CSF samples were taken from the cisterna magna. Conclusions. Our data suggest that lumbar CSF cytology may be useful when the MRI is equivocal for the presence of metastatic involvement of the spine by medulloblastoma. Received: 11 August 1997 Accepted: 26 January 1998     

Fast fluid-attenuated inversion recovery (FLAIR) magnetic resonance imaging of the brain: a comparison of multi-shot echo-planar and fast spin-echo techniques

Purpose. To evaluate fast spin-echo and multi-shot echo-planar fluid-attenuated inversion recovery (FLAIR) sequences in paediatric brain imaging. Materials and methods. Matched images from 32 patients with suspected tumour or white matter disease were independently evaluated by two paediatric neuroradiologists. The observer preferences for image quality and lesion detection were analysed for differences between fast spin-echo FLAIR and multi-shot echo-planar FLAIR. Diagnostic quality was compared with that of fast spin-echo T2-weighted images. Results. Images of a diagnostic quality equivalent to that of fast spin-echo T2-weighted images were achieved with both FLAIR techniques. Grey and white matter differentiation and cerebrospinal fluid (CSF) nulling were significantly better on fast spin-echo FLAIR sequences. CSF flow artefact was reduced on multi-shot echo-planar FLAIR. There was no difference in lesion detection. Fast spin-echo FLAIR images were visually preferred at the expense of longer imaging time. Conclusion. Fast FLAIR techniques are complementary to fast spin-echo T2-weighted sequences in imaging of the paediatric brain. We find that the fast spin-echo FLAIR sequence is preferable to the multi-shot echo-planar technique. Received: 20 August 1996 Accepted: 6 November 1996     

Which MRI sequence of the spine best reveals bone-marrow metastases of neuroblastoma?

Background: MRI is an effective tool in evaluating bone marrow metastases. However, no study has defined which MRI sequences or image characteristics best correlate with bone-marrow metastases in neuroblastoma. Objective: To identify and refine MRI criteria and sequence selection for the diagnosis of bone-marrow metastases in children with neuroblastoma. Materials and methods: Ninety-one children (mean age: 3.2 years; standard deviation: 2.8 years) enrolled in the RDOG IV study participated in our study. Forty-five children had bone metastases determined by bone-marrow aspiration or biopsy (n=4), radionuclide imaging (n=2), or both (n=39). Spine lesions were characterized using coronal T1-weighted (T1W) sagittal short tau inversion recovery (STIR) and coronal gadolinium-enhanced T1-weighted (GAD) MR sequences. Contingency table analysis was performed to determine which MRI sequences and characteristics were associated with metastases. The MRI criteria for metastatic disease were then developed for each imaging sequence. The sensitivity, specificity, predictive values, and accuracy of these criteria were determined for the whole group, children younger than 12 months old, and children 12 months and older. Results: The MR characteristics that had significant (P 0.05) associations with metastases were homogeneous low T1-signal intensity, homogeneous high STIR-signal intensity, and heterogeneous pattern on T1, STIR, or GAD. Homogeneous low T1-signal had the highest sensitivity (88%), but a specificity of 62% for detecting metastases. A heterogeneous pattern on GAD was highly specific (97%), but relatively insensitive (65%) for detecting metastases. These MR characteristics were most accurate in children 12 months and older. Conclusion: The combination of non-contrast-enhanced T1W and GAD sequences can be used to determine the presence of spinal metastases in children with neuroblastoma, particularly those children who are 1 year and older.Presented at the 41st annual meeting of The Society for Pediatric Radiology, Tucson, Arizona, 1998     

