Which of the following is true for the Caldwell position in…

Which of the following is true for the Caldwell position in skull radiography?I.       Petrous ridge is in the upper 1/3 of the orbitII.      With OML perpendicular to the IR, tube is 15° caudad for basic positionIII.     Petrous ridge is projected in the lower one-third of the orbit

Increase of intrathoracic pressure is achieved by forcible e…

Increase of intrathoracic pressure is achieved by forcible exhalation against a closed glottis and asking the patient to “bear down” as if to move his/her bowels. This technique demonstrates esophageal varices and sliding type esophageal hiatal hernia and is called the: