Magnetic Resonance Imaging (MRI) Practice Test

What type of images are typically collected to assess brain lesions after a contrast agent is administered?

1. T1 weighted images

2. T2 weighted images

3. Proton density images

4. SWI images

The correct answer is: T1 weighted images

T1 weighted images are typically collected to assess brain lesions after the administration of a contrast agent due to their ability to provide superior visualization of anatomical structures and to highlight areas where the contrast agent accumulates. When a contrast agent, such as gadolinium, is injected, it enhances the T1 signal in regions where there is an increase in vascular permeability, commonly seen in lesions, tumors, or areas of inflammation. Consequently, T1 weighted MRI is advantageous for identifying and characterizing such abnormalities, making it the preferred choice for this purpose. Other modalities, like T2 weighted images, primarily highlight fluid and edema but do not provide the same level of detail in terms of contrast enhancement for lesions. Proton density images focus more on the density of protons in tissues but may not offer insight into vascular changes or lesions effectively. Susceptibility-weighted imaging (SWI) provides information on venous structures and hemorrhage but is less effective for the general assessment of lesions compared to T1 weighted images after contrast administration.