Dual Energy CT Myelography after Lumbar Osteosynthesis

Abstract

Purpose: The purpose of this study was to evaluate the benefits of CT myelography in the DE technique in patients with lumbar osteosynthesis.

Materials and Methods: In 30 patients a DE-CT scan of the spine with tube voltages of 80 kV and 140 kV was performed and a virtual monochromatic series of 120 kV was generated after intrathecal contrast injection. The impact of metal artifacts on the spinal canal and the spinal foramina was evaluated. The visualization of nerve roots was compared between a VRT series of the dural sac and conventional myelography.

Results: With tube voltages of 140 kV, the artifacts were least pronounced. As no overlay disturbance was present, VRT visualization of the nerve roots was more reliable than conventional myelography.

Conclusion: In patients after osteosynthesis, CT in the DE technique provides minimal artifact disturbance using a tube voltage of 140 kV. “Virtual myelography” seems to be superior to conventional myelography for the evaluation of nerve roots. This could reduce additional conventional radiography, may shorten the entire examination and radiation time and diminish unnecessary painful movements for the patient.

Key Points: DE-CT myelography is a promising method in patients after spinal osteosynthesis.

Citation Format:

• Grams AE, Sender J, Moritz R et al. Dual Energy CT Myelography after Lumbar Osteosynthesis. Fortschr Röntgenstr 2014; 186: 670 – 674

Zusammenfassung

Ziel: Das Ziel dieser Studie war es den Nutzen der CT-Myelografie in DE-Technik bei Patienten nach lumbaler Osteosynthese zu untersuchen.

Material und Methoden: Bei 30 Patienten wurde nach intrathekaler Gabe von Kontrastmittel eine DE-CT-Untersuchung der Lendenwirbelsäule mit Röhrenspannungen von 80 kV und 140 kV durchgeführt und eine virtuelle, monochromatische Serie von 120 kV generiert. Es wurde der Einfluss von Metallartefakten auf den Spinalkanal und die Neuroforamina beurteilt und die Darstellung der Wurzeltaschen zwischen einer VRT-Serie und konventionellen Röntgenaufnahmen verglichen.

Ergebnisse: Mit Röhrenspannungen von 140 kV waren die Artefakte am wenigsten stark ausgeprägt. Mit der VRT-Darstellung war es im Gegensatz zu den konventionellen Aufnahmen möglich die Wurzeltaschen ohne Überlagerung durch das Osteosynthesematerial darzustellen.

Schlussfolgerung: Bei Patienten mit lumbaler Osteosynthese erhält man im Rahmen der DE-CT mit 140 kV einen nur minimal durch Artefakte überlagerten Datensatz. Die „virtuelle Myelografie“ mittels VRT-Rekonstruktionen scheint vorteilhaft gegenüber der konventionellen Myelografie bezüglich der Darstellung der spinalen Wurzeltaschen. Dies könnte zusätzliche konventionelle Aufnahmen und somit die Untersuchungs- und Durchleuchtungszeit reduzieren sowie unnötige, schmerzhafte Bewegungen für den Patienten vermeiden.

Kernaussage: Die DE-CT-Myelografie stellt eine vielversprechende Methode bei Patienten nach spinaler Osteosynthese dar.

Key words

spine - CT - surgery

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