Author + information
- Received October 1, 2015
- Revision received October 12, 2015
- Accepted October 13, 2015
- Published online February 2, 2016.
- Adnan Bajwa, BSca,
- Roman Wesolowski, PhDb,
- Ashish Patel, PhDa,
- Prakash Saha, PhDa,
- Francesca Ludwinski, PhDa,
- Mohammed Ikram, PhDa,
- Mostafa Albayati, MBBS, BSca,
- Alberto Smith, PhDa,
- Eike Nagel, MD, PhDb,c and
- Bijan Modarai, PhDa,∗ ()
- aAcademic Department of Vascular Surgery, Cardiovascular Division, King’s College London, BHF Centre of Research Excellence & NIHR Biomedical Research Centre at King’s Health Partners, St. Thomas’ Hospital, London, United Kingdom
- bDepartment of Cardiovascular Imaging, Division of Imaging Sciences and Biomedical Engineering, King’s College London, BHF Centre of Research Excellence, Wellcome Trust−EPSRC Medical Engineering Centre & NIHR Biomedical Research Centre at King’s Health Partners, St. Thomas’ Hospital, London, United Kingdom
- cInstitute for Experimental and Translational Cardiovascular Imaging, DZHK Centre for Cardiovascular Imaging, University Hospital Frankfurt, Goethe University Frankfurt, Frankfurt am Main, Germany
- ↵∗Reprint requests and correspondence:
Dr. Bijan Modarai, Academic Department of Vascular Surgery, King’s College London, St. Thomas’ Hospital, Westminster Bridge Road, London SE1 7EH, United Kingdom.
Background Use of blood oxygenation level-dependent cardiovascular magnetic resonance (BOLD-CMR) to assess perfusion in the lower limb has been hampered by poor reproducibility and a failure to reliably detect post-revascularization improvements in patients with critical limb ischemia (CLI).
Objectives This study sought to develop BOLD-CMR as an objective, reliable clinical tool for measuring calf muscle perfusion in patients with CLI.
Methods The calf was imaged at 3-T in young healthy control subjects (n = 12), age-matched control subjects (n = 10), and patients with CLI (n = 34). Signal intensity time curves were generated for each muscle group and curve parameters, including signal reduction during ischemia (SRi) and gradient during reactive hyperemia (Grad). BOLD-CMR was used to assess changes in perfusion following revascularization in 12 CLI patients. Muscle biopsies (n = 28), obtained at the level of BOLD-CMR measurement and from healthy proximal muscle of patients undergoing lower limb amputation (n = 3), were analyzed for capillary-fiber ratio.
Results There was good interuser and interscan reproducibility for Grad and SRi (all p < 0.0001). The ischemic limb had lower Grad and SRi compared with the contralateral asymptomatic limb, age-matched control subjects, and young control subjects (p < 0.001 for all comparisons). Successful revascularization resulted in improvement in Grad (p < 0.0001) and SRi (p < 0.0005). There was a significant correlation between capillary-fiber ratio (p < 0.01) in muscle biopsies from amputated limbs and Grad measured pre-operatively at the corresponding level.
Conclusions BOLD-CMR showed promise as a reliable tool for assessing perfusion in the lower limb musculature and merits further investigation in a clinical trial.
Dr. Bajwa is supported by a grant from the British Heart Foundation (FS/13/74/30425). Dr. Nagel has received research support from Siemens Healthcare, Bayer Healthcare, and Philips Healthcare (significant) as well as MEDIS (moderate) and TomTec (minor); and has received minor educational support from CVI42 and MEDIS. Dr. Modarai is supported by grants from the British Heart Foundation (FS/11/37/28819). All other authors have reported that they have no relationships relevant to the contents of this paper to disclose. Drs. Nagel and Modarai are joint senior authors.
- Received October 1, 2015.
- Revision received October 12, 2015.
- Accepted October 13, 2015.
- 2016 American College of Cardiology Foundation