Table 3.

Limits delineating stations 1–2 through 4

Limit	1–2	3S	3I	4S	4IR	4IL
Top	u	u	v	v	b	c
Bottom	v	v	γ	δ	c	b
Right	w	w	w	w	θ	w
Left	α	α	α	α	α	θ
Anterior	β	$P_{\text{sternum}}^{min}(I_{u,v})$	$P_{\text{trachea}}^{min}(I_{v,\gamma })$	${\mathrm{\Psi }}_{\text{ascend}}^{min}(I_{v,\delta })[y]$	o	n
Posterior	$P_{\text{trachea}}^{max}(I_{u,v})$	$A_{\text{spine}}^{max}(I_{u,v})$	$A_{\text{trachea}}^{max}(I_{v,\gamma })$	$max(P_{\text{trachea}}^{max}(I_{v,\gamma }),p,q,r,s)$	s	r

Station 3 consists of two cuboids, 3S and 3I, located superior and inferior to the aortic arch, respectively. Station 4 consists of two cuboids: a superior cuboid 4S and a smaller cuboid, 4IR or 4IL, that shares its superior face with a part of the inferior face delineating 4S. If B_RMB ≤ B_LMB (i.e., b ≤ c per Table 2), then 4IR completes station 4; otherwise, 4IL completes station 4