Purpose
The purpose of this feasibility study is to investigate a prototype automatic kV selection tool for contrast-enhanced abdominopelvic CT,
evaluating its potential for radiation dose reduction and its effect on diagnostic image quality across adult patients of varying sizes and several types of abdominal CT examinations in a blinded reader study with matched control patients scanned at 120 kV.
The benefits of reduced tube kilovoltage (kV) CT have been exploited for pediatric patients for several years [1],
but have been difficult to extrapolate to an...
Methods and Materials
After obtaining IRB approval,
we retrospectively evaluated image quality and radiation dose in 36 patients scanned using the prototype automatic kV selection tool.
The scans were clinically indicated and informed consent was not required. Results were compared to results from control patients scanned using identical protocols,
phase of enhancement,
slice thickness,
oral contrast,
and patient width (within 5 cm,
measured at the level of the liver dome). Whenever possible,
scanner type was also matched. Auto kV patients were scanned on a 128-slice dual-source scanner (Definition...
Results
36 patients were scanned with Auto kV,
(mean age 55+/-19 (SD),
range: 16-81),
and size-matched to 36 control patients undergoing identical examinations (mean age 60+/-15 years,
range 17-89). There were 13 CT enterography exams,
13 CT urogram exams,
5 liver/pancreatic exams,
4 routine abdominopelvic exams,
and 1 CT angiogram. Lateral width in Auto kV patients was median 37.0 cm (range: 28 to 55),
compared to 36.5 cm in controls (range: 27-42). Of the 36 Auto kV exams,
the tube potential was changed to 80 kV...
Conclusion
In this initial assessment,
we have demonstrated that a prototype automatic kV selection tool can be used to select the most dose-efficient kV for a particular patient,
based on their size,
diagnostic task,
and scanner limitations while insuring that diagnostic image quality is maintained. This kV prescription also selects the corresponding automatic exposure control settings (i.e.,
quality reference mAs) that is needed in order to achieve a desired image quality defined by the reference scanning technique and the contrast gain setting (noise constraint) in the...
References
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Schmidt B,
Bradley D,
Suess C,
Hildebolt C.
Radiation dose and image quality in pediatric CT: effect of technical factors and phantom size and shape.
Radiology 2004;233:515-522
2. Guimaraes LS,
Fletcher JG,
Yu L,
et al.
Feasibility of dose reduction using novel denoising techniques for low kV (80 kV) CT enterography: optimization and validation.
Acad Radiol 2010;17:1203-1210
3. Yu L,
Bruesewitz M,
Thomas K,
Fletcher J,
Kofler J,
McCollough C.
Optimal tube potential for radiation dose reduction in pediatric CT: principles,
clinical...