In this prospective study, we will recruit newly diagnosed esophageal cancer patients and perform MR/PET before and after chemoradiation therapy. In MR, new image sequences will be added to the conventional sequences, such as high resolution image, DWI, DCE, cine imaging.

Total 80 patients will be recruited and followed after treatment complete for at least two years. We will compare the staging accuracy of MR/PET and PET/CT, and also analyze parameters that are predictive of disease recurrence and patient survival.

Inclusion Criteria:

1. newly diagnosed esophageal cancer patient
2. age older than 20 years

Exclusion Criteria:

1. For the safety reason, patients with the following conditions are contraindicated to enter magnetic resonance imaging (MRI) machine due to the high magnetic field, including: cardiac pacemaker, metallic artificial valve, intracranial and mediastinal vascular clips, cardiac defibrillator, nerve stimulator, implanted drug deliver system, metallic foreign body in the eye globe, cochlear implant, metallic fragments in the dangerous body part, Swan-Ganz catheter, and other metallic implants within 8 weeks: such as cardiac valve, stent, coil, filter, and clips.
2. patient who will receive endoscopic local therapy alone
3. unable to finish the standard surgical or radiation treatment
4. history of surgery or radiotherapy to the mediastinum
5. renal insufficiency, contraindication to MR imaging and contrast injection patient who have the severe allergic reaction the Gadollium contrast agent
6. patient who have the claustrophobic symptoms are also not suitable for this MR examination
7. pregnancy or lactating women

In this prospective study, we will recruit newly diagnosed esophageal cancer patients and perform MR/PET before and after chemoradiation therapy.Total 80 patients will be recruited and followed after treatment complete for at least two years.