Periradicular infiltration of the lumbar spine: is iterative reconstruction software necessary to establish ultra-low-dose protocols? A quantitative and qualitative approach

Low-dose multi-detector computed tomography for periradicular infiltrations at the cervical and lumbar spine

Periradicular infiltrations are frequently performed in daily neuroradiological routine and are often guided by multi-detector computed tomography (MDCT), thus leading to radiation exposure. The purpose of this study was to evaluate MDCT with low dose (LD) and model-based iterative reconstruction for image-guided periradicular infiltrations at the cervical and lumbosacral spine. We retrospectively analyzed 204 MDCT scans acquired for the purpose of cervical or lumbosacral periradicular interventions, which were either derived from scanning with standard dose (SD; 40 mA and 120 kVp) or LD (20–30 mA and 120 kVp) using a 128-slice MDCT scanner. The SD cases were matched to the LD cases considering sex, age, level of infiltration, presence of spinal instrumentation, and body diameter. All images were reconstructed using model-based iterative image reconstruction and were evaluated by two readers (R1 and R2) using 5- or 3-point Likert scales (score of 1 reflects the best value per category). Furthermore, noise in imaging data was quantitatively measured by the standard deviation (StDev) of muscle tissue. The dose length product (DLP) was statistically significantly lower for LD scans (6.75 ± 6.43 mGy*cm vs. 10.16 ± 7.70 mGy*cm; p < 0.01; reduction of 33.5%). Image noise was comparable between LD and SD scans (13.13 ± 3.66 HU vs. 13.37 ± 4.08 HU; p = 0.85). Overall image quality was scored as good to very good with only minimal artifacts according to both readers, and determination of the nerve root was possible in almost all patients (LD vs. SD: p > 0.05 for all items). This resulted in high confidence for intervention planning as well as periprocedural intervention guidance for both SD and LD scans. The inter-reader agreement was at least substantial (weighted Cohen’s κ ≥ 0.62), except for confidence in intervention planning for LD scans (κ = 0.49). In conclusion, considerable dose reduction for planning and performing periradicular infiltrations with MDCT using model-based iterative image reconstruction is feasible and can be performed without clinically relevant drawbacks regarding image quality or confidence for planning.

O2-O3 chemodiscolysis: How much, how long? Retrospective outcome evaluation of different treatment sessions in partially-responder patients

PURPOSE

To retrospectively evaluate the clinical and instrumental outcome of different treatment sessions of oxygen-ozone (O₂-O₃) chemodiscolysis in patients with lumbar disc herniation.

METHODS

We evaluated 73 patients partially responders to a single session of oxygen-ozone (O₂-O₃) chemodiscolysis and submitted to multiple injections sessions. All patients completed a pre- and post-treatment clinical (VAS and modified McNab score) and instrumental MRI follow-up. Imaging evaluation included assessment of intervertebral disc area (IDA). Pre- and post-treatment differences were compared to evaluate differences in variation between groups. Correlation analysis was used to evaluate the relationship between morphological and clinical parameters.

RESULTS

Based on the type and number of treatments performed, patients were divided into three groups: Group A) patients submitted to an additional periradicular anaesthetic/steroid injection; Group B) patients submitted to an additional session of intradiscal O₂-O₃ injection; Group C) patients submitted to two further sessions of intradiscal O₂-O₃ injection.The results showed an improvement of pain scores in all groups, and a smaller disc area change in group B. Comparing the differences between pre- and post-treatment features among the three different groups of patients, we did not find any statistically significant difference. Correlation analysis did not show any statistically significant correlation between the morphological changes of the intervertebral disc and the clinical output scores.

CONCLUSIONS

In our retrospective observation of partially responder patients, multiple intradiscal ozone injections were not associated with a higher disc shrinkage nor superior clinical outcome compared to a single intradiscal O₂-O₃ application with an additional periradicular injection session.