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Subcutaneous tissue thickness is an independent predictor of image noise in cardiac CT.

Staniak HL, Sharovsky R, Pereira AC, Castro CC, Benseñor IM, Lotufo PA, Bittencourt MS - Arq. Bras. Cardiol. (2013)

Bottom Line: The mean image noise in CT was 36.3 ± 8.5 HU, and the mean image noise in non-contrast scan was 17.7 ± 4.4 HU.The best predictors were SS thickness, with a correlation of 0.70 (p < 0.001), and noise in the non-contrast images, with a correlation of 0.73 (p < 0.001).When evaluating the ability to predict low image noise, the areas under the ROC curve for the non-contrast noise and for the SS thickness were 0.837 and 0.864, respectively.

View Article: PubMed Central - PubMed

Affiliation: Universidade de São Paulo, Hospital Universitário, São PauloSP, Brasil.

ABSTRACT

Background: Few data on the definition of simple robust parameters to predict image noise in cardiac computed tomography (CT) exist.

Objectives: To evaluate the value of a simple measure of subcutaneous tissue as a predictor of image noise in cardiac CT.

Methods: 86 patients underwent prospective ECG-gated coronary computed tomographic angiography (CTA) and coronary calcium scoring (CAC) with 120 kV and 150 mA. The image quality was objectively measured by the image noise in the aorta in the cardiac CTA, and low noise was defined as noise < 30 HU. The chest anteroposterior diameter and lateral width, the image noise in the aorta and the skin-sternum (SS) thickness were measured as predictors of cardiac CTA noise. The association of the predictors and image noise was performed by using Pearson correlation.

Results: The mean radiation dose was 3.5 ± 1.5 mSv. The mean image noise in CT was 36.3 ± 8.5 HU, and the mean image noise in non-contrast scan was 17.7 ± 4.4 HU. All predictors were independently associated with cardiac CTA noise. The best predictors were SS thickness, with a correlation of 0.70 (p < 0.001), and noise in the non-contrast images, with a correlation of 0.73 (p < 0.001). When evaluating the ability to predict low image noise, the areas under the ROC curve for the non-contrast noise and for the SS thickness were 0.837 and 0.864, respectively.

Conclusion: Both SS thickness and CAC noise are simple accurate predictors of cardiac CTA image noise. Those parameters can be incorporated in standard CT protocols to adequately adjust radiation exposure.

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Related in: MedlinePlus

Scatter plots of each of the predictors vs. cardiac CTA noise, including theregression lines. A) AP diameter; B) Lateral width; C) BMI; D) CAC noise; and E)Skin-sternum thickness.
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f02: Scatter plots of each of the predictors vs. cardiac CTA noise, including theregression lines. A) AP diameter; B) Lateral width; C) BMI; D) CAC noise; and E)Skin-sternum thickness.

Mentions: All individual parameters were significantly associated with the noise in the cardiacCTA. Pearson correlation values are shown in Table2, and the correlation matrix is shown in Figure 2. In a pairwise comparison, the CAC noise, BMI and SS thickness havea more significant correlation with cardiac CTA noise than any of the chest diameters (p< 0.001 for all comparisons). The correlation of CAC noise with outcome showed atrend towards being more significant than BMI (p = 0.05), whereas the CAC noise and SSthickness (p = 0.16), as well as the SS thickness and BMI correlations (p = 0.13) werenot significantly different. In the multivariate analysis, the best prediction modelincluded the association of CAC noise and SS thickness, with an adjusted R2of 0.61 (p < 0.0001).


Subcutaneous tissue thickness is an independent predictor of image noise in cardiac CT.

Staniak HL, Sharovsky R, Pereira AC, Castro CC, Benseñor IM, Lotufo PA, Bittencourt MS - Arq. Bras. Cardiol. (2013)

Scatter plots of each of the predictors vs. cardiac CTA noise, including theregression lines. A) AP diameter; B) Lateral width; C) BMI; D) CAC noise; and E)Skin-sternum thickness.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3987400&req=5

f02: Scatter plots of each of the predictors vs. cardiac CTA noise, including theregression lines. A) AP diameter; B) Lateral width; C) BMI; D) CAC noise; and E)Skin-sternum thickness.
Mentions: All individual parameters were significantly associated with the noise in the cardiacCTA. Pearson correlation values are shown in Table2, and the correlation matrix is shown in Figure 2. In a pairwise comparison, the CAC noise, BMI and SS thickness havea more significant correlation with cardiac CTA noise than any of the chest diameters (p< 0.001 for all comparisons). The correlation of CAC noise with outcome showed atrend towards being more significant than BMI (p = 0.05), whereas the CAC noise and SSthickness (p = 0.16), as well as the SS thickness and BMI correlations (p = 0.13) werenot significantly different. In the multivariate analysis, the best prediction modelincluded the association of CAC noise and SS thickness, with an adjusted R2of 0.61 (p < 0.0001).

Bottom Line: The mean image noise in CT was 36.3 ± 8.5 HU, and the mean image noise in non-contrast scan was 17.7 ± 4.4 HU.The best predictors were SS thickness, with a correlation of 0.70 (p < 0.001), and noise in the non-contrast images, with a correlation of 0.73 (p < 0.001).When evaluating the ability to predict low image noise, the areas under the ROC curve for the non-contrast noise and for the SS thickness were 0.837 and 0.864, respectively.

View Article: PubMed Central - PubMed

Affiliation: Universidade de São Paulo, Hospital Universitário, São PauloSP, Brasil.

ABSTRACT

Background: Few data on the definition of simple robust parameters to predict image noise in cardiac computed tomography (CT) exist.

Objectives: To evaluate the value of a simple measure of subcutaneous tissue as a predictor of image noise in cardiac CT.

Methods: 86 patients underwent prospective ECG-gated coronary computed tomographic angiography (CTA) and coronary calcium scoring (CAC) with 120 kV and 150 mA. The image quality was objectively measured by the image noise in the aorta in the cardiac CTA, and low noise was defined as noise < 30 HU. The chest anteroposterior diameter and lateral width, the image noise in the aorta and the skin-sternum (SS) thickness were measured as predictors of cardiac CTA noise. The association of the predictors and image noise was performed by using Pearson correlation.

Results: The mean radiation dose was 3.5 ± 1.5 mSv. The mean image noise in CT was 36.3 ± 8.5 HU, and the mean image noise in non-contrast scan was 17.7 ± 4.4 HU. All predictors were independently associated with cardiac CTA noise. The best predictors were SS thickness, with a correlation of 0.70 (p < 0.001), and noise in the non-contrast images, with a correlation of 0.73 (p < 0.001). When evaluating the ability to predict low image noise, the areas under the ROC curve for the non-contrast noise and for the SS thickness were 0.837 and 0.864, respectively.

Conclusion: Both SS thickness and CAC noise are simple accurate predictors of cardiac CTA image noise. Those parameters can be incorporated in standard CT protocols to adequately adjust radiation exposure.

Show MeSH
Related in: MedlinePlus