Liver Attenuation Assessment in Reduced Radiation Chest Computed Tomography

Area of Science:

• Radiology
• Medical Imaging
• Low-Dose CT

Background:

• Normal-dose computed tomography (NDCT) provides baseline measurements for abdominal organs.
• Reduced radiation computed tomography (RRCT) aims to decrease radiation exposure while maintaining diagnostic quality.
• Artificial intelligence (AI) denoising methods are being explored to improve image quality in low-dose CT.

Purpose of the Study:

• To evaluate the reliability of liver and spleen Hounsfield unit (HU) measurements in sub-millisievert chest RRCT.
• To assess the diagnostic performance of RRCT for fatty liver detection compared to NDCT.

Main Methods:

• Prospective study comparing unenhanced NDCT with two denoised RRCT (dRRCT) series.
• Measurements of hepatic and splenic attenuation were taken on all four series.
• Statistical analysis (Wilcoxon test) was used to compare HU measurements.
• Fatty liver detection performance was evaluated using NDCT as the reference standard.

Main Results:

• Liver attenuation differed significantly between NDCT and RRCTs (P < 0.01).
• RRCT demonstrated high specificity (>98.5%), sensitivity (>50%), and accuracy (>94.3%) for fatty liver detection.
• Six patients (8.3%) were diagnosed with fatty liver on NDCT.

Conclusions:

• While HU measurements differ between NDCT and RRCTs, RRCT shows potential diagnostic value for hepatosteatosis.
• Abdominal organ attenuation in RRCT protocols may vary from NDCT and requires validation for new low-dose protocols.