In radiology, the<unk>  is a radiologic sign found on a frontal neck radiograph where subglottic tracheal narrowing produces the shape of a church<unk>  within the trachea itself. The presence of the<unk>  supports a diagnosis of croup, usually caused by paramyxoviruses. it can also be defined as the replacement of the usual squared-shoulder appearance of the subglottic area by cone shaped narrowing just distal to the vocal cords. This is called the<unk>  or pencil-point sign.
Steeple sign
Bing's sign
Puddle sign
Claybrook sign
Lincoln sign
Limbus sign
Boas' sign
Blumberg sign