Equilibrium-phase high spatial resolution contrast-enhanced MR angiography at 1.5T in preoperative imaging for perforator flap breast reconstruction Contrast. For CE-MRA a fixed dose of 10 mL gadofosveset trisodium (Ablavar®, Lantheus Medical Imaging, Billerica, MA), a blood pool contrast agent, was administered intravenously as a single dose at a speed of 1.0 ml/s in the median cubital vein, using a remote controlled injection system (Medrad Spectris, Indianola, PA). Contrast injection was followed by 20 mL saline flush injected at the same rate. Real time bolus monitoring software (BolusTrak, Philips Medical Systems, Best, The Netherlands) was used to visualize the arrival of the bolus in the abdominal aorta with a refresh rate of proximally 1 frame/sec. Upon first sight of contrast arrival in the abdominal aorta, image acquisition for the first-pass CE-MRA sequence was started. Equilibrium-phase imaging commenced approximately 2 minutes fter completion of the first-pass sequence, after allowing systemic contrast equilibration in the arterial and venous blood pool. First-pass CE-MRA. First-pass CE-MRA consisted of single station 3D acquisition of the abdominal wall as previously described.20 Patients were asked to hold their breath as long as possible (inspiration phase) during the acquisition, which lasted approximately 33 seconds. Equilibrium-phase high-spatial resolution CE-MRA. A 3D isotropic high spatial resolution equilibrium-phase acquisition of the lower abdomen and pelvic region, comprising both the DIEA and gluteal perforator branches, was performed. As the equilibrium-phase acquisition lasted for approximately 5 minutes, depending on the dimensions of the patient, patients were asked to breathe in a shallow pattern in order to reduce breathing-related motion artifacts as much as possible. Image analysis All equilibrium-phase CE-MRA datasets were analyzed in consensus by a radiologist (BV) and the plastic surgeon (ST) scheduled to perform the DIEP flap dissection and breast reconstruction. A dedicated post-processing workstation was used for image analysis (Vitrea release 4.1.2.0, Vital Images, Minnetonka, MN). Using the original source images as well as coronal and sagittal multiplanar reconstructions (MPR) both first-pass (source) images and equilibrium-phase images were evaluated for (I) image quality; (II) the location of the single best DIEA perforator at each side of the patient; and (III) the total number of visualized DIEA perforator branches on each side of the patient. Image quality was assessed on a three-point scale (i.e. excellent quality, diagnostic quality and non-diagnostic quality) and by determination of the vessel-to-noise (VNR) and vessel-to-background (fat tissue) (VBR) ratios of the single best perforator branch21. The single best perforator branch was located following the criteria used before by Chernyak et al.6 118
5. lay-out phd DEFINITIEF_digitaal2
To see the actual publication please follow the link above