When to Add Contrast
A non-contrast CT scan of the brain perfectly shows fresh hemorrhage, skull fracture and severe swelling - this is enough for injury and suspected stroke. Contrast is needed for other purposes: it accumulates where the blood-brain barrier is broken, and makes tumors, metastases, abscesses and areas of active inflammation visible. Contrast studies are also used for monitoring after surgery and radiation therapy. If a volumetric process is suspected, MRI remains the method of choice, but when it is unavailable or contraindicated - for example, in the presence of a pacemaker - CT with contrast solves the problem.
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.