MEDRADSC 3L03 Study Guide - Midterm Guide: Zygomatic Arch, Symphysis, Greater Wing Of Sphenoid Bone

• School: McMaster University
• Department: Medical Radiation Sciences
• Course: MEDRADSC 3L03
• Professor: Leslie Murray

Document Summary

Indications: skull fractures (medial & lateral displacement), neoplastic processes, paget disease. 24x30 or 10x12 lengthwise with 40 sid, 40 grid. Patient lying supine: top of cassette at level of vertex, oml perpendicular (chin tuck, msp perpendicular to ir, eam equidistant (no rotation) Pass through a point 2cm (0. 75 ) superior to eams. Collimate to include vertex & sides of skull. Can use a 15 degree sponge if there is space between head & ir. Best demonstrates petrous ridges converging over the foramen magnum (makes a v ), occipital bone. Purpose of angle: throw facial bones off the skull. Dorsum sellae in the shadow of the foramen magnum. Too little of an angle or chin insufficiently tucked (oml not perpendicular) = sella will be within/above magnum. Petrous ridges adjacent to lat border of foramen magnum. Foramen magnum should not have dorsum sella in it - angle was not at 30 degrees or oml was not perpendicular.