Transient hepatic intensity difference

Transient hepatic intensity differences (THIDs) are a phenomenon observed on MRI imaging of the liver. They are considered a direct equivalent to transient hepatic attenuation differences (THADs) noted on CT. They may be focal or nonfocal.


Focal lesions

A focal THID lesion can arise from four pathological mechanisms

  • directly by a siphoning effect (lobar multisegmental shape)
  • indirectly by means of portal hypoperfusion (sectorial shape) due to portal branch compression or infiltration
  • by thrombosis resulting in a portal branch blockade
  • by flow diversion caused by an arterioportal shunt
Nonfocal lesions

These can be sectorial, polymorphous or diffuse and can arise from a variety of etiologies.

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Article information

rID: 17528
Synonyms or Alternate Spellings:
  • Transient hepatic intensity differences (THID)
  • THID
  • Transient hepatic intensity difference (THID)
  • THIDs

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Cases and figures

  • Case 1: THID secondary to portal vein thrombosis
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