Copyright ©2012 Baishideng Publishing Group Co.
World J Radiol. Mar 28, 2012; 4(3): 63-74
Published online Mar 28, 2012. doi: 10.4329/wjr.v4.i3.63
Table 1 Patterns of discrepancy between perfusion-weighted imaging and diffusion-weighted imaging
PatternIncidence %Main etiologyIndicationsPotential interventions
< 6 hTotal
IPWI > DWI[20,47,51-53,114,121,125,127-130,135], target mismatch57~8649~70Large-artery atherosclerosis, cardioembolism, cryptogenicLarger lesion on PWI and DWI. Part of tissue at risk and oligemia. Infarct may growth without effective therapy. More common in white patientsReperfusion therapy: Thrombolytic therapy or angioplasty, stenting
IIPWI = DWI[20,52,125,131]~17~28Cryptogenic, large-artery atherosclerosis, cardioembolism, lacunar infarctionNo additional tissue at risk. Collateral flow limits the infarct volume to that depicted at DWI. Most common in patients with diabetesNeuroprotection
IIIPWI < DWI[51,52,114,123,132], inverse mismatch~296~34Cryptogenic, cardioembolism, large-artery atherosclerosis, lacunar infarctionSmaller lesion on PWI and DWI. Partial reperfusion may occur at the time of MR scanNeuroprotection
IVPWI (-), DWI (+)[47,114,125]~8~24Single small MCA branch occlusion, small subclinical infarctFull reperfusion may occur or due to collaterals at the time of MR scan. More common in Asian patientsNeuroprotection
VPWI (+), DWI (-)[47,80,128,133,134], total mismatch~8~3Migraine, TIAPure perfusion deficit (tissue at risk but not committed to infarction)Reperfusion therapy
VIPWI (-), DWI (-)[20,135]~14~18Migraine, TIANo abnormality on both PWI and DWI. Normal or hypoperfusion on PETNo interventional therapy
VIIPWI or DWI > 100 mL[82,112], malignant mismatchLarge-artery atherosclerosisPoor outcome, strongly associated with reperfusion-related brain hemorrhageExclusion of therapy