Protocol for measurement of liver fat by computed tomography.
To develop a protocol for measurement of liver fat using computed tomography (CT), we conducted a preliminary study with 118 men and 76 women to determine a readily identifiable vertebral landmark at which the CT image displayed both liver and spleen. Analysis of five landmarks revealed that the CT image obtained at the T12-L1 level simultaneously displayed the liver and spleen in 90% of the men and women. The T12-L1 protocol was cross-validated on a sample of 130 men and 113 women. In this sample, we also assessed the regional characteristics of liver and spleen tissue attenuation at the T12-L1 level by subdividing each image into quartiles from anterior to posterior, each of which were further divided into medial and lateral regions. A similar analysis was performed on images located 12 mm above and below T12-L1. The T12-L1 image displayed both liver and spleen in 92% (403 of 437) of the combined study sample. There was a significant (P<0.005) stepwise increase in attenuation values [Hounsfield units (HU)] from the inferior to superior image. Although some significant (P<0.05) differences were observed between the eight regions by comparison to the whole liver or spleen, the average magnitude of the difference was <2.0 HU for liver and <3.5 HU for spleen. Acquisition of a single CT image at the T12-L1 level is a practical and reliable method for routine measurement of liver fat in research and clinical settings.
Davidson
Lance E
LE
School of Physical and Health Education, Division of Endocrinology and Metabolism, Department of Medicine, Queen's Univ., Kingston, Ontario, Canada K7L 3N6.
Kuk
Jennifer L
JL
Church
Timothy S
TS
Ross
Robert
R
D000328:Adult; D000368:Aged; D002985:Clinical Protocols; D005234:Fatty Liver / Q000000981:diagnostic imaging* / Q000473:pathology; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008055:Lipids / Q000032:analysis*; D008099:Liver / Q000737:chemistry* / Q000000981:diagnostic imaging* / Q000473:pathology; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging / Q000473:pathology; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D015203:Reproducibility of Results; D013154:Spleen / Q000000981:diagnostic imaging / Q000473:pathology; D013904:Thoracic Vertebrae / Q000000981:diagnostic imaging / Q000473:pathology; D014057:Tomography, X-Ray Computed / Q000379:methods*
D008055:Lipids