Measure: To estimate the cranial capacity of each skull in the Gizmo, measure the area of the part of the cranium that houses the brain. This part of the cranium is roughly behind the red line in the diagram at right.
Chemical dyes are sometimes injected into patients prior to an MRI (magnetic resonance imaging) to enhance internal images. However, certain widely used MRI dyes may cause a number of side effects, including a serious, potentially fatal disease known as nephrogenic systemic fibrosis, or NSF.
Head MRI is done in the hospital or radiology center. You lie on a narrow table, which slides into a large tunnel-shaped scanner. Some MRI exams require a special dye, called contrast. The dye is usually given before the test through a vein (IV) in your hand or forearm. The dye helps the radiologist see certain areas more clearly. During the MRI, the person who operates the machine watches you from another room.