Imaging Studies. A chest X-ray is a low-sensitivity tool that cannot detect lesions of less than 1 cm [].In patients with extrathoracic cancer, detection of a new nodule on an X-ray has a 25% probability of indicating a metastatic lesion [].Chest computed tomography (CT) with slices of 1-1.25 mm is the preferred approach for assessing lungs to evaluate and determine the size of the lesion []..