Search results for " Subtraction"

Background subtraction and peak search from threefold gamma event data

1990

Abstract A method for subtracting background from triple-coincidence γ events is presented. In our data set it was used to remove 40% of the noise without affecting photopeaks with intensity of >18 counts. An example of performance of Ward's clustering algorithm applied to three-dimensional photopeak searching is also presented. Several standard clustering algorithms were found to be applicable only to background-subtracted data.

A new concept to treat lumbar spine stenosis in a mini invasive way

2017

Minimally Invasive Monitoring of Chronic Central Venous Catheter Patency in Mice Using Digital Subtraction Angiography (DSA)

2015

PLoS ONE 10(6), e0130661 (2015). doi:10.1371/journal.pone.0130661

Prolonged Cerebral Circulation Time Is the Best Parameter for Predicting Vasospasm during Initial CT Perfusion in Subarachnoid Hemorrhagic Patients

2016

Purpose We sought to imitate angiographic cerebral circulation time (CCT) and create a similar index from baseline CT perfusion (CTP) to better predict vasospasm in patients with subarachnoid hemorrhage (SAH). Methods Forty-one SAH patients with available DSA and CTP were retrospectively included. The vasospasm group was comprised of patients with deterioration in conscious functioning and newly developed luminal narrowing; remaining cases were classified as the control group. The angiography CCT (XA-CCT) was defined as the difference in TTP (time to peak) between the selected arterial ROIs and the superior sagittal sinus (SSS). Four arterial ROIs were selected to generate four correspondin…

Extrathoracic Arteriosclerotic Vascular Changes Preclude the Use of the Internal Thoracic Artery for Coronary Artery Bypass Grafting

1996

During a two-years period we have treated 6 patients where use of the internal thoracic artery for coronary artery grafting was precluded because of extrathoracic arteriosclerotic vascular lesions. In four patients with severe aorto-iliac occlusive disease preoperative digital angiography demonstrated collateralisation of the lower extremity by either the left, right, or both internal thoracic arteries (ITA). In these cases use of the ITA was excluded in order to preserve the collateral supply and coronary bypass grafting was performed using only saphenous vein. In two patients with proximal occlusion of the left subclavian artery the right ITA was used as in-situ bypass to graft the left a…

DOSE-RELATED EFFICACY OF A CONTINUOUS INTRACISTERNAL NIMODIPINE TREATMENT ON CEREBRAL VASOSPASM IN THE RAT DOUBLE SUBARACHNOID HEMORRHAGE MODEL

2009

Objective Intracisternal continuous therapy is a concept in the treatment of cerebral vasospasm after subarachnoid hemorrhage. The purpose of the current study was to investigate the effect of intracisternal nimodipine after induced vasospasm. Methods Sixty-five male Wistar rats were randomized into 4 groups: the control sham-operated group, the control subarachnoid hemorrhage-only group, and the treatment groups receiving 5 or 10 microL/hour of intracisternal nimodipine continuously for 5 days via subcutaneously implanted Alzet osmotic pumps (Durect Corp., Cupertino, CA). Vasospasm was analyzed 5 days later by means of digital subtraction angiography. Morphological examination of the brain…

A multicenter 12-month experience with a new iliac side-branched device for revascularization of hypogastric arteries.

2016

Abstract Objective The aim of this study was to investigate the 1-year safety and efficacy of a new iliac side-branched device (IBD) for revascularization of the hypogastric arteries. Methods Patients receiving the E-liac (Jotec GmbH, Hechingen, Germany) side-branched device at six German vascular centers either as a stand-alone procedure or in combination with abdominal aortic aneurysm exclusion were included in a prospectively created data bank. Collected data were analyzed for baseline characteristics, procedural events, and clinical follow-up; variables included endoleaks, reinterventions, and internal iliac artery (IIA) patency. Results Between January 2012 and January 2015, a total of…

Single-centre experience and preliminary Results of intravascular ultrasound in endovascular aneurysm repair

2019

Background Intravascular ultrasound (IVUS) has been introduced as diagnostic adjunct to provide new insights into the diagnosis and therapy of vascular disease. Herein, we compared the outcomes of conventional endovascular aneurysm repair (EVAR) and EVAR with IVUS in patients presenting with infrarenal abdominal aortic aneurysm using a propensity-matched cohort. Methods From May 2013 to August 2017, 221 patients were retrospectively analyzed. Of that, 122 patients were eligible for inclusion and underwent propensity score matching. Perioperative mortality and morbidity, renal function impairment, endoleak incidence, mean contrast medium usage, operative time, radiation exposure (including f…

Local Delivery of Nimodipine by Prolonged-Release Microparticles—Feasibility, Effectiveness and Dose-Finding in Experimental Subarachnoid Hemorrhage

2012

Background and purposeTo investigate the effect of locally applied nimodipine prolonged-release microparticles on angiographic vasospasm and secondary brain injury after experimental subarachnoid hemorrhage (SAH).Methods70 male Wistar rats were categorized into three groups: 1) sham operated animals (control), 2) animals with SAH only (control) and the 3) treatment group. SAH was induced using the double hemorrhage model. The treatment group received different concentrations (20%, 30% or 40%) of nimodipine microparticles. Angiographic vasospasm was assessed 5 days later using digital subtraction angiography (DSA). Histological analysis of frozen sections was performed using H&E-staining as …

CT angiography versus intraarterial digital subtraction angiography for assessment of aortoiliac occlusive disease.

1997

The purpose of this study was to evaluate the accuracy of CT angiography (CTA) with a single helical acquisition for assessment of stenoses and occlusions of the iliac arteries.In our prospective study, intraarterial digital subtraction angiography and IV CTA were performed from the suprarenal aorta to below the femoral bifurcation in 30 patients with vascular occlusive disease. Maximum-intensity-projection images in multiple views were also obtained. The accuracy of CTA with and without analysis of axial images was determined.Sensitivity and specificity of CTA were 100% for iliac artery occlusions with a confidence interval 85-100% and 97-100%, respectively. When axial scans were interpret…