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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

Receiver operating characteristic curves for each of the predictors as anestimator of ‘low image noise’ in cardiac CTA. The area under the ROC curve valueis presented in the legend for each parameter. APD: anteroposterior diameter; LW:lateral width; SS: skin-sternum thickness; BMI: body mass index; CAC: calciumscore.
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f03: Receiver operating characteristic curves for each of the predictors as anestimator of ‘low image noise’ in cardiac CTA. The area under the ROC curve valueis presented in the legend for each parameter. APD: anteroposterior diameter; LW:lateral width; SS: skin-sternum thickness; BMI: body mass index; CAC: calciumscore.

Mentions: Similarly, the best independent predictor of 'low noise' was SS thickness with an areaunder the ROC curve (AUC) of 0.86 (95% confidence interval (CI): 0.79 - 0.94) (Figure 3), followed by CAC noise (AUC of 0.84; 95%CI: 0.75 - 0.93), BMI (AUC of 0.80; 95% CI: 0.69 - 0.91), chest AP diameter (AUC of0.62, 95% CI: 0.49 - 0.75), and chest lateral width (AUC of 0.59; 95% CI: 0.47 - 0.73)(Figure 2).


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)

Receiver operating characteristic curves for each of the predictors as anestimator of ‘low image noise’ in cardiac CTA. The area under the ROC curve valueis presented in the legend for each parameter. APD: anteroposterior diameter; LW:lateral width; SS: skin-sternum thickness; BMI: body mass index; CAC: calciumscore.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

f03: Receiver operating characteristic curves for each of the predictors as anestimator of ‘low image noise’ in cardiac CTA. The area under the ROC curve valueis presented in the legend for each parameter. APD: anteroposterior diameter; LW:lateral width; SS: skin-sternum thickness; BMI: body mass index; CAC: calciumscore.
Mentions: Similarly, the best independent predictor of 'low noise' was SS thickness with an areaunder the ROC curve (AUC) of 0.86 (95% confidence interval (CI): 0.79 - 0.94) (Figure 3), followed by CAC noise (AUC of 0.84; 95%CI: 0.75 - 0.93), BMI (AUC of 0.80; 95% CI: 0.69 - 0.91), chest AP diameter (AUC of0.62, 95% CI: 0.49 - 0.75), and chest lateral width (AUC of 0.59; 95% CI: 0.47 - 0.73)(Figure 2).

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