Extrarenal rhabdoid tumours outside the central nervous system in infancy

Background  Malignant rhabdoid tumours (RT) are increasingly recognized in young children, probably as a consequence of advances in accurate histological diagnosis rather than a true increase in frequency. Although typically presenting as renal tumours in infancy, extrarenal tumours outside the central nervous system (CNS) in children less than 12 months of age are now well recognized, but previous literature on their imaging features is very limited. Objective  To demonstrate the imaging features of extrarenal RTs outside the CNS. Materials and methods  A retrospective database review was made from 1989 to 2007 of patients diagnosed with extrarenal RT in infancy, i.e. below 12 months of age. Results  There were nine patients (six boys and three girls). The age at presentation varied from 1 to 11 months (average 6 months). Tumours were located in the thorax/mediastinum (n=3), liver (n=3), neck (n=1), shoulder (n=1) and axilla (n=1). The imaging modalities used included US (n=8), CT (n=7) and MRI (n=6). Bone scan was positive in one patient, while metastases at the time of diagnosis occurred in four patients. On MRI the tumours tended to show nonspecific hypointensity on T1-W images and heterogeneous hyperintensity on T2-W images, with heterogeneous enhancement. Conclusion  This is the largest radiological series of extrarenal RTs outside the CNS in infancy. In our series no imaging features were found specific to the diagnosis. A tendency towards large size and mediastinal/paravertebral location were noted. A hypodense solid component on CT and a heterogeneous hyperintensity on T2-W MR images suggest that this tumour should be considered in the routine differential diagnosis of soft-tissue tumours in infancy, in addition to rhabdomyosarcoma.     

Human herpes virus type 7 DNA in the cerebrospinal fluid of children with central nervous system diseases

Human herpes virus type 7 (HHV-7) has been associated with unspecific febrile syndrome, exanthem subitum (ES), viral rashes and Epstein-Barr virus (EBV) like syndrome. Neurological complications such as hemiplegia or seizures have been described in a few children with ES. Whether HHV-7 may also affect the CNS in the absence of ES is unknown. In this study, we investigated CSF samples from children with different neurological diseases for the presence of HHV-7 specific DNA. A HHV-7 specific nested polymerase chain reaction (PCR) was established amplifying a 478 bp DNA sequence of the glycoprotein U23 of HHV-7 strain SB. 68 children with CNS diseases with inflammatory CSF findings (n=24), CNS diseases without inflammatory CSF findings (n=18) and febrile seizures (n=26) were examined. A total of 26 children with infectious diseases in the absence of neurological disease and 11 children without signs of a peripheral infection and without neurological disease served as controls. The CSF samples of six children from the study groups were HHV-7 PCR positive, but none from the controls. These children were diagnosed with aseptic meningitis (n=1), viral encephalitis/meningoencephalitis (n=2), facial palsy (n=1), vestibular neuritis (n=1) and febrile seizure (n=1). Conclusion These results indicate that human herpes virus type 7 infection is associated with central nervous system disease in children and should be considered in children whether inflammation in the cerebrospinal fluid is present or not. Received: 4 September 2000 and in revised form: 2 December and 23 December 2000 /  Accepted: 27 December 2000     

Whole-body magnetic resonance imaging: a useful additional sequence in paediatric imaging

Background: Whole-body MR (WBMR) imaging allows the acquisition of images of the entire body in a matter of minutes. Its use has primarily been in the evaluation of possible metastases in the setting of a known primary tumour. Objective: To document the value of WBMR imaging in ten children in whom this was added as an additional sequence when the primary diagnosis had not yet been made. Materials and methods: Ten children, age range 4 months–15 years (mean 7 years 4 months) had WBMR imaging after initial MR showed an abnormality that raised the possibility of systemic disease. Initial scanning was of the brain (n=1), spine (n=2), retroperitoneum (n=4), hips (n=1), femur (n=1) and wrist (n=1). Results: Abnormalities were detected in eight patients. Two patients had acute lymphoblastic leukaemia, and another had an anaplastic lymphoma, unsuspected prior to the WBMR. Two patients had a previously undiagnosed neuroblastoma with bone marrow metastases. Two patients had Langerhans cell histiocytosis. Another had multiple bone lesions due to cystic angiomatosis. Conclusions: WBMR imaging may be a useful additional sequence in children in whom a systemic and especially a bone marrow abnormality is suspected.Presented at 40th annual meeting of ESPR, Genoa, June 2003     

