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Vascular suppression technique in MRI using Gd-DTPA: improving image quality of MR myelography.

PURPOSE
To delete signals of juxta-thecal venous structures on MR myelograms, we evaluated the potential of Gd-DTPA as a negative contrast material in experiments and actual MR myelograms.


METHOD
We measured the signals of Gd-DTPA solutions of various concentrations on T2-weighted turbo-SE and turbo-STIR images. The experiments revealed that 0.83 mmol/L Gd-DTPA worked as a negative contrast material in turbo-STIR. Subsequently, we obtained turbo-STIR myelograms of 31 patients who complained of lumbago or sciatica before and after intravenous administration of 0.15 mmol/kg Gd-DTPA, which was presumed to provide the optimal plasma density in vivo.


RESULTS
On postcontrast MR myelograms, the venous signals around the thecal sac decreased remarkably in almost all the cases as compared with precontrast images. In these cases, the nerve roots could be observed clearly.


CONCLUSION
Gd-DTPA can work as a negative contrast material in turbo-STIR sequences. This characteristic should be used to improve the image quality of MR myelography using turbo-STIR.