Correct!
3. Obtain prior imaging to determine if the opacities at chest radiography show long-term stability
It is always advisable to make every effort to review prior imaging, particularly when abnormalities are detected at thoracic imaging studies. For example, the detection of a non-calcified nodule in an adult patient raises the possibility of lung malignancy; however, if such a lesion is shown to be stable in size for a number of years, the possibility of malignancy is effectively excluded without need for additional exposure to ionizing radiation and associated expense. Ventilation / perfusion scintigraphy is useful for the detection of pulmonary embolism as well as assessment of differential lung perfusion and for shunt detection, but it is unlikely that the opacities detected at chest radiography are due to emboli. Thoracic MRI can be useful for evaluation of some mediastinal and chest wall abnormalities, and, in selected patients, to assist in lung cancer staging, but is not preferred for assessment of lung parenchymal abnormalities. Decubitus chest radiography is useful for the detection of both pleural effusion and pneumothorax, but neither are considerations in this case. Finally, 18FDG-PET scan could prove useful for evaluation of the abnormalities detected at chest radiography in this patient, but use of 18FDG-PET is somewhat premature at this point; typically, thoracic CT will be employed for characterization of lung parenchymal abnormalities before the decision to perform 18FDG-PET is considered.
Clinical Course: No prior imaging was available for direct evaluation, but the report of a thoracic CT from 3 years earlier at another institution indicated the presence of emphysema, some mild basilar fibrotic change, and some mild peribronchial and mediastinal lymph node enlargement, the latter attributed to the patient’s chronic lymphocytic leukemia. A repeat contrast-enhanced thoracic CT (Figure 2) was performed.
Figure 2. Contrast-enhanced axial thoracic CT displayed in soft tissue in lung windows (top image on the left) and soft tissue windows (top image on the right). Video images of the axial thoracic CT scan in lung windows (bottom image on the left) and soft tissue windows (bottom image on the right).
Regarding this examination, which of the following is correct? (Click on the correct answer to proceed to the fourth of nine panels)