Imaging findings in primary intracranial atypical teratoid/rhabdoid tumors

Background: Intracranial atypical teratoid/rhabdoid tumors (AT/RT) are rare and extremely aggressive neoplasms seen primarily in childhood. Imaging features are often considered non-specific. However, correct diagnosis of AT/RT is important because these tumors have a markedly different clinical prognosis and require more aggressive therapy.Objective: To determine the imaging features of AT/RT.Materials and methods: We retrospectively analyzed imaging findings in 11 patients with primary intracranial AT/RT presenting over a period of 5 years. CT (n=11), MR (n=7), clinical (n=11) and pathological (n=11) features were evaluated. FISH analysis showing monosomy of chromosome 22 (absence of bcr 22q11 locus) was available for three patients. Immunohistochemical staining for INI-1 (BAF47) was performed on all tumors. Results: There were 11 patients, 6 boys and 5 girls. The age of presentation varied from 1 month to 15 years (average age 3 years 8 months). Six tumors were located in the posterior fossa and five in the supratentorial compartment. The tumors showed a hyperdense solid component (64%) that showed moderate to marked enhancement with contrast medium. On MR imaging, the predominant signal pattern was isointensity on T1-weighted images (57%) and T2 shortening with heterogeneity on T2-weighted images (86%). All tumors were large in size (average 4.2×3.7 cm), and there was a tendency for calcification (36%), hemorrhage (46%), necrosis (46%) and perifocal edema (100%). There was also a high tendency for subarachnoid dissemination, with five patients (46%) demonstrating brain and/or spinal metastasis. At follow-up (n=7), six patients showed local recurrence. At the time of recurrence, all these patients showed extensive leptomeningeal spread of the disease in both intracranial and intraspinal compartments. Conclusion: There are no specific imaging features for intracranial AT/RT. But a high tendency toward large size, a hyperdense solid component on CT scan with calcification, hemorrhage, necrosis and subarachnoid spread suggest that this tumor should be considered in the differential diagnosis of large pediatric intracranial tumors.     

Comparative analysis of MR sequences to detect structural brain lesions in tuberous sclerosis

Background: Tuberous sclerosis (TS) is a neurocutaneous genetically inherited disease with variable penetrance characterized by dysplasias and hamartomas affecting multiple organs. MR is the imaging method of choice to demonstrate structural brain lesions in TS. Objective: To compare MR sequences and determine which is most useful for the demonstration of each type of brain lesion in TS patients. Materials and methods: We reviewed MR scans of 18 TS patients for the presence of cortical tubers, white matter lesions (radial bands), subependymal nodules, and subependymal giant cell astrocytoma (SGCA) on the following sequences: (1) T1-weighted spin-echo (T1 SE) images before and after gadolinium (Gd) injection; (2) nonenhanced T1 SE sequence with an additional magnetization transfer contrast medium pulse on resonance (T1 SE/MTC); and (3) fluid-attenuated inversion recovery (FLAIR) sequence. Results: Cortical tubers were found in significantly (P<0.05) larger numbers and more conspicuously in FLAIR and T1 SE/MTC sequences. The T1 SE/MTC sequence was far superior to other methods in detecting white matter lesions (P<0.01). There was no significant difference between the T1 SE/MTC and T1 SE (before and after Gd injection) sequences in the detection of subependymal nodules; FLAIR sequence showed less sensitivity than the others in identifying the nodules. T1 SE sequences after Gd injection demonstrated better the limits of the SGCA. Conclusion: We demonstrated the importance of appropriate MRI sequences for diagnosis of the most frequent brain lesions in TS. Our study reinforces the fact that each sequence has a particular application according to the type of TS lesion. Gd injection might be useful in detecting SGCA; however, the parameters of size and location are also important for a presumptive diagnosis of these tumors.     

