Affiliations: Department of Radiology, The First Affiliated Hospital
of Anhui Medical University, Hefei, Anhui, China | General Electric CT Research Center, Beijing,
China | Tokyo Women's University, Tokyo, Japan
Note: [] Corresponding author: Bin Liu, MD, Department of Radiology, The
First Affiliated Hospital of Anhui Medical University, Hefei 230022, Anhui,
China. Tel.: +86 139 5516 7161; E-mail: liubin1305@126.com
Abstract: Purpose: The purpose of this study was to investigate the value of
spectral CT monoenergetic imaging for detecting hemoglobin levels. Material and methods: Sixty-five hospitalized patients received
chest non-contrast CT scan in gemstone spectral imaging (GSI) mode on a GE
Discovery CT750 HD. This study was approved by the hospital ethics committee
and informed consent was signed by every patient. Raw data were reconstructed
at 1.25 mm and then transferred to a AW4.4 workstation. The CT value of the
ascending aorta at 40 keV∼140 keV was measured under GSI viewer of AW4.4.
Hemoglobin contents were measured biochemically within 24 hrs after CT scan.
The SPSS 16.0 software package was used to analyze the correlation between the
obtained CT value and hemoglobin level. Results: At 40 keV ∼ 100 keV, the CT value decreased followed by
the increase of keV and gradually stabilized at 100 keV ∼ 140 keV with an
amplitude variation of 10 HU. The CT values measured at 40 keV ∼ 140 keV
were well correlated with hemoglobin levels. The optimal correlation was
observed at the monoenergetic level of 70 keV (r=0.633, p=0.000). The
relationship between CT value and hemoglobin content could be expressed as CT
value=13.015+0.245 × hemoglobin content. At 40 keV ∼ 140 keV, there
is strong linear correlation between the CT value of the ascending aorta and
hemoglobin content. The optimal linear relationship was observed at 70 keV.
Conclusion: Spectral CT monoenergetic imaging can be applied for
quantitative determination of hemoglobin content within a specified area of the
circulatory system.
Keywords: Poly-energetic imaging, monoenergetic imaging, energy spectrum scan, hemoglobin
