Arterial calcification is a multi-faceted disorder that is associated with various diseases, including atherosclerosis and diabetes. Although the presence of vascular calcification is not necessarily harmful in itself, it is often associated wit a substantially worsened clinical prognosis and impacts patient treatment. Despite the potential dual risks of exposure to ionizing radiation and iodinated contrast medium from CT angiography (CTA), a major reason that interventional physicians such as vascular surgeons and cardiologists continue to prefer CTA is that MR angiography (MRA) does not reliably identify vascular calcifications. In addition to the adverse prognostic implications, the presence of dense calcifications greatly increases the difficulty of arterial access for percutaneous revascularizatin procedures and decreases success rates for balloon angioplasty. In a recently published pilot study, we determined that iliofemoral vascular calcifications have such short T2* relaxation times that they show negligible signal intensity even when imaged with an ultra-short echo MRI technique. Taking advantage of this tissue property, we demonstrated for the first time that it was possible to reliably create projection MR images of peripheral vascular calcifications with image quality approaching that provided by CT. However, many questions remain to be answered before we can bring our methodology for imaging of vascular calcifications into clinical use.
Our specific aims are as follows: 1. To evaluate the relaxation properties of calcifid and non-calcified peripheral vascular plaque in patients with PAD, so as to inform the development of an optimal imaging strategy to specifically identify calcified lesions. 2. To validate a fast, robust 3D imaging strategy for both proximal and distal vascular calcifications that can be efficiently performed in conjunction with peripheral MRA, using CTA as the reference standard. 3. To determine if diamagnetic blooming artifact alters the apparent MRI volume of vascular calcifications.
Vascular calcifications are often associated with a substantially worsened clinical prognosis and adversely impact interventional therapy. CT angiography is the de facto reference standard for in vivo imaging of vascular calcifications, but exposes patients to the potential risks of ionizing radiation and iodinated contrast medium. On the other hand, MR angiography avoids these risks but does not reliably detect vascular calcifications. The overall goals of this two-year project are to develop an optimal MR imaging strategy for vascular calcifications and then perform a pilot study to demonstrate the generalizability of the imaging strategy. We will additionally characterize vascular calcifications and non-calcified plaque by measuring their relaxation and magnetic properties.
| Serhal, Ali; Koktzoglou, Ioannis; Aouad, Pascale et al. (2018) Cardiovascular magnetic resonance imaging of aorto-iliac and ilio-femoral vascular calcifications using proton density-weighted in-phase stack of stars. J Cardiovasc Magn Reson 20:51 |
| Koktzoglou, Ioannis; Edelman, Robert R (2018) Radial fast interrupted steady-state (FISS) magnetic resonance imaging. Magn Reson Med 79:2077-2086 |
| Edelman, Robert R; Serhal, Ali; Pursnani, Amit et al. (2018) Cardiovascular cine imaging and flow evaluation using Fast Interrupted Steady-State (FISS) magnetic resonance. J Cardiovasc Magn Reson 20:12 |
| Ferreira Botelho, Marcos P; Koktzoglou, Ioannis; Collins, Jeremy D et al. (2017) MR imaging of iliofemoral peripheral vascular calcifications using proton density-weighted, in-phase three-dimensional stack-of-stars gradient echo. Magn Reson Med 77:2146-2152 |
