Why inject contrast into a joint?
A conventional CT scan shows the bone, but the articular cartilage, labrum and ligaments on it are practically invisible. The introduction of contrast into the joint cavity changes the situation: the drug fills all its pockets and outlines the contours of intra-articular structures. Cartilage defects, tears in the labrum of the shoulder or hip joint, and loose intra-articular bodies become clearly visible. The method is especially valuable when MRI is contraindicated - in the presence of a pacemaker or metal structures that produce pronounced artifacts. The procedure is performed in two stages: first, joint puncture with controlled injection of contrast, then scanning.
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.