**Question:** X-ray features of ASD are all except –

A. Increased pulmonary vascular markings
B. Enlarged cardiac silhouette
C. Prominent bronchial shadows
D. Normal cardiac silhouette

**Core Concept:**
ASD (Atrial Septal Defect) is a type of congenital heart defect where there is a hole between the two atria (right and left atrium) of the heart. This leads to a shunting of blood between the two atria and pulmonary and systemic circulations. X-ray findings in ASD depend on the size and type of the defect, but common features include increased pulmonary vascular markings and an enlarged cardiac silhouette.

**Why the Correct Answer is Right:**
The correct answer, "Normal cardiac silhouette," is right because an ASD results in an enlarged cardiac silhouette due to the shunting of blood between the two atria. An enlarged cardiac silhouette indicates an increased blood volume in the heart.

**Why Each Wrong Option is Incorrect:**
A. Increased pulmonary vascular markings: This is a common feature of ASDs, indicating increased blood flow to the lungs due to the shunting of blood from the systemic circulation to the pulmonary circulation.
B. Prominent bronchial shadows: This is unrelated to ASD and more related to bronchial compression or lung disease.
D. Enlarged cardiac silhouette: As mentioned earlier, this feature is associated with increased blood volume in the heart due to shunting, not a normal cardiac silhouette.

**Clinical Pearl:**
In cases of congenital heart defects like ASD, X-ray findings can help in diagnosis and guide further evaluation or intervention. However, physicians should carefully consider the specific defect type and size to interpret the findings accurately. ASD can present with different radiographic features, and an understanding of these features will assist in reaching an accurate diagnosis and plan appropriate management.