Edward Weinberger

Cervical spine MRI in abused infants.

OBJECTIVE To determine clinical utility of screening with cervical spine MRI to detect unsuspected cord injury in children with head injury from child abuse. DESIGN Prospectively collected case series. Setting-Tertiary care childrens hospital and county medical examiners office. PATIENTS Twelve children with intracranial injury secondary to child abuse. None was clinically suspected to have cord injury. Includes all eligible children whose attending felt: (a) needed follow-up cranial imaging: (b) could be safely imaged; and (c) whose caretakers consented between November, 1991 and September, 1994. INTERVENTIONS MRI scans of the cervical spine were obtained either more than 3 days after clinical presentation or postmortem. MAIN OUTCOME MEASURES Clinical observations by neurologist, child protection team pediatrician and medicinal examiners by prospective protocol. MRI scans evaluated by prospective radiology protocol with emphasis on cervical cord injury. RESULTS Four of the five autopsied children had small subdural or subarachnoid hemorrhages at the level of the cervical spine; MRI scan did not identify them. MRI did not identify cord injury in any child studied. CONCLUSION Routine cervical spine MRI scans are probably not warranted in children with head injury secondary to child abuse without clinical symptoms of cervical cord injury.

Discoid menisci in children: MR features.

Objective To define the MR appearance of discoid meniscus in children. Materials and Methods In 22 children (15 girls and 7 boys; age range 5–17 years: median age, 9 years) who were referred for evaluation of painful knees 27 discoid lateral menisci were identified. Meniscal shape and signal intensity and abnormalities of the surrounding structures were evaluated and compared with adult standards. Clinical (II knees) or surgical (10 knees) follow-up was available on 16 patients (21 knees). Results The menisci were classified as slab type (no. 20) or wedge type (no. 7). Transverse diameter at the midbody was 22.4 mm (range 10.5–36.7 mm) for discoid lateral menisci and 6 mm (range 5.1–28.3 mm) for medial menisci. Of 27 menisci, 23 had a central band of diffusely increased signal. Extension of intrameniscal signal to the joint space was noted in 16 of 23 menisci. Of 9 patients with intrameniscal signal who underwent surgery, only 7 had tears. Associated popliteal cysts occurred in 3 knees. No medial meniscal injury was observed. Conclusion The characteristic MRI appearance of symptomatic discoid meniscus in children is that of a diffusely thick meniscus with a slab configuration and diffusely increased intrameniscal signal that may or may not extend to the joint surface.

Marinesco-Sjögren Syndrome: Clinical and Magnetic Resonance Imaging Features in Three Children

The authors describe clinical and MRI features of a girl and two boys, aged 9, 17 and 19 years, respectively, with Marinesco‐Sjögren syndrome. The clinical findings included the major features of the syndrome. including growth deficiency, ataxia, cataracts, hypogonadism (in two) and seizures (in two). Truncal hypotonia (in three), microcephaly (in two) and Ieg spasticity (in two) were also present. MRI showed a very small cerebellar vermis in all three patients, various supratentorial abnormalities, an apparcntly small anterior pituitary gland in two and the absence of a posterior pituitary gland in all three. The MRI features are similar to the few reported pathologic findings for persons with Marinesco‐Sjögren syndrome. MRI may be helpful in the early diagnosis of the disorder.

Magnetic resonance imaging and spectroscopy in fetal ethanol exposed Macaca nemestrina

Magnetic resonance imaging (MRI) and proton magnetic resonance spectroscopy (1H-MRS) offer noninvasive ways to observe structural and biochemical changes which might serve as valuable diagnostic markers for detecting brain damage from prenatal ethanol teratogenesis. Cranial MR imaging and spectroscopy were performed on 20 nonhuman primates (Macaca nemestrina) with known prenatal ethanol exposures and well-documented cognitive and behavioral levels of performance. The choline: creatine ratio detected by 1H-MRS in the brain increased significantly with increasing duration of in utero ethanol exposure. These signal alterations occurred in the absence of gross structural brain anomalies (detectable by MRI) and were significantly correlated with alcohol-related cognitive and behavioral dysfunction. These observations are consistent with reports of elevated choline: creatine ratios associated with various neurologic insults and disease states. The association observed between brain choline:creatine ratios and in utero ethanol exposure suggest a role for 1H-MRS in elucidating mechanisms of ethanol teratogenicity.

Perceived Anxiety of Pediatric Patients to Magnetic Resonance

Magnetic resonance imaging (MRI), a nonionizing radiologic technique without known adverse physical effects, is utilized frequently in children and adolescents. The MRI technique requires prolonged immobility in a narrow, confined space, and concern has been raised regarding possible patient anxiety and noncompliance. Several reports suggest that up to 10% of adults undergoing MRI may experience anxiety and/or claustrophobia. 1 However, to our knowledge, no studies of the subjective MRI experiences of children and adolescents have been published. We report here the general characteristics of 491 consecutive Pediatric patients who were evaluated with MRI at our institution, including the experience of anxiety in 85 older children and adolescents.

