Biomedical subjects

Caroline D Robson

Publications and source records attributed to Caroline D Robson.

5 recordsLinked to original sources

PubMed2003

CT versus MR in neonatal brain imaging at term.

BACKGROUND: Recent reports have highlighted the lifetime risk of malignancy from using ionizing radiation in pediatric imaging. Computed tomography (CT), which uses ionizing radiation, is employed extensively for neonatal brain imaging of term infants. Magnetic resonance (MR) provides an alternative that does not use ionizing radiation. OBJECTIVE: The purpose of this study was to assess the cross-modality agreement and interobserver agreement of CT and MR brain imaging of the term or near-term neonate. MATERIALS AND METHODS: Brain CT and MR images of 48 neonates were retrospectively reviewed by two pediatric neuroradiologists. CT and MR examinations had been obtained within 72 h of one another in all patients. CT was obtained with 5 mm collimation (KV=120, mAs=340). MR consisted of T1-weighted imaging (TR/TE=300/14; 4-mm slice thickness/1-mm gap), T2-weighted imaging (TR/TE/etl= 3000/126/16; 4-mm slice thickness/1-mm gap), and line scan diffusion imaging (LSDI) (TR/TE/b factor=1258/63/750; nominal 4-mm slice thickness/3-mm gap). The brain was categorized as normal or abnormal on both CT and MR. RESULTS: Ischemic injury was the most common brain abnormality demonstrated. McNemar's test indicated no significant difference between CT and MR test results for reader 1 (P=0.22) or reader 2 (P=0.45). The readers agreed on the presence or absence of abnormality on CT in 40 patients (83.3%) and on MR in 45 patients (93.8%). For CT, the kappa coefficient indicated excellent interobserver agreement (kappa=0.68), although the lower limit of the 95% confidence interval extends to kappa=0.55, which indicates only good-to-moderate agreement. For MR, the kappa coefficient indicated almost perfect interobserver agreement (kappa=0.88) with the 95% confidence interval extending to a lower limit of kappa=0.76, which represents excellent agreement. CONCLUSION. Because MR demonstrates findings similar to CT and has greater interobserver agreement, it appears that MR is a superior test to CT in determining brain abnormalities in the term neonate. Furthermore, since MR eliminates the use of ionizing radiation, a putative cause of malignancy, it should be the standard in neonatal brain imaging. Future efforts should be directed to improving neonatal access to MR to avoid the routine use of CT in infants.

Brain↗

PubMed2003

Psammomatous calcification in association with a benign thyroglossal duct cyst.

Embryologic remnants of thyroid tissue often line the thyroglossal duct tract and may commonly become cystic. Calcification in such a cyst is thought to be a specific marker for malignancy, which may develop in 1% of thyroglossal duct cysts. We describe a 3-year-old boy with a midline neck mass that showed radiologic calcification. Pathologic evaluation revealed psammomatous calcification in association with a benign thyroglossal duct cyst. These findings, not previously reported (to our knowledge), expand the radiologic differential diagnosis of calcified neck masses and broaden the spectrum of pathologic findings seen in association with benign thyroglossal duct cysts.

Calcinosis↗

PubMed2003

The presentation and management of nasal dermoid: a 30-year experience.

OBJECTIVE: To review the presentation of nasal dermoid in children and present guidelines for its management. DESIGN: Retrospective study (January 1, 1970, through December 31, 2000). SETTING: Tertiary-care pediatric medical center. PATIENTS: Number of patients: 42 (28 boys and 14 girls). Intervention Extensive review of the initial presentation, significant family and medical history, workup, surgical approach, complication, and rate of recurrence. RESULTS: Mean age of presentation was 32 months. The most common presentation was a nasoglabellar mass, in 13 patients (31%). Five patients presented with an associated craniofacial abnormality. Thirty-nine patients (93%) underwent a preoperative imaging workup. Thirty-one (74%) did not show any clinical and/or radiographic indication of intracranial extension. Thirty-four (81%) underwent extracranial excision, and 8 (19%) underwent combined intracranial-extracranial excision. Five patients (12%) presented with recurrence, extracranially in 4 and intracranially in 1. No other complication was noted, with a mean follow-up of 7 years. CONCLUSIONS: Nasal dermoid is a rare congenital anomaly. Preoperative evaluation is essential to rule out intracranial extension. Surgical strategy depends on the location and extent of the lesion, ranging from local excision to a combined intracranial-extracranial approach. Recurrence is uncommon and often easily managed.

Adolescent↗

PubMed2003

Marked regression of metastatic pilocytic astrocytoma during treatment with imatinib mesylate (STI-571, Gleevec): a case report and laboratory investigation.

Pilocytic astrocytomas are the most common childhood glioma. Most children with pilocytic astrocytomas survive many years with their tumor, but alternative treatment approaches are needed for those with refractory or metastatic disease. Signaling by the platelet-derived growth factor tyrosine kinase receptor pathways have been postulated to contribute to the development of gliomas. The authors treated a single patient with refractory, metastatic pilocytic astrocytoma with the tyrosine kinase inhibitor imatinib mesylate and observed marked, transient regression of tumor during treatment. Immunohistochemistry was used to assess expression of reported target genes of imatinib mesylate in this patient's tumor tissue and of the PDGFR in pilocytic astrocytomas from 19 other patients. Immunohistochemistry showed that the patient's tumor cells did not express any of the reported target molecules inhibited by imatinib mesylate. PDGFR expression was detected in tumor vasculative in the panel of 20 tumors, and not in the tumor cells. The authors suggest that the PDGFR-signaling pathway postulated to contribute to the development of gliomas in adults might not contribute to pilocytic astrocytomas in children, and that treatment with imatinib mesylate should be considered in patients with refractory pilocytic astrocytoma.

Astrocytoma↗

PubMed2002

Diffusion imaging in neonates.

Diffusion imaging is a useful technique for the evaluation of many normal and pathologic processes occurring in the neonate and often provides complementary information for conventional MR and other imaging techniques.

Blood-Brain Barrier↗