Current Clinical Concerns in CT: Results : IV Contrast Administration
Saline Flush
1. Do you have any protocols for using saline flush?
| Answer: We are developing them, but typically use 100 cc of Omnipaque-350 and push 25 cc of saline to follow. |
2. What types of studies are you saline chasing? Do you see this becoming the standard?
| Answer: It is great for all CT angiograms, but super critical for coronary CT angiography. |
3. Do you use a double-barrel injector for administering a saline flush?
| Answer: We are currently using MEDRAD dual head injector for the Saline Flush studies. The dual head injector allows for ease of use. In the past, people have put both contrast and saline in a single cartridge and mixed them and had reasonable results. However, the dual head injector works best. The injector we use is noted as the stelent by MEDRAD. |
4. What are your injection rates and volume reductions with a saline flush?
| Answer: We do not always decrease the volume of contrast used, but this makes more efficient use of the contrast. |
References
Dorio PJ et al. Using a saline chaser to decrease contrast media in abdominal CT AJR 2003; 180: 929-934
- Summary: This single detector helical study assessed the impact of a protocol with decreased volume of IV contrast, followed by a saline flush on abdominal visceral enhancement. Patients were administered either 150 mL of 300 mgI/ml contrast material or 100 mL of the contrast followed by a 50 mL saline flush. This study did not involve a double-headed power injector, and describes in detail the technique for loading sterile saline into the power injector. Contrast infusion rates ranged from 1 to 3 mL/second. In patients with liver metastases, the 150 mL of contrast resulted in a small, but significantly higher liver attenuation and tumor attenuation. Furthermore, the tumor conspicuity was slightly higher using 150 mL of contrast, but the authors did not feel that it would be a clinically significant difference. The mean conspicuity of hepatic metastases was not significantly different in the 2 groups. However, for renal and splenic imaging, the 150 mL of contrast resulted in significantly higher enhancement, which the authors felt could be clinically important. Abdominal aorta and inferior vena cava enhancement was also signficantly higher when 150 mL of contrast were infused.
Haage P et al . Reduction of contrast material dose and artifacts by a saline flush using a double power injector in helical CT of the thorax AJR 2000; 174: 1049-1053
- Summary: This single detector helical study compared thoracic CT examinations in 50 patients who received 60 mL of 370 mgI/ml contrast followed by a 30 mL saline flush. These 50 patients had undergone a previous thoracic CT with 75 mL of 370 mgI/ml contrast. A double power injector was used to administer the saline flush. There was no significant difference in attenuation levels in the pulmonary artery and ascending aorta, nor in the grading for depiction of mediastinal and hilar structures. However, the saline flush reduced the superior vena cava attenuation and associated perivenous artifact.