Correct!
4. Unenhanced high-resolution chest CT
Among the choices listed, unenhanced high-resolution thoracic CT (HRCT) is the best choice. HRCT would be the most useful examination to confirm that the abnormalities detected at chest radiography persist, and, assuming they do, to characterize these opacities. 68Ga-citrate imaging can be used for diffuse lung diseases, but typically in the context of a more widespread alveolitis, not small nodular opacities. Flexible fiberoptic bronchoscopy could be of benefit for this patient, but is invasive and HRCT results could inform if this procedure is even indicated, and, if so, where best to attempt tissue sampling. 99mTc-MAA ventilation – perfusion scanning is used to assess pulmonary blood flow, typically for thromboembolic disease assessment or in the context of pre-operative testing for differential pulmonary blood flow assessment, but neither consideration is relevant to this patient. Mediastinoscopy is commonly employed to sample paratracheal or anterior subcarinal lymph node stations, often in the context of lung cancer staging, but occasionally to establish a diagnosis for patients with enlarged lymph nodes or masses in these areas, but neither situation is germane to this patient’s presentation.
The patient underwent unenhanced HRCT (Figure 4).
Figure 4. Left: Representative static axial images from the high-resolution chest CT images through the upper lungs. Right: video of the axial CT images.
Which of the following is correct regarding the description of the thoracic CT findings? (Click on the correct answer to procced to the fifth of seven panels)