Dual-Energy Computed Tomography for Fat Quantification in the Liver and Bone Marrow: A Literature Review

BACKGROUND:  With dual-energy computed tomography (DECT) it is possible to quantify certain elements and tissues by their specific attenuation, which is dependent on the X-ray spectrum. This systematic review provides an overview of the suitability of DECT for fat quantification in clinical diagnostics compared to established methods, such as histology, magnetic resonance imaging (MRI) and single-energy computed tomography (SECT).

METHOD:  Following a systematic literature search, studies which validated DECT fat quantification by other modalities were included. The methodological heterogeneity of all included studies was processed. The study results are presented and discussed according to the target organ and specifically for each modality of comparison.

RESULTS:  Heterogeneity of the study methodology was high. The DECT data was generated by sequential CT scans, fast-kVp-switching DECT, or dual-source DECT. All included studies focused on the suitability of DECT for the diagnosis of hepatic steatosis and for the determination of the bone marrow fat percentage and the influence of bone marrow fat on the measurement of bone mineral density. Fat quantification in the liver and bone marrow by DECT showed valid results compared to histology, MRI chemical shift relaxometry, magnetic resonance spectroscopy, and SECT. For determination of hepatic steatosis in contrast-enhanced CT images, DECT was clearly superior to SECT. The measurement of bone marrow fat percentage via DECT enabled the bone mineral density quantification more reliably.

CONCLUSION:  DECT is an overall valid method for fat quantification in the liver and bone marrow. In contrast to SECT, it is especially advantageous to diagnose hepatic steatosis in contrast-enhanced CT examinations. In the bone marrow DECT fat quantification allows more valid quantification of bone mineral density than conventional methods. Complementary studies concerning DECT fat quantification by split-filter DECT or dual-layer spectral CT and further studies on other organ systems should be conducted.

KEY POINTS: · DECT fat quantification in the liver and bone marrow is reliable.. · DECT is clearly superior to SECT in contrast-enhanced CT images.. · DECT bone marrow fat quantification enables better bone mineral density determination.. · Complementary studies with split-filter DECT or dual-layer spectral CT as well as studies in other organ systems are recommended..

CITATION FORMAT: · Molwitz I, Leiderer M, Özden C et al. Dual-Energy Computed Tomography for Fat Quantification in the Liver and Bone Marrow: A Literature Review. Fortschr Röntgenstr 2020; 192: 1137 - 1152.