Correlation Of Image Quality Research Articles

A cross-sectional study on the correlation of image quality, effective dose, and body composition with thyroid, chest, and abdominal computed tomography scans

A cross-sectional study on the correlation of image quality, effective dose, and body composition with thyroid, chest, and abdominal computed tomography scans

Correlation of Image Quality according to the Distance of the Magnetic Isocenter

Correlation of Image Quality according to the Distance of the Magnetic Isocenter

Breast Mass Evaluation: Factors Influencing the Quality of US Elastography

To investigate factors influencing the quality of ultrasonographic (US) elastography in the evaluation of suspicious breast masses. This prospective study was conducted with institutional review board approval; written informed consent was obtained. Between January 2009 and February 2009, real-time US elastography of 312 breast masses (245 benign, 67 malignant) was performed in 268 consecutive patients (mean age, 45.7 years ± 10.2 [standard deviation]) prior to US-guided core biopsy. Five breast radiologists who had performed the examinations assessed the quality of elasticity images as inadequate, low, or high without histologic information. Age, body mass index (BMI), mammographic density, lesion size, lesion depth, and breast thickness at US were analyzed for their association with image quality by using the χ(2) test, Student t test, and multivariate analysis. Sensitivities and specificities for the differentiation of benign from malignant masses on the basis of elastography were calculated and compared between groups of quality scores by using the logistic regression method. The quality of elasticity images was assessed as inadequate in 21 (6.7%) cases, low in 134 (42.9%), and high in 157 (50.3%). According to univariate analysis, smaller lesion size (P = .001), shallower lesion depth (P = .005), less breast thickness where the lesion was located (P < .0001), and benign pathologic finding (P = .004) were significantly associated with higher image quality. There was no correlation of image quality with age (P = .213), BMI (P = .191), mammographic density (P = .091), or distance from the nipple (P = .100). Multivariable analysis showed that breast thickness at the location of target lesions was the most important factor influencing elasticity image quality (P = .001). There were significant differences in sensitivity between higher-quality and lower-quality images (87.0% vs 56.8%, respectively; P = .015) in the differentiation of benign from malignant masses. Breast thickness at the location of the lesion was the most important factor influencing image quality at US elastography. Sensitivity for classification of benign and malignant masses improved with higher quality scores.

Correlation of image quality with exposure index and processing protocol in a computed radiography system

The correlation of image quality with the exposure index (EI) and the processing protocol was investigated in a Kodak computed radiography (CR) system using clinical radiographs and a water phantom containing an aluminium and a copper step-wedge. The phantom was exposed to different dose levels and the acquired images were processed using four clinical protocols. The quality of these images was evaluated in terms of image brightness, contrast and noise. In clinical radiographs, there was no straightforward correlation of image quality with EI. In phantom images, higher EI values improved contrast and reduced noise but after a point this improvement does not justify the implied increase in patient dose. Image brightness, contrast and noise were also strongly dependent on the processing protocol. To obtain the images of satisfactory quality with the Kodak CR system, a dose slightly higher than those used in 400 relative speed screen-film systems and a processing protocol designated for the specific radiographic examination are required.