Thirty-four patients with acute hemispheric ischemic strokes underwent both CT angiography and contrast-enhanced transcranial color-coded duplexsonography (TCCD) to study the effectiveness of the combined noninvasive techniques for evaluation of the circle of Willis. In 3/34 patients, CT angiography and contrast-enhanced TCCD demonstrated middle cerebral artery (MCA) occlusion, in 5 others MCA stenosis. A severe posterior cerebral artery stenosis was missed by CT angiography. In 8 patients, contrast-enhanced TCCD failed because of poor bone windows. In these patients, CT angiography was normal. CT angiography and contrast-enhanced TCCD are complementary noninvasive diagnostic tools. Disagreements between the diagnostic findings of these methods still need further evaluation by digital subtraction angiography. / Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.

Background: Cerebral complications of coronary catheterizations are transient ischemic attack (TIA) and stroke. Silent stroke (SCI) does not cause acute neurological dysfunction. It might cause many disorders including dementia. Sonolysis is therapeutic method. Sonolysis should be the method for reducing the risk of symptomatic and asymptomatic brain ischemic lesions in patients undergoing elective coronary angioplasty or stenting. Aims: To analyse patients with cardiac disease indicated for elective coronary catheterization: 1) Assess the incidence of acute/subacute SCI on brain magnetic resonance (MR) imaging; 2) Investigate factors influencing the frequency and type of microembolic signals (MES) detected using transcranial Doppler (TCD) in patients undergoing elective coronary intervention, and to correlate the frequency and type of MES with detection of new brain ischemic lesions using MR. Examine changes in cognitive function at 30 days post procedure in relation to pretreatment scores; 3) Test the clinical efficacy and safety of perioperative sonolysis in patients undergoing elective coronary catheterization. Methods: 1) 144 patients were enrolled to the study. Brain MR was performed before cardiac intervention. The presence of acute and subacute SCI was evaluated, SCI volume was measured and risk...

Ce mémoire par article décrit le développement d’instrumentation optique et d’algorithmes qui ont servi à l’étude du développement rétinien du modèle murin par tomographie par cohérence optique (OCT de l’anglais, Optical Coherence Tomography). Le document est divisé en deux parties importantes. Le Chapitre 1 introduit les bases théoriques nécessaires à la compréhension de la problématique, alors que le Chapitre 2 décrit les outils qui ont été développés ou adaptés durant le projet pour mener à bien les expériences. Spécifiquement, les particularités du système optique développé pour permettre la focalisation d’un faisceau sur la rétine, maximiser le signal et minimiser l’impact des aberrations sphériques et de dispersion sur la qualité de l’image sont détaillées. Les algorithmes de traitement de signal OCT permettant la visualisation une tomographie sont aussi détaillés. La seconde partie est un manuscrit en préparation pour soumission au journal Investigative Ophthalmology & Visual Science pour publication. Le but de ce manuscrit est d’établir des chartes de référence détaillant la croissance et la maturation morphologique des tissus rétiniens de la souris wild-type (129S1/SvImJ) entre 7 et 21 jours de vie (Chapitre 3). L’article détaille l’algorithme de traitement d’images et de segmentation dédié à la quantification de l’épaisseur des tissus rétiniens dans le temps. Enfin, un aperçu des travaux de recherche rendus possibles par les outils développés dans ce projet est présenté. Cette section montre entre autres le potentiel de ces outils pour étudier des maladies développementales de la rétine. / This master thesis is including a manuscript submitted for publication and is divided into two sections. In particular, the document describes the development of optical instrumentation and methodological tools to study the retinal development in an animal model through optical coherence tomography (OCT). The first section is divided into two chapters. Chapter 1 describes the theoretical basis and the problem to solve. Chapter 2 describes the tools developed or adapted to enable the performance of the experiments. In particular, this chapter details the optical system designed to allow the optimal focalization of the light beam onto the retina, which maximizes the signal and minimizes the impact of spherical aberrations and light dispersion on image quality. Also, the processing algorithm used to segment retinal tissues from OCT tomography is discussed. The second section is divided into two chapters. Chapter 3 is a manuscript that was submitted for publication to Investigative Ophthalmology & Visual Science. This work describes the growth and maturation of specific retinal layers in the wild type mouse (129S1/SvImJ) between 7 and 21 days of life. The manuscript also describes the image processing and segmentation algorithm that allows the quantification of the thickness of the layers over time. Then, Chapter 4 describes specific research projects where these OCT imaging tools can be applied. Specifically, this chapter shows the potential to study retinal developmental diseases as well as perfusion methods.

