Determine whether scan delay 120s is optimal for indirect-CT venography(CTV)

Congress:

ECR 2019

Poster Number:

C-2142

Type:

Scientific Exhibit

Keywords:

Cardiovascular system, Veins / Vena cava, Interventional vascular, CT-Angiography, Catheter arteriography, Catheter venography, Angioplasty, Computer Applications-General, Thrombolysis, Blood, Trauma, Outcomes

Authors:

T. Tran, C. H. Kristiansen, F. Haidl, S. Roy, J. C. Lindstrom, H. Ashraf, P. Lauritzen; Oslo/NO

DOI:

10.26044/ecr2019/C-2142

DOI-Link:

https://dx.doi.org/10.26044/ecr2019/C-2142

Fig. 1: Fig.1 shows single scans of the popliteal vein from 30s (top image) to 210s...

Fig. 2: Fig.2 demonstrates the setup of the Nexfin device for monitoring.

Fig. 3: Fig.3 shows the change in mean attenuation in the popliteal vein at 30s...

Fig. 4: Fig.4 shows the attenuation in the inferior vena cava, external iliac, common...

Table 1: Table 1 compares our study to a study by Szapiro et al in 2001. Both studies...

Aims and objectives

Individual tailoring of scan delay to cardiac output (CO) may facilitate optimal CT venography of peripheral veins. CO is a product of the heart rate (HR) and the stroke volume (SV), CO = HR x SV. The CO at rest for a healthy person weighting 70 kg is approximately 5 L/min, assuming a HR of 70 strokes/min and a stroke volume of 70 ml/stroke.CO is one of the most important patient-related factors affecting the timing of contrast enhancement(Ref.1). When the CO is decreased, the time...

Methods and materials

Twenty-four patients with clinical suspicion of deep vein thrombosis were prospectively included. CTV was performed with a fixed scan delay of 120 seconds after intravenous injection of 350 mg/mL iodinated contrast medium. Additionally, single scans of the popliteal vein were obtained at 30 s intervals from 30 to 210 s to determine TPA. (Fig.1) shows single scans of the popliteal vein from 30s (top image) to 210s (bottom image), a region of interest (ROI) was placed in the vein on both sidesmeasuring the attenuation in...

Results

Median CO was 7.8 L/min (range: 4.1-11.5) and median HR 72.4 bpm (range: 58.4-102). Mean TPA was 159 s (95% CI: 141,176). TPA varied inversely with both CO and HR. The correlation coefficients between TPA and CO, and between TPA and HR were -0.52 (p=0.009) and -0.41 (p=0.047) respectively. The regression coefficients were -10.4 for CO and -2.1 for HR. This indicates a 74 s variation in optimal scan delay from highest to lowest CO. (Fig.3) shows the change in mean attenuation in the popliteal...

Conclusion

At 120s a majority of patients had not reached peripheral venous peak attenuation, although attenuation was higher in larger central veins.(Table 1)compares our study to a study by Szapiro et al in 2001 (Ref.3). Both studies demonstate that the TPA is reached earlier in larger central veins. Lengthening the scan delay closer to TPA of 159s or individually tailoring the scan delay to CO may be helpful, but the diagnostic benefit has yet to be determined.

Personal information

University of Oslo, Norway www.uio.no/english Akershus University Hospital Departement of Interventional Radiology 1478 Lørenskog, Norway www.ahus.no Email: [email protected]

References

1.Bae KT. Intravenous contrast medium administration and scan timing at CT:considerations and approaches. Radiology. 2010;256(1):32-61. 2.Joosten A, Desebbe O, Suehiro K, et al. Accuracy and precision of non- invasive cardiac output monitoring devices in perioperative medicine: a systematic review and meta-analysisdagger. British journal of anaesthesia. 2017;118(3):298-310. 3.Szapiro D, Ghaye B, Willems V, Zhang L, Albert A, Dondelinger RF. Evaluation of CT time-density curves of lower-limb veins. Invest Radiol. 2001;36(3):164-169.