standard thorax
angle of mandible to L1 (3mm)
standard H&N
top of shell to 2cm below level of carina (1.5mm)
standard brain
top of cast board to C7 (2mm)
standard breast
just below orbits to 10cm below CT ref (3mm)
standard abdomen
T1 to bottom of L5 (3mm)
standard pelvis
T12 to mid femur
CT ref pelvis
greater trochanter, mid sep
CT ref breast
20mm from inframammary fold, mid sep