Study on the effect of three-low technique in aortic computed tomography angiography for patients with body mass
Zhijian Chen1, Shaogang Wang1, Ran Zhang2
1Department of Radiology, Nantong Third People's Hospital, Affiliated Nantong Hospital 3 of Nantong University, Nantong, China.
Insights
This study demonstrates that a three-low technique significantly reduces radiation dose and contrast agent volume in computed tomography angiography (CTA) for patients with a body mass index (BMI) under 30 kg/m2, maintaining diagnostic image quality.
Area of Science:
- Radiology
- Medical Imaging
- Cardiovascular Imaging
Background:
- Aortic computed tomography (CT) angiography (ACTA) is crucial for diagnosing aortic diseases.
- Conventional ACTA often uses high radiation doses and contrast volumes, increasing risks like nephropathy.
- A need exists for safer ACTA protocols, especially for patients with lower body mass index (BMI).
Purpose of the Study:
- To evaluate a novel "three-low" technique (low tube voltage, low contrast injection rate, low contrast volume) for ACTA.
- To assess its efficacy and safety in patients with BMI < 30 kg/m2.
- To compare it against conventional ACTA protocols.
Main Methods:
- Eighty patients with BMI < 30 kg/m2 were randomized into two groups.
- The "three-low" group (n=40) received 100 kV, 3 mL/s, 50 mL contrast.
- The control group (n=40) received 120 kV, 5 mL/s, 80 mL contrast.
Main Results:
- The "three-low" group showed a 76.2% reduction in effective radiation dose (2.46 mSv vs. 10.32 mSv).
- Contrast volume was reduced by 37.5% (50 mL vs. 80 mL).
- Despite higher noise, SNR and CNR were lower, but image quality was subjectively similar and met diagnostic standards.
Conclusions:
- The "three-low" technique is a valuable alternative for ACTA in patients with BMI < 30 kg/m2.
- It significantly lowers radiation exposure and contrast agent usage.
- Diagnostic image quality is preserved, meeting clinical requirements.
Background:
Aortic computed tomography (CT) angiography (ACTA) is a key noninvasive tool for assessing aortic diseases, which typically requires high tube voltage and large volumes of contrast agent, thus potentially increasing radiation exposure and the risk of contrast agent-induced nephropathy. This study aimed to explore the effect of three-low technique (low tube voltage, low contrast agent injection rate, and low contrast agent volume) in CTA for patients with a body mass index (BMI) <30 kg/m2, thus this technique may be used as an alternative to conventional ACTA.
Methods:
Eighty patients with a BMI less than 30 kg/m2 undergoing CTA examination with a Philips iCT 256-slice scanner were randomly assigned into two groups according to the examination technique used: three-low group (n=40): tube voltage: 100 kV, contrast agent injection rate: 3 mL/s, contrast agent volume: 50 mL; control group (n=40): tube voltage: 120 kV, injection rate: 5 mL/s, contrast agent: 80 mL. Aortic CT value and image noise were detected, the signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were computed, and the subjective score of the image quality was evaluated. The effective radiation dose was computed according to a formula.
Results:
Compared with the control group, the effective radiation dose was decreased by 76.2% (10.32±0.46 vs. 2.46±0.71 mSv), while the aortic CT value was increased by approximately 13% (360.14±56.52 vs. 402.12±88.34 HU), the image noise (22.23±5.34 vs. 13.32±3.54) was higher, while the contrast agent volume (80 vs. 50 mL), SNR (24.2±7.4 vs. 20.6±6.1) and CNR (22.4±6.5 vs. 18.3±6.2) were lower in the three-low group, and all these differences between the two groups were statistically significant (all P<0.05). There was no statistically significant difference in the subjective score of image quality (4.4±0.8 vs. 4.2±0.9) between the two groups (P>0.05).
Conclusions:
Three-low technique has a good application value in CTA for patients with a BMI of lower than 30 kg/m2; the effective radiation dose was decreased by 76.2%, the contrast agent volume was decreased by 37.5%, and all images met the diagnostic requirements.
Related Concept Videos
01:28Imaging Studies for Cardiovascular System V: CT
01:27Imaging Studies III: Computed Tomography
01:25Imaging Studies for Cardiovascular System VI: Calcium -Scoring CT
01:10Computed Tomography
The technique was invented in the 1970s and is based on the principle that as X-rays pass through the body, they are absorbed or reflected at different levels. In the technique, a patient lies on a motorized platform while a computerized axial tomography (CAT) scanner rotates...