Quantitative analysis of iodine enhancement
Philips CT Clinical Science
A 77 year-old male was examined and was found to have several liver lesions. Dual-energy CT was used to assess the level of iodine enhancement in each lesion.
A contrast-enhanced DECT study was performed using a Philips iCT 256-slice CT scanner. The images were reconstructed using the iDose4 reconstruction technique (Figure 1a and b), and were assessed using the Spectral Analysis application (extended Brilliance Workspace version 4.5, Philips Healthcare). Regions of interest (ROIs) were placed in two lesions and a visually homogenous region of liver parenchyma, and dual-energy analysis was performed.
- Axial scan mode
- iDose4 Level 4
- 80 / 140 kVp
- 460 / 90 mAs
- 2.5 mm slice thickness
- 0.5 second rotation speed
- 64 × 0.625 mm collimation
- 75.2 mGy × cm DLP
- (32cm) 9.4 x 2 mGy CTDIvol
- 1.13 mSv effective dose
Lesion enhancement visualized at 80 kVp.
Lesion enhancement visualized at 140 kVp.
Figure 3: Dual energy CT map
iDose4 reduced image noise and allowed greater detail to be seen in the quantitative analysis.
Quantitative analysis of iodine enhancement was performed on the dual-energy data in delayed phase images relative to liver parenchyma (Figure 2a and 2b). One lesion (ROI 2 in Figure 2a and 2b) demonstrated washout in the delayed enhancement phase, subsequent to early enhancement in the arterial phase. The other lesion (ROI 1 in Figure 2a and 2b) demonstrated central hypoenhancement in the delayed phase and other phases. The use of the iDose4 reconstruction technique reduced image noise and allowed greater detail to be seen in the quantitative analysis (Figure 3).
Quantitative analysis of the iodine enhancement was demonstrated using a combination of dual-energy CT acquisition and a reconstruction technique. The advanced technologies of the iCT, in combination with iDose4, allow imaging at low dose with high image quality.