Hybrid imaging: A complementary effect on head and neck oncology

It is well known that cross-sectional anatomical imaging techniques such as ultrasound, computed tomography (CT), magnetic resonance imaging (MRI) etc. have important roles in non-invasive diagnosis and in tumour treatment strategies. Likewise, nuclear medicine procedures such as positron emission tomography (PET) and single photon emission computerized tomography (SPECT) are unparalleled in their ability to assess information about metabolic function. Despite their advantages over conventional imaging, they have their own limitations in oncologic imaging. These limitations can be overcome by combining anatomical and functional imaging techniques. These techniques have different working principles and consequently complement each other with respect to the information obtained. The combination (fusion) of two imaging techniques has been developed in recent years, defining the so-called “hybrid techniques’’ or “fusion imaging”. Combinations of anatomical imaging techniques (ultrasound with CT or MR imaging), as well as associations between anatomical (CT or MR imaging) and molecular (SPECT or PET) imaging modalities are currently being used in clinical practice. This paper highlights the fusion of various imaging modalities and their applications in the arena of head and neck cancers.