The value of power Doppler ultrasonography in the differential diagnosis of intracranial extraaxial fluid collections.

PURPOSE The aim of this study was to determine the value of power Doppler ultrasonography in the differential diagnosis of intracranial extraaxial fluid collections in enlarged subarachnoid spaces. MATERIALS AND METHODS The study included 11 patients referred to our hospital's radiology department between April 2001 and February 2002 who were determined to have intracranial extraaxial effusion based on the results of cranial ultrasonography (US), computed tomography (CT), and magnetic resonance imaging (MRI). Transfontanel examinations of the enlarged subarachnoid spaces, including cortical vascular structures, with a 4-7 MHz linear probe were used to make differential diagnoses of extracerebral fluid collections. RESULTS In 8 of the 11 patients, the diagnosis was an enlarged benign extraaxial subarachnoid space. In one case, the differentiation of mirror artifacts of an epidural hematoma from a cephalhematoma was constructed by the cortical vascular structure with power Doppler US. In 2 cases, subdural hematomas were seen. CONCLUSION Power Doppler US is a safe and complementary method to cranial US that is useful in the differential diagnosis of extraaxial intracranial fluid.