Search results for " Subtraction"
showing 8 items of 68 documents
Localization of small islet-cell tumors. Preoperative and intraoperative ultrasound, computed tomography, arteriography, digital subtraction angiogra…
1985
A total of 42 islet-cell tumors were examined between 1972 and 1984. Problems of localization were only encountered in 31 tumors less than 2 cm in diameter. Of 31 small tumors, 27 were correctly localized using a combined diagnostic approach: ultrasound was successful in 12/20 tumors, CT in 9/21, angiography in 20/31, intraarterial digital subtraction angiography in 1/2, and pancreatic venous sampling in 13/16. The smallest tumor found by ultrasound and CT was 7 mm in diameter. Intraoperative ultrasound demonstrated all 9 insulinomas examined. Currently, the most useful techniques for localizing small islet-cell tumors are ultrasound, CT, and angiography. CT is particularly useful for tumor…
Implementation of computed tomography angiography (CTA) and computed tomography perfusion (CTP) in Polish guidelines for determination of cerebral ci…
2021
Background: Brain death/death by neurologic criteria (BD/DNC) guidelines are routinely analyzed, compared and updated in the majority of countries and are later implemented as national criteria. At the same time, extensive works have been conducted in order to unify clinical procedures and to validate and implement new technologies into a panel of ancillary tests. Recently evaluated computed tomography angiography and computed tomography perfusion (CTA/CTP) seem to be superior to traditionally used digital subtraction angiography (DSA), transcranial Doppler (TCD) and cerebral perfusion scintigraphy for diagnosis of cerebral circulatory arrest (CCA). In this narrative review, we would like t…
Basics of Image Interpretation in Interventional Neuroradiology
2011
The majority of patients with cerebral vascular diseases, demanding neuroradiological interventions are those, who present with potential life-threatening spontaneous intracranial/intracerebral haemorrhages due to cerebral aneurysms or/and arteriovenous malformations (AVMs) or with cerebral infarction due to intra-arterial thrombi in cerebral arteries. Neuroradiological procedures (interventional neuroradiology) (IN), always, performed in general anaesthesia can be divided into occluding and opening interventions.
Kontrastmittelgestützte 3D-MR-Angiographie der Becken- und Beinarterien mit automatischer Tischverschiebung bei 1,0 Tesla
2000
PURPOSE Assessment of the value of contrast-enhanced MR angiography (ceMRA) using an automatic tracking technique at 1.0 Tesla in comparison with digital subtraction angiography (DSA) of the pelvic and lower limb arteries. MATERIALS AND METHODS In 15 patients with peripheral arterial occlusive disease a ceMRA (3D FLASH, TR/TE = 6.2/2.3 ms, Flip angle alpha = 30 degrees, Matrix 170 x 256) using a new automatic tracking technique was accomplished. The reference method was DSA. Twenty-one vessel segments of each patient were graded as normal, stenosed (> 50%) or occluded. Image material was evaluated independently by two radiologists. RESULTS In comparison, the interobserver agreement showed a…
Softwareassistierte CT-Nachverarbeitung am Beispiel der Karotiden
2004
Ziel der Arbeit: Es sollte ein Softwareassistent fur die automatisierte Auswertung von CT-Angiographien entwickelt werden, der die Visualisierung des Gefaslumens und eine quantitative Auswertung von Stenosen ermoglicht. Die klinische Erprobung erfolgt am Beispiel der A. carotis. Methodik: Bei insgesamt zwolf Patienten mit Verdacht auf eine hohergradige Stenose der Karotiden wurde eine CT-Angiographie (CTA) mit einem Mehrzeilen-CT durchgefuhrt. Diese Daten wurden mit dem neuen Softwareassistenten analysiert und ausgewertet. Die Ergebnisse verglich man mit der digitalen Subtraktionsangiographie (DSA). Ergebnisse: Die Nachverarbeitungszeit der CT-Datensatze mit Hilfe des Softwareassistenten li…
Interdisciplinary management of peripheral arteriovenous malformations: review of the literature and current proceedings.
2021
Arteriovenous malformations (AVMs) are a rare congenital vascular disorder. They represent a fast-flow vascular malformation. Clinically, AVMs present a heterogenous expression and can affect every part of the body. Here, we will solely focus on extracranial AVMs. Generally, AVMs progress with the patient's age. Patients often suffer from pulsation, skin discoloration, pain, ulceration, bleeding, and disfigurement. Diagnostic tools include color-coded duplex sonography, MRI and CT imaging, as well as the clinical examination. 4D dynamic perfusion-computed tomography may help in the interventional planning. Digital subtraction angiography is required during interventional therapy. AVMs pose …
The efficacy of Ozone Therapy on different types of lumbar disc herniation : Proposal for guidance updates [abstract]
2018
Objective: To explore the possible mechanisms of pain relief by ozone therapy in patients with different types of lumbar intervertebral disc protrusion.
 Methods: The medical records of a total of 250 patients with protrusion of lumbar intervertebral disc (159 males, 91 females, aged 14–85 years) admitted in the South Hospital from January 2009 to June 2014 were retrospectively reviewed. Patients with protrusion of lumbar intervertebral disc were divided into four groups according to T2-weighted magnetic resonance imaging and digital subtraction angiography findings during ozone injection: type I, fibrous ring rupture without nucleus pulposus protrusion; type II, fibrous ring rupture w…
Branching Ratios and Spectral Functions of $\tau$ Decays: final ALEPH measurements and physics implications
2005
The full LEP-1 data set collected with the ALEPH detector at the $Z$ pole during 1991-1995 is analysed in order to measure the $\tau$ decay branching fractions. Extensive systematic studies are performed, in order to match the large statistics of the data sample corresponding to over 300 000 measured and identified $\tau$ decays. Branching fractions are obtained for the two leptonic channels and eleven hadronic channels defined by their respective numbers of charged particles and $\pi^0$'s. Using previously published ALEPH results on final states with charged and neutral kaons, corrections are applied to the hadronic channels to derive branching ratios for exclusive final states without kao…