57 research outputs found
Three examples of perfusion patterns in acute lacunar infarction.
<p>Mismatch (1), inverse mismatch (2), and match (3) between diffusion-weighted and perfusion-weighted images (DWI, PWI). DWI (a) shows the initial ischemic lesion (white arrow). PWI derived maps demonstrate the perfusion deficit: time to peak (b), cerebral blood flow (c), and cerebral blood volume (d). Follow-up DWI (e) and FLAIR (f) show the ischemic lesion (white arrow). Note that case 2 is also an example of lesion reversal after intravenous thrombolysis.</p
Endovascular stentectomy using the snare over stent-retriever (SOS) technique: An experimental feasibility study
<div><p>Feasibility of endovascular stentectomy using a snare over stent-retriever (SOS) technique was evaluated in a silicon flow model and an in vivo swine model. In vitro, stentectomy of different intracranial stents using the SOS technique was feasible in 22 out of 24 (92%) retrieval maneuvers. In vivo, stentectomy was successful in 10 out of 10 procedures (100%). In one case self-limiting vasospasm was observed angiographically as a technique related complication in the animal model. Endovascular stentectomy using the SOS technique is feasible in an experimental setting and may be transferred to a clinical scenario.</p></div
Stentectomy technique.
<p>1.) The loop of a microsnare was slipped over the tip of a microcatheter, slightly tightened, (1A) and the microcatheter was inserted into a long sheath or guide catheter (1A) 2.) The microcatheter together with snare was positioned a few milimeters proximal of the mal-deployed stent (1C) 3.) A stent-retriever was advanced through the microcatheter and partially unfolded, so that the distal part of the stent-retriever attached to the vessel wall. 4.) The partially unfolded stent-retriever was pushed forward carefully, until the distal markers of the stent-retriever overlapped with the proximal markers of the mal-deployed stent (1D). Using a stent-retriever with a comparable or larger diameter than the target stent seems to be helpful. 5.) The stent-retriever is being resheathed while applying slight pressure, hereby „grabbing”the proximal end of the mal-deployed stent (1E). Doing so, some or all of the proximal markers of the maldeployed stent move towards the tip of the microcatheter (1E). 6.) The microsnare is being opened (1F), pushed forward over the microcatheter and over the proximal end of the maldeployed stent (1G). 7.) Finally, the microsnare is pulled close again (1H). 8.) The stent-retriever and the snare are „locked”in their position by tightening a torque on the wire of both devices directly adjacent to the hemostatic valve (not shown). 9.) To extract the maldeployed stent, the snare and the stent-retriever are being pulled back slowly into the sheath or guide catheter (1I) (aspirate to prevent embolism). 10.) If it should be impossible to pull a stent into the sheath or guide catheter, one should consider to “move” the stent into a less relevant vessel, like the external carotid artery or in a brachial or femoral vessel that can be reached more easily by a vascular surgeon.</p
Comparison between the systems of Mannheim and Stanford [1] for a field size of 1 cm.
<p>Comparison between the systems of Mannheim and Stanford [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0126246#pone.0126246.ref001" target="_blank">1</a>] for a field size of 1 cm.</p
A shows a volume rendering of a mouse 30 minutes after i.v. injection of ExiTron nano 12000.
<p>B is a curved maximum intensity projection in coronal orientation of the same scan. A and B demonstrate the feasibility to perform CT angiography during the early intravascular phase of the tested contrast agent. Additionally, A and B show the early contrast agent uptake by the RES with increasing contrast of liver and spleen. C is a coronally oriented curved maximum intensity projection of a mouse that did not receive contrast agent.</p
A and B show intrasplenic (*) and intrahepatic (LMet) growing tumors 26 days after intrasplenic injection of C15A3 colon tumor cells.
<p>A and B were acquired 4 hours after i.v. injection of 100 µl ExiTron nano 12000. B, C, and D illustrate contrast enhancement of the abdominal and mediastinal lymph nodes (LN) and of the adrenal glands (AdrG). C was acquired 4 hours after i.v. injection of 100 µl ExiTron nano 12000; D was acquired 22 days after i.v. injection of 100 µl ExiTron nano 12000. Micro-CT scanning parameters: 40 sec scan time; 190° rotation; 1200 projections; voxel size 41×41×55 µm<sup>3</sup>.</p
Time course of contrast enhancement within the vascular system and the liver of C57BL/6J mice (n = 3 per group) after a single i.v. injection of 100 µl ExiTron nano 6000 or ExiTron nano 12000.
<p>Measurements were performed by placing a ROI within the left ventricle (vessel contrast) and within the liver avoiding large intrahepatic vessels. The baseline level ( = 100%) refers to measurement of the relative density of the liver and the vascular system prior to administration of contrast agent.</p
Proof of principle using an orthotopic implant model.
<p>(a) CT scans used to measure tumor depths and example for a plan using 3 irradiation angles (0°, 270° and 315°). (b) Graphical user interface of the planning application with a standard treatment scheme. (c) Dose distribution of a three-beam plan (details shown in b) in the head phantom measured with a Gafchromic film. (d) Treated tumors show extensive necrotic areas (white arrow) after irradiation, which were not present in untreated tumors. (e) Survival plots of irradiated and untreated mice.</p
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