Kerley B lines

Kerley B lines are thin, horizontal lines found at the lung bases on a chest radiograph or CT scan, representing interstitial pulmonary edema. They are considered a radiologic sign of cardiac failure, particularly left-sided heart failure, and other conditions leading to increased pulmonary venous pressure. The presence of Kerley B lines indicates the accumulation of fluid in the interlobular septa of the lungs, which are the partitions that separate the secondary lobules of the lung.

Etiology

Kerley B lines are most commonly associated with left ventricular failure, mitral valve disease, and conditions that lead to pulmonary venous hypertension. Other causes may include lymphatic obstruction within the lung, which can be due to malignancy or infection, and pulmonary veno-occlusive disease.

Pathophysiology

In the setting of elevated pulmonary venous pressure, fluid transudates from the pulmonary capillaries into the interstitial space of the lungs. The accumulation of fluid within the interlobular septa manifests radiographically as Kerley B lines. These lines are typically 1-2 cm in length and are perpendicular to the pleural surface, reflecting the anatomy of the interlobular septa.

Clinical Significance

The detection of Kerley B lines on imaging is a significant indicator of interstitial edema and can aid in the diagnosis of underlying cardiac or pulmonary conditions. Their presence can prompt further diagnostic evaluation and management of the patient to address the cause of pulmonary congestion.

Diagnosis

Kerley B lines are diagnosed through imaging studies, primarily on a chest radiograph. They can also be seen on CT scans of the chest with higher sensitivity. The identification of these lines by a radiologist or other trained healthcare professional can help in the assessment of patients with suspected pulmonary edema or heart failure.

Treatment

The treatment of Kerley B lines involves addressing the underlying cause of the pulmonary edema. This may include management of heart failure with medications such as diuretics, ACE inhibitors, or beta-blockers, and treatment of any underlying pulmonary or systemic conditions contributing to the fluid overload.

Prognosis

The prognosis for patients with Kerley B lines depends on the underlying cause of the pulmonary edema and the patient's response to treatment. Early detection and management of the condition can improve outcomes.