Non-linear image blending improves visualization of head and neck primary squamous cell carcinoma compared to linear blending in dual-energy CT

Publication

Non-linear image blending improves visualization of head and neck primary squamous cell carcinoma compared to linear blending in dual-energy CT

Journal Paper/Review - Dec 6, 2014

Scholtz J-E, Vogl T J, Lehnert T, Bauer Ralf, Kerl J M, Wagenblast J, Bodelle B, Frellesen C, Schulz B, Albrecht M, Kaup M, Hüsers K, Wichmann J L

Citation

Scholtz J, Vogl T, Lehnert T, Bauer R, Kerl J, Wagenblast J, Bodelle B, Frellesen C, Schulz B, Albrecht M, Kaup M, Hüsers K, Wichmann J. Non-linear image blending improves visualization of head and neck primary squamous cell carcinoma compared to linear blending in dual-energy CT. Clin Radiol 2014; 70:168-75.

Type

Journal Paper/Review (English)

Journal

Clin Radiol 2014; 70

Publication Date

Dec 6, 2014

Issn Electronic

1365-229X

Pages

168-75

Brief description/objective

AIM
To compare non-linear and linear image-blending post-processing techniques in dual-energy CT (DECT) of primary head and neck squamous cell carcinoma (SCC) regarding subjective and objective image quality.

MATERIALS AND METHODS
Head and neck DECT studies from 69 patients (48 male, 21 female; mean age 62.3 years) were retrospectively evaluated. All tumour lesions were histologically confirmed SCC. Linearly blended 80/140 kVp images series with varying weighting factors of 0.3 (M_0.3), 0.6 and 0.8 were compared with non-linearly blended images. Attenuation of tumour lesion, various soft-tissue structures, the internal jugular vein, and image noise were measured, tumour signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were calculated. Overall image quality, delineation of tumour lesion, image sharpness, and noise level were rated individually by three radiologists using five-point Likert scales. Interobserver agreement was calculated using intraclass correlation coefficient (ICC).

RESULTS
Enhancement of tumour lesions (non-linear, 137.5 ± 20.1 HU; M_0.3, 92.7 ± 14.4 HU; M_0.6, 110 ± 15.4 HU; M_0.8, 123 ± 18.2 HU), CNR (non-linear, 12 ± 8; M_0.3, 4 ± 4.7; M_0.6, 7.5 ± 5.5; M_0.8, 8 ± 5.5), subjective overall image quality and tumour delineation were significantly increased (all p < 0.001) with the non-linear blending technique compared to all investigated linear blending weighting factors. Overall interobserver agreement was substantial (ICC 0.70; 95% CI: 0.66-0.73).

CONCLUSION
Post-processing of DECT using a non-linear blending technique provides improved objective and subjective image quality of head and neck SCC compared to linearly blended images series.