Accuracy and Utility of Point-of-Care Chest Ultrasonography Performed by the Pulmonary Physician Compared to Computed Tomograph

Abstract

PURPOSE: Patients presenting with cardiopulmonary insufficiency require accurate and rapid diagnosis often made by computed tomography (CT). While CT is sensitive and specific, it exposes patients to ionizing radiation and contrast. Ultrasound is accurate when compared to CT for life-threatening pleural and pulmonary parenchymal abnormalities in an intensive care setting but has not been studied when used by pulmonologists in non-critically ill patients. The aim of this study was to determine accuracy of point-of-care chest ultrasonography performed by pulmonary physicians, in the diagnosis of cardiopulmonary symptoms, as compared to CT of the chest. METHODS: We prospectively studied adult subjects undergoing CT for cardiopulmonary insufficiency. Pulmonary physicians trained in ultrasonography performed bedside chest ultrasound either before or within 3 hours of the CT. Ultrasonographers were blind to the results of the CT scan. Using a 3.5 MHz phased array transducer, they evaluated each lung for A or B line pattern, alveolar consolidation, pleural effusion and lung sliding. Results of the ultrasound were subsequently compared to findings on CT as reported by a radiologist. RESULTS: We studied 94 adult subjects prospectively. Point-of-care ultrasound performed by a pulmonologist correlated with findings on CT in 88 of 94 (93.6%) subjects. The most frequent findings were pulmonary edema (13.8%), pleural effusion (9.9%) and consolidation (8.9%). 38.2% of patients had no pleural or parenchymal abnormalities detected on either CT or ultrasound. Ultrasound findings did not correlate with CT in 6 (6.4%) subjects. Of these, 1 had a medially located left upper lobe mass, 2 had scattered small nodules, 1 had cystic lung disease, 1 had minimal atelectasis and 1 received a very limited ultrasound exam secondary to body habitus and difficulty positioning the patient. CONCLUSIONS: Point-of-care ultrasonography performed by the pulmonary physician provides accurate diagnosis in patients presenting with cardiopulmonary insufficiency. CLINICAL IMPLICATIONS: When ultrasound reveals pleural or parenchymal abnormalities that correlate with clinical findings, CT may be unnecessary.