Cyst-like cortical tubers in patients with tuberous sclerosis complex: MR imaging with the FLAIR sequence

Background: Tuberous sclerosis complex (TSC) is an inherited disorder characterized by the presence of cortical tubers, the majority of which are solid and show high signal on FLAIR images. Low-signal tubers are less frequent. Objective: To evaluate cystic cortical tubers in patients with TSC on the basis of their appearance on FLAIR images. Materials and methods: MR examinations of 73 patients were retrospectively reviewed and 17 children (aged 25 days to 12.3 years) with a typical cyst-like tubers were selected for further analysis. The age of the patients, the number of lesions, and the shape and MR intensity were analyzed. Results: Cyst-like cortical tubers were detected in 82% of children below 7 years of age and in 18% of those older then 7 years (P=0.00086). Most of the cystic lesions were of the shrunken type (72%), the expansile type being less frequently seen (28%). Conclusions: FLAIR images confirm the cystic character of some of the cortical tubers in TSC patients although the pathogenesis of cystic change is still unknown.     

MR imaging of abdominopelvic involvement in neurofibromatosis type 1: a review of 43 patients

Background: Plexiform neurofibromas are a frequent complication of neurofibromatosis type 1. This article discusses MR imaging findings and distribution of plexiform neurofibromas in the abdomen and pelvis. Objective: To define the most prevalent patterns of involvement and MR imaging findings in abdominopelvic neurofibromatosis type 1. Materials and methods: We reviewed the MR appearance of abdominopelvic lesions in 23 male and 20 female patients (median age: 16 years) with type 1 neurofibromatosis. The patients were part of a multi-institutional study of 300 patients. Imaging included coronal or sagittal, and axial short tau inversion recovery images. Results: The most common abdominopelvic involvement was in the abdominopelvic wall (n=28, 65%) and lumbosacral plexus (n=27, 63%). Retroperitoneal involvement was frequent (n=15, 35%). Lesions were less often intraperitoneal (21%) (P=0.001). Pelvic disease (n=27, 63%), neural canal involvement (n=18, 42%), and hydronephrosis (n=4, 9%) were also noted. Target-like appearance of plexiform lesions was noted in more than half the patients. Conclusion: Abdominopelvic involvement in neurofibromatosis type 1 is primarily extraperitoneal. Although lesions are most prevalent in the abdominopelvic wall and lumbosacral plexus, retroperitoneal and pelvic involvement is common and usually affects important organs. MR imaging added information in the initial and follow-up clinical evaluation of these patients.     

MR imaging of glioblastoma in children: usefulness of diffusion/perfusion-weighted MRI and MR spectroscopy

Background Glioblastoma is relatively uncommon in childhood and maybe difficult to differentiate from other brain tumors such as primitive neuroectodermal tumor, ependymoma, or benign astrocytoma. Objective To describe the characteristic MR features in children with glioblastoma and to evaluate the usefulness of diffusion and perfusion MR imaging and MR spectroscopy in pediatric glioblastoma. Materials and methods MR imaging in 11 children (12 tumors) with biopsy-proven glioblastoma was reviewed retrospectively. In one patient, there was a recurrent glioblastoma. We reviewed CT and MRI imaging for tumor location, density/signal intensity, and enhancement pattern. Routine MR imaging was performed with a 1.5-T scanner. In six patients, diffusion-weighted MR images (DWIs) were obtained with a single-shot spin echo EPI technique with two gradient steps, and apparent diffusion coefficients (ADCs) were calculated. Using the gradient EPI technique, perfusion-weighted MR images (PWIs) were obtained in four patients from the data of dynamic MR images. The maximum relative cerebral blood volume (rCBV) ratio was calculated between the tumor and contralateral white matter in two cases. In three patients, proton MR spectroscopy was performed using a single voxel technique with either STEAM or PRESS sequences. The locations of the tumor were the thalamus and basal ganglia (n=8), deep white matter (n=3), and brain stem (n=1).Results Intratumoral hemorrhage was seen in four tumors. The tumors showed high-signal intensity or DWIs, having a wide range of ADC values of 0.53–1.30 (mean ±SD=1.011±0.29). The maximum rCBV ratios of glioblastoma were 10.2 and 8.5 in two cases. MR spectroscopy showed decreased N-acetylaspartate (NAA) and increased choline in three cases. The MR findings of glioblastoma in children were: a diffusely infiltrative mass with hemorrhage involving the deep cerebral white matter, thalami, and basal ganglia. Conclusion Diffusion/perfusion MR imaging and MR spectroscopy are very helpful in diagnosing glioblastoma, determining the biopsy site, and evaluating tumor recurrence.This paper was presented as a scientific contribution at the 39th Annual Congress of the European Society of Paediatric Radiology, Bergen, Norway, June 2002     

Diagnostic equivalency of fast T2 and FLAIR sequences for pediatric brain MRI: a pilot study

Background

Faster and motion robust magnetic resonance imaging (MRI) sequences are desirable in pediatric brain MRI as they can help reduce the need for monitored anesthesia care, which is a costly and limited resource that carries medical risks.

Objective

To evaluate the diagnostic equivalency of commercially available accelerated motion robust MR sequences relative to standard sequences.

Materials and methods

This was an institutional review board-approved prospective study. Subjects underwent a clinical brain MRI using conventional multiplanar images at 3 Tesla followed by fast axial T2 and FLAIR (fluid-attenuated inversion recovery) sequences optimized for an approximately 50% reduction in acquisition time. Conventional and fast images from each subject were reviewed by two blinded pediatric neuroradiologists. The readers evaluated the presence of 12 findings. Intra-observer agreement was estimated for fast versus conventional sequences. For each set of sequences, interobserver agreement calculations and chi-square tests were used to evaluate differences between fast and conventional acquisitions. An independent third reader reviewed the intra-observer discrepancies and adjudicated them as being more conspicuous on fast sequence, conventional sequence or the equivalent. The readers also were asked to rate motion artifacts with a previously validated score.

Results

Images from 77 children (mean age: 11.3 years) were analyzed. Intra-observer agreement (fast versus conventional) ranged between 89.2% and 92.3%. Interobserver agreement ranged between 86.1% and 88.4%. Interobserver agreement was significantly higher for conventional FLAIR relative to fast FLAIR for small (<5 mm) foci of T2 in the white matter. Otherwise, interobserver agreement was not different between the fast and conventional sequences. For awake subjects, fast sequences had significantly fewer artifacts (P<0.05).

Conclusion

Conventional T2 and FLAIR sequences can be optimized to shorten acquisition while maintaining diagnostic equivalency. These faster sequences were also less susceptible to motion artifacts.

     

Post-contrast FLAIR MR imaging of the brain in children: normal and abnormal intracranial enhancement

Objective To describe the normally enhancing intracranial structures on fluid-attenuated inversion recovery (FLAIR) MRI and evaluate the usefulness of postcontrast FLAIR images of the brain in the assessment of enhancing lesions by comparing postcontrast FLAIR imaging with postcontrast T1-weighted (T1-W) imaging in children.Materials and methods In 218 children, 249 pre- and postcontrast FLAIR MRI examinations of the brain were obtained consecutively between August 2001 and April 2002. The normally enhancing intracranial structures on FLAIR imaging were assessed in 77 MRI studies of 74 children who showed normal intracranial imaging findings. In 86 MRI studies in 68 children who showed enhancing intracranial lesions, lesion conspicuity on postcontrast FLAIR imaging was compared with that on postcontrast T1-W imaging for all lesions (n=107), intra-axial lesions (n=40), or extra-axial lesions (n=67).Results The normally enhancing intracranial structures on FLAIR MRI were the choroid plexus (99%, 76/77), pituitary stalk (84%, 65/77), pineal gland (71%, 55/77), dural sinuses (26%, 20/77), and cortical veins (9%, 7/77). Of all the enhancing lesions, lesion conspicuousness on postcontrast FLAIR imaging was better than postcontrast T1-weighted imaging in 42, equal in 28, and worse in 37. Of 40 intra-axial lesions, lesion conspicuousness on postcontrast FLAIR imaging was better in 6, equal in 10, and worse in 24. Of 67 extra-axial lesions, lesion conspicuity on postcontrast FLAIR imaging was better in 36, equal in 18, and worse in 13. Conspicuousness of extra-axial lesions was significantly better than that of intra-axial lesions on postcontrast FLAIR imaging (P<0.001).Conclusions The choroid plexus, pituitary stalk, pineal gland, dural sinuses, and cortical veins show normal enhancement on postcontrast FLAIR MRI in children, and postcontrast FLAIR imaging appears better than postcontrast T1-W imaging in the assessment of extra-axial enhancing lesions in children.Presented at the 46th Annual Meeting of the Society for Pediatric Radiology, San Francisco, California, USA, May 2003     

