MRI Brain Imaging Basics Quiz

Patient Positioning and Immobilization

• Patient positioned so that longitudinal alignment light lies in the midline and horizontal alignment light passes through the nasion.
• Straps and foam pads used for immobilization.

MRI Sequences of the Brain

• T1-Weighted Axial Imaging: 5-6 mm slice thickness, provides detailed anatomical information, detects tumors, and is used as a baseline for post-contrast imaging.
• T2-Weighted Axial Imaging: 5-6 mm slice thickness, highlights lesions, edema, and cysts, and is good for detecting white matter diseases and brain abnormalities.
• T1-Weighted Coronal Imaging: 5-6 mm slice thickness, provides a different perspective of brain anatomy, especially useful for assessing the pituitary gland and other coronal structures.
• Fluid-Attenuated Inversion Recovery (FLAIR) Imaging: 5-6 mm slice thickness, suppresses CSF signal and enhances lesion visibility, helpful in detecting multiple sclerosis lesions and vascular abnormalities.
• Diffusion-Weighted Imaging (DWI): 5-6 mm slice thickness, b-values typically 0 and 1000 sec/mm², detects areas of restricted diffusion, valuable for diagnosing acute stroke and evaluating tissue damage.
• Diffusion Tensor Imaging (DTI): 2-3 mm slice thickness, maps white matter tracts, assesses brain connectivity, and studies conditions like traumatic brain injury and white matter diseases.
• Susceptibility-Weighted Imaging (SWI): 1-2 mm slice thickness, detects hemorrhages, microbleeds, and venous abnormalities, useful in cases of head trauma and vascular disorders.
• Functional MRI (fMRI): includes T2*-weighted or BOLD sequences, maps brain activity and connectivity during tasks or at rest, used in research and preoperative planning.
• Magnetic Resonance Spectroscopy (MRS): acquires spectra from specific regions of interest, measures biochemical information about brain tissue, aids in characterizing brain lesions, tumors, and metabolic disorders.
• Perfusion MRI (pMRI): uses dynamic contrast enhancement or arterial spin labeling, measures blood flow to assess brain perfusion, valuable in diagnosing and monitoring acute stroke, vasculitis, and tumor response to treatment.

Importance of Brain MRI Imaging

• Brain MRI imaging essential for MRI technologists to perform MRI exams effectively and interpret MRI results accurately.
• Provides information about brain anatomy, detects abnormalities, and measures blood flow and diffusion in the brain.

Common Indications for Brain MRI

• MS
• Primary tumor assessment and/or metastatic disease
• AIDS (toxoplasmosis)
• Infarction (cerebral vascular accident (CVA) versus transient ischemic attack (TIA))
• Hemorrhage
• Hearing loss
• Visual disturbances
• Infection
• Trauma
• Unexplained neurological symptoms or deficit
• Preoperative planning
• Radiation treatment planning
• Follow-up (surgical or treatment)

Equipment and Patient Positioning

• Head coil (quadrature or multi-coil array)
• Immobilization pads and straps
• Earplugs/headphones
• High-performance gradients for EPI, diffusion, and perfusion imaging
• Patient positioned supine on the examination couch with their head within the head coil, inter-pupillary line parallel to the couch, and head straight.

Test your knowledge on brain MRI imaging basics with this quiz. Covering topics such as understanding MRI technology, interpreting results, and optimizing parameters for brain scans.