Chapter 2: Radiological Anatomy

MRI AND CT

Magnetic resonance imaging (MRI) creates more detailed images of the soft tissues of the human body compared to computed tomography (CT) or X-ray. MRI may produce both two- and three-dimensional images of the human body while it provides excellent contrast between the different soft tissues of the body. MRI is particularly well-suited for imaging the brain, muscles, tendons, nerves, vascular structures, and organs.

1. Brain and skull—Diagnostic data may be useful for assessing brain lesions, fractures, hemorrhage, infarction, tumor, hydrocephalus, and/or cerebral edema.

   1. Epidural hematoma (Figure 2-1)

   2. Subdural hematoma (Figure 2-2)

   3. Subarachnoid hemorrhage (Figure 2-3)

2. Chest—Diagnostic data may include assessment of fracture, infection, bleeding, tumor, pulmonary emboli, pneumothorax, emphysema, and fibrosis.

   1. Pulmonary embolus (Figure 2-4)

   2. Pneumothorax (Figure 2-5)

ULTRASOUND

Ultrasound may utilize Doppler to determine the direction and velocity of blood flow within vascular structures. This is a helpful tool in confirming the presence of venous and arterial vascular structures. Red color represents higher frequency Doppler flows “toward” the probe, whereas blue represents lower frequency Doppler flows “away” from the ultrasound probe.

1. Nerve blocks

   1. Brachial plexus (interscalene) (Figure 2-6)

   2. Brachial plexus (supraclavicular) (Figure 2-7)

   3. Brachial plexus (infraclavicular) (Figure 2-8)

   4. Brachial plexus (axillary) (Figure 2-9)

   5. Femoral nerve (Figure 2-10)

   6. Popliteal nerve (Figure 2-11)

2. Transesophageal echocardiography

   1. Transgastric short axis (Figure 2-12)

   2. Midesophageal 4 chamber (Figure 2-13)

   3. Pericardial effusion (Figure 2-14)