Merosin-deficient congenital muscular dystrophy (CMD): a study of 25 Brazilian patients using MRI

Background: Merosin-deficient congenital muscular dystrophy (CMD) is characterized clinically by hypotonia and muscular weakness and, on imaging studies, by white matter (WM) abnormality. Objective: To evaluate MRI findings in Brazilian patients with merosin-deficient CMD. Materials and methods: Twenty-five patients were evaluated using MRI. Three patients presented with partial merosin deficiency and 22 with total merosin deficiency. Follow-up examinations were done in 7 cases. T1- and T2-weighted images were performed in all examinations, and fluid-attenuated inversion recovery (FLAIR) was performed in 15. Enhanced images were done in 11 cases. The WM involvement was classified according to location and severity. Results: From 1991 to 2004, 32 MRI examinations were performed. Severe involvement was found in 23 patients in the frontal and temporal lobes, in 18 patients in the parietal lobes, and in 7 patients in the occipital lobes. The brain stem (n=5), cerebellum (n=6), internal capsules (n=1), and external capsules (n=5) were also affected. One patient had occipital pachygyria, and one had cerebellar vermian hypoplasia. No gadolinium enhancement was noted. Follow-up MRI showed no interval change (n=4), progression (n=1), or improvement of the findings (n=2). Conclusion: This series of patients demonstrated that there was no correlation between the extent of WM abnormality on MRI and the clinical status and degree of merosin deficiency (partial or total). Bilateral WM involvement was seen to be more prominent in the parietal, frontal, and temporal regions of the brain. The brain stem and internal and external capsules were less affected. Cerebellar WM involvement is rare. Changes on follow-up imaging studies did not correlate with the clinical status of the patient.     

Clinical characteristics of neonates With VACTERL association

Background: The VACTERL association (VA) is the non‐random co‐occurrence of vertebral anomalies, anal atresia, cardiovascular malformations, tracheoesophageal fistula and/or esophageal atresia, renal anomalies, and/or limb anomalies, and is referred to by the first letters of its components. Studies investigating the clinical characteristics of VA patients and probing of the observed current six component types are limited, and none of them is focused on neonates. We investigated the clinical characteristics of our patients diagnosed as having VA in the newborn period. Methods: We retrospectively reviewed the neonates whose final diagnosis was VACTERL association. Presence of at least three components of previously reported six anomalies was accepted as VACTERL association. Sex, birthweight, gestational age, postnatal age, anomalies of the systems that are included in VA, and the other features were recorded. Results: There was a male predominance (14/11) of 28 patients; and there were three patients with ambiguous genitalia. The most common observed VACTERL component was vertebral anomalies (n= 26), followed by anal atresia (n= 19), tracheoesophageal fistula/esophageal atresia (n= 17), renal anomalies (n= 15), limb anomalies (n= 15) and cardiac anomalies (n= 14). The most frequent combination was VCTL (n= 4). Fifteen (57%) patients had non‐VACTERL anomalies and the most frequent of these was ambiguous genitalia (n= 3). Conclusion: VA patients may have different clinical characteristics in different populations, and clinicians may miss some component features if the patients are evaluated after the neonatal period.     

