The contrast-enhanced CT scan in the diagnosis of isodense subdural hematoma.

The authors review 29 cases of surgically-proven isodense subdural hematomas examined by non-contrast and contrast-enhanced computerized tomography scans. Three types of isodense collections were noted: homogeneous isodense collections, mixed-density collections, and gravitational layering within subdural collections. Contrast enhancement within the cerebral cortex, cortical vessels, and subdural membranes led to the correct diagnosis in each case. Contrast-enhanced scans are essential for the evaluation of isodense subdural hematomas.