CT Chest Findings Indicating Improvement After Intrapleural Lytic Therapy

Cardiac and Pulmonary Vascular Assessment

The American College of Radiology recommends that decreased pulmonary edema or ground-glass opacities compared to prior imaging indicates improved heart failure status, though CT has limited evidence for routine HF follow-up 1, 2
Reduction in pleural effusion size may reflect improved cardiac function in patients with low ejection fraction 1
Absence of new pericardial effusion is important given the patient's severe heart failure 3

A main pulmonary artery diameter <29 mm or decreased from baseline suggests improved pulmonary pressures, with a diameter ≥29 mm having 87% sensitivity and 89% specificity for pulmonary hypertension 4, 5
MPA to ascending aorta ratio <1.0 indicates absence of severe pulmonary hypertension 4, 5, 3
Segmental artery to bronchus ratio ≤1:1 in most lobes suggests normal or improved pulmonary vascular pressures 6, 3
Normal or improved interventricular septal position without leftward bowing suggests reduced RV pressure overload 4, 5

Resolution of any ground-glass opacities suggests improvement in pulmonary edema from heart failure 3
Absence of the "signet ring sign" (bronchus-to-artery ratio >1:1) rules out new bronchiectasis from chronic infection or inflammation, according to the European Respiratory Society 6, 3
No mosaic attenuation pattern excludes chronic thromboembolic disease complicating the pulmonary hypertension 6, 3

Recognize that pulmonary artery diameter <29 mm does not exclude pulmonary hypertension, especially in the presence of parenchymal lung disease, as stated by the American College of Radiology 4
Be aware that ground-glass abnormalities can occur in pulmonary arterial hypertension and do not always indicate pulmonary edema, according to the European Respiratory Society 3