Cross-sectional imaging of the oesophagus using CT and PET/techniques

Abstract

Multidetector computed tomograpy (MDCT) is the most frequent imaging modality in the diagnostic workup of oncologic diseases of the abdomen. Although CT has been used for preoperative evaluation of oesophageal cancer, the major role of CT has been the depiction of lymph nodes, distant metastases, or both, rather than the evaluation of the local status of oesophageal cancer. The sensitivity of conventional or helical CT protocols for the localisation of oesophageal cancer, especially early-stage cancer, is not satisfactory. This may be attributed to the fact that conventional or helical CT cannot offer optimal conspicuity of oesophageal cancers against the normal oesophageal wall, or because the oesophagus is too long to be imaged entirely using thin slices during a single breath hold on conventional or helical CT scans, especially in the absence of lumen distension, since inadequately distended hollow viscera on CT may hide small lesions and may even mimic pseudolesions. Thus, optimal distension of the oesophagus and stomach is important to overcome this limitation. The combination of the MDCT technique with thin-slice sections and the possibility to obtain high-quality, isotropic, multiplanar reconstructions and the water filling, or the application of gas-producing effervescent granules to distend the stomach and the oesophagus, are important factors that may increase the efficacy of CT for local staging of oesophageal cancer. Using this technique is not only useful for a complete preoperative staging of oesophageal malignancies according to TNM classification but also clinically relevant for evaluation of a broad spectrum of inflammatory and traumatic diseases. The introduction of FDG PET in combination with MDCT resulted in further optimizing the diagnostic workup of oesophageal cancer and other malignant diseases rendering this technique to be the modality of choice depending on its availability. In this book chapter we review the value of the hydro-MDCT technique and hydro-FDG-PET-CT technique in the diagnostic workup of oesophageal diseases.