Ultrasound guided versus CT-controlled pararadicular injections in the lumbar spine: a prospective randomized clinical trial

Abstract

Background and purpose: Injection therapies play a major role in the treatment of lower back pain and are to date performed mainly under CT- or fluoroscopic guidance. We conducted this study to evaluate the accuracy, time savings, radiation doses, and pain relief of US-guided pararadicular injections versus CT-controlled interventions in the lumbar spine in a prospective randomized clinical trial.

Materials and methods: Forty adult patients were consecutively enrolled and assigned to a US or CT group. US-guided pararadicular injections were performed on a standard US device by using a broadband curved-array transducer (9-4 or 5-1 MHz). In the in-plane technique, the needle was advanced through the respective segmental intertransverse ligament. The needle tip position was verified by CT. The CT-guided approaches were performed under standardized procedures by using the CT-positioning laser function.

Results: The accuracy of US-guided interventions was 90%. The mean time to final needle placement in the US group was 4.0 ± 1.8 minutes, and in the CT group, 7.6 ± 2.1 minutes. The mean radiation doses, including CT confirmation for study purposes only, were 20.3 ± 9.0 mGy cm for the US group and 42.6 ± 36.1 mGy cm for the CT group. Both groups showed the same significant pain relief (P < .05) without relevant "intermethodic" differences of pain relief (P > .05).

Conclusions: US-guided pararadicular injections show a therapeutic effect similar to that in the time-consuming, expensive, ionizing CT or fluoroscopically guided pararadicular injections and result in a significant reduction of procedure time expenditure and avoidance of radiation.

Fig 1.

US sagittal paravertebral scan at the PAP: pararadicular injection at the level L2-L3 (left image) and annotated scan (right image). The thick line indicates the transverse processes; dotted lines, intertransverse ligaments; arrow, injection needle.

Fig 2.

Boxplot of median values and SDs of pain-intensity levels indicated by the patients on the VAS. The first column of each group represents the preinterventional evaluation (VAS1), and the second column of each group shows the postinterventional pain course after 1 month (VAS2). CT indicates CT-guided interventions; US, ultrasound-guided interventions.

Fig 3.

Boxplot of median values and SDs of procedure time. CT indicates CT-guided interventions; US, ultrasound-guided interventions.