What is the definition or description of: pet-ct lung cancer diagnosis?

Imaging test.: A pet/ct is a combined whole body x-ray (ct scan) and a functional image based on how much sugar is taken up in various parts of the body. It is not a way of diagnosing lung cancer, which requires a biopsy, but it can help deciding if a biopsy is needed. A lung nodule on x-ray may be benign or cancerous. If that nodule takes up a lot of sugar on pet, it is more likely to be cancer.

Combination: Pet-ct uses a combination of x-rays and a scan for metabolic activity to be more sensitive than either alone. Ct can show the size and shape of structures or masses within the chest. Pet detects increased metabolic activity associated with an infection or a growing cancer. Correlation of the two tests together is more accurate than either one alone.

Clinical: Lung cancer is diagnosed by obtaining tissue from somewhere. This would be a pathologic diagnosis. Cancer can be inferred by by various imaging studies, but positive studies need to be confirmed by tissue diagnosis. There are false positive and false negative results with any diagnostic study.

No such thing: Pet scan identifies increased cellular metabolism. The suv is a measure of how metabolically active a "spot" or "nodule" is. It does not diagnose. Lung cancer (all cancers) is diagnosed by obtaining tissue and examining by pathologist. Any lung nodule must be thoroughly investigated and closely followed by a comprehensive thoracic team.