This poster was previously presented in German at the Deutscher Röntgenkongress 2012 (Hamburg)
Type:
Educational Exhibit
Keywords:
Interventional non-vascular, Musculoskeletal spine, CT, MR, Ablation procedures, Education and training
Authors:
C. Rehnitz, S. Sprengel, M. Weber; Heidelberg/DE
DOI:
10.1594/ecr2013/C-2182
Imaging findings OR Procedure details
Standard technique: Figs 1-3
• Spinal CT-guided RFA analog to RFA in peripheral OO without specific protection techniques
• Prerequisites: ØIntact cortical bone as an isolator between OO and central cord/spinal nerve.
ØDistance OO/critical nerval structure
> 1 cm (Ref 4)
• RFA principle: The RF-elektrode has an active tip=> conducts a current=> local ion movement=> friction heat=> ablation (coagulation necrosis)
•: Step by step: optimal access planing (using 3D multiplanar reconstructions).
Bone puncture (e.g..
Bonopty® ,
AprioMed,
Sweden).
Placement of the active tip (we recommend 0.7 or 1.0 cm) into the nidus.
Ablation.
• Ablation time: Min.
4 min at 90 C.
We recommend: >6 min => lower relapse rates (Ref 5)
Advanced technique: Figs 4-15
- Ablation of osteoblastoma: Figs 4-7
Prediction of the ablation size:
Ø length of the tip: ~ 0,5 – 2 cmØ Die maximal length of the ablation area can be predicted with the following equation11. long axis of the ablation zone = 2 x length of the active tip
2. transversal axis = 2/3 of the length axis
=>oval shape of the ablation area
- Ablation in proximity to critical structures: Figs 8-11 (direct nerve contact); Figs 12-15 (protection of the spinal cord)
- Typical MR imaging patterns before and after RFA: Figs 16-21