Characteristics of Unstable Carotid Plaques - New Image Modalities.

Ischemic stroke is a socially significant health problem due to high mortality and disability. One of the leading causes for cerebrovascular accidents is the carotid atherosclerosis. The mechanism of its formation presents not only lipid accumulation in the arterial wall but a complex inflammatory disease. The aims of this review are to point the new methods and approaches for diagnostic of the unstable and high-risk carotid plaques. The old plaque imaging modalities emphasized mainly to the degrees of luminal stenosis. The new possibilities reveal plaque morphology so detailed even compared to histological verification. Recent techniques as Shear wave elastography, optical coherence tomography, Superb microvascular imaging, USPIO MRI give information about the pathological mechanisms of carotid atherosclerosis. The efforts are directed to predict the atherosclerotic burden, plaque instability and the occurrence of cerebrovascular events for each patient and to optimize personal management.

Adult brain activation during visual learning and memory tasks. An experimental approach to translational neuroscience.

RATIONALE, AIMS, AND OBJECTIVES: Human brain connectome is a new and rapidly developing field in neuroscience. The pattern of structural and functional connectivity in the brain is not fixed but is continuously changing in response to experiences. Exploring these phenomena opens a powerful arsenal of analyses and computational approaches that could provide important new insights into clinical and cognitive neuroscience. The aim of the present study was to investigate the activations of adult brain cortical areas during a memory task performance by using functional MRI with a specific focus on gender differences. METHODS: Twenty-nine right-handed subjects (15 men and 14 women) were scanned. The memory paradigm consisted of 4 consecutive sets of "on" and "off" blocks with a total duration of 4 minutes. The subjects were first presented with 4 pictures (fixation F-part) of the same theme-landscapes, portraits, anatomical images of internal organs, and geometric figures denoted by specific mismatching nouns (seasons, personal names, internal organs, and figures), followed by 3 of the presented pictures and questions for memory evaluation (recall R-part). For the active conditions, the participants were instructed to read the statements carefully and answer with a button press. RESULTS: We found reliable occipital and temporal signal responses across the block design contrasts with statistical significant differences within the groups in both genders. Statistical significance in brain cortical activation was not found between men and women. CONCLUSION: The results highlighted several detailed distinctions between the genders and potential future directions in brain activation studies as part of the multidisciplinary approach in translational neuroscience.

Cortisol Correlates with Structural Magnetic Resonance Imaging Parameters in Middle Aged Bulgarian Patients with Metabolic Syndrome: A Pilot Study.

BACKGROUND: There is a dose-dependent relationship between chronically increased cortisol levels and the number of metabolic syndrome (MetS) components. Both cortisol and MetS are linked to various brain abnormalities. AIM: To investigate an association of MetS components and salivary cortisol levels with cortical thickness in middle-aged Bulgarian patients with MetS. MATERIALS AND METHODS: We examined 26 healthy volunteers (mean age 50, 16±3.1 yrs) divided into two groups depending on whether or not they were diagnosed with MetS. Salivary cortisol was sampled and tested at two time points -morning and evening. Cortical thickness measures were obtained from structural T1-images using FreeSurfer software. We performed vertex-wise analysis across entire cortex and for preselected brain regions in frontal, temporal and cingulate cortex partial correlation analysis, accounting for gender. RESULTS: The control group consisted of 12 women; in the MetS group there were 6 men and 8 women. The whole brain analysis showed that waist circumference (WC) was negatively correlated with cortical thickness in rostro-lateral area in left frontal lobe and the right lateral orbito-frontal cortex. Morning cortisol levels, accounting for sex and WC, correlated negatively with thickness in left superior temporal area (r = -0.477, p = 0.039) and entorhinal area (r = -0.465, p = 0.045) and left mediotemporal cortex (r = -0.477, p = 0.038). CONCLUSION: Our pilot study confirmed that WC is associated with brain atrophic changes mainly in the frontal lobe. Our finding that cortisol levels negatively correlate with thinning of the cortex in temporal lobe should be further explored in subsequent study.

Ultrasound tomography in diagnosing cystic pancreatic neoplasms.

UNLABELLED: The clinical, radiologic, and pathologic features of cystic pancreatic lesions are well known, and yet preoperative diagnosis is often difficult to make. AIM: To present the role of ultrasound study in conventional and interventional diagnostics of cystic pancreatic neoplasms. PATIENTS AND METHODS: 65 patients (17 men, 48 women) with cystic pancreatic lesions were examined by ultrasound and computer tomography and investigated using a number of diagnostic interventional procedures over three years. We used Siemens-Adara ultrasound system, GE Sytec 3000i CT equipment and a set of biopsy needles and catheters. RESULTS: We performed ultrasound studies for all 65 patients to determine the structural characteristics of the cystic lesions. Lesions varied in size from 15 to 130 mm in diameter. In 50 patients we used US control to perform the invasive procedures for cytological and histological examination. In 9 cases the invasive procedures were repeated. In 15 cases we preferred to use CT guidance. We were able to detect 46 pseudo cysts, 9 mucinous neoplasms, 6 serous cystadenomas, 3 intraductal papillary mucinous neoplasms and 2 lymphoepithelial cysts. CONCLUSIONS: Ultrasound tomography is an imaging method of sufficient informative value with respect to the structural characteristics of cystic pancreatic neoplasms. US-guided invasive manipulations of cystic pancreatic lesions are easy to perform, quick and effective diagnostic methods. In some cases punctures and biopsies under CT control appear to be the imaging modality of choice.

Improvement of visualization in computed tomographic colonography after mechanic air insufflation.

OBJECTIVE: Our aim was to develop an insufflation system for CT colonography enabling even and quick air inflation as well as pressure control and optional emergency decompression. PATIENTS AND METHODS: A modified air insufflation system for CT colonography, consisting of an electric air pump, manometer, safety valve, and a balloon tip is presented. Thirty one patients underwent CT colonography from August to December, 2004. RESULTS: Optimal distension was achieved in 30 patients; the distension was incomplete (partial) only in one case. The insufflation was performed within 60 seconds in 28 of the cases, in 2 patients--within 180 seconds and in one patient--after 180 seconds. CONCLUSIONS: The presented insufflation system allows optimization of CT colonography technique, reduces the risk of adverse events during examination and improves the precision of the method.

Fine needle aspiration biopsy of dense pulmonary lesions under computed tomography control.

UNLABELLED: The AIM of this article was to present our experience in the field of invasive diagnosis of dense pulmonary lesions (both benign and malignant). We consider the advantages and shortcomings of this method and the complication frequency (pneumothorax, haemothorax). MATERIALS AND METHODS: 92 patients (39 women and 53 men, aged between 24-70 years) underwent fine needle aspiration biopsy (FNAB) under computed tomography control (CTC). All biopsies were carried out by cutting needles 19-20G under computed tomography control with GE Sytec 3000 and Somaton Emotion Siemens. RESULTS: 86 biopsies were suitable for both cytological and histological diagnosis and 6 biopsies were suitable for cytological diagnosis alone. In 85 cases the material was obtained at the very first insertion of the biopsy needle while in the other 7 cases correction of the biopsy angle was performed after CT control. Twelve patients had partial pneumothorax as a complication and no haemothorax was registered. CONCLUSION: Under the control of modern CT equipment,when the biopsy needle is chosen correctly, the lesion is marked exactly and the manipulation is performed precisely, it is usually possible to obtain enough material for cytological and histological investigation with low risk of serious complications.