Cranial MR in phenylketonuria

Phenylketonuria (PKU) is an autosomal recessive disease in which defects in phenylalanine metabolism result in hyperphenylalaninemia. Untreated patients generally have poor motor function and are profoundly retarded. We report a patient with PKU whose cranial magnetic resonance abnormalities correlate with known histopathologic changes. The ability to image the pathologic changes in PKU may have important implications regarding treatment and prognosis of these patients.

Bacterial ileocecitis caused by Escherichia coli O157:H7.

Escherichia coli O157:H7 is most commonly linked to hemorrhagic colitis and the hemolytic uremic syndrome. Diagnostic ultrasound was used to demonstrate terminal ileum abnormalities suggestive of bacterial ileocecitis, a recently described entity that resembles acute appendicitis, in a patient whose stool culture yielded E. coli O157:H7. This case extends the spectrum of disease caused by E. coli O157:H7 and expands the number of organisms that can cause bacterial ileocecitis.

Rapid computed tomography technique to measure ventricular volumes in the child with suspected ventriculoperitoneal shunt failure II. Clinical application.

Objectives Assessment of ventricular volume change is critical in the child with suspected shunt failure. Minimal increases may represent high pressures in the child with reduced ventricular compliance but are difficult to detect subjectively. Objective techniques described limit anatomic sampling and are time intensive. The purpose of this study was to develop a rapid technique to measure ventricular volumes in children with suspected shunt failure. Methods Ventricular volumes were calculated in 12 children with baseline and emergent computed tomography scans performed for suspected shunt failure. Volumes and percent interval changes were correlated with clinical course. Two observers performed the volume analysis blinded to the clinical information; 1 observer performed the analysis twice. Time to perform the analysis was recorded for 5 studies. Results The intraobserver and interobserver correlation coefficients were 0.99 and 0.96/0.97, respectively. The mean time to perform the analysis was 2 minutes 42 seconds. Median percent change in patients with and without shunt obstruction was +50% (range: +24%–+367%) and +2% (range: −22%–+36%), respectively. Among patients subjectively read as having stable ventricular sizes, volume changes of −11% to +32% were calculated. Conclusions The technique has excellent intra- and interobserver correlation and is rapidly performed. The range of percent volume changes between patients with and without shunt malfunction overlaps. Subjective assessment of ventricular changes is significantly less sensitive than the volume calculation technique. The technique may be most useful in patients with decreased ventricular compliance in whom small interval changes may represent large pressure increases.

Rapid computed tomography technique to measure ventricular volumes in the child with suspected ventriculoperitoneal shunt failure I: Validation of technique with a dynamic phantom

Objectives Assessment of ventricular volume change is critical and can be difficult in the child with suspected shunt failure. Objective techniques described to measure ventricular volumes have used limited anatomic sampling or have been computationally intensive. Phantoms used to evaluate these techniques have used static volumes. The purpose of this study was to construct a computed tomography (CT) phantom to simulate changing ventricular volumes and to evaluate a new program to measure volumes. Methods The phantom is 5 Foley catheters embedded in gelatin. The balloons were filled and then scanned at 15-mL increments from 0–300 mL. The program measures the voxels of specified density within a larger volume created by applying a region of interest to a stacked volume. Calculated volumes and percent changes were compared with actual volumes and percent changes. Results Calculated volumes were consistently 7%–9% (mean: −7.8%) less than actual injected volumes across the entire 0- to 300-mL range. For true changes between −50% and +50%, all calculated changes were within ±2.5% points of true percent change; for true changes between +50% and +100%, all calculated changes were within ±5% points of true percent change. Conclusions A dynamic CT phantom simulating changing ventricular volumes can be constructed from readily available materials. A new volumetric program accurately measures ventricular volumes and percent change from baseline across a wide range of volumes.

Quantitative comparison of conventional spin echo and fast spin echo during brain myelination

PURPOSE Fast SE (FSE) sequences have largely replaced conventional SE (CSE) T2-weighted sequences in the brain and have been generally accepted as qualitatively comparable. The purpose of the present study was to subject these sequences to a quantitative comparative analysis in the brain. METHOD A quantitative analysis of relative signal intensities of white and gray matter was performed comparing CSE and FSE T2-weighted sequences in brains of 20 children at varying stages of myelination. RESULTS AND CONCLUSION At all ages in individual patients, white matter had less signal intensity (SI) relative to gray matter on FSE than CSE, though the relative difference in SI was small. This resulted in white matter appearing slightly more myelinated on FSE than CSE. This difference is attributed to differences in magnetization transfer. In myelinated brain (white matter hypointense to gray matter), contrast-to-noise was greater with FSE, while in unmyelinated brain, contrast-to-noise was greater with CSE.