Purpose
Epidural steroid injections with CT guidance have become a widely used intervention in the treatment of spinal radiculopathy.
CT guided epidural injections may be required at multiple levels and on multiple occasions for maximal therapeutic effect.
The lowest radiation dose in accordance with the ALARA principle should be a primary treatment goal,
taking into account the requirement for accurate needle placement and verification of epidural position,
before injection of therapeutic substances.
Reported radiation doses vary greatly between different institutions for CT guided epidural interventions.
The...
Methods and materials
Study Design: Retrospective case note and image audit of 200 consecutive patients presenting over 2 months with intention to treat by epidural or perineural steroid injection,
irrespective of spinal level,
pathology involved and first time or repeat intervention.
There was one exclusion where the treatment DLP was not recorded.
Radiation dose was collected prospectively.
Technical factors and clinical notes were recorded prospectively.
Technical success was based on review of images demonstrating epidural contrast opacification after CT guided needle placement.
In all cases CT guidance was...
Results
Region
Lowest DLP
Median DLP
Highest DLP
Mean DLP
Cervical (n=41)
0.8
3
14.9
3.79
**Lumbar (n=141)
0.9
4.8
102.4
11.42
SIJ (n=13)
1.2
3.2
26.4
6.06
Thoracic (n=5)
5.4
7
87.9
22.82
Total: Consecutive 200 patients 9.700
** excludes one case where needle placement DLP was combined with a diagnostic scan.
Scanner
Lowest DLP
Median DLP
Highest DLP
Mean DLP
160 slice (n=77)
0.8
2.6
29.4
3.92
**16 slice (n=123)
1.6
5.9
102.4
10.82
** excludes one case where needle placement DLP was combined...
Conclusion
Thin slice multi-level axial scanning with high rotation speed and partial sector reconstruction has a reduced radiation dose compared to published data using pulsed or continuous CT fluoroscopy.
Needle conspicuity is inversely related to slice thickness and scan acquisition time; image noise ultimately increases to obscure needle tip identification as patient size increases,
and for scan factors less than 10 mA or 2mAs.
Modest increases in mA (20-50 mA) can be used to assist final needle tip positioning where body habitus increases quantum mottle and...
Personal information
D.Brand is a Unaccredited Radiology Registrar at Adelaide MRI.
References
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