How would the central ray be directed for an AP projection of the knee in a patient whose ASIS-to-tabletop measurement is 26 cm?

This is a diagnostic image  of the cervical/thoracic spine First determine the position / projection and then answer the following question.  What is the CR entrance? twining.jpg  

Chest radiographs should exhibit:

Which of the following are the main subdivisions of the stomach? (more then one answer is correct.  Choose all the correct answers)

What position for the ribs would best demonstrate axillary ribs?

For the oblique elbow, the interepicondylar plane/line is placed at approximately a 30 degrees rotation from the IR for the external rotation and 45 degree rotation for the internal rotation.  

A 15- to 20-degree internally rotated AP oblique ankle projection with accurate positioning demonstrates which of the following joints as open spaces?

What is the correct cephalic CR angle range for the axial image of the clavicle?

For an AP lumbar image,, at what level does the CR enter at the MSP?

What type of CR angle is required for the AP axial projection of the foot?