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The brain infarct core delineation using computed tomography angiography source images in acute stroke patients
Rohan, Vladimír ; Choc, Milan (advisor) ; Kalvach, Pavel (referee) ; Kalita, Zbyněk (referee) ; Smrčka, Martin (referee)
Background and Purpose: Ischemic stroke is the 3rd most common cause of death and most common cause of permanent disability in developed countries. Rapid diagnostic work-up with reliable assessment of infarcted brain tissue and potentionally salvageable brain tissue is critical for acute stroke management. The first aim of this study is to asses delineation of infarct core in acute stroke patients using whole brain perfused blood volume (PBV) maps. These maps are calculated by automatic processing from computed tomography angiography source images (CTA-SI) and non-contrast computed tomography (NCCT) data. The second aim is to determine optimal quantitative threshold of PBV for infarct core identification in acute stroke setting. Material and methods: PBV maps were constructed using prototype software from NCCT and CTA-SI data in 37 acute ischemic stroke patients with angiographically proved recanalization after intravenous thrombolytic treatment. These PBV maps were automatically compared with final infarct extension on follow-up NCCT. The anatomic pixel-by-pixel correlation was assessed using Matthew's correlation coefficient (MCC) for infarct core delineation using different critical values of PBV. The optimal threshold with the best correlation was used for infarct volume computation. Minimal PBV...
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není uveden
Foltán, René ; Mazánek, Jiří (advisor) ; Kalvach, Pavel (referee) ; Klozar, Jan (referee)
In the thesis the author deals with the surgical technique of the genioglossus advancement and hyoid myotomy (GAHM) in the obstructive sleep apnoea syndrome (OSAS) therapy. He focuses in particular on methods used to widen the upper airway by surgical modification of facial bones. Following the definition of the research objective in Chapter 1 and the general introduction in Chapter 2, we can find in Chapter 3 the description and definition of OSAS as well as physiological, pathophysiological and epidemiological notes on sleep, ventilation in sleep and OSAS. In Chapter 4 the author recommends some new methods of examining the upper airway that can be applied in an ordinary dental surgery to predict the risk of development or occurrence of OSAS in some patients. Chapter 5 includes an overview of therapeutic options for OSAS and a detailed description of different GAHM techniques. In accordance with the research objectives and the methodology described in Chapter 6, the results in Chapter 7 show, for a large sample of examined patients, the dependence of obesity (as expressed by the BMI) on the severity of OSAS, along with some cephalometric values in which such dependence has not been published so far. Then the chapter documents a high success rate of GAHM treatment of OSAS in operated patients. This is so,...
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Atherosclerotic changes in internal carotid artery in neurological asymptomatic population
Srp, Antonín ; Kalvach, Pavel (advisor)
When selecting the topic of my thesis role played two facts. The first of them was my interest in the field of neurology, particularly the rapidly developing a stroke issues. The second contribution has been my experience from the 3rd year, when I was in the students' scientific activities working under the auspices of the Institute of Anatomy at the cadaveric femoral arteries. In consultation with your supervisor, prof. Kalvach, we agreed that it would be beneficial to these two facts together and try to contribute to the ever-increasing knowledge of stroke in recent years rarely performed studies
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The extent of calcification in cerebral arteries in correlation to age
Massamba, Nzuzi Laura Garcia ; Kalvach, Pavel (advisor)
It is a common experience of radiologists that the density of organs is changing during our life. This phenomenon is especially conspicuous as a decreasing density of bones, defined either as diffuse osteoporosis, or in more focal appearance as osteomalacia. On the other hand we can observe an increasing density of the vascular wall with aging. One of the most influential elements is Calcium (Ca2+). We were attracted by these moves of Calcium, being washed out from the bones and being washed in into the vessel wall. I have carried out an analysis of the intensity of vascular Calcium deposits in two different regions of the body. The abdominal aorta was investigated in 25 patients of which 13 were women and 12 were man, and cerebral arteries were investigated in 23 ischemic stroke patients of which 13 were women and 10 were male. Previous studies on cerebral arteries have suggested that predilection for sites for atherosclerosis include the bifurcations of the common carotid artery, the sinus portion and the curved terminal part of the ICA and the proximal part of the VA. Most of the time, routine brain CT miss these sites, unless they are intensive. For these reasons only large and highly calcified plaques are detectable on brain CT. (7). Other studies have also been carried out in order to analyse the...
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Effects of CO2, alcohol, and caffeine on cerebral blood flow and cerebral autoregulation
Bláha, Martin ; Beneš, Vladimír (advisor) ; Haninec, Pavel (referee) ; Kalvach, Pavel (referee)
1. Alcohol intoxication increases cerebral blood flow from 8 to 24 % 2. Alcohol intoxication does not impair dynamic cerebral autoregulation 3. Caffeine (300 mg per oral) decreases cerebral blood flow by 20 % 4. Without CO2 influence, caffeine (300 mg per oral) decreases cerebral blood flow from 10 to 20 %. 5. Caffeine decreases CBF despite severe peripheral cerebrovascular vasodilatation (during hypercapnia caffeine decreases CBF from 11 to 12 %) 6. There is not a statistically significant reduction of CBF during hypocapnia. 7. Vasomotor reactivity testing - Carbon Dioxide challenge test is not affected by pre-test caffeine intake 9. CO2 is a strong regulator of cerebral blood flow (through the regulation of the tone of cerebral vessels) 10. Cerebral vasomotor reactivity in healthy humans is 86.5 ± 19.1, and CO2 reactivity is 3.0 ± 0.6 %/mmHg 11. Cerebral autoregulation is significantly impaired during hypercapnia (autoregulation index decreases from baseline values of 4 ± 0.8 to 0.9 ± 0.9) 12. Increase of etCO2 by 1mmHg decrease ARI by 8.24 % 13. Traumatic brain injuries cause significant impairment of cerebral autoregulation 14. The cyclic leg cuff autoregulation test appears better suited for clinical use than the hyperemic leg cuff step release method. 15. Cerebral autoregulation may respond with...
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Hemodynamic parameters of the cervical carotid bed of saline in the throes of stenosis of the carotid bulb and the bed capacity of treated recanalization excercise
Gregová, Daniela ; Kalvach, Pavel (advisor) ; Zvěřina, Eduard (referee) ; Beneš, Vladimír (referee) ; Bauer, Jiří (referee)
With the increasing number of patients suffering from some metabolic diseases leading to the development of atherosclerosis there is an urgent need for early diagnosis of the scale. If we think about disability sclerotic cerebral arteries, the optimal method of investigation is duplex ultrasonography, which is relatively inexpensive and friendly for the patient. To assess not only the structure and extent of atherosclerotic plaque, but also to assess the extent of any narrowing of the arteries and to evaluate the hemodynamic impact of structural changes present. It is an ideal candidate for screening in primary or secondary prevention of stroke, as well as for regular checks dispensarized patients. Knowledge of normal hemodynamic conditions in the cervical carotid stream is necessary in the assessment of various pathological conditions. This paper seeks to offer the most comprehensive view on the issue of carotid stenoses ultrasonografisty eyes. For practical reasons we focus on localized stenosis in the carotid bulb, the number is high above the stenosis in other locations.
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