X-Ray Quiz – Discussion

X-Ray Quiz – Discussion

X-Ray Quiz - Discussion - antler sign and third mogul sign
X-Ray Quiz – Discussion – antler sign and third mogul sign

The annotated image illustrates the salient features including antler sign and third mogul sign:

  1. Upper lobe vessels are prominent, indicating pulmonary venous hypertension. The named signs for prominent upper lobe vessels are: redistribution, antler sign, upturned mustache sign and cephalization.
  2. Right heart border three intercostal spaces and extends well into the right hemithorax, indicating right atrial enlargement. Normally right heart border is just outside the spinal column.
  3. Prominent left atrial appendage is seen on the left heart border. This is known as third mogul sign. First two moguls are aortic knuckle and main pulmonary artery.
  4. Elevation of left bronchus air column indicating left atrial enlargement. This causes a widening of the carinal angle [1].

A “third mogul” can also occur due to submitral aneurysms and post operative left ventricular pseudoaneurysm after mitral valve replacement [2].

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  1. Kumaresh A, Kumar M, Dev B, Gorantla R, Sai PV, Thanasekaraan V. Back to Basics – ‘Must Know’ Classical Signs in Thoracic Radiology. J Clin Imaging Sci. 2015 Jul 31;5:43.
  2. Aldridge S, Frazer J, Tawn J, Wilde P. Left ventricular aneurysm formation: an iatrogenic cause for the third mogul. Br J Radiol. 1988 Jun;61(726):463-8.




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