Publication Details

Title :

Low-dose attenuation correction in diagnosis of non-alcoholic fatty liver disease


Abdominal Radiology

Impact Factor:



Amjad M. Ahmed 1

Mohamed E. Ebid 1

Amr M. Ajlan 2

Mouaz H. Al-Mallah 1 3 4


King Abdulaziz Cardiac Center King Abdulaziz Medical City for National Guard – Health Affairs Riyadh Kingdom of Saudi Arabia

King AbdulAziz University Hospital Jeddah Kingdom of Saudi Arabia

King Saud Bin Abdulaziz University for Health Sciences Riyadh Kingdom of Saudi Arabia

King Abdullah International Medical Research Center Riyadh Kingdom of Saudi Arabia

Year of Publication:






Non-enhanced computed tomography (CT) is a valuable modality in the diagnosis of non-alcoholic fatty liver disease (NAFLD). However, it is not clear if low-dose CT attenuation correction (CTAC) scans have the same accuracy to diagnose NAFLD. Our aim is to evaluate the diagnostic accuracy of low-dose CTAC in the diagnosis of NAFLD using non-enhanced CT as a gold standard.


A total of 864 patients who underwent a clinically indicated hybrid nuclear imaging scanning between May 2011 and April 2014 were included in the study. Diagnosis of fatty liver was established if an absolute liver attenuation was <40 Hounsfield units and/or a liver-to-spleen ratio was <1.1. The diagnostic accuracy parameters were calculated to detect NAFLD by low-dose CTAC using unenhanced CT as a gold standard.


The prevalence of fatty liver by diagnostic CT and low-dose attenuation correction were 9.9 and 12.9% (using liver attenuation <40HU and liver-to-spleen ratio <1.1), respectively, with 32.9 and 34.9% (using absolute liver attenuation or ratio-to-spleen criteria), correspondingly. Low-dose CTAC had sensitivity (81.3%), specificity (94.0%), positive predictive value (60.2%), and negative predictive value (97.8%) using both diagnostic criteria. Using either of the diagnostic criteria resulted in sensitivity (76.8%), specificity (83.5%), PPV (66.3%), and NPV (89.5%).


Low-dose CT could be used as a tool to rule out the presence of fatty liver if neither liver attenuation of less than 40 HU nor liver-to-spleen below 1.1 is present.