Lumbosacral spine: Early and delayed MR imaging after administration of an expanded dose of gadopentetate dimeglumine in healthy, asymptomatic subjects

PURPOSE: To determine normal magnetic resonance (MR) imaging enhancement characteristics of the lumbosacral spine after intravenous administration of an expanded dose of gadopentetate dimeglumine. MATERIALS AND METHODS: T1- weighted MR images of the lumbosacral spine were acquired before and after injection of 0.3 mmol/kg gadopentetate dimeglumine in 12 healthy subjects (eight men, four women; age range, 22-57 years). RESULTS: In 10 (91%) of the 11 subjects who completed the investigation, multifocal linear enhancement within the thecal sac that generally extended from the conus to the nerve- root sheaths was demonstrated. In all cases, enhancement was seen in the facet joints and the intervertebral disks parallel to the vertebral endplates. CONCLUSION: After an expanded dose of intravenous gadopentetate dimeglumine, multiple intrathecal and extrathecal structures were enhanced. Recognition of normal enhancement patterns after an expanded gadopentetate dimeglumine dose is important because such enhancement after routine injection of 0.1 mmol/kg gadopentetate dimeglumine is often thought to indicate disease.