Radiographs are 2D images obtained by using X-rays (röntgen beams). The X-rays penetrate the patient’s tissues and are caught on a film lying underneath the patient. This results in a photo in black and white and shades of grey. The grey image obtained via X-rays is dependent on the composition of the tissue the X-rays have penetrated. The easier the X-rays penetrate the tissue, the less dense the tissue and the darker the resulting image. As such, lungs will be rather black and bones light up in white. These grey values give information on the density and the composition of the assessed tissues. X-rays can be taken from the
- Chest: following organs can be assessed: heart, lungs, ribs, diaphragm, a part of the spine, esophagus, lymph nodes.
- Abdomen: following organs can be assessed: intestines, stomach, liver, spleen, kidneys, bladder, pancreas and part of the spine.
- Limb and spine: this mainly allows assessment of the bone.
- Head and teeth: this allows assessment of the bone, but sinuses and nasal cavity as well.
Limitations
Because X-rays are 2D images and inform the veterinarian based on a difference in density, the surrounding tissues can make it difficult to interpret the X-ray. Overlapping tissues or liquid are shown as well on the X-ray and can sometimes hide the presence of tissue masses such as tumours. X-rays are mainly useful to have an overview and cannot show small details within organs. Only anomalies that impact the size, shape or position of the organ can be clearly distinguished. More details can be obtained via ultrasound, a CT scan, an MRI scan, endoscopy or exploratory surgery.