Correct!
4. The frontal chest radiograph shows mildly enlarged central pulmonary arteries
The chest radiographic findings are rather subtle, but the central pulmonary arteries appear mildly enlarged (Figure 2).
Figure 2. Frontal (A) and lateral (B) chest radiography. The central pulmonary arteries (red arrow= right pulmonary artery; green arrow= left pulmonary artery; yellow arrowhead= main pulmonary artery) appear mildly enlarged. Note the filling of the retrosternal clear space, consistent with right ventricular enlargement.
The lung volumes are normal and the lung parenchyma shows no evidence of cystic change or fibrotic lung disease. Although the central pulmonary arterial enlargement is subtle and these findings could be interpreted as within the range of normal (they were not noted prospectively), the chest radiograph should not be considered normal- mild opacity with faint reticulation is present at the left apex, representing radiation change following the treated left breast malignancy. The mediastinal contours appear normal otherwise.
The patients IgM Mycoplasma antibody test was positive, so she was treated with three doses of azithromycin empirically as well as 20 mg prednisone twice daily and intravenous immune globulin. Her upper respiratory symptoms had resolved, but her shortness of breath had become progressive. The patient underwent echocardiography, which showed right atrial and ventricular enlargement and subjectively decreased right ventricular systolic function, but with left ventricular function preserved (ejection fraction= 65%). Right ventricular systolic pressure was calculated at 55-65 mmHg, and pulmonary hypertension was felt to be present. Moderate tricuspid regurgitation was present. A ventilation / perfusion (V/Q) scintigraphy study (Figure 3) was performed to exclude pulmonary embolism.
Figure 2: Ventilation (A) and perfusion (B) scintigraphy.
Regarding this examination, which of the following is correct? (Click on the correct answer to proceed to the third of six panels)