The appearance of tissues on an MR image is primarily influenced by which relaxations?

Prepare for the Diagnostic and Therapeutic Modalities Test. Utilize flashcards and multiple-choice questions with detailed hints and explanations. Ensure success on your exam!

Multiple Choice

The appearance of tissues on an MR image is primarily influenced by which relaxations?

Explanation:
MRI contrast comes from how quickly protons recover along the main field (T1) and how quickly they lose their transverse coherence (T2). The imaging parameters, specifically TR (repetition time) and TE (echo time), determine which relaxation dominates: short TR and short TE emphasize T1 differences, while long TR and long TE emphasize T2 differences. Because tissue contrast in standard sequences is driven by these two relaxation properties, both T1 and T2 shape how tissues appear on the image. There isn’t a T3 relaxation in conventional MRI, so the relevant relaxations are T1 and T2. For example, fluids with long T2 tend to look bright on T2-weighted images but dark on T1-weighted images, illustrating how the two relaxations together set appearance.

MRI contrast comes from how quickly protons recover along the main field (T1) and how quickly they lose their transverse coherence (T2). The imaging parameters, specifically TR (repetition time) and TE (echo time), determine which relaxation dominates: short TR and short TE emphasize T1 differences, while long TR and long TE emphasize T2 differences. Because tissue contrast in standard sequences is driven by these two relaxation properties, both T1 and T2 shape how tissues appear on the image. There isn’t a T3 relaxation in conventional MRI, so the relevant relaxations are T1 and T2. For example, fluids with long T2 tend to look bright on T2-weighted images but dark on T1-weighted images, illustrating how the two relaxations together set appearance.

More Multiple Choice Questions
Subscribe

Get the latest from Passetra

You can unsubscribe at any time. Read our privacy policy