However, the broader use of CT has also raised concerns regarding radiation exposure for patients as well as for the performing interventionalists 16, 17, 18, 19, 20, 21. Due to these advantages, CT has been used with increased frequency for pain-relieving injections at the spine 15. Furthermore, interventional procedures at the spine under CT guidance afford the interventionalist several advantages over conventional fluoroscopic methods, as the interventionalist has a direct visualization of the needle tip to target soft tissues during the whole procedure as well as a superior contrast resolution and an improved ability to navigate in case of difficult anatomical situations, such as severe osseous stenosis 14. Compared to non-navigated approaches, using interventional CT scanning has shown not only to improve safety as well as precision and pain reduction, but also to reduce the overall treatment duration for periradicular infiltrations 12, 13. Specifically, multi-detector CT (MDCT) is often used, allowing for initial procedure planning and subsequent surveillance of the procedure.
As conventional fluoroscopy is still the standard modality in clinical routine, cross-sectional imaging modalities like computed tomography (CT) are receiving more and more acceptance in the interventional routine and are therefore well evaluated in case of safety, technical nuances, and radiation dose parameters. The procedure of a periradicular infiltration is commonly performed with image guidance to guarantee a precise navigation with respect to the individual anatomy in the area of intervention 11. Furthermore, periradicular infiltrations have been implemented as reliable methods to guide pain management, especially among patients in whom conservative approaches such as drug treatment have been exhausted 9, 10. Therefore, these procedures are among the most frequently performed exams in daily neuroradiological routine 4, 5, 6, 7, 8. Furthermore, periradicular infiltrations can be a good add-on tool to diagnose the distinct site causing symptoms (diagnostic periradicular infiltrations) 3. Periradicular infiltrations are well known to be an effective symptomatic treatment performed in patients with radiculopathy-associated pain syndromes (therapeutic periradicular infiltrations)-especially in patients with underlying disc prolapse, one of the most frequent causes of radiculopathy 1, 2. 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. 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). This resulted in high confidence for intervention planning as well as periprocedural intervention guidance for both SD and LD scans. The dose length product (DLP) was statistically significantly lower for LD scans (6.75 ± 6.43 mGy*cm vs. Furthermore, noise in imaging data was quantitatively measured by the standard deviation (StDev) of muscle tissue. 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). The SD cases were matched to the LD cases considering sex, age, level of infiltration, presence of spinal instrumentation, and body diameter. 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 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.
Periradicular infiltrations are frequently performed in daily neuroradiological routine and are often guided by multi-detector computed tomography (MDCT), thus leading to radiation exposure.