Question

Advantages of diffusion tensor imaging include: a. demonstrates abnormalities when conventional MRI is normal. b. provides functional maps of brain activity. c. it is indispensable for planning stroke therapy. d. can be used to calculate perfusion metrics.

Short answer

Answer: Demonstrates abnormalities when conventional MRI is normal.

Step-by-step solution

Option a: Demonstrates abnormalities when conventional MRI is normal

DTI can indeed detect abnormalities in the brain's white matter when conventional MRI may fail to show any significant findings. DTI allows for the visualization and quantification of water diffusion, revealing microstructural changes in the white matter. Therefore, option a is a correct advantage of DTI.

Option b: Provides functional maps of brain activity

Although DTI is a powerful tool for visualizing white matter structure, it does not directly provide functional maps of brain activity. Functional magnetic resonance imaging (fMRI) is the imaging technique responsible for measuring brain activity. So, option b is not a correct advantage of DTI.

Option c: Indispensable for planning stroke therapy

DTI might be helpful in certain cases while planning stroke therapy, but it is not indispensable for this purpose. Other imaging techniques, such as non-contrast CT and MRI, are more commonly used in stroke assessment and to guide therapy. Consequently, option c is not a correct advantage of DTI.

Option d: Can be used to calculate perfusion metrics

Perfusion metrics provide valuable information on how blood flows within the brain tissue. DTI is not specifically aimed at calculating such metrics. Perfusion-weighted MRI is the technique mainly used for this purpose. Therefore, option d is not a correct advantage of DTI. In conclusion, among the given options, only a (demonstrates abnormalities when conventional MRI is normal) is a correct advantage of diffusion tensor imaging.