Bedside ultrasound is more sensitive than chest x-ray for identifying pulmonary edema in patients presenting with dyspnea, according to a study published in the April issue of the Journal of Ultrasound in Medicine.
And the modality's greater sensitivity isn't its only benefit, wrote a team led by Dr. William Wooten of Mount Carmel Health System in Columbus, OH.
"Bedside ultrasound appears to offer several advantages over chest radiography in the workup of patients with dyspnea beyond its superior sensitivity in the diagnosis of pulmonary edema," the team wrote. "First, bedside ultrasound exposes the patient to less radiation. Second, imaging costs to payers may be reduced."
Chest x-ray has been the commonly used imaging modality to assess patients for pulmonary edema, but its interpretation can be variable, affected by clinicians' level of expertise, Wooten and colleagues wrote. That's why lung ultrasound may be a better tool.
"Lung ultrasound may produce more objective findings through evaluation of vertical comet tail artifacts known as B-lines, which are created by a decrease in the ratio of alveolar air to fluid pulmonary content," the group explained.
The study included 99 patients who presented in the emergency room with dyspnea between August 2016 and March 2017. Of these, 32.3% had congestive heart failure, and 40.4% had chronic obstructive pulmonary disease. Each patient underwent an ultrasound exam within an hour of having a chest x-ray. The researchers used the final diagnosis from the patient's discharge summary as the reference standard (J Ultrasound Med, April 2019, Vol. 38:4, pp. 967-973).
The team found that bedside ultrasound had higher sensitivity compared with chest x-ray, at 96% versus 65%. Specificity was comparable between the two modalities. Of 18 patients with negative x-ray findings and a discharge diagnosis of pulmonary edema, 16 (89%) had positive findings on ultrasound.
| Chest x-ray vs. ultrasound for pulmonary edema | |||
| Measure | Chest x-ray | Ultrasound | p-value |
| Sensitivity | 65% | 96% | < 0.001 |
| Specificity | 96% | 90% | 0.26 |
Additionally, patients may be more comfortable with bedside ultrasound, Wooten and colleagues noted.
"Anecdotally, we observed that patients appeared to prefer the bedside ultrasound, as it kept the provider at the bedside longer, and the patient did not have to leave the room or family to undergo the chest radiography," the group wrote.
Bedside ultrasound shows promise for patient care when it comes to diagnosing pulmonary edema, but it could also benefit hospitals, according to the authors.
"This study has the potential to affect the care of patients with congestive heart failure, which is the most common cause of hospitalization in the Medicare population and is growing substantially as people are living longer," the team concluded. "As hospitals are being penalized for 30-day readmissions for congestive heart failure, it is crucial that these patients have an accurate diagnosis and are properly treated."
![Examples of ultrasound findings and techniques. (A) Images in a 39-year-old male patient with a mass in the left thigh. The mass is heterogeneous on the B-mode US image (compared with the patient in D) and showed increased microvascularity (superb microvascular imaging [SMI]) and shear-wave elastography (SWE) values. Undifferentiated pleomorphic sarcoma was diagnosed at biopsy (with pleomorphic rhabdomyosarcoma in surgical specimen). (B) Images in an 18-year-old male patient with a mass in the left leg. The mass is hypoechoic on the B-mode image, with no other findings suggestive of malignancy. The lesion is in contact with the cortex of the tibia, which is slightly irregular. CT revealed a doubtful anteromedial tibial erosion. The microvascular study demonstrated high vascularization, suggestive of malignancy. Periosteal Ewing sarcoma was diagnosed with both histologic and immunohistochemical confirmation. (C) Images in a 69-year-old female patient with a lump growing on the outside of the left leg. Multiple SWE examinations were performed (please note the high values obtained in the measurements, whereas the color map highlights the stiffness relative to adjacent tissues). SMI showed areas of increased vascularization to target for sampling. Undifferentiated spindle cell sarcoma was diagnosed at biopsy, with residual leiomyosarcoma in the surgical specimen after neoadjuvant therapy. (D) Images in a 56-year-old female patient with a mass in the right thigh. The mass is heterogeneous at both B-mode ultrasound (similar to patient A) and MRI (coronal T2-weighted spectral attenuated inversion recovery [SPAIR]; T1-weighted pre-contrast and postcontrast imaging), which even shows uptake after the administration of paramagnetic contrast material, which is traditionally suggestive of malignancy. Low values at SMI and elastography are suggestive of benignity. Spindle cell lipoma was diagnosed at biopsy, with atypical spindle cell lipomatous tumor in the surgical specimen.](https://img.auntminnie.com/mindful/smg/workspaces/default/uploads/2026/08/images-radiol250278fig2.APCFLSvX6p.jpg?auto=format%2Ccompress&dpr=2&fit=crop&h=167&q=70&w=250)
