FDG-PET in patients at risk for acute respiratory distress syndrome: a preliminary report

To compare the pattern of lung uptake of 18F-fluorodeoxyglucose (FDG) by positron emission tomography (PET) imaging in patients with lung contusion that developed or did not progress to acute respiratory distress syndrome (ARDS).

Prospective, observational study.

Trauma Center (academic urban hospital).

Eight patients with blunt thoracic trauma and pulmonary contusion, confirmed by computed tomography (CT) on admission, underwent repeat CT and FDG-PET (on the same day) 24-72 h after admission.

No subjects met the criteria for ARDS at the time of the PET and second CT. Four subjects subsequently developed ARDS 1-3 days after the PET scan; the other four did not develop the syndrome. Three of the four subjects who subsequently developed ARDS showed diffuse FDG uptake throughout the entire lungs, while those who did not develop ARDS showed significant FDG uptake only in areas of focal lung opacity (non or poorly aerated lung units) on CT. FDG uptake in normally aerated lung regions was higher for those who subsequently developed ARDS than those who did not, approaching statistical significance. The normally aerated tissue:liver ratio was significantly higher in subjects who developed ARDS than in those who did not (P = 0.029).

In this small series of patients with thoracic trauma, diffuse lung uptake of FDG was detected by PET imaging 1-3 days prior to clinically determined ARDS.