Palla's sign

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Palla's sign
Chest X-ray showing Palla's sign
Synonyms
Pronounce
Specialty	Radiology, Pulmonology
Symptoms	Prominent pulmonary artery on chest X-ray
Complications
Onset
Duration
Types
Causes	Pulmonary embolism
Risks
Diagnosis	Chest X-ray, CT pulmonary angiography
Differential diagnosis
Prevention
Treatment
Medication
Prognosis
Frequency
Deaths

Palla's sign is a radiological sign seen on a chest X-ray that indicates the presence of a prominent pulmonary artery, often associated with a pulmonary embolism. It is named after the radiologist who first described it. The sign is characterized by an enlarged right descending pulmonary artery, which can be seen as a prominent shadow on the X-ray image. This finding can help in the diagnosis of pulmonary embolism, a condition where one or more arteries in the lungs become blocked by a blood clot.== Palla's Sign == Palla's sign is a radiological sign seen on a chest X-ray that is indicative of pulmonary embolism. It is characterized by the enlargement of the right descending pulmonary artery, which can be observed as a prominent bulge on the X-ray image. This sign is named after the radiologist who first described it.

Clinical Significance

Palla's sign is considered a classic but not always present indicator of pulmonary embolism. It is one of several radiographic signs that may be observed in patients with this condition, alongside others such as Westermark's sign and Hampton's hump. The presence of Palla's sign can aid in the diagnosis of pulmonary embolism, especially when correlated with clinical findings and other diagnostic tests such as CT pulmonary angiography.

Pathophysiology

The appearance of Palla's sign is due to the increased pressure and volume in the pulmonary artery caused by the obstruction of blood flow. This obstruction is typically due to a thrombus (blood clot) that has traveled to the lungs from another part of the body, often the deep veins of the legs, a condition known as deep vein thrombosis (DVT).

Diagnosis

While Palla's sign can be a useful indicator, it is not sufficient on its own to diagnose pulmonary embolism. A comprehensive evaluation including clinical assessment, laboratory tests such as D-dimer levels, and imaging studies is necessary. Ventilation/perfusion scan and CT pulmonary angiography are more definitive tests for diagnosing pulmonary embolism.

Treatment

The treatment of pulmonary embolism involves anticoagulation therapy to prevent further clot formation and to allow the body to naturally dissolve the existing clot. In severe cases, thrombolytic therapy or surgical intervention may be required. The presence of Palla's sign does not alter the treatment plan but serves as a clue in the diagnostic process.

See Also

• Pulmonary embolism
• Westermark's sign
• Hampton's hump
• Deep vein thrombosis
• CT pulmonary angiography