RESUMEN
<p><b>OBJECTIVE</b>To determine the imaging features of magnetic resonance imaging (MRI) and 2D time of flight (TOF) MR angiography (MRA) and study the value in the differential diagnosis and surgical planning for carotid space tumors.</p><p><b>METHODS</b>Twenty-six patients with suspected pulsatile carotid space mass were imaged by MRI and 2D TOF MRA from 1996 to 2003. Its characteristic findings were analyzed for lesion shape, margin, signal intensity, angle of common carotid bifurcation, and the relationship between the great vessels and carotid space mass.</p><p><b>RESULTS</b>Of the 26 patients, 22 were verified histopathologically, including 15 carotid body tumors (1 patient had bilateral carotid body tumors), 4 carotid artery aneurysms, 3 schwannomas, and 1 metastatic carcinoma. The rest four patients had clinical pseudomasses proved by MRI and MRA as considerable dilated or tortuous carotid artery as compared with the contralateral one. Combined MRI and MRA assessment of carotid body tumors and carotid artery aneurysm yielded an accuracy of 100%. It was also revealed that the anatomy shown on the MRI and axial MRA source images was consistent with that found by surgery.</p><p><b>CONCLUSION</b>MRI in combination with MRA is considered as non-invasive imaging technique for the evaluation of carotid space tumor showing superiority to other modalities in the differential diagnosis between vascular versus non-vascular tumours. This method may take the place of traumatic carotid angiography.</p>