What is MRI and how does it work?

Magnetic Resonance Imaging (MRI) is an advanced, non-invasive imaging technique that uses strong magnetic fields and radiofrequency waves to create detailed images of soft tissues. It works by detecting signals from hydrogen protons in the body (primarily in water) as they realign after being disturbed, without using ionizing radiation.

What are the main advantages of MRI over other imaging methods?

MRI offers several key benefits: it is completely noninvasive and avoids x-rays or ionizing radiation, provides high-resolution images with superior soft tissue contrast compared to CT scans, and allows imaging in multiple planes (axial, sagittal, coronal) while visualizing both structure and function, such as blood flow.

What are T1-weighted and T2-weighted images in MRI?

In MRI, image weighting adjusts how tissues appear by modifying scanning parameters. T1-weighted images show fat as bright and fluid (like CSF) as dark, while T2-weighted images show fluid as bright and fat with intermediate brightness.

What are common clinical applications of MRI?

MRI is widely used for first-line investigation of brain and spinal cord tumors, detailed evaluation of soft tissues, joints, and ligaments, assessment of vascular flow and production of angiographic images, and diagnosis of congenital anomalies and deep-seated lesions.

How are contrast agents used in MRI?

Contrast agents, such as paramagnetic substances, may be administered during an MRI scan to enhance image quality. They help identify small lesions more clearly, particularly in sensitive areas like the brain.

Is MRI safe, and does it involve radiation?

MRI is considered safe as it does not use ionizing radiation (like x-rays) and has no known biological hazards. It is a noninvasive procedure that relies on magnetic fields and radiofrequency waves.

MRI – Principles and T1 vs T2 Weighting