MRI Thoracic Spine Without IV Contrast for Soft Tissue Mass Evaluation

Clinical Presentation and Diagnosis

The American College of Radiology recommends MRI of the thoracic spine without IV contrast as the best initial imaging modality for a patient with a palpable soft lump over the thoracic central spine causing wrist numbness when pressure is applied, suggesting a soft tissue mass with potential neural compression 1, 2
A palpable soft lump is likely to be a soft tissue pathology, such as a lipoma, ganglion, neurofibroma, or other mass, according to the American College of Radiology 1
Positional wrist numbness suggests nerve compression, likely thoracic nerve root or sympathetic chain involvement causing referred symptoms, as noted by the American College of Radiology 3

MRI without IV contrast provides superior soft tissue resolution to characterize the mass, evaluates for nerve root compression, and assesses the spinal cord for any compression or signal abnormality, as recommended by the American College of Radiology 1, 2, 4
MRI without IV contrast is the single best modality for evaluating soft tissue masses in the thoracic spine, allowing for complete preoperative surgical planning if intervention is needed, according to the American College of Radiology 1, 2

The American College of Radiology suggests that MRI without and with IV contrast should be obtained instead if there is clinical suspicion for infection or neoplasm, such as fever, recent infection, immunosuppression, IV drug use, history of cancer, unexplained weight loss, constant pain, or age >65 1, 2, 5

CT without contrast is complementary but not primary, as it depicts osseous detail well but misses soft tissue pathology, and is appropriate only when MRI is contraindicated or for presurgical bony anatomy assessment, as noted by the American College of Radiology 2
Plain radiographs have no role in evaluating soft tissue masses in the thoracic spine, as they cannot characterize soft tissue masses and would miss the pathology entirely, according to the American College of Radiology 1, 6

The American College of Radiology recommends not delaying MRI if myelopathy signs develop, such as spasticity, hyperreflexia, gait disturbance, or bladder dysfunction, as this requires immediate evaluation 2, 3
The American College of Radiology advises against ordering CT with IV contrast alone, as there is no literature supporting this for soft tissue mass evaluation 2
The American College of Radiology suggests assessing for red flags, including progressive neurologic deficits, which would escalate urgency 1, 3