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Biomedical subjects

Anne M Hubbard

Publications and source records attributed to Anne M Hubbard.

4 recordsLinked to original sources

Ultrafast fetal MRI and prenatal diagnosis.

Improvements in magnetic resonance imaging (MRI) technology continue to provide faster scan times and higher resolution increasing the applications for fetal imaging. MRI is an adjunct to good prenatal ultrasound scan (US). It provides significant additional information that improves diagnostic accuracy in evaluation of the fetal brain, spine, neck, chest, abdomen, and urinary tract. MRI provides important anatomic information that helps in planning delivery and surgical procedures.

Abdomen↗

Evaluation of iron overload by single voxel MRS measurement of liver T2.

PURPOSE: To overcome the difficulty of poor signal-to-noise ratio of magnetic resonance imaging (MRI) in evaluating heavy iron overload by using a single voxel magnetic resonance spectroscopy (MRS) technique. MATERIALS AND METHODS: A single voxel STEAM pulse sequence with a minimum TE of 1.5 msec and a sampling volume of 36.6 cm(3) was developed and applied to 1/T2 measurement of the liver in 14 patients with thalassemia whose liver iron concentration was determined through biopsy. RESULTS: The iron level ranged from 0.23 to 37.15 mg Fe/g dry tissue with a median value of 18.06. In all cases, strong MR signals were obtained. 1/T2 was strongly correlated with the liver iron concentration (r = 0.95, P < 0.00005). CONCLUSION: The single voxel MRS measurement of T2 in liver iron overload overcomes the difficulty of lack of detectable signals in conventional MRI when the iron level is high. There is an excellent correlation between the iron level and 1/T2.

Adolescent↗

Fetal imaging.

Presently, MRI is an adjunct to prenatal sonography. It provides information that can aid in the diagnosis of fetal anomalies, affect prenatal counseling and management of the pregnancy, and guide prenatal intervention and delivery planning. With further advances in technology, particularly shorter scan times and better image resolution, the applications for fetal imaging are likely to increase.

Congenital Abnormalities↗

A new look at myelomeningoceles: functional level, vertebral level, shunting, and the implications for fetal intervention.

OBJECTIVE: Previous reports have suggested that 80% to 85% of patients who have a myelomeningocele (MMC) and undergo surgical repair after birth develop hydrocephalus and require the placement of a ventricular shunt. However, the rate of shunting as a function of spinal level is not well established. We sought to determine the distribution of postnatally repaired MMC lesions as characterized by both functional and radiologic assessment, as well as the incidence of shunting when patients were categorized according to these 2 methods. METHODS: A retrospective chart review of 297 patients who were born with open MMCs and followed in the spina bifida clinic at the Children's Hospital of Philadelphia was performed. The presence or absence of a shunt was determined for each patient. Functional spinal level was determined by the best-recorded neurologic examination and vertebral level by spine radiographs. RESULTS: The overall rate of ventricular shunting was 81%. The level of the lesion significantly affected the incidence of shunting, with more cephalad lesions correlating with higher rates. This was true both for functional and radiologic categorizations. A significantly higher shunt rate was found among patients with sacral lesions when categorized by radiologic rather than functional criteria. In 86% of patients, the functional level was found to be equal to or higher (worse) than the radiologic level. CONCLUSIONS: This study describes the natural history of ventricular shunting in MMC patients with relation to both radiologic and functional criteria. Fetal MMC closure is being performed in some centers in an attempt to decrease the incidence of shunting and to improve leg function in selected patients. The present data may serve as a comparison group and aid in the design and analysis of a prospective trial to assess the efficacy of this new procedure.

Cerebrospinal Fluid Shunts↗