Diagnostic approach to restricted-diffusion patterns on MR imaging

Abstract

The vast majority of restricted-diffusion abnormalities result from acute stroke, and as such, the diagnosis may be problematic when this MRI feature results from other causes. Distinct patterns of restricted diffusion seen with various disease conditions can play an important diagnostic role. The association of certain diseases with a given restricted-diffusion pattern allows for a focused assessment to determine a specific etiology.

Diffusion-weighted and apparent diffusion coefficient images for case studies Figure 1. (A, B) Diffusion-weighted imaging (DWI) (arrowheads) and apparent diffusion coefficient (ADC) with restricted diffusion in right middle cerebral artery territory due to acute cerebral infarction. (C, D) DWI (arrowheads) and ADC with restricted diffusion of left parietooccipital cortex due to Creutzfeldt-Jakob disease. (E, F) DWI and ADC with restricted diffusion of cerebral cortex (arrows), basal ganglia, and thalamus (arrowhead) secondary to hyperammonemic encephalopathy. (G, H) DWI (arrowhead) and ADC with restricted diffusion of both caudate nuclei due to ischemic infarction. (I, J) DWI (arrowheads) and ADC with restricted diffusion of centrum semiovale from carbon monoxide poisoning. (K, L) DWI (arrowheads) and ADC with restricted diffusion of white matter and basal ganglia from hypoxic-ischemic injury. (M–O) DWI, ADC, and DWI with restricted diffusion of hemispheric white matter (arrowheads) and cerebral cortex (arrowhead) due to hypoxic-ischemic injury. (P, Q) DWI (arrowhead) and ADC with restricted diffusion of right cerebellar hemisphere secondary to pyogenic abscess. (R, S) DWI (arrowhead) and ADC with ring pattern restricted diffusion of posterior right frontal white matter due to demyelinating disease.

Diagnostic patterns on restricted diffusion Figure 2. *Subacute/chronic. B = basal ganglia; CJD = Creutzfeldt-Jakob disease; CO = carbon monoxide; HSE = herpes simplex encephalitis; H-I = hypoxic-ischemic; PRES = posterior reversible encephalopathy syndrome; RCVS = reversible cerebral vasoconstrictive syndrome; T = thalamus.