MR findings of complicated multifetal gestations

This paper presents a review of various complications of multifetal gestations identified on MR imaging and highlights findings of those complications unique to monochorionic twinning. The goal is to illustrate the potential of MR as a useful application in these clinical circumstances. A total of 32 women with multifetal gestations and suspected complication detected initially by US underwent T2-weighted MR imaging. Additional T1-weighted images were obtained when intracranial hemorrhage was suspected. MR and US findings were compared in all cases. Of 32 cases, six demonstrated fetal complications specific to monochorionic twinning; the findings consisted of conjoined twins (n=2), twin-twin transfusion syndrome (n=1), co-twin demise with embolic disease (n=2), and twin-reversed arterial perfusion. (TRAP) syndrome (n=1). MR imaging confirmed US findings in all cases and was particularly helpful in delineating the extent of intracranial complications of monochorionic twins. The technique also showed improved anatomical detail in cases of conjoined twins. MR imaging provided additional information in cases of complicated monochorionic twinning, making it a useful complementary technique when combined with initial sonographic assessment.     

Reversible acute methotrexate leukoencephalopathy: atypical brain MR imaging features

Background: Unusual acute symptomatic and reversible early-delayed leukoencephalopathy has been reported to be induced by methotrexate (MTX). Objective: We aimed to identify the occurrence of such atypical MTX neurotoxicity in children and document its MR presentation. Materials and methods: We retrospectively reviewed the clinical findings and brain MRI obtained in 90 children treated with MTX for acute lymphoblastic leukaemia or non-B malignant non-Hodgkin lymphoma. All 90 patients had normal brain imaging before treatment. In these patients, brain imaging was performed after treatment completion and/or relapse and/or occurrence of neurological symptoms. Results: Of the 90 patients, 15 (16.7%) showed signs of MTX neurotoxicity on brain MRI, 9 (10%) were asymptomatic, and 6 (6.7%) showed signs of acute leukoencephalopathy. On the routine brain MRI performed at the end of treatment, all asymptomatic patients had classical MR findings of reversible MTX neurotoxicity, such as abnormal high-intensity areas localized in the deep periventricular white matter on T2-weighted images. In contrast, the six symptomatic patients had atypical brain MRI characterized by T2 high-intensity areas in the supratentorial cortex and subcortical white matter (n=6), cerebellar cortex and white matter (n=4), deep periventricular white matter (n=2) and thalamus (n=1). MR normalization occurred later than clinical recovery in these six patients. Conclusions: In addition to mostly asymptomatic classical MTX neurotoxicity, MTX may induce severe but reversible unusual leukoencephalopathy. It is important to recognize this clinicoradiological presentation in the differential diagnosis of acute neurological deterioration in children treated with MTX.     

Inverse relationship between beta-endorphin immunoreactivity in cerebrospinal fluid and nucleus tractus solitarius in sudden infant death

In nucleus tractus solitarius (NTS) beta-endorphin (BEND) induces bradycardia and respiratory depression which have been reported to precede death in sudden infant death (SID). Of SID victims, 50% have elevated levels of beta-endorphin immunoreactivity (BENDI) in the cerebrospinal fluid (CSF), and 50% had undetectable levels. We therefore investigated the relationship of BENDI in the CSF to BENDI levels in the NTS area. This study included SID victims (CSF fromn=47, brain stem fromn=16), borderline SID victims (CSF and brain stem fromn=2), sudden death in childhood (CSF and brain stem fromn=1), and controls (CSF fromn=32, brain stem fromn=11). BEND in CSF and NTS area, after extraction, was measured by radioimmunoasay. High performance liquid chromatography was used for closer identification of BENDI. We found that the SID victims divided into two subpopulations, one having a relatively high BENDI level in CSF and one having no detectable level (P<0.01). Furthermore, an inverse relationship was found between BENDI level in CSF and BENDI level in NTS area in the SID victims (P<0.05). We conclude that increased BENDI level in CSF is associated with low BENDI level in the NTS area in 50% of SID victims. The low BENDI level in CSF is associated with low BENDI level in the NTS area in 50% of SID victims. The low BENDI level in the NTS area may be due to increased release of BEND.     

