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Stefania M R Rizzo

Publications and source records attributed to Stefania M R Rizzo.

7 recordsLinked to original sources
PubMed2005

Reducing radiation dose in emergency computed tomography with automatic exposure control techniques.

Computed tomography (CT) scanning is being increasingly used for evaluation of trauma, which most commonly involves younger individuals. As younger patients are at higher risk for radiation-induced cancer compared to older patients, radiation dose reduction is an important issue in emergency CT scanning. With automatic exposure control techniques, users select a desired image quality and the system adapts tube current to obtain the desired image quality with greater radiation dose efficiency. These techniques can help in reducing radiation dose by 10-60% in most instances. This review article presents a comprehensive description of fundamentals, clinical applications and radiation dose benefits of automatic exposure control in emergency CT scanning.

Automation↗
PubMed2005

Metallic prosthesis: technique to avoid increase in CT radiation dose with automatic tube current modulation in a phantom and patients.

The institutional review board approved this Health Insurance Portability and Accountability Act-compliant study protocol, with waiver of informed consent. The purpose of the study was to retrospectively evaluate the combined automatic tube current modulation technique in patients with orthopedic metallic prostheses. Five hundred abdominal-pelvic computed tomographic (CT) studies performed with combined modulation technique were reviewed to identify nine patients with metallic prostheses (mean age, 66 years; range, 35-86 years; male-female ratio, 5:4). On the basis of age and transverse abdominal images, these patients were matched with nine others with no metallic prostheses (mean age, 56 years; range, 36-72 years; male-female ratio, 4:5) who were control patients. Images were graded for extent and severity of streak artifacts (grade 1, streak artifact present but not substantially compromising evaluation of adjacent structures; grade 2, streak artifact present and slightly compromising evaluation of adjacent structures; and grade 3, streak artifact present and severely compromising evaluation of adjacent structures). Student t test was performed for statistical analysis. There was no difference in mean effective tube current-time product between study and control patients (P > .49). With automatic tube current modulation, an increase in CT dose caused by metallic prostheses can be successfully avoided.

Adult↗
PubMed2005

CT images of abdomen and pelvis: effect of nonlinear three-dimensional optimized reconstruction algorithm on image quality and lesion characteristics.

The purpose of this study was to retrospectively assess the effect of a postprocessing nonlinear three-dimensional optimized reconstruction algorithm on image quality and lesion characteristics in abdominal and pelvic computed tomographic (CT) images. Institutional review board approved the HIPAA-compliant study protocol; informed consent was waived. Abdominal and pelvic CT images (40 patients; male-female ratio, 20:20; age range, 28-86 years) at 5-mm (n = 20) and 2-mm (n = 20) section thicknesses were postprocessed with the algorithm at three noise reduction levels. Image noise at the level of porta hepatis and acetabulum was evaluated with a five-point scale (1, no or minimal noise; 5, unacceptable noise), and presence and number of lesions and conspicuity were assessed. Statistical analysis was performed (Wilcoxon signed rank test, analysis of variance). Significant noise reduction was noted at all three levels with the algorithm (P < .05). Reduction in image contrast was noted with only one noise reduction level (P < .0001). The algorithm improves image noise without affecting lesion conspicuity and detection on low-dose abdominal and pelvic CT images.

Adult↗
PubMed2005

Do metallic endoprostheses increase radiation dose associated with automatic tube-current modulation in abdominal-pelvic MDCT? A phantom and patient study.

OBJECTIVE: Our objective was to assess the effect of orthopedic metallic prostheses on radiation dose associated with MDCT using z-axis automatic tube-current modulation and a fixed tube current in a phantom and patient study. CONCLUSION: Z-modulation is associated with a 34.1% increase in the mean tube current-time product and no change in the extent of streak artifacts in patients with a metallic prosthesis, compared with patients without a prosthesis. However, compared with the fixed-tube-current technique, z-modulation is associated with a 28.9% decrease in the mean tube current-time product.

Adult↗
PubMedDate not supplied

Computed tomography radiation dose optimization: scanning protocols and clinical applications of automatic exposure control.

As multi-detector-row computed tomography (CT) technology evolves, manifold applications of CT scanning have been adopted in clinical practice and optimization of scanning protocols to comply with an "as low as reasonably achievable" radiation dose have become more complex. Automatic exposure control techniques, which have been recently introduced on most state-of-the-art CT equipment, aid in radiation dose optimization at a selected image quality. The present article reviews the fundamentals of automatic exposure control techniques in CT, along with the scanning protocols and associated radiation dose reduction.

Automation↗