At the end of November 2014, after installation and commissioning, our advanced PET/CT began to be officially put into use and patients were examined. One of the patients, Mr. Liu, 64 years old, was found to have right lower lung occupancy in the previous physical examination, and underwent thoracoscopic thoracotomy + wedge resection of right lower lung mass in our thoracic surgery department, and the postoperative pathology suggests hypo-differentiated squamous carcinoma, and he recovered well after the surgery. In order to evaluate the surgical effect, he came to our department for PET/CT examination, which showed good resection of the lung lesion (Figure 1). However, PET/CT at the patient’s rectum showed a mass with abnormally active metabolism (Figure 2), suggesting a malignant tumor of the rectum, but no enlarged lymph node shadow with abnormal metabolism was seen in the pelvis. After further colonoscopy and pathological biopsy, the diagnosis of rectal villous tubular adenoma with focal carcinoma was confirmed, and the rectal cancer lesion was surgically resected in a timely manner after transferring to the Department of Gastrointestinal Surgery. As the most advanced molecular imaging equipment in the world today, PET/CT is to inject extremely small amount of positron tracer into the human body, and then detect the distribution of these positron radionuclides in the whole body organs with special in vitro detection instrument (PET), and then combined with the precise positioning of CT, it can accurately display the physiological metabolism and anatomical structure of the human body organs. The biggest advantage of PET/CT is that it can obtain the whole body image of the patient at one time, which can understand the whole body condition of the patient at a glance, and enable the clinician to diagnose malignant tumors and other systemic diseases and formulate the treatment plan more accurately. Compared with traditional imaging examinations, it is characterized by high sensitivity, good resolution and clear images. Patients undergoing PET/CT examination only need to inject a tiny amount of imaging agent intravenously, and the whole examination process is safe, non-invasive and painless. the emergence of PET/CT enables doctors to diagnose tumors earlier and more accurately, so that patients can receive timely and effective treatment. The PET/CT purchased by our hospital, equipped with 64-row 128-slice CT, has the features of fast acquisition time, high resolution, etc., and can detect millimeter lesions. Secondly, it is equipped with PET accurate quantitative analysis system, which can quickly and accurately evaluate the treatment efficacy of tumors, and furthermore, it is equipped with whole-body low-dose high-definition imaging technology, which has the lowest radiation dose for the examination, and it is one of the most advanced PET/CT in China at present. PET/CT is one of the most advanced PET/CT in China. After the installation of CT, the first trial patients, accidentally found that Mr. Liu, a lung cancer patient, suffered from the second cancer (rectal cancer), so that the patient was able to early surgical removal of cancerous foci, if not for this PET/CT trial, Mr. Liu’s rectal cancer did not know to be delayed until what time to be discovered, perhaps a few months after the discovery of the tumor may have spread and metastasized. This PET/CT examination enabled Mr. Liu’s rectal cancer to be detected and treated at an early stage, showing the advantages of PET/CT at the first trial.