What is the clinical significance of enhanced MRI?

Magnetic resonance imaging is a very important examination method in clinical practice. Here we would like to remind everyone that there are many people who cannot undergo MRI examinations, such as those with pacemakers, and many women with contraceptive rings in their bodies, or those with artificial corneas installed in their eyes. These people cannot undergo MRI examinations. Enhanced MRI is more popular now. So what is the clinical significance of enhanced MRI?

Strengthen the clinical significance of MRI:

1. If no obvious abnormality is found in the plain scan, but the clinician or other examinations highly suspect the presence of a lesion, it is necessary to perform an enhanced scan. Because CT relies on density differences to display lesions, some lesions of solid organs such as the liver and kidneys cannot be displayed during plain scans because their density is no different from that of the surrounding normal tissues. The blood supply or source of the lesion is more or less different from that of normal tissue. After the contrast agent is injected into the vein, the amount or phase of the contrast agent entering the lesion and normal tissue with the blood will be different. The density increase caused by the contrast agent will also be different, thus showing the lesions that cannot be displayed by plain scan.

2. The lesion was detected during plain scan, but the imaging manifestations with differential diagnostic significance, such as the lesion's edge, internal structure, blood supply, and relationship with adjacent tissues, were not clear, and the type of lesion or specific disease could not be determined. Enhanced scanning can make the above pathological features appear on CT or MR images, providing important basis, sometimes the key basis, for the differential diagnosis of lesions.

3. There are many types of tumors and tumor-like lesions in certain organs (such as the liver), and their benign and malignant types and treatment methods vary greatly, but plain scans often show similar results, making differentiation difficult. However, various lesions typically show different enhancement levels and their changes in the arterial phase, portal venous phase, and delayed phase. The sequence of enhancement within the lesions, the distribution and morphology of the enhanced areas all have different manifestations. Most of them can be clearly diagnosed through multi-phase enhanced scanning. However, it is still difficult to identify a small number of cases.

4. The boundaries of some tumor lesions are unclear during plain scan and cannot be distinguished from surrounding edema, inflammatory lesions, surgical or radiotherapy injuries. Therefore, it is impossible to clearly determine the invasion range of the tumor and the effect of treatment. Enhanced scanning enhances tumor tissue. The enhancement performance of inflammatory lesions, injuries and tumor tissue is different. Edema is not enhanced, so the scope, size and shape of the tumor can be clearly displayed. For tumors that have been clearly diagnosed, enhanced scanning can be performed directly during follow-up examinations after treatment without the need for plain scanning.

5. Except for bones, fat, and gas, the density of various tissues and blood vessels in the human body is very small during CT scans. The density of most solid tumors is also close to these tissues. Therefore, it is sometimes impossible to distinguish between vascular sections and lesions, vascular lesions and other lesions. After contrast agent injection, the density of vascular lumen and vascular lesions increases significantly, making them easily distinguishable from other normal tissues and lesions. MR has a high soft tissue resolution, and blood vessels have a flow void effect, making them easy to distinguish even with a plain scan. People who need to be examined: those who have undergone MRI scan.