Alexander Ewald Lembcke MD, Presenter: Nothing to Disclose

Patrick Alexander Hein MD, Abstract Co-Author: Nothing to Disclose

Jürgen Mews, Abstract Co-Author: Employee, Toshiba Corporation

Patrik Rogalla MD, Abstract Co-Author: Nothing to Disclose

We sought to evaluate the feasibility of a low contrast media volume injection protocol for noninvasive coronary angiography using 320-detector row computed tomography.   

Sixty consecutive patients (mean age: 62.8 years, range: 37-76 years) were scanned using a 320-detector row CT unit (Aquilion One, Toshiba, Japan) and randomely assigned alternatively to a dedicated low volume (35 ml injected at 7.5 ml/s; Group A, n=30) or to the standard volume (70 ml injected at 5.0 ml/s; Group B, n=30) contrast media injection protocol. All patients met the following criteria: indication for noninvasive coronary angiography, body weight 60-80 kg, anterior-posterior chest diameter 22-28 cm, regular sinus rhythm with a heart rate ≤ 65 bpm and no signs of congestive heart failure. Patients were examined with a standardized, prospectively ECG-triggered single-beat non-spiral CT scan technique (100kV, 260-580 mA according to the chest diameter). Automated bolus tracking was used and the scan was instantly perfomed after a density of 300 HU was reached in the left ventricle. Both groups were compared with respect to enhancement within the main pulmonary artery (PT), left atrium (LA), left ventricle (LV), ascending aorta (AA), descending aorta (DA) and near the origin of left and right coronary artery (LCA and RCA, respectively).

Both patient groups were comparable with regard to body weight and heart rate and all data sets had diagnostic image quality. Mean enhancement values were significantly lower (p<0.05) for group A compared with group B for PA (105±20 vs. 286±152 HU), for LA (368±77 vs. 479±95 HU) and for LV (408±79 vs. 463±92 HU), respectively. However, there were no significant differences for mean enhancement values for AA (503±97 vs. 515±53), DA (477±108 vs. 469±58), LCA (461±83 vs. 479±58 HU) and RCA (455±91 vs. 467±65), respectively.      

Using a wide area detector CT system for noninvasive coronary angiogrphy, the combination of the snap-shot like data acquisition and a dedicated contrast media injection protocol offers the possibility for a substantial reduction of contrast media volume without significant loss of vascular enhancement in the coronary arteries.  

Such optimized injection protocols with a low volume of contrast media might be routinely used for coronary CT angiography, especially when scanning patients with reduced renal function.

Lembcke, A, Hein, P, Mews, J, Rogalla, P, Vascular Enhancement in Single-Beat Cardiac Imaging Using Volume Computed Tomography: Low Dose versus Standard Dose Contrast Material Protocol  .  Radiological Society of North America 2009 Scientific Assembly and Annual Meeting, November 29 - December 4, 2009 ,Chicago IL. http://archive.rsna.org/2009/8016017.html