MRI Requirements for Thoracic Spine Kyphoplasty
For thoracic spine kyphoplasty, a non-contrast MRI is sufficient for routine osteoporotic compression fractures, but contrast-enhanced MRI (without and with IV contrast) is required when infection or neoplasm is suspected.
Standard Imaging Protocol for Kyphoplasty Planning
Non-Contrast MRI is Usually Appropriate
MRI thoracic spine without IV contrast is the primary imaging modality for kyphoplasty planning in straightforward osteoporotic compression fractures, as it identifies marrow edema to determine fracture acuity, assesses canal compromise, detects cord signal abnormality, and characterizes marrow-replacing lesions 1.
Non-contrast MRI is particularly valuable because the STIR (short tau inversion recovery) sequences are highly sensitive for detecting vertebral edema from fresh fractures or micro-fractures, which has critical therapeutic relevance in differentiating acute from chronic vertebral deformities 2.
A prospective study demonstrated that preoperative MRI changed the therapeutic plan in 57% (16/28) of kyphoplasty patients—identifying additional acute levels requiring treatment, excluding old fractures from intervention, and detecting incidental pathology including renal carcinoma and aortic aneurysm 2.
When to Add Contrast Enhancement
MRI thoracic spine without and with IV contrast becomes necessary when there is clinical concern for infection or neoplasm, as postcontrast sequences are significantly more sensitive for identifying thoracic spinal infection and its complications, assessing small marrow-replacing lesions, and identifying intradural disease 1.
The addition of IV contrast is critical in patients with red flags including: fever, recent infection, immunosuppression, IV drug use, history of cancer, unexplained weight loss, constant pain unrelieved by rest, or age >65 years with suspicion of malignancy 1, 3, 4.
For suspected spine infection, MRI without and with IV contrast has 96% sensitivity and 94% specificity, with contrast helping to identify abnormal epidural fluid collections, define their size and extent, and characterize enhancement patterns that distinguish infection from expected postoperative changes 1.
Complementary CT Imaging
CT thoracic spine without IV contrast serves as a complementary study, not a replacement for MRI, as it better depicts osseous detail for assessing pedicle anatomy, vertebral body integrity, and posterior cortical compromise but misses marrow pathology and soft tissue abnormalities 1.
CT is particularly useful for presurgical planning in technically challenging cases (T4-T8 levels with slender pedicles) where extrapedicular or transcostovertebral approaches may be required, and for identifying posterior wall involvement with retropulsion 5, 6, 7.
CT with IV contrast alone has no role in kyphoplasty planning, as there is no literature supporting its use for initial assessment 1.
Critical Clinical Pitfalls to Avoid
Do not rely on plain radiographs or CT alone to determine which levels require treatment, as MRI is essential for identifying acute versus chronic fractures through marrow edema patterns—this distinction directly impacts which levels should undergo kyphoplasty 2.
Do not proceed with kyphoplasty based solely on radiographic vertebral height loss without MRI confirmation of fracture acuity, as the study by 2 showed that 5 patients had lesions that appeared acute on CT but were actually old fractures on MRI, avoiding unnecessary procedures.
Do not order MRI with IV contrast only (without the non-contrast sequences), as precontrast images are required for comparison to confirm areas of suspected abnormality and properly evaluate enhancement patterns 1.
Do not delay MRI if new neurologic deficits or myelopathy signs emerge (spasticity, hyperreflexia, gait disturbance, bladder dysfunction), as this requires immediate evaluation for cord compression or epidural abscess 1, 3, 8.
Algorithmic Approach
For routine osteoporotic compression fracture kyphoplasty candidates: Order MRI thoracic spine without IV contrast as the primary study 1, 2.
Add contrast (MRI without and with IV contrast) if any red flags present: suspected infection (fever, recent infection, immunosuppression, IV drug use), suspected neoplasm (history of cancer, unexplained weight loss, age >65 with concerning features), or posterior wall involvement with neurologic symptoms 1.
Add CT thoracic spine without IV contrast for presurgical planning when treating mid-to-high thoracic levels (T4-T8) or when posterior cortical compromise is identified on MRI, to better delineate osseous anatomy for extrapedicular approaches 1, 5, 7.
Correlate MRI findings with clinical presentation to finalize the surgical plan, as MRI may identify additional acute levels requiring treatment or exclude chronic deformities from intervention 2.