Purpose
The iodine delivery rate (IDR = contrast media flow rate * concentration) determines the enhancement in computed tomography angiography (CTA)1.
Imaging of the aortic root and the peripheral vessels in pre-TAVI assessment may benefit from high IDR.
Thus the purpose of this study was to assess the feasibility of high IDR in pre -TAVI evaluation.
Methods and Materials
32 consecutive patients who were referred to pre-TAVI evaluation were evaluated.
MDCT protocol consists of a retrospective ECG gated Dual-Energy CT scan of the aortic root followed by a high pitch non ECG triggered scan of the aorta and peripheral arteries.
Contrast media (CM) bolus was applied in a biphasic protocol: 1.
90 ml of CM (300 mg/ml*9 ml/s); 2: 60 ml of 50% CM and 3.: 40ml saline chaser,
at the same flow rate (Total iodine load 36 g,
IDR=2.7 gI/s).
Scan start delay...
Results
CM injection was possible without any flow related problems.
No extravasation was found.
Assessment of aortic root diameters and assessment of peripheral access route was possible in all patients.
Mean attenuations were: ascending aorta 486HU (SD61) (DE 120kV mix phase) and 625 (SD88) (DE 100kV),
descending aorta 327HU (SD116),
abdominal aorta 382HU (SD131),
right femoral artery 521 (SD158) and left femoral artery 533HU (SD157).
Conclusion
Use of high IDR (and thus high flow rates) is feasible in the comprehensive assessment of TAVI patients.
Attenuations were suitable for interpretation of aortic root diameters as well as assessment of the peripheral access.
High enhancement values may facilitate future CM bolus optimization.
References
1Bae KT.
Optimization of contrast enhancement in thoracic MDCT.
Radiologic clinics of North America 2010; 48:9-29