Best Imaging for Compression Fracture
Plain radiographs (anteroposterior and lateral spine X-rays) should be the initial imaging modality for suspected vertebral compression fractures, followed by MRI when you need to confirm the diagnosis in radiograph-negative cases, determine fracture acuity, or differentiate benign from malignant causes 1, 2.
Initial Imaging Approach
Start with plain radiographs of the affected spinal region. This is the most cost-effective and accessible first-line test 2, 3. However, recognize that radiographs have significant limitations—they miss minimally deforming fractures and cannot reliably distinguish acute from chronic fractures or detect soft tissue pathology 1, 4.
When to Proceed to MRI
MRI is the diagnostic gold standard and should be obtained in these specific scenarios 1, 3, 5:
- Radiographs are negative but clinical suspicion remains high (closed-fist percussion test positive, patient cannot lie supine comfortably) 2, 6, 5
- Need to determine if fracture is acute versus chronic - this is critical for treatment decisions, especially if considering vertebral augmentation 1, 3
- Multiple vertebral deformities present and you need to identify which are symptomatic 1
- Concern for malignancy - look for pedicle involvement, soft tissue mass, or lack of fatty marrow preservation 7, 4, 8
- Neurological deficits on examination 3
- Imaging is >3 months old or symptoms have changed 1
Key MRI Sequences and Findings
Use fluid-sensitive sequences (STIR or fat-saturated T2-weighted imaging) to detect bone marrow edema, which indicates acute fracture 1, 8. Acute osteoporotic fractures show edema with partial preservation of fatty marrow, while malignant fractures typically show complete marrow replacement 8.
Important caveat: Bone marrow edema typically resolves within 1-3 months, so it's not a precise measure of fracture age 1. Contrast is unnecessary for osteoporotic fractures 1.
Advanced Imaging Considerations
CT plus MRI combined offers superior diagnostic accuracy (higher sensitivity and specificity than either alone) for differentiating benign from malignant fractures 7. Consider CT when:
- MRI is contraindicated or unavailable 3
- You need better cortical bone detail
- Sequential radiographs can serve as an alternative reference standard if both MRI and CT are unavailable 5
SPECT/CT shows 63-80% agreement with MRI for detecting acute fractures and may be useful in complicated cases with multiple collapsed vertebrae of different ages, though this is typically based on institutional preference 1.
FDG-PET/CT is reserved for suspected vertebral osteomyelitis presenting as compression fracture—consider this when you see severe pain, persistent fever, elevated inflammatory markers, or bacteremia without another source 1.
Clinical Examination to Guide Imaging
Before ordering advanced imaging, perform the closed-fist percussion test (sensitivity 87.5%, specificity 90%) and assess whether the patient can lie supine comfortably (sensitivity 81%, specificity 93%) 6, 5. A positive closed-fist percussion test combined with sitting radiographs increases the probability of acute VCF from 22% to 97% 5.
Common Pitfalls
- Don't rely solely on radiographs to exclude compression fractures—they miss minimally deforming fractures
- Don't assume bone marrow edema on MRI means the fracture is definitely acute (can persist up to 3 months)
- Don't order contrast-enhanced MRI for routine osteoporotic fractures—it adds no diagnostic value 1
- Don't forget that multiple "hot spots" on bone scan should be interpreted cautiously as they may not all represent acute fractures 1