Article Figures & Data
Figures
- Fig 1.
ROI placement in the cortical gray and juxtacortical white matter, in the thalamic parenchyma and posterior limb of the internal capsule, in the caudate nucleus (orange ROIs), in an extraocular muscle (red ROI), and in the medulla oblongata (blue ROI) on an axial plane showing the basal ganglia (A), the orbital cavity (B), and the posterior fossa (C).
- Fig 2.
Image noise in extraocular muscle in CI compared with 65-keV virtual monoenergetic images regarding different radiation dose protocols. Significant differences are indicated. The asterisk indicates P = .02; double asterisks, P = .004; triple asterisks, P < .001).
- Fig 3.
The CNR of gray-white matter differentiation in CI compared with 65-keV virtual monoenergetic images regarding different radiation dose protocols. Significant differences are indicated (asterisk, P = .04; double asterisks, P = .02; triple asterisks, P < .001).
- Fig 4.
Examples of improved image quality in 65-keV virtual monoenergetic images acquired with a CTDIvol with 55 mGy (A), 49.8 mGy (B), and 44.7 mGy (C) compared with CI, respectively (D–F).
Tables
CTDIvol (mGy) CI VMI65keV 55 49.8 44.7 55 49.8 44.7 Attenuation GM 34.0 ± 1.4 33.4 ± 1.5 34.1 ± 1.7 34.6 ± 1.3 34.2 ± 1.2 35.1 ± 1.5 WM 26.5 ± 1.2 26.1 ± 1.5 27.0 ± 1.6 26.4 ± 1.1 26.0 ± 1.3 27.1 ± 1.4 Thalamus 33.6 ± 1.5 33.2 ± 1.6 34.4 ± 1.9 34.4 ± 1.4 33.9 ± 1.4 35.5 ± 1.8 Posterior limb 26.5 ± 2.2 26.3 ± 2.0 26.6 ± 2.2 26.1 ± 1.4 26.0 ± 1.7 26.6 ± 2.0 Caudate nucleus 34.5 ± 4.4 35.2 ± 2.1 35.4 ± 2.3 35.7 ± 1.5 35.8 ± 1.8 36.3 ± 2.1 Extraocular muscle 32.8 ± 5.6 31.1 ± 6.4 33.2 ± 8.1 31.9 ± 5.6 30.8 ± 6.2 35.4 ± 9.9 Medulla oblongata 31.5 ± 4.3 32.0 ± 4.5 34.6 ± 4.9 31.1 ± 3.3 31.0 ± 3.0 33.9 ± 3.7 Noise GM 4.5 ± 0.8 4.6 ± 0.7 4.8 ± 0.8 3.1 ± 0.6 3.1 ± 0.5 3.2 ± 0.5 WM 4.5 ± 0.7 4.8 ± 0.8 4.9 ± 0.7 3.0 ± 0.5 3.2 ± 0.5 3.3 ± 0.6 Thalamus 5.8 ± 0.8 6.0 ± 1.0 6.1 ± 1.1 4.0 ± 0.7 4.2 ± 0.8 4.3 ± 0.9 Posterior limb 5.2 ± 1.0 5.5 ± 1.1 5.6 ± 1.3 3.6 ± 0.8 3.7 ± 0.9 3.9 ± 1.0 Caudate nucleus 5.4 ± 1.1 5.6 ± 1.2 5.6 ± 0.8 3.7 ± 0.9 3.8 ± 0.8 3.8 ± 0.6 Extraocular muscle 5.3 ± 1.4 5.6 ± 1.6 6.1 ± 2.1 3.6 ± 1.1 3.7 ± 1.3 4.2 ± 1.6 Medulla oblongata 6.1 ± 1.2 6.4 ± 1.2 6.7 ± 1.4 4.4 ± 1.0 4.6 ± 0.9 4.7 ± 0.9 GM-WM CNR 2.5 ± 0.5 2.4 ± 0.5 2.3 ± 0.5 3.4 ± 0.5 3.3 ± 0.5 3.2 ± 0.5 ↵a Results are means ± SDs.
CTDIvol (mGy) CI VMI65keV 55 49.8 44.7 55 49.8 44.7 GWMA 3 (3–3) 3 (3–3) 3 (3–3) 5 (5–5) 5 (5–5) 5 (4–5) CMAS 3 (3–3) 3 (3–3) 3 (3–4) 5 (5–5) 5 (5–5) 5 (5–5) CMAI 3 (3–3) 3 (3–3) 3 (2–3) 5 (5–5) 5 (5–5) 4 (4–5) SSA 4 (4–5) 4 (4–4) 4 (4–5) 4 (4–5) 4 (4–5) 4 (4–5) Noise 3 (3–3) 2 (2–3) 3 (3–3) 4 (4–4) 4 (4–4) 4 (4–4) Artifacts 3 (3–4) 3 (2–3) 3 (2–3) 4 (4–5) 4 (4–5) 4 (4–4) Note:—GWMA indicates assessment of gray-white matter differentiation of the basal ganglia; CMAS, assessment of corticomedullary differentiation supratentorially; CMAI, assessment of corticomedullary differentiation infratentorially; SSA, assessment of subcalvarial space.
↵a Results are medians (quartiles).