Studium of the clinical impact of different forms of cardiac resynchronization therapy by patients with chronic heart failure MUDr. Lucie Burianová ABSTRACT: Introduction: Biventricular (BiV) pacing decreases mortality and improves quality of life of patients with severe heart failure. Haemodynamic and short time clinical studies suggest that isolated leftventricular pacing could have the same effect. Aims: Compare the effect of BiV and leftventricular pacing by subjects with dilated cardiomyopathy and severe heart failure with the attention to signs of dyssynchrony and remodelation of the left chamber. In methodical substudy compare the results of left chamber volumes and ejection fraction (EF LK) measured by CT angiography and 2-dimensional echocardiography with use of contrast agent (K-ECHO). Methods: Patients indicated for cardiac resynchronization therapy were randomized for either BiV or leftventricular pacing. After implantation of the device they were examinated clinically and by echocardiography every 3 months in the period of one year. Four years from the onset of the study the major adverse events in both groups were evaluated. The results of left chamber volumes and EF LK measured by K-ECHO and CT angiography were compared. Results: We enrolled 33 patients. We found clinical improvement in both...

京都大学 / 0048 / 新制・論文博士 / 博士(医学) / 乙第13133号 / 論医博第2137号 / 新制||医||1024(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 溝脇 尚志, 教授 妹尾 浩, 教授 鈴木 実 / 学位規則第4条第2項該当 / Doctor of Medical Science / Kyoto University / DFAM

Atrial fibrillation is the most prevalent arrhythmia worldwide and remains one of the major causes of morbidity and mortality. Atrial fibrillation is an arrhythmia that has a various etiology and takes number of clinical forms. Due to the heterogenity of atrial fibrillation, it is necessary to individualize the optimal treatment strategy, ie conservative pharmacological therapy or interventional therapy as catheter ablation. Inncorrect indication of catheter ablation of atrial fibrillation leads to low success rate of the procedure and increases the risk of the procedure. The success rate of catheter ablation of atrial fibrillation depends on many clinical parameters, including the size and volume of the left atrium and the presence of pathological tissue in the atrial myocardium. In everyday practice, echocardiography (2D-echocardiography) is the most dominant method in estimation of the left atrial parameters, for it's simplicity, non- invasiveness, financial costs and the absence of ionizing radiation. Different methods for assesment of left atrial parameters are cardiac CT, cardiac magnetic resonance imaging and methods of 3-D echocardiography or 3-D angiography. The results of the present studies show that in patients with non-valvular atrial fibrillation who are indicated for catheter...

Computed tomography angiography (CTA) of the brain poses challenges on the imaging system; the contrast between blood vessels and surrounding soft tissue is very low, and to render small intricate vessel structures high spatial resolution is needed. Higher precision angiography would facilitate more accurate diagnosis of pathological conditions. The aim of this work was to analyze the factors which contribute to the image quality in cerebrovascular imaging contexts and make a comparison between state-of-the-art energy-integrating and photon counting CT systems. A geometrical model was devised to mimic the conditions of cerebral angiography. Different parameters and detectors were used to reconstruct images of a spherical head phantom. Compton noise was added to several image acquisitions after a Monte Carlo study was used to estimate the scatter to primary ratio (SPR) with a spherical phantom. The images were evaluated qualitatively and quantitatively. A real phantom was scanned with an experimental photon counting detector and compared with the simulated approach. The work resulted in qualitative reconstructed images, a decrease in SPR when introducing air gaps and improved resolution but worsened contrast as a result of smaller detector sizes. The SPR was shown to be higher in cone-beam geometry than fan-beam geometry. Electronic noise present with energy integrating detectors was shown to degrade image quality significantly in low dose imaging, reducing contrast when imaging vascular-like structures. Photon counting detectors without electronic noise could provide greater image quality and better diagnostic information.

