Measurements used in the research based on an example of an X-ray image in a PA (posterior–anterior) projection. (a) Midclavicular line—right; (b) Lateral sternal line—right; (c) Lateral sternal line—left; (d) Midclavicular line—left; (e) Upper clavicular line—left; (f) Lower clavicular line—left; (g) Upper clavicular line—right; (h) Lower clavicular line—right; (i) Diaphragm dome line. Red letters are explained in Appendix A, Table A1.