Devices for recording, imaging, and modulating neural activity — from diagnostic EEG to therapeutic brain stimulation. Clinical and research applications.
Electroencephalography (EEG)Diagnostic
Records electrical activity of the brain
Non-invasive scalp electrodes measure voltage fluctuations from neuronal firing. Used for epilepsy diagnosis, sleep studies, brain death assessment, and cognitive research. Temporal resolution: milliseconds.
Clinical use since 1924 | Manufacturers: Natus, Compumedics, Nihon Kohden
Functional MRI (fMRI)Imaging
Measures brain activity via blood flow changes
Detects BOLD (blood-oxygen-level dependent) signal changes associated with neural activity. Spatial resolution: 1-3mm. Used for pre-surgical mapping, cognitive neuroscience, and psychiatric research.
Field strength: 1.5T - 7T | Manufacturers: Siemens, GE, Philips
Structural MRIAnatomical
High-resolution brain anatomy imaging
Provides detailed 3D images of brain structures. Detects tumors, stroke, multiple sclerosis lesions, and neurodegenerative atrophy. T1, T2, and FLAIR sequences for different tissue contrasts.
Resolution: 1mm isotropic | Clinical standard for neuroimaging
Magnetoencephalography (MEG)Magnetic
Records magnetic fields from neural activity
Superconducting quantum interference devices (SQUIDs) detect magnetic fields produced by neuronal currents. Millisecond temporal resolution. Used for epilepsy focus localization and pre-surgical planning.
306 channels | Manufacturers: MEGIN, Elekta
Positron Emission Tomography (PET)Metabolic
Measures brain metabolism and molecular targets
Tracers like FDG-18 measure glucose metabolism. Amyloid and tau PET detects Alzheimer's pathology. Dopamine transporter PET for Parkinson's diagnosis.
Tracers: FDG, PiB, Flortaucipir | Combined PET/CT or PET/MRI systems
CT Scan (Brain)Structural
Rapid brain imaging for emergencies
X-ray computed tomography for acute stroke, hemorrhage, trauma, and mass effect detection. Acquisition time: 5-10 minutes. First-line imaging in emergency settings.
Slice count: 64-320 | Non-contrast CT standard for acute stroke
Transcranial Magnetic Stimulation (TMS)Therapeutic
Non-invasive brain stimulation
Electromagnetic induction generates electrical currents in specific brain regions. FDA-approved for treatment-resistant depression, migraine, and OCD. Repetitive TMS (rTMS) protocols for neuromodulation.
Manufacturers: MagVenture, NeuroStar, BrainsWay
Deep Brain Stimulation (DBS)Implantable
Neural implant for movement disorders
Implanted electrodes deliver continuous electrical stimulation to targeted brain regions (subthalamic nucleus, globus pallidus). Used in Parkinson's disease, essential tremor, dystonia. Over 200,000 implants worldwide.
Manufacturers: Medtronic, Boston Scientific, Abbott
Brain-Computer Interface (BCI)Emerging
Direct neural-to-digital communication
Invasive (Utah array, Neuralink) and non-invasive (EEG-based) systems that translate neural signals into computer commands. Applications: assistive communication for paralysis, prosthetic control.
Clinical trials ongoing | Blackrock Neurotech, Synchron, Neuralink
Electrocorticography (ECoG)Invasive
Direct cortical surface recording
Electrode arrays placed directly on exposed brain surface during neurosurgery. Higher spatial resolution than EEG. Used for epilepsy monitoring and research BCI applications.
Subdural grid or strip electrodes | Intraoperative monitoring