[1] Royal Hailarnshire Hosp, Sheffield Pulm Vasc Dis Unit, Sheffield, S Yorkshire, England
[2] Royal Haliamshire Hosp, Dept Thrombosis & Haematol, Sheffield, S Yorkshire, England
[3] Royal Hailamshire Hosp, Dept Radiol, Sheffield, S Yorkshire, England
[4] Sheffield Teaching Hosp NHS Fdn Trust, Sheffield, S Yorkshire, England
[5] Univ Sheffield, Sheffield, S Yorkshire, England