Mustafa Altaha MBBS, Presenter: Nothing to Disclose

Jeffrey David Jaskolka MD, Abstract Co-Author: Nothing to Disclose

Kongteng Tan FRCR, Abstract Co-Author: Nothing to Disclose

Manuela Rick, Abstract Co-Author: Employee, Siemens AG

Peter Schmitt PhD, Abstract Co-Author: Employee, Siemens AG

Ravi Menezes PhD, Abstract Co-Author: Nothing to Disclose

Bernd J. Wintersperger MD, Abstract Co-Author: Speakers Bureau, Bayer AG Speakers Bureau, Siemens AG

To evaluate the diagnostic accuracy of non-enhanced prototype Quiescent-Interval Single-Shot (QISS) and conventional TSE-based subtraction Magnetic Resonance Angiography (MRA) in the assessment of the peripheral arteries in patients with critical limb ischemia.

In this prospective cohort study, patients (n=20; 70% male, 69.7±10.8years) referred for treatment of chronic limb ischemia (Rutherford stages 4-6) underwent non-enhanced QISS and TSE-based subtraction MRA at 1.5T ≤ 1 week prior to digital subtraction angiography (DSA). QISS MRA was performed with 3mm axial slices (pixel: 1x1mm2) from toes to aortic bifurcation, 3D TSE-based subtraction MRA was restricted to the tibial region in the coronal plane (voxel: 1.3x1.2x1.3mm3). Two blinded readers evaluated data sets with respect to presence of stenosis (≥50%) and image quality on a segmental (n=14) and also regional level (femoropopliteal/tibial/pedal). For statistical analysis results were compared to DSA, both on a segmental and regional level.

22 limbs in 20 patients with 295 segments were available for DSA comparison. QISS image quality was rated as good-excellent in 80% (n=245/308) of segments with no non-diagnostic segments. Sensitivity at the segmental level was 93% (95CI:86-96%) with a specificity of 95% (95CI:91-98%). Positive and negative predictive values were 93% (95CI:88-96%) and 95% (95CI:90-97%), respectively. On a regional level sensitivity was 90% (95CI:78-96%) with a specificity of 60% (95CI:20-90%). After exclusion of pedal segments regional specificity improved to 75% (95%CI:24-97%) with no change in segmental/regional sensitivity. Interreader comparison demonstrated fair agreement between readers (κ=0.393) for QISS. Motion artifacts affected image quality of the TSE-based technique which was rated non-diagnostic in 65% (n=101/156) and poor in 25% (n=39/156) of segments; no further analysis was performed.

QISS MRA demonstrates excellent diagnostic performance in patients with critical limb ischemia, particularly at the femoropopliteal and tibial level. In this patient population, QISS MRA was more robust than TSE-based subtraction MRA, which was affected by patient motion.

The low susceptibility of QISS MRA to patient motion provides stable diagnostic information in challenging patients with critical limb ischemia and contra-indication to Gd-based contrast agents.

Altaha, M, Jaskolka, J, Tan, K, Rick, M, Schmitt, P, Menezes, R, Wintersperger, B, Non-Enhanced MR Angiography in Critical Limb Ischemia: Comparison of Quiescent-Interval Single-Shot (QISS) and TSE-based Subtraction Techniques to Digital Subtraction Angiography.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14014477.html