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Adherence to guideline-recommended secondary cardiovascular prevention therapy (statins and cardiac rehabilitation) has been demonstrated to reduce the risk of all-cause mortality (Statins RRR 0.25, 95% CI 0.19-0.30; Cardiac Rehabilitation RRR 0.26, 95% CI 0.14-0.36) and secondary events.1,2 Yet, ≥50% of patients discontinue statin use within 12-month after an initial prescription and completion of cardiac rehabilitation is ≤20% in Ontario.3,4 Low statin adherence and cardiac rehab completion limits patients from realizing the full benefits of therapy. A meta-analysis of randomized controlled trials of adherence to statins for secondary prevention reported that nonadherence to statins was greater in non-white ethnicities compared to white ethnicities (OR 1.28, 95% CI 1.04-1.59) with geographical variation in outcomes.5 In respect to cardiac rehabilitation, the literature suggests that non-white ethnicities are less likely to complete cardiac rehabilitation compared to white participants.6,7 However, a gap remains in our knowledge of cardiac rehabilitation completion among immigrants due to lack of outcome reporting across clinical trials. The literature suggests that immigrants have improved health profiles relative to Canadian-born patients. Specifically, immigrants with ≤10 years of Canadian residency have greater medication adherence than immigrants with >10 of Canadian residency when compared to Canadian-born participants.6-9 This thesis was a planned sub-study of the Interventions Supporting Long-Term Adherence and Decreasing Cardiovascular Events (ISLAND) randomized control trial. The ISLAND study was a pragmatic, randomized controlled trial investigating the effect of educational reminders on adherence to guideline-recommended therapy post-myocardial infarction. Study participants were allocated in a 1:1:1 ratio to one of three groups: i) usual care, ii) educational reminders sent via post, or iii) combination post and interactive voice response educational reminders. Investigators were blinded to the allocation sequence, participant allocation, and outcome assessment. Medication adherence and completion of cardiac rehabilitation were assessed 12-months from baseline. This sub-study of ISLAND focused on participants who completed a 12-month outcome assessment with a recorded response to the following question, “Were you born a Canadian citizen?”. Immigrants experienced greater odds of statin adherence at 7-days (OR 1.36, 95% CI 1.00-1.85) and 30 days (OR 1.36, 95% CI 0.96-1.94) at one-year post-myocardial infarction, after adjusting for age, diabetes, sex, and smoking status. We found no evidence that immigration status was associated with cardiac rehabilitation completion (OR 0.91, 95% CI 0.72-1.14) after adjusting for age, diabetes, sex, smoking status, average neighborhood income quintile, education, and marital status. The odds of statin adherence at 7-days (OR 1.33, 95% CI 0.89-2.18) and 30-days (OR 1.39, 95% CI 0.89-2.18) was greater in visual minorities than white patients, however the difference was not statistically significant. We found no evidence of an association between ethnicity and cardiac rehabilitation completion (OR 0.98, 95% CI 0.75-1.29). Our analysis could not fully evaluate the healthy immigrant effect due to an insufficient sample size of immigrants with <10 years of Canadian residency exposure (n=29). In conclusion, we report a statistically significant 36% increase in the odds of 7-day and 30-day statin adherence in immigrants compared to Canadian-born patients. We also report that the odds of cardiac rehabilitation decreased by 9% in immigrants compared to Canadian-born patients at 12-months post-myocardial infarction but this was not statistically significant. Our findings offer support for the “healthy immigrant effect” continuing in immigrants with >10 years of Canadian residency exposure. We were unable to evaluate outcomes in immigrants with <10 years Canadian residency exposure due to a lack of sample size (n=29). / Thesis / Master of Science (MSc) / The primary purpose of this research project was to assess whether immigrants, individuals who reside in Canada but were born outside of the country, who have experienced a previous heart attack were adhere to heart health therapies better than Canadian-born patients. The heart health therapies of interest to our investigation are two guideline-recommended heart attack prevention therapies, statins and cardiac rehabilitation. The study design of our research project was a cohort sub-study of the ISLAND randomized control trial which investigated adherence to heart health therapies in patients residing in Ontario, Canada. Our major finding was that immigrants who lived in Canada for >10 years were more adherent to statin therapy for a previous heart attack compared to Canadian-born participants. Our findings support the hypothesis that immigrants tend to demonstrate behaviours associated with improved outcomes compared to their Canadian-born counterparts.

Background: The relevance of drusen-like deposits (DLD) in patients with systemic lupus erythematosus (SLE) is to a large extent uncertain. Their genesis is proposed to be correlated to immune-complex and complement depositions in the framework of SLE. The intention of this study was to determine potential morphological differences in the choroid and retina as well as potential microvascular changes comparing two cohorts of SLE patients divergent in the presence or absence of DLD using multimodal imaging. Methods: Both eyes of 16 SLE patients with DLD were compared to an age- and sex-matched control-group consisting of 16 SLE patients without detectable DLD. Both cohorts were treated with hydroxychloroquine (HCQ) and did not differ in the treatment duration or dosage. Using spectral-domain optical coherence tomography (SD-OCT) choroidal volume measures, choroidal vascularity indices (CVI) and retinal layer segmentation was performed and compared. In addition, by the exploitation of optical coherence tomography angiography vascular density, perfusion density of superficial and deep retinal capillary plexuses and the choriocapillaris were analyzed. For the choroidal OCT-scans, a subset of 51 healthy individuals served as a reference-group. Results: CVI measures revealed a significant reduction in eyes with DLD compared to healthy controls (0.56 (0.54−0.59) versus 0.58 (0.57−0.59) (p = 0.018) and 0.56 (0.54−0.58) versus 0.58 (0.57−0.60) (p < 0.001)). The photoreceptor cell layer presented significant thinning in both eyes of subjects with DLD compared to control subjects without DLD (68.8 ± 7.7 µm vs. 77.1 ± 7.3 µm for right eyes, p = 0.008, and 66.5 ± 10.5 µm vs. 76.1 ± 6.3 µm for left eyes, p = 0.011). OCTA scans revealed no significant changes, yet there could be observed numerically lower values in the capillary plexuses of the retina in eyes with DLD than in eyes without DLD. Conclusions: Our results illustrated significant alterations in the choroidal and retinal analyzes, suggesting a correlation between DLD and the progression of inflammatory processes in the course of SLE leading to retinal degeneration. For this reason, DLD could serve as a biomarker for a more active state of disease.