with a pronounced/ distinct thrombus load
or
in the presence of a pronounced thrombus load

Consequently, the histological relationship between the underlying plaque burden and thrombus content is unknown, yet this grade supposedly represents the highest thrombus load. Notably, such assumptions may be erroneous and, in fact, lead to faulty decisions concerning the potential of percutaneous revascularization to open the occluded vessel.
http://www.medscape.com/viewarticle/758474_4

We measured an objective standard (‘‘percent clot area’’) for thrombus load by quantifying the proportion of cross-sectional aortic area occupied by thrombus at the level of maximum aortic diameter using diameters taken from 2D CT images.
http://www.jevtonline.org/doi/pdf/10.1583/09-2732.1

Beware of huge thrombus load in every patient with STEMI .The contribution of mechanical occlusion vs thrombus (in the total occlusion ) is the single most important factor in determining the intervention strategy.
https://drsvenkatesan.wordpress.com/2013/03/24/primary-pci-g...

Therefore, non-manual devices may be indicated in STEMI patients with a large thrombus load in case residual, more organized, thrombus remains after ...
http://www.google.com/search?as_q= thrombus load STEMI&as_ep... (p.610)

The following information was retrieved: maximum aneurysm diameter, aneurysm thrombus load (maximum thickness, percentage of sac circumference wall coverage, percentage of maximum sac area occupancy); number, diameter, and nature (lumbar, inferior mesenteric, accessory renal, middle sacral) of patent aortic side-branch arteries; thrombus thickness at each aortic branch ostium, and aneurysm diameter at that level.
http://www.ncbi.nlm.nih.gov/pubmed/15818458

This study examined the correlation of preoperative thrombus load and location to the incidence of TIIE and late sac regression.
http://www.ncbi.nlm.nih.gov/pubmed/21515018