Janine Rennert MD, Presenter: Nothing to Disclose

Ernst Michael Jung MD, Abstract Co-Author: Nothing to Disclose

Lukas Prantl MD, Abstract Co-Author: Nothing to Disclose

Stefan G.E. Feuerbach MD, Abstract Co-Author: Nothing to Disclose

Claudia Fellner PhD, Abstract Co-Author: Nothing to Disclose

Quantitative evaluation of post surgery tissue perfusion of free flaps of the lower leg with contrast enhanced ultrasound and MRI.  

10 adult patients (20-56 years, mean 39) with free flaps of the lower upper legs (5 parascapular, 3 radial and 2 osteocutaneous parascapular flaps) were examined 3 months after surgery. Perfusion weighted imaging (dynamic susceptibility contrast) was performed after intravenous bolus injection of 25 ml Gd-DTPA (1.5 T, Symphony, Siemens). Ultrasound was carried out by an experienced examiner with a linear probe (6-9 MHz, Logiq 9,GE) after intravenous bolus injection of 2.4 ml Sonovue® (Bracco). In MRI time-to-peak maps as well as time curves in different regions of interest were qualitatively evaluated, in CHI time intensity curves were analysed. A score from 1-5 (1=low, 5=excellent) was used for analysis of colour coded perfusion images by three independent readers.  

With Cohen´s kappa analysis the correlation for perfusion imaging reading of all 10 cases was 0.61 for the region of anastomosis, 0.55 for the central and 0.64 for the distal part of the free flaps. The result for the time-to-peak maps was 0.91. In 5 cases CHI and MRI perfusion imaging showed an excellent (score 4-5) contrast enhancement of the cutaneous, subcutaneous und muscular parts of the free flaps (3 radial, 2 parascapular). In 2 cases of mediasclerosis only the region of anastomosis showed a good (score 3) perfusion of the muscularly part, but perfusion in central and distal parts of the free flaps was reduced (score 1-2). All cases of osteocutaneous flaps showed an inhomogeneous perfusion of all parts. Correlation between CHI and MRI time to peak analysis was 0.68 (Spearman test).

These first results introduce CHI and MRI perfusion imaging as a reliable post surgery monitoring in patients with free flaps.

New and effective diagnostic procedere for post monitoring of free flaps with high resolution linear contrast enhanced ultrasound

Rennert, J, Jung, E, Prantl, L, Feuerbach, S, Fellner, C, Perfusion Imaging of Free Flaps with Contrast Harmonic Imaging (CHI) Ultrasound and Magnetic Resonance Imaging (MRI): First Results  .  Radiological Society of North America 2009 Scientific Assembly and Annual Meeting, November 29 - December 4, 2009 ,Chicago IL. http://archive.rsna.org/2009/8002304.html