Liver angulometry: a simple method to estimate liver volume and ratios

Area of Science:

• Radiology
• Surgical Planning
• Medical Imaging Analysis

Background:

• Volumetry is the standard for assessing liver volumes (right liver, left liver, left lateral segments, total liver, future liver remnant).
• Accurate liver volume assessment is crucial for surgical planning, especially before hepatectomy.

Observation:

• A novel technique, angulometry, uses liver angle measurements on CT scans to predict liver volume ratios.
• Measurements were taken at four preselected CT scan levels, with Level 2 proving most accurate for angulometry.

Findings:

• Angulometry showed a non-significant difference compared to volumetry in estimating the left liver (LL) as a percentage of total liver (TL) volume (38% vs. 36%).
• Angulometry slightly overestimated the left lateral segments (LLS) percentage of TL volume (25% vs. 20%), with a P < 0.05.
• The mean overestimation of LLS percentage by angulometry was 2.7% ± 7.0%.

Implications:

• Angulometry offers a simple and accurate method for estimating future liver remnant (FLR) to total liver (TL) volume ratios from one or two CT slices.
• This technique can assist clinicians in pre-operative planning for right or extended right hepatectomy and post-portal vein occlusion procedures.