RETURN TO ABSTRACT LISTING


Background
Focal T1 hypointense signal within the spinal bone marrow is not an uncommon finding. Multiple benign and malignant lesions can overlap in demonstrating T1 hypointensity, which can cause a diagnostic dilemma. A common approach to these lesions is often asking for more imaging investigation including different modalities depending on clinical setting and/or postcontrast T1-weighted images, which does not necessarily lead to definitive characterization and thus, no follow-up or treatment planning. The objective of this educational exhibit is to offer a case-based imaging review of various conditions displaying T1 hypointense signals attributed to either benign or malignant etiologies.

Educational Goals / Teaching Points
• Useful imaging tips to differentiate benign versus malignant etiologies including location (vertebral body, endplate involvement, posterior element involvement), morphology (ill-defined, well defined, geographic), diffuse versus focal, versus multifocal pattern, and correlate findings on other sequences or modalities. • Role of demographics, clinical history, and associated medical conditions. • Most appropriate and efficient follow-up strategies.

Key Anatomic/Physiologic Issues and Imaging Findings/Techniques
T1-weighted MRI signal intensity of focal spinal lesions will be reviewed. The entities that will be covered include nonmalignant etiologies such as atypical hemangioma, infection, degenerative changes, trauma, metabolic-related etiologies, and malignant etiologies such as metastatic lesions, multiple myeloma, and leukemia.

Conclusion
The diagnosis of spinal T1 focal hypointense lesions is challenging. To confidently characterize spine focal T1 hypointense lesions, it can be helpful to combine features such as location, shape, and solitary versus multifocal with other imaging sequence characteristics, clinical history, and demographics.