Kronig isthmus
Kronig isthmus is a band of resonance representing the apex of lung, also it's described as the narrow strap-like portion of the resonant field that extends over the shoulder, that connect the larger areas of resonance over the pulmonary apex in front and behind. Boundaries Medially: Scalene Laterally: Acromion process Anteriorly: Clavicle Posteriorly: Trapezius References Lung anatomy