Imaging of vascular lesions of the head and neck.

The imaging armamentarium for imaging head and neck vascular lesions and the imaging features of each have been reviewed. Imaging is an indispensable part of the diagnosis and treatment planning of these lesions. The architecture and vascularity of these lesions are keys to their correct diagnosis. High-flow lesions (AVMs and hemangiomas) can be distinguished readily from low-flow lesions (venous malformations and lymphatic malformations) with these techniques, without the need for conventional angiography in the majority of cases. More-over, the architecture of the lesions depicted on imaging studies can lead to a reasonably specific diagnosis. MR imaging is the best tool for this assessment, but complementary information from ultrasound or CT can help arrive at the correct diagnosis when the results of MR imaging are equivocal. Ultrasound can correctly characterize the lesion as high flow or low flow but is limited in its ability to determine the full extent of the lesion. The usefulness of CT is more limited. Application of newer CT techniques (multidetector helical CT with image reconstruction) may increase the role of CT in high-flow lesions, but the greater soft tissue contrast sensitivity of MR imaging remains its strong suit. Conventional angiography is usually reserved for pretherapeutic evaluation.