Brain Mass Effect
Mass effect is the compression and displacement of normal brain structures caused by an adjacent space-occupying process. [1] It commonly results in deformation of ventricles and sulci due to displacement of brain tissue. [1]
What Causes Mass Effect
Mass effect can be produced by intracranial masses such as tumors, hemorrhages, edema, or obstruction of cerebrospinal fluid (CSF) flow. [3] Mass effect can occur with traumatic brain injury-related collections and with stroke-related or tumor-related space-occupying edema. [3]
How Mass Effect Shows Up on Imaging
Mass effect is often inferred from imaging evidence of displaced midline structures, compressed ventricles, and sulcal effacement. [1] Midline shift is a commonly used imaging marker of mass effect that reflects displacement of midline brain structures. [2]
Why Mass Effect Matters Clinically
Mass effect can increase intracranial pressure and impair cerebral perfusion by physically deforming brain tissue and altering CSF pathways. [2] Progressive space-occupying effects can be associated with neurological deterioration. [2]
Related Terms Commonly Seen in Radiology Reports
Sulcal effacement indicates crowding of brain grooves due to local volume effect. [1] Basilar cistern compression and ventricular compression reflect narrowing of CSF-containing spaces by the mass effect. [1]
Practical Interpretation Limits
The degree of mass effect on imaging can be subjective in some contexts since measurable findings such as midline shift may not be present in all cases. [4]