Kramer Harald, Michaely Henrik J, Requardt Martin, Rohrer Martin, Reeder Scott, Reiser Maximilian F, Schoenberg Stefan O
Institute of Clinical Radiology, University Hospital of Munich, Ludwig Maximilian University of Munich, Munich, Germany.
Eur Radiol. 2007 Jun;17(6):1394-402. doi: 10.1007/s00330-006-0493-x. Epub 2006 Nov 18.
In time-resolved MRA (TR MRA), injection parameters and contrast agent (CA) dose are important factors influencing image quality. In this study, three different injection schemes with different CA volumes were evaluated in 12 healthy volunteers. Injection rates between 0.2 and 0.8 ml/s were evaluated with CA volumes of 10 and 20 ml. To measure circulatory parameters, cine cardiac MRI was performed before each exam. Spatial resolution could be reduced to 2 x 1.4 x 2 mm3, temporal resolution was 2.25 s/frame. To exclude signal saturation at high CA concentrations, a phantom with fixed CA concentrations was placed in the field of view. SNR was measured, and the area under the curve of the arterial signal of the different injection schemes was calculated. Results showed the largest diagnostic window at a relatively slow injection rate of 0.4 ml/s and a CA volume of 10 ml. Circulatory parameters have an important impact on CA arrival, so delay times have to be set depending on these parameters.
