Figure 4. Thoracic spine T2-weighted MRI, right parasagittal view. The Pancoast tumor (P) is evident as a paraspinal mass anterior to and invading the upper-to-midthoracic spine. An abnormal hyperintense signal is seen in the thoracic vertebrae and/or ribs from T1 (upper arrow) through T6 (lower arrow), suggestive of tumor infiltration. The craniocaudal dimension of the mass is 8.7 centimeters (measurement not shown).