Thomas Albrecht MD, Presenter: Nothing to Disclose

Bernhard Meyer MD, Abstract Co-Author: Research Consultant, Mercury Computer Systems, Inc Stockholder, Mercury Computer Systems, Inc Research grant, Siemens AG Research grant, Bracco Group Research grant, Bayer AG

Stefan Klein MD, Abstract Co-Author: Nothing to Disclose

Andrik Johannes Aschoff MD, Abstract Co-Author: Nothing to Disclose

Jan Skrok, Abstract Co-Author: Nothing to Disclose

Karl-Juergen Wolf MD, Abstract Co-Author: Nothing to Disclose

A compact bolus injection can increase arterial enhancement in peripheral MDCTA, but timing is more critical to avoid bolus overriding or venous overlap. This study compared a compact bolus injection protocol utilizing Iomeprol 400 mg I/mL with a standard injection protocol using Iomeprol-300 mg I/mL at equivalent total iodine dose for peripheral MDCTA.

Sixty-four patients randomized to receive 134mL Iomeprol-300 (n=32; 40.2gI; 1.2gI/s -  standard protocol), or 100mL Iomeprol-400 (n=32; 40.0gI; 1.6gI/s - compact bouls protocol) at 4mL/sec (injection duration: 33.5s and 25s, respectively) underwent peripheral MDCTA on 40- or 64-slice scanners (table speed 48mm/s) using bolus-tracking. Arterial contrast density (HU) was measured intermittently from the abdominal aorta to the plantar arteries; vascular opacification was assessed qualitatively from the pelvic arteries to the feet. Cases of venous overlap or bolus overriding were recorded.

There were no significant differences between both groups with regards to age, BW, height, severity of PAOD or cardiovascular risk factors. Mean arterial contrast density was higher with the compact bouls in all arterial segements analysed; this difference ranged between 26 and 63HU and was significant (p<0.05) for aorta, pelvic, thigh, and calf arteries. Mean contrast density from the aorta to the plantar arteries was significantly (p<0.01) higher with Iomeprol-400 (279±57HU vs. 234±32HU). A trend towards better qualitative assessment of arterial opacification was noted for the compact bolus (P=0.01). Venous overlap occurred significantly more frequently with the standard protocol (18/32 patients) than with the compact bouls (11/32; P < 0.05)) but did not interfere with image interpretation. Slight overriding of the contrast bolus was seen in 1 (standard protocol) and 2 (compact bolus) patients respectively.

The more compact bolus achieved with Iomeprol-400 compared to Iomeprol 300 at identical injection rate and iodine dose leads to greater arterial contrast enhancement and fewer cases of venous contamination without increased risk of bolus overriding in peripheral MDCTA

A compact bouls using high concentration contrast medium provides better arterial enhancement than a standard bolus protocol and should therefore be preferred for clinical MDCTA of run-off vessels.

Albrecht, T, Meyer, B, Klein, S, Aschoff, A, Skrok, J, Wolf, K, MDCTA of Peripheral Run-off Vessels: Impact of a Compact Bolus at High Iodine Concentration on Arterial Enhancement and Image Quality.  Radiological Society of North America 2008 Scientific Assembly and Annual Meeting, February 18 - February 20, 2008 ,Chicago IL. http://archive.rsna.org/2008/6021962.html