Biomedical subjects
S Rebsamen
Publications and source records attributed to S Rebsamen.
MRI, MRA, and neurodevelopmental outcome following neonatal ECMO.
Cranial magnetic resonance imaging (MRI) of 31 newborn infants treated with venoarterial cardiopulmonary bypass for severe but reversible respiratory failure, revealed major focal parenchymal lesions in 7 of 31 infants (23%) and demonstrated abnormal enlargement of extra-axial and ventricular cerebrospinal fluid spaces in 16 of 31 (51%). No preferential left versus right lateralization of focal injury was observed in conjunction with right common carotid artery and jugular vein ligation. No statistically significant relationships were found between major brain lesions on MRI scans and the clinical characteristics of the pre-extracorporeal membrane oxygenation (ECMO), ECMO, and post-ECMO course. Major focal brain lesions were significantly associated with an asymmetric cerebrovascular response to carotid ligation of the right versus left middle cerebral arteries as detected by magnetic resonance angiography (P < .05). Enlarged cerebrospinal fluid spaces were not significantly related to the presence of parenchymal MRI lesions, but were associated with lower Bayley neurodevelopmental scores for mental (MDI) and psychomotor evaluations (PDI) at 6 and 12 months (P < .05). It is concluded that asymmetries of cerebral vascular adaptation detected by magnetic resonance angiography after ECMO may be associated with major brain lesions revealed by MRI. Thereafter, the presence of enlarged cerebrospinal fluid spaces on MRI is associated with a poor shortterm developmental outcome.
Surveillance scanning of children with medulloblastoma.
BACKGROUND: The standard follow-up care for children with medulloblastoma includes regular clinical evaluations and surveillance scanning of the central nervous system with computed tomography or magnetic resonance imaging. The evaluations and scanning assess the response of the tumor to treatment, detect any recurrence of disease, and monitor any complications of treatment. We compared the effectiveness of a periodic history taking and physical examination with that of surveillance scanning in detecting recurrent tumors. METHODS: We reviewed the medical records, including 794 scanning reports or scans, of 86 children with posterior fossa medulloblastoma who were followed regularly between 1980 and 1991. Recurrent tumors were classified as symptomatic if neuroimaging studies had been prompted by clinical symptoms or signs and as radiographic if the tumor had been detected by imaging in an asymptomatic patient. RESULTS: Twenty-three of the 86 children (27 percent) had a recurrence of tumor. Four recurrences (17 percent) were detected on scanning only, and 19 (83 percent) were associated with symptoms arising a median of four months after the previous scan. The median and range of survival after a recurrence of the tumor were 5 months and < 1 to 38 months, respectively, for a symptomatic recurrence and 20 months and 10 to 32 months, respectively, for a radiographic recurrence (P = 0.03). No patient survived after a recurrence. The longer survival of patients with recurrent tumors detected by scanning most likely reflects the small number of patients and lead-time and length biases associated with screening. CONCLUSIONS: Among children with medulloblastoma, surveillance scanning is of little clinical value. Scanning detected a minority of recurrences, and no patient who had a recurrence survived.
Magnetic resonance imaging of pediatric posterior fossa tumors.
MR detected abnormality in all 115 pediatric patients who subsequently had pathologically proven posterior fossa tumors. In 114, the initial magnetic resonance (MR) diagnosis was that of brain tumor. In 1, with less than 1-cm2 area of gadolinium enhancement, the significance of the initial finding was uncertain. Common posterior fossa tumor subgroups (brainstem gliomas, cerebellar astrocytomas, primitive neuroectodermal tumors, and ependymomas) have relatively consistent presentations on imaging studies. However, less common tumors mimic the MR appearance of more common ones, while common tumors may also have atypical appearances.
Multiple ureteral diverticula: a possible radiographically demonstrable risk factor in development of transitional cell carcinoma.
Six cases of multiple ureteral diverticula are reported. Most were associated with urinary tract obstruction or stasis and infection. One-third had transitional cell carcinoma, a frequency similar to that reported in previous series. These diverticula are a radiographically demonstrable reflection of urothelial hyperplasia/metaplasia and may represent a risk factor for development of transitional cell carcinoma.