Biomedical subjects

Nancy Rollins

Publications and source records attributed to Nancy Rollins.

6 recordsLinked to original sources

PubMed2005

Cerebral MR venography in children: comparison of 2D time-of-flight and gadolinium-enhanced 3D gradient-echo techniques.

PURPOSE: To prospectively compare two-dimensional (2D) time-of-flight cerebral magnetic resonance (MR) venography with gadolinium-enhanced three-dimensional (3D) gradient-echo cerebral MR venography in children. MATERIALS AND METHODS: This investigation had investigational review board approval and was Health Insurance Portability and Accountability Act compliant; parental informed consent was obtained. Thirty-seven patients (20 boys, 17 girls) who ranged in age from 4 days to 15 years underwent 2D and 3D MR venography. Two pediatric neuroradiologists compared the visibility of the superior sagittal, straight, transverse, and sigmoid sinuses and the internal jugular veins on images obtained with the two sequences. RESULTS: In 17 (46%) of the 37 patients, the sequences were equivalent in terms of their depiction of venous anatomy. In 19 (51%) of the 37 patients, 3D MR venography was superior to 2D MR venography. Suboptimal enhancement of veins occurred in one (3%) patient at 3D MR venography. Venous anomalies suggested at 2D MR venography but not present at 3D MR venography included flow gaps in the nondominant transverse sinuses of four patients, unilateral transverse sinus atresia in eight, and a narrowed superior sagittal sinus in two. Two-dimensional MR venography results failed to reveal a persistent falcine sinus associated with straight sinus atresia in one patient and suggested transverse sinus thrombosis in two patients in whom 3D MR venography results were normal. Additionally, the extent of dural thrombosis was overestimated at 2D MR venography in one patient. As compared with 3D MR venography, 2D MR venography failed to reveal sigmoid sinus stenosis in one patient and poorly depicted posterior fossa dural sinus anatomy in two patients with dural arteriovenous fistula. CONCLUSION: Three-dimensional MR venography is often superior to 2D MR venography in the delineation of major cerebral venous structures in children. Most of the artifactual loss of vascular signal seen with the use of 2D MR venography occurred in nondominant transverse sinuses.

Adolescent↗

PubMed2005

MR venography in the pediatric patient.

BACKGROUND AND PURPOSE: Little is known about age-related changes in posterior fossa venous anatomy on 2D time-of-flight MR venography (MRV) or about artifacts that limit its accuracy in diagnosing venous occlusive disease. We evaluated pediatric appearances of posterior fossa venous drainage. METHODS: One hundred and eight children with normal MR imaging or minimal congenital anomalies underwent 2D MRV. Transverse sinus dominance and absence and the presence of an occipital sinus were correlated with age. Venous structure conspicuity was compared on source and maximum intensity projection images. RESULTS: Right, left, and codominance of the transverse sinus, respectively, was as follows: at < 25 months, 37%, 21%, and 42%; 25 months to 5 years, 35%, 30%, 35%; and > or =6 years, 50%, 16%, 34%. Transverse sinus dominance was not related to age between the three groups (P=.58, chi-square contingency), but some relationship was observed when patients <6 years were compared to those > or =6 years (P=.032). Chi-square trends showed a mildly positive correlation between age and an absent transverse sinus (P=.026) and a decreasing trend in the presence of an occipital sinus with age (P=.038). Saturation effects due to in-plane/slow flow were worse in patients <25 months; effects in the transverse sinuses or internal jugular veins were miminized with coronal or axial imaging, respectively. CONCLUSION: 2D TOF MRV shows age-related changes in venous anatomy. Caution should be used before posterior fossa venous occlusive disease is diagnosed on the basis of signal intensity loss, especially in neonates and young infants.

Adolescent↗

PubMed2005

Semilobar holoprosencephaly seen with diffusion tensor imaging and fiber tracking.

A neonate with semilobar holoprosencephaly was studied with diffusion tensor imaging and fiber tracking. Fiber tracking showed that the frontooccipital fasciculi were in continuity across the ventral midline, interposed between fused caudate and dysplastic fornices. Tractography of the posterior limbs of the internal capsules showed fibers arching ventrally toward the expected location of the motor cortex; some fibers also coursed dorsally, presumably to the sensory cortex. There was a posterior commissural white matter bundle representing a callosal splenium. Diffusion tensor imaging and fiber tracking revealed white matter structures not apparent on routine imaging sequences, which are in agreement with pathologic descriptions of the holoprosencephalic brain.

