A 65-year-old man with a 40-pack-year smoking history visits the clinic for a routine evaluation. A screening chest radiograph reveals a new 15-mm noncalcified solitary pulmonary nodule in the right upper lobe. No previous chest radiographs are available for comparison. Arrange the following diagnostic modalities in the most appropriate standard chronological sequence for the evaluation of this patient's pulmonary nodule.
- 1Noncontrast computed tomography (CT) of the chest
- 2Positron emission tomography (PET) scan
- 3Image-guided percutaneous tissue biopsy
Answer
The correct chronological sequence is: Noncontrast CT of the chest, followed by a PET scan, and finally an image-guided percutaneous tissue biopsy.
The correct standard chronological sequence for evaluating a new, large (>8 mm) solitary pulmonary nodule in a high-risk patient without prior imaging begins with a noncontrast CT of the chest. This characterizes the lesion anatomically. Because this patient has a high pretest probability for malignancy, the next step in the algorithm is a PET scan to assess metabolic activity and evaluate for regional metastases. Finally, an image-guided biopsy is performed to obtain a definitive tissue diagnosis prior to surgical resection or other specific oncologic therapies.
Step-by-Step Solution
Key Concept
Sequential diagnostic imaging and evaluation of a high-risk solitary pulmonary nodule.