Sabin O. Cotul, Cecilia Pîglesan, Stefan Tamas
Department of Nuclear Medicine,
3rd Medical Clinic, Cluj-Napoca
(LAS) is a radio-isotope method for the investigation of liver
perfusion and its alteration in various hepatic diseases. It
measures the arterial and portal venous fractions of total liver
blood flow. The percentage of liver blood flow supplied by hepatic
artery is estimated mathematically by the hepatic perfusion
index (HPI), normally between 25% and 40%.
The decrease of portal blood
flow in liver cirrhosis is compensated („buffer”
mechanisms) by increased arterial supply, with higher HPI value.
For a patient with chronic liver disease, HPI over 50% suggests
arterialization of hepatic perfusion, guiding the diagnose to
liver cirrhosis. Splenic curve is completing the diagnostic
informations of the hepatic curve. Corroborated with per rectal
scintigraphy and liver SPECT, LAS offers a good hemodynamic
staging of chronic inflammatory liver diseases.
Malignant tumors (primitive
or metastases) increase the arterial supply of the liver and
decrease the portal flow, HPI being over 50% (currently 65%-90%).
Benign tumors do not change portal/arterial liver blood flow
ratio. SPECT or non-scintigraphic morphological investigations
increase the diagnostic value of LAS for primitive liver tumors.
Liver cancer occurring on cirrhosis is a limitative factor for
Hepatic metastases increase
the arterial perfusion (and HPI value) very quickly, before
their size allows morphologic imaging diagnosis. LAS is therefore
an early method to diagnose liver metastases being especially
used in colorectal cancer.
Other clinical applications
of LAS are: follow up of liver toxicity of drugs, evaluation
of portal vein permeability, post surgery follow up of the liver
- hepatic blood flow - hepatocellular carcinoma - cirrhosis