Clival and Paraclival Lesions: Imaging Features and Differential Diagnosis

A practical radiology review of Clival and Paraclival Lesions: Imaging Features and Differential Diagnosis, focused on imaging findings, differential diagnosis, reporting points, and high-yield teaching pearls.

Anatomy & Physiology Pearls

• Spheno-occipital synchondrosis → fuses late teens–mid-20s ⏳ → incomplete fusion in young = don’t confuse with lytic lesion

Normal clival marrow

• T1 ≥ pons = normal
• T1 < pons = suspect pathology (marrow replacement, edema, tumor)

Marrow grading

• Grade 1: >50% low T1 signal
• Grade 2: 20–50%