Elevated beta-endorphin immunoreactivity in the cerebrospinal fluid in victims of sudden infant death correlates with hypoxanthine in vitreous humour

Beta-endorphin (BEND) may induce respiratory depression. Elevated levels of beta-endorphin immunoreactivity (BENDI) in the CSF are found in children with apnoea and in about 50% of sudden infant death (SID) victims. Premortal hypoxia in SID victims has been indicated by elevated hypoxanthine (HX) levels in the vitreous humour (VH). In this study we correlated BENDI in CSF with HX in VH in SID victims (n=19) and controls (n=18). BEND in CSF was measured by RIA, and HPLC was used for identification of BENDI. HX in VH was measured by HPLC. All the SID victims had elevated levels of HX in VH. The BENDI in CSF divided the SID victims into two subpopulations (P<0.01); one with undetectable levels (<4.3 fmol/ml) (n=10) and one with high levels (160–400 fmol/ml) (n=9).In the SID subpopulation with high levels of BENDI in CSF,we found a correlation between BENDI in CSF and HX in VH (r=0.92). Control infants who died a stressful death, such as during heart operations (n=2), had high levels of BENDI in CSF and low levels of HX in VH. Controls who died of infections (n=11) had low levels of BENDI in CSF and elevated levels of HX in VH. Because hypoxia in itself does not increase BENDI in CSF, increased BENDI in CSF is probably not secondary to hypoxia but may be of aetiological significance. We therefore suggest that SID victims with high levels of BENDI in CSF, which correlate with the elevated levels of HX in VH, may die from premortal hypoxia possibly induced by BEND.     

Central nervous system relapse of rhabdomyosarcoma

1 Purpose

The optimal management of central nervous system (CNS) relapse of rhabdomyosarcoma (RMS) is unclear. We examined diagnosis, management, and outcomes of patients with RMS developing CNS relapse.

2 Methods

Records of 23 patients diagnosed with CNS relapse between 1999 and 2016 were reviewed. Median age at presentation of CNS relapse was 15 years (range, 1–34 years). High‐risk features at initial presentation were as follows: 16 alveolar patients, 13 Stage IV, and 13 with primary tumor in parameningeal locations.

3 Results

CNS relapse occurred at a median 12 months (range, 1–23 months) from diagnosis and most common presenting symptoms were headache (n = 9), nausea/vomiting (n = 8), visual difficulty (n = 5), and none (n = 5). Leptomeningeal metastases were detected in 21 patients while only 2 developed parenchymal metastases without leptomeningeal involvement. Fifteen patients received CNS‐directed radiation therapy (RT), including craniospinal irradiation to a median 36 Gy (range, 18–36 Gy) and/or whole brain radiotherapy to a median 30 Gy (range, 6–41.4 Gy). Three patients received concurrent chemotherapy. Follow‐up magnetic resonance imaging was conducted in 13 patients after RT initiation with 8 demonstrating improvement, 2 with stable disease, and 3 with progression. Twelve patients were tested for reactivity to I‐131‐labeled monoclonal antibody 8H9, and three tested positive and received at least one intra‐Ommaya dose; all three lived >12 months post‐CNS relapse. Twenty‐one patients died of CNS disease and two of metastatic disease at other sites. Median survival post‐CNS relapse was 5 months (range, 0.1–49 months).

4 Conclusions

The prognosis for patients with RMS developing CNS relapse remains poor. Treatment including CNS‐directed RT should be considered and investigation into preventative therapies is warranted.