When ultrasound is not enough
The primary method for examining the thyroid gland is ultrasound: it is safe, informative and allows puncture to be performed under control. Computed tomography is prescribed in specific situations when ultrasound is powerless: with retrosternal spread of goiter (ultrasound does not “see” behind the sternum), with suspected compression and displacement of the trachea, when assessing the spread of the tumor process to surrounding structures and when searching for retrosternal lymph nodes. An important nuance: if radioactive iodine therapy is planned, a study with iodine-containing contrast is postponed for several weeks - this issue must be agreed with the endocrinologist.
What is the power of computed tomography?
MSCT creates an image using X-rays and produces thin sections with high spatial resolution. It is indispensable where bone, lung tissue, fresh hemorrhage and precise vessel geometry are important, as well as in emergency situations - the examination takes seconds.
Three-dimensional reconstructions are constructed from the resulting sections: this allows the surgeon to see the anatomy in volume in advance and plan the intervention.
When you need contrast
Intravenous contrast dramatically increases the information content in the study of blood vessels, tumors, inflammatory processes and parenchymal organs. It shows the nature of the blood supply to the formation, which often determines its nature.
Before a contrast study, kidney function is assessed by creatinine level and an allergic history is clarified - reactions to iodine-containing drugs are rare, but require attention.
CT or MRI
- CT scan is better: bones, lungs, acute hemorrhage, stones, vessels, emergency conditions
- MRI is better: brain and spinal cord, soft tissues, joints, pelvis, liver
- CT is faster and more accessible, MRI does not provide radiation exposure
About radiation exposure
Computed tomography uses x-rays and is therefore prescribed according to indications. Modern machines use dose reduction protocols, and the information obtained from sound research usually far outweighs the risk. During pregnancy, CT scans are performed only for health reasons.