Technical Aspect of CT Angiography of Lower Extremities

Abstract

Objective: To assess the less invasive technique of CT angiography for evaluation of lower extremity arteries with nonionic water soluble iodinated contrast medium.
Methods: One hundred thirty patients underwent a CT angiography of lower extremity using smart prep technique above the iliac creast 1 inch. and the following parameters: helical, rotation time : 0.8 seconds, rotation length : full, detector configuration : 16x1.25 mm, helical thickness : 1.25, pitch : 1.375:1, speed : 27.50 mm/rotation, beam collimation : 20 mm, image interval : 1.0 mm, gantry tilt : 0.0, SFOV : large, x-ray energy 140 kV, 260 mA.
Results: The data of CT acquisition and contrast medium parameters were scanning coverage (mm): 1040 ± 88, scanning duration (sec): 33 ± 5, number of transverse sections: 1063 ± 348, iodine dose (g): 89.8 ± 5.3, Concentration of contrast medium (mg/ml): 356.7 ± 24.4, volume of contrast medium (ml): 120 ± 0, contrast medium injector rate (ml/sec): 4 ± 0, injection duration (sec): 30 ± 0, scanning -to-injection duration ratio: 1.08 ± 0.2, delay between contrast medium initiation and scanning (sec): 26 ± 5.3.
Conclusion: The conventional study for lower extremity arteries is conventional angiography which is invasive method. This method required admission and absolute bed rest at least 8-12 hours after procedure. The CT angiography takes advantage over conventional angiography, including 3D volumetric analysis, minimally invasive vascular opacification and depiction of mural calcium. The faster and more slices of current generation of 16 slices multidetector CT scanner is possible to study entire length of lower extremities.