Aims: To evaluate the feasibility of quantitative analysis of muscle stiffness by Acoustic Radiation Forced Impulse (ARFI) elastography over a course of graduate isometric voluntary contractions. Material and methods: The stiffness of the bilateral biceps muscle of 13 healthy volunteers was measured in real time by ARFI elastography, while the forearm was in neutral- extended position, 90 degree self-flexed positions and 90 degree self-flexed position, with altered weights ranging from 1 to 8 kg placed on flattened palmar surfaces consecutively. The determined increases in biceps muscle stiffness were measured for both arms and correlated with the loadings weights adopted at progressive trial stages. Results: The mean shear wave velocity (SWV) values of biceps muscles in a neutral position, in 90 degree flex position and 90 degree flex position with 1 to 8 kg weights on palmar surfaces were 2.162±0.302 m/sec, 3.382±0.581 m/sec, and 3.897±0.585 to 5.562±0.587 m/sec, re- spectively. Significant correlations between the muscle SWV values and related palmar weights and between the SWV values of right and left sides at different trial stages were identified (r=0.951 and r=0.954, respectively). A mutual propagation path of deep regions to entire areas was described to account for the distribution of increase in stiffness with increases in palmar weights. The confidence of method regarding inter-observer difference was confirmed by the correlation analyses of the re- sults (r=0.998). Conclusions: ARFI elastography is a feasible imaging modality for quantifying the stiffness of isometrically voluntarily contracting muscles.

Background and purpose Multiple aneurysms have a high reported incidence, but the optimal treatment strategy is not clear. The aim of this study was to evaluate the safety and effectiveness of single-stage endovascular treatment of multiple aneurysms with a combination of various endovascular techniques. Materials and methods Fifty-three consecutive patients with multiple intracranial aneurysms who underwent single-stage endovascular treatment for ≥2 aneurysms from June 2011 to May 2016 were included in the study. Patient and aneurysm characteristics, treatment technique, complications, clinical and angiographic outcomes were retrospectively evaluated. Results 125 of 128 aneurysms (97.6%) were treated by the following endovascular techniques: simple coiling in 19, balloon-assisted coiling in 27, stent-assisted coiling in 33, flow diverters in 43, intrasaccular flow modifiers in 2, and a neck-bridging device in 1. Overall mortality and mortality directly related to the single-stage treatment was 15% (8/53) and 3.7% (2/53), respectively. Clinical and angiographic follow-up was available in 44 (83%) patients for 104 (83.2%) aneurysms for a mean duration of 16.2 months (range 3–51 months). According to the last angiographic follow-up, overall occlusion rates were complete in 85 (81.7%), near complete in 8 (7.6%), and incomplete in 11 (10.5%) aneurysms. Conclusions Single-stage endovascular treatment of multiple aneurysms with combined endovascular techniques is technically feasible and increases the treatment possibility of all detected aneurysms. However, the safety of the procedure is controversial due to relatively high complication rates. In particular, in patients with bilateral internal carotid artery aneurysms, staged therapy may be used instead of simultaneous treatment with flow diverters to avoid thromboembolic events.