MRI provides excellent depiction of the anatomic structures and most pathologic abnormalities within the spine. However, several pathologic states require specific evaluation of the cerebrospinal fluid (CSF) and its function. For example, evaluation of possible CSF obstruction or leak, and cystic masses in the intr
adural and paradural spaces require evaluation of surrounding CSF hemodynamics. Traditionally these questions have been addressed with myelography using iodinated contrast agent and either standard radiography or CT.
In general gadopentatate dimeglumine (GD) has been shown to be a safe contrast agent for MRI. 8,9 Although adverse reactions to intravenous GD administration have been described, the majority of these are transient and minor; typically nausea, vomiting, headache, or dizziness, with an extremely low reported incidence (0.2% to 0.42%). 8,9
While intrathecal injection of GD is not FDA approved, several animal studies have been reported 10-12 and recently Zeng et al 13 published a pilot study describing this technique in humans. In addition, Krumina et al 14 report a series in which 52 patients underwent intrathecal-GD-enhanced MR myelography without significant adverse reaction and excellent depiction of spinal pathology. Using a standard lumbar puncture technique, 0.2 to 1 cc of GD was infused into the subarachnoid space after being mixed with 3 to 5 cc of CSF or normal saline. MRI was then performed, including T1-weighted sequences, resulting in excellent depiction of several pathologic abnormalities such as spinal stenosis, herniated disks, vascular malformations, CSF leaks, and paraspinal masses (figure 1). There were no serious adverse reactions in this series and the incidence of nausea, vomiting, and headache was similar to standard myelography.
The advantage of this procedure is its ability to marry the excellent anatomic resolution of MRI with the functional evaluation of the CSF provided by myelography and therefore combine two commonly utilized imaging procedures into one. While long-term safety data has not been collected, preliminary data suggests that this new imaging technique is safe in humans, with an adverse reaction rate similar to standard myelography. 14 Since a lumbar puncture is a relatively simple and commonly performed procedure, the imaging advantages of this technique are gained with little or no need of added procedure expertise, making this a technique that could be easily integrated into any radiology practice.
In general gadopentatate dimeglumine (GD) has been shown to be a safe contrast agent for MRI. 8,9 Although adverse reactions to intravenous GD administration have been described, the majority of these are transient and minor; typically nausea, vomiting, headache, or dizziness, with an extremely low reported incidence (0.2% to 0.42%). 8,9
While intrathecal injection of GD is not FDA approved, several animal studies have been reported 10-12 and recently Zeng et al 13 published a pilot study describing this technique in humans. In addition, Krumina et al 14 report a series in which 52 patients underwent intrathecal-GD-enhanced MR myelography without significant adverse reaction and excellent depiction of spinal pathology. Using a standard lumbar puncture technique, 0.2 to 1 cc of GD was infused into the subarachnoid space after being mixed with 3 to 5 cc of CSF or normal saline. MRI was then performed, including T1-weighted sequences, resulting in excellent depiction of several pathologic abnormalities such as spinal stenosis, herniated disks, vascular malformations, CSF leaks, and paraspinal masses (figure 1). There were no serious adverse reactions in this series and the incidence of nausea, vomiting, and headache was similar to standard myelography.
The advantage of this procedure is its ability to marry the excellent anatomic resolution of MRI with the functional evaluation of the CSF provided by myelography and therefore combine two commonly utilized imaging procedures into one. While long-term safety data has not been collected, preliminary data suggests that this new imaging technique is safe in humans, with an adverse reaction rate similar to standard myelography. 14 Since a lumbar puncture is a relatively simple and commonly performed procedure, the imaging advantages of this technique are gained with little or no need of added procedure expertise, making this a technique that could be easily integrated into any radiology practice.
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