title: An en bloc approach to CT perfusion for the evaluation of limb ischemia.
abstract: We examine volumetric CT perfusion in soft tissues of the entire foot with an en bloc technique to provide a meaningful measure of differentiation between mild and major vascular impairment. With Institutional Review Board approval, 22 healthy male subjects between the ages of 21 and 50 (mean 37) were enrolled. Volumetric computed tomography using an en bloc technique was conducted on 14 subjects for validation while unilateral vascular obstruction was simulated in the calves of the remaining 8 subjects. Perfusion estimates were made using in-house software and differences in perfusion estimates between feet were evaluated with Student's t-test at 95% confidence. Subjects with simulated major vascular obstruction (calf blood pressure cuff inflated to 200 mmHg) showed significantly higher ratios of perfusion estimates between the unobstructed and obstructed foot compared to subjects with simulated mild vascular obstruction (cuff inflated to 120 mmHg), mean 4.6, SD 2.6 vs. mean 1.3, SD 0.2; P = 0.05. CT perfusion using an en bloc technique shows promise for the future evaluation of patients with critical limb ischemia and particularly for re-characterization post medical, surgical or endovascular intervention.
authors.affiliation: Medical Imaging, University Health Network, 399 Bathurst St., McLaughlin Pavilion, 3rd Floor Rm 431, Toronto, ON, M5T 2S8, Canada. joe.barfett@utoronto.ca
authors.forename: Joe
authors.initials: J
authors.lastname: Barfett
authors.forename: Nivethan
authors.initials: N
authors.lastname: Velauthapillai
authors.forename: Christian
authors.initials: C
authors.lastname: Kloeters
authors.forename: David J
authors.initials: DJ
authors.lastname: Mikulis
authors.forename: Jeffrey D
authors.initials: JD
authors.lastname: Jaskolka
mesh_terms: D000328:Adult; D000465:Algorithms; D001331:Automation; D001783:Blood Flow Velocity; D054893:Cone-Beam Computed Tomography; D005528:Foot / Q000098:blood supply*; D006801:Humans; D007511:Ischemia / Q000000981:diagnostic imaging* / Q000503:physiopathology; D007866:Leg / Q000098:blood supply*; D008297:Male; D008875:Middle Aged; D055420:Perfusion Imaging / Q000379:methods*; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012039:Regional Blood Flow; D015203:Reproducibility of Results; D012720:Severity of Illness Index; D012984:Software; D013997:Time Factors; D055815:Young Adult