In a comparison study between MRI and ultrasound for predicting cerebral palsy in very low birth weight (VLBW) infants, researchers from Stanford University Medical Center in Palo Alto, CA, found that MRI is superior to ultrasound in both sensitivity and positive predictive value for cerebral palsy, whereas both ultrasound and MRI showed relatively high specificity and negative predictive value.
Based on the results of the study, the authors recommend that ultrasound screening be performed for all VLBW infants, including at near-term. If ultrasound is predictive of cerebral palsy, then MRI may not be needed. If ultrasound is not predictive of cerebral palsy, MRI with diffusion tensor imaging should be performed. Pat Barnes, MD, one of the authors of the study, explained, "Since ultrasound is more readily available (including its portability in the intensive care setting) and less expensive, it is used first. If it shows findings predictive of cerebral palsy, then there is probably no need for MRI. If conventional MRI is needed, then diffusion tensor imaging is done at that time and would be important to do especially if the conventional MRI is negative or nonspecific."
According to the authors, other indications could also influence the choice of imaging technique used. "For managing the acutely ill preterm newborn, especially for intraventricular hemorrhage and posthemorrhagic hydrocephalus, ultrasound is indicated. If there are other or additional concerns (for example, white matter injury), then MRI with diffusion tensor imaging is clearly superior," said Dr. Barnes.
The researchers are currently investigating the role of MR spectroscopy in predicting cerebral palsy in VLBW infants. According to Dr. Barnes, "We are now just collecting that data. The potential is that MR spectroscopy may detect metabolic changes when no macrostructural changes (by ultrasound or conventional MRI) or microstructural changes (by diffusion tensor imaging) are present."
The study will be presented on May 3 during the American Roentgen Ray Society Annual Meeting in Miami Beach, FL.
Source: Eurekalert & othersLast reviewed: By John M. Grohol, Psy.D. on 21 Feb 2009
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