title: In vivo venous assessment of red blood cell aggregate sizes in diabetic patients with a quantitative cellular ultrasound imaging method: proof of concept.
abstract: BACKGROUND
  Diabetic patients present higher level of red blood cell (RBC) aggregation contributing to the development of vascular complications. While it has been suggested that this hematology/rheology parameter could bring additional prognostic information for the management of those patients, RBC aggregation screening is not included as a clinical practice. Most medical centers are not equipped to measure properly this parameter, although sedimentation tests can bring some indication. Here, we aimed at evaluating the feasibility of using ultrasound to assess in-vivo hyper-aggregation in type 2 diabetic patients.
  
  
  METHODS
  Seventeen diabetic patients and 15 control subjects underwent ultrasound measurements of RBC aggregation in both cephalic and great saphenous veins. Non-invasive in-vivo ultrasound measurements were performed using a newly developed cellular imaging technique, the structure factor size and attenuation estimator (SFSAE). Comparisons with an ex-vivo gold standard rheometry technique were done, along with measurements of pro-aggregating plasma molecule concentrations.
  
  
  RESULTS
  In-vivo RBC aggregation was significantly higher in diabetic patients compared with controls for cephalic vein measurements, while a trend (p = 0.055) was noticed in the great saphenous vein. SFSAE measurements were correlated with gold standard in-vitro measures, fibrinogen and C-reactive protein plasma concentrations.
  
  
  CONCLUSIONS
  RBC aggregation can be measured in-vivo in diabetic patients using ultrasound. Prospective studies are needed to determine whether the SFSAE method could help clinicians in the early management of vascular complications in this patient population.
authors.affiliation: Laboratory of Biorheology and Medical Ultrasonics, Research Center, University of Montreal Hospital (CRCHUM), Québec, Canada.
authors.forename: Julien
authors.initials: J
authors.lastname: Tripette
authors.affiliation: Laboratory of Biorheology and Medical Ultrasonics, Research Center, University of Montreal Hospital (CRCHUM), Québec, Canada; Institute of Biomedical Engineering, University of Montreal, Québec, Canada.
authors.forename: Linh-Chi
authors.initials: LC
authors.lastname: Nguyen
authors.affiliation: Laboratory of Biorheology and Medical Ultrasonics, Research Center, University of Montreal Hospital (CRCHUM), Québec, Canada.
authors.forename: Louise
authors.initials: L
authors.lastname: Allard
authors.affiliation: Department of Radiology, University of Montreal Hospital (CHUM), Québec, Canada; Department of Radiology, Radio-Oncology and Nuclear Medicine, University of Montreal, Québec, Canada.
authors.forename: Pierre
authors.initials: P
authors.lastname: Robillard
authors.affiliation: Institute of Biomedical Engineering, University of Montreal, Québec, Canada; Department of Radiology, University of Montreal Hospital (CHUM), Québec, Canada; Department of Radiology, Radio-Oncology and Nuclear Medicine, University of Montreal, Québec, Canada.
authors.forename: Gilles
authors.initials: G
authors.lastname: Soulez
authors.affiliation: Laboratory of Biorheology and Medical Ultrasonics, Research Center, University of Montreal Hospital (CRCHUM), Québec, Canada; Institute of Biomedical Engineering, University of Montreal, Québec, Canada; Department of Radiology, Radio-Oncology and Nuclear Medicine, University of Montreal, Québec, Canada.
authors.forename: Guy
authors.initials: G
authors.lastname: Cloutier
mesh_terms: D001809:Blood Viscosity; D002097:C-Reactive Protein / Q000032:analysis; D002318:Cardiovascular Diseases / Q000209:etiology; D016022:Case-Control Studies; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000150:complications / Q000000981:diagnostic imaging*; D004903:Erythrocyte Aggregation / Q000502:physiology*; D004909:Erythrocyte Indices; D004912:Erythrocytes / Q000166:cytology*; D005260:Female; D006442:Glycated Hemoglobin / Q000032:analysis; D006400:Hematocrit; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012212:Rheology; D012501:Saphenous Vein / Q000000981:diagnostic imaging; D014463:Ultrasonography
chemical_list: D002097:C-Reactive Protein; D006442:Glycated Hemoglobin; C517652:hemoglobin A1c protein, human