8.4.1 MRI and fMRI

• What does MRI stand for?

  Magnetic Resonance Imaging
• What does fMRI stand for?

  Functional Magnetic Resonance Imaging
• Radio waves excite the hydrogen nuclei
• fMRI tracks brain activity by measuring blood flow, while MRI captures anatomical structures.
• What type of energy does MRI use?

  Magnetic field and radio waves
• What does fMRI measure to detect brain activity?

  Blood flow changes
• One advantage of fMRI is its high spatial resolution
• MRI does not use ionizing radiation, unlike CT scans.
• Hydrogen nuclei emit signals as they relax
• What do detectors measure in MRI to construct images?

  Radio wave signals
• fMRI focuses on brain function, while MRI focuses on brain morphology.
• What is one limitation of MRI in brain imaging?

  High cost
• What is one application of MRI in brain imaging?

  Diagnosing brain tumors
• fMRI can be used to study cognitive processes by detecting which brain areas are active during specific tasks.
• Safety considerations for MRI include avoiding metal objects near the strong magnetic field.
• Steps in the principles of fMRI

  1️⃣ Application of a strong magnetic field

  2️⃣ Emission of radio waves

  3️⃣ Changes in blood flow

  4️⃣ Detection of signals

  5️⃣ Brain activity mapping
• What does fMRI use to create images?

  Strong magnetic field and radio waves
• Which brain imaging technique aligns hydrogen nuclei using a strong magnetic field?

  MRI
• MRI is a non-invasive procedure that does not use ionizing radiation.
• What type of field is used in MRI to align hydrogen nuclei?

  Strong magnetic field
• One advantage of MRI is that it does not use ionizing radiation
• MRI is particularly useful for imaging the brain because it visualizes soft tissues clearly.
• Match the feature with its corresponding method in MRI:

  Imaging Method ↔️ Strong magnetic field and radio waves

  Resolution ↔️ High

  Radiation Exposure ↔️ No ionizing radiation
• Steps involved in creating an image using MRI

  1️⃣ Alignment of hydrogen nuclei with a strong magnetic field

  2️⃣ Excitation of nuclei by radio waves

  3️⃣ Emission of signals as nuclei release energy

  4️⃣ Data processing to construct an image
• What type of waves are used to disturb the alignment of hydrogen nuclei in MRI?

  Radio waves
• MRI can be used to diagnose brain tumors and detect strokes.
• What does fMRI detect changes in to track brain activity?

  Blood flow
• Unlike MRI, fMRI tracks brain activity
• fMRI is a non-invasive method with high spatial resolution.
• Match the primary purpose with the correct imaging method:

  Anatomical imaging ↔️ MRI

  Functional imaging ↔️ fMRI
• Which type of radiation is used in CT scans but not in MRI?

  Ionizing radiation
• CT scans have higher resolution than MRI for soft tissue imaging.

  False
• MRI uses a strong magnetic field to align hydrogen nuclei
• Steps involved in MRI imaging

  1️⃣ Align hydrogen nuclei with a strong magnetic field

  2️⃣ Disturb this alignment using radio waves

  3️⃣ Detect the signals emitted as the nuclei return to their aligned state

  4️⃣ Construct high-resolution images using these signals
• MRI images are created using signals emitted by hydrogen nuclei returning to their aligned state.
• As hydrogen nuclei return to their aligned state in MRI, they emit signals
• MRI involves exposure to ionizing radiation.

  False
• MRI is particularly useful for imaging the brain
• What does fMRI detect in the brain?

  Blood flow changes
• Match the imaging method with its primary focus:

  MRI ↔️ Anatomical structures

  fMRI ↔️ Brain activity