Chest CT scan may be helpful in the diagnosis of lung cancer. Findings on CT scan suggestive of lung cancer include, a solitary pulmonary nodule, centrally located masses, mediastinal invasion
CT scans help stage the lung cancer. A CT scan of the abdomen and brain can help visualize the common sights of metastases: adrenal glands, liver, and brain. CT scans diagnose lung cancer by providing anatomical detail to locate the tumor, demonstrating proximity to nearby structures, and deciphering whether lymph nodes are enlarged in the mediastinum.
CT Scan
Chest CT scan may be helpful in the diagnosis of lung cancer. Findings on CT scan suggestive of lung cancer include:[1]
Common radiological appearances of lung cancer. Centrally located mass with mediastinal invasion (arrow, A), peripherally situated mass abutting the pleura (arrow, B), mass with smooth, lobulated margins (arrow, C) and with spiculated, irregular margins (arrow, D), via <https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4419420/figure/F1/>This is an open-access article distributed under the terms of the Creative Commons Attribution-Noncommercial-Share Alike 3.0 Unported, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.[1]
Lung cancers with atypical radiological pattern. Squamous cell cancer presenting as a cavitating mass (arrow, A). Adenocarcinoma presenting as dense consolidation (arrow, B). Bronchoalveolar carcinoma (adenocarcinoma in situ) presenting as ground-glass opacity (arrow, C) and mixed density, solid (arrow), and ground-glass nodules (arrowhead) in D via <https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4419420/figure/F2/>This is an open-access article distributed under the terms of the Creative Commons Attribution-Noncommercial-Share Alike 3.0 Unported, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.[1]
Stage T1 and T2 tumors. Stage T1 tumor due to size <3 cm (arrow, A). Stage T2 endobronchial tumor (arrowhead) causing pneumonitis restricted to the upper lobe (arrow) in B. T2a tumor >3 cm but <5 cm (arrow, C). T2b tumor >5 cm but <7 cm (arrow in D) via <https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4419420/figure/F3/>This is an open-access article distributed under the terms of the Creative Commons Attribution-Noncommercial-Share Alike 3.0 Unported, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.[1]
Stage T3 tumors. T3 tumor due to size >7 cm in size (arrow, A), eroding the ribs (arrow, B), infiltrating the mediastinal pleura but not the vessels (arrow, C), and causing atelectasis of the entire lung (arrowhead, D via<https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4419420/figure/F4/>This is an open-access article distributed under the terms of the Creative Commons Attribution-Noncommercial-Share Alike 3.0 Unported, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.[1]
Stage T4 tumors. T4 tumor due to invasion of pulmonary artery (arrow, A), descending aorta (arrow, B), vertebral body (arrow, C), superior vena cava with thrombus (arrow, D)via<https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4419420/figure/F5/>This is an open-access article distributed under the terms of the Creative Commons Attribution-Noncommercial-Share Alike 3.0 Unported, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.[1]
CT scans help stage the lung cancer. A CT scan of the abdomen and brain can help visualize the common sights of metastases: adrenal glands, liver, and brain.
The benefits of CT Scans in lung cancer patients are the following:[2]
Metastatic disease. Bilateral pleural effusions-M1a (arrow, A), lung metastases-M1a (arrows, B), adrenal metastasis-M1b (arrow, C), vertebral metastasis-M1b (arrow, D), brain metastasis-M1b (arrow, E), liver metastases-M1b (arrows, F)via<https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4419420/figure/F10/>This is an open-access article distributed under the terms of the Creative Commons Attribution-Noncommercial-Share Alike 3.0 Unported, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.[1]
Adrenal adenoma versus metastasis. Enhancing solid adrenal nodule on CT scan in a case of lung cancer (arrow, A) suggestive of metastatic deposit. Unenhanced CT scan shows fatty attenuation within the nodule with an HU value of 0 suggesting the possibility of an adenoma (arrow, B). FDG PET/CT shows no tracer concentration in the nodule, confirming the diagnosis of adenoma. Enhancing solid adrenal nodule on CT scan in another patient of lung cancer (arrow, D), which is indeterminate in nature. FDG PET/CT shows abnormal focal tracer concentration in the nodule (arrow, E) highly suggestive of a metastatic deposit via<https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4419420/figure/F11/>This is an open-access article distributed under the terms of the Creative Commons Attribution-Noncommercial-Share Alike 3.0 Unported, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.[1]
Unfortunately, research has shown that there are a number of false positives associated with CT scanning because a CT scan on its own cannot determine malignancy.
A positive result for a tumor using a CT scan is typically followed up with a biopsy for confirmation.
