Low-voltage (80-kVp) abdominopelvic computed tomography allows 60% contrast dose reduction in patients at risk of contrast-induced nephropathy.

Purpose: The purpose of this study was to evaluate the quality of image in abdominopelvic late phase computed tomography (CT) with a low tube voltage plus low dose contrast medium (CM) protocol (80-kVp, 60% CM). A compared with the conventional protocol (120-kVp, 100% CM) B in the same patients.
Material and Methods: This study included with 22 patients {36 to 77 kg (mean: 55.5 kg)} who had renal insufficiency and had experience of performance conventional CT without renal insufficiency during pre-18 months. The CT value of the portal vein, liver parenchyma, abdominal aorta, psoas muscle was measured. The estimated mean CNR (contrast-to-noise ratios), FOM (figure of merit), DLP (dose length product) and ED (effective dose) were compared between protocol A and B. Moreover, two radiologists assessed the visual quality of the CT images.
Results: The mean DLP and ED in the protocol B was about 50% lower than that in the protocol A (p < 0.01). The mean CT value of the portal vein and abdominal aorta in the protocol B were significantly higher than that in the protocol A (p < 0.01). All of the FOM in the protocol B was significantly higher than that in the protocol A (p < 0.01). However, there was no significant difference in the mean CNR and visual quality between protocol A and B.
Conclusion: Performance of abdominopelvic CT using a low tube voltage plus reduced CM dose (80-kVp, 60% CM) achieved reduction of the radiation dose without impairing image quality in relatively light weight group.
Clinical Relevance/application: In abdominopelvic CT, protocol of low tube voltage (80-kVp) plus iodine dose reduction (60%) is able to provide the same quality of traditional protocols, also able to reducing radiation exposure (50%).
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