Salvage of suboptimal enhancement of pulmonary artery in chest CT: Experience using a dual-layer detector spectral CT

Congress:

ESTI ESCR 2018

Poster Number:

P-0047

Type:

Scientific Poster

Keywords:

Embolism / Thrombosis, Contrast agent-intravenous, CT-Angiography, CT, Vascular, Thorax, Arteries / Aorta

Authors:

K. N. Jeon, K. Bae, S. B. Cho, S. Park, J. I. Moon, H. J. Baek, B. H. Choi, K. H. Ryu; Changwon/KR

DOI:

DOI-Link:

https://dx.doi.org/

Fig. 1: 69-year-old man with colon cancer. Image obtained from routine chest CT...

Table 1: Table 1. Characteristics of patients with suboptimal opacification of pulmonary...

Fig. 2: Graph of mean vascular attenuation of pulmonary artery measured at each energy...

Fig. 3: Graph of mean background noise at each energy level in 41 patients with...

Purpose

To evaluate the quality of virtual monoenergetic images (VMIs) from dual-layer detector spectral CTand the effect of VMIs at low energy on detection of pulmonary embolism (PE) in patients with suboptimally enhanced pulmonary artery in chest CT.

Methods and Materials

Of 798 consecutive chest CT scans performed with routine protocol at 120 kVp using a dual-layer detector CT, 41 suboptimally enhanced cases with mean HU of pulmonary artery ≤ 180 HU were included (Table 1). Mean HU of pulmonary artery, background noise, CNR, and SNR ofVMIs reconstructed at 40-200 keV were compared to those of conventional 120-kVp images. VMI with the best CNR wascompared with 120-kVp image with regards to subjective image quality. Two radiologistsindependently reviewed the conventional 120-kVp image and the VMI with the...

Results

Sufficient attenuation of pulmonary artery (> 180 HU) was achievedin 40/41 (97.6%) patientsat 40-70 keV (Fig 1). The mean attenuation of the pulmonary artery on the VMIs at 40–65 keV was significantly (p < 0.001) higher than that on the conventional 120-kVp image (Fig 2). Noise levels of VMIs were gradually increased with decreasing keV. The mean background noise at 40–65 keV was significantly (p < 0.05) higher than that at 120 kVp (Fig 3). The mean background noises at 70 keVwas not significantly different...

Conclusion

VMIs obtained at low energy levels from dual-layer detector spectral CT can be used to obtain sufficient pulmonary artery opacification and can increase diagnostic performance for detecting PE in patients with a suboptimally enhanced pulmonary artery on chest CT. Low and consistent noise enables the use of VMI at low energies to obtain sufficient pulmonary arterial opacification with good CNR and SNR.

References

1. Ozawa Y, Hara M, Shibamoto Y. The frequency of insufficient contrast enhancement of the pulmonary artery in routine contrast-enhanced chest CT and itsimprovement with an increased injection rate: a prospective study. J Thorac Imaging 2011;26:42-47 2. Delesalle MA, Pontana F, Duhamel A, et al. Spectral optimization of chest CTangiography with reduced iodine load: experience in 80 patients evaluated with dual-source, dual-energy CT. Radiology 2013; 267:256-266 3. Yuan R, Shuman WP, Earls JP, et al. Reduced iodine load at CT pulmonary angiography with dual-energy monochromatic...

Personal Information

Kyung Nyeo Jeon, M.D., Ph.D. Department of Radiology, Gyeongsang National University School of Medicine, Jinju, and Gyeongsang National University Changwon Hospital, 555 Samjeongja-dong, Seongsan-gu, Changwon, 51472, Korea E-mail: [email protected]