Brain↗

PubMed2002

Subdural hematoma in term infants.

Subdural hematomas are uncommon in term infants. The study objectives were to evaluate risk factors for and clinical significance of small subdural hematomas observed on computerized tomography. During a 3-year period, 26 near-term and term nonasphyxiated infants were found to have a subdural hematoma on computed tomography. Clinical indications for computed tomography were respiratory symptoms in 15 infants and neurologic symptoms in 10 infants; one infant had a skull fracture. Subdural hematomas were less than 3-mm maximum transverse dimensions in all infants: location was infratentorial (n = 7), supratentorial (n = 7), and in both sites (n = 12). Four infants also had evidence of edema and hemorrhage within the anterior temporal lobe. Delivery was vaginal in 25 of 26 infants, and forceps were used in 13 (50%) infants. Twenty-five infants were managed expectantly; one infant underwent surgical elevation of a depressed skull fracture. No infant required surgical evacuation of the subdural hematoma. At discharge, nine infants with subdural hematoma exhibited an abnormal examination, i.e., mild hypotonia (n = 7) and Erb's palsy (n = 2). The clinical syndrome attributed to subdural hematoma was most often a subtle clinical problem. The presence of subdural hematoma documented by computed tomography is not necessarily always indicative of birth trauma and may occur as sequelae of an otherwise uncomplicated delivery.

Hematoma, Subdural↗

PubMedDate not supplied

Acute methotrexate neurotoxicity: findings on diffusion-weighted imaging and correlation with clinical outcome.

BACKGROUND AND PURPOSE: Acute lymphocytic leukemia (ALL) is a common malignancy of childhood treated with methotrexate (MTX), which is associated with acute neurotoxicity. We evaluated diffusion-weighted (DW) and conventional MR images in children with ALL and acute MTX-induced neurotoxicity, with clinical correlation. METHODS: Five patients aged 12-15 years underwent fluid-attenuated inversion recovery (FLAIR), T2-weighted fast spin-echo and gradient-echo, T1-weighted gadolinium-enhanced spin-echo, and DW imaging within 24 hours of symptom onset. Records were reviewed for the temporal relationship to MTX administration, strokelike symptoms, and neurologic outcome. RESULTS: Six strokelike events were temporally related to intrathecal MTX given 6-11 days before symptom onset. FLAIR images showed abnormal hyperintensity in the callosal splenium in one patient but were otherwise normal. Diffusion abnormalities were frontoparietal in three events and frontal in one; nonfluent aphasia was seen in all. Bilateral frontoparietal diffusion abnormalities were associated with bilateral upper-extremity weakness, right-sided hemiparesis, or left-sided hemiparesis (one patient each); one patient had mild facial droop. Unilateral precentral subcortical diffusion abnormality was associated with contralateral motor deficit and ipsilateral upper-extremity sensory loss. Strokelike symptoms resolved rapidly and were not associated with other signs of encephalopathy. Subsequent intrathecal MTX administration was not associated with recurrence in four patients. CONCLUSION: Diffusion abnormalities in acute MTX neurotoxicity indicated cerebral dysfunction but not necessarily overt structural injury to the cerebrum. Subsequent demyelination or gliosis could not be predicted on the basis of diffusion abnormalities. A single strokelike episode with diffusion abnormalities should not necessarily prompt modification of potentially curative chemotherapeutic regimens.

Acute Disease↗

PubMedDate not supplied

Diffusion tensor imaging in lissencephaly.

Lissencephaly is a rare brain malformation characterized histologically by arrested neuronal migration such that the brain resembles that of a fetus before 23-24 weeks gestation. We studied a neonate with lissencephaly by using diffusion tensor imaging and suggest the dysplastic densely cellular layer IV is visible as a band of anisotropic diffusion. Fiber tracking showed lack of connectivity between the cortex and deep white matter and an abnormal limbic system.

Brain↗