Diagnostic Imaging
The Diagnostic Imaging domain tests radiographic positioning, exposure, radiation safety, contrast studies, ultrasound basics, and artifact recognition. You must decide whether an image is diagnostic and what to change.
Core rules
- Take orthogonal views: at least two views at 90 degrees for most structures.
- Thoracic radiographs: take at peak inspiration, with the patient straight; use a horizontal beam for pleural fluid if needed.
- Abdominal radiographs: include diaphragm to pubis; use contrast only when indicated and after baseline films.
- Radiation safety: follow ALARA; collimate, wear lead apron and thyroid shield, use a dosimeter, and restrain with sandbags or devices rather than hands.
- Label films with patient ID, date, view, and hospital; do not obscure anatomy.
Worked example
A lateral thorax looks rotated and the diaphragm is flat. Reasoning: the patient is likely in expiratory phase or rotated. Repeat at peak inspiration after manual ventilation or a brief pause, and check sternal alignment. A rotated film can mimic cardiomegaly and cause a false diagnosis.
Traps
Accepting one view, collimating too tightly, failing to measure the patient for exposure, and ignoring personal dosimeter badges. Also, mislabeling left and right.