Hungarian Radiology

[Networks]

LOMBAY Béla

OCTOBER 10, 2005

Hungarian Radiology - 2005;79(05)

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Hungarian Radiology

[Board Meeting of the Hungarian College of Radiology]

PALKÓ András, FORRAI Gábor

Hungarian Radiology

[The role of MRI in the clinical examination following breast cancer screening]

SZABÓ Éva, BIDLEK Mária, GŐDÉNY Mária

[INTRODUCTION - Breast cancer screening was performed in 27 325 female patients at the National Institute of Oncology from 1st of January 2002 to May 30th of 2005. Complementary examinations were necessary in 1876 women. MR-mammography was performed in 65 of these cases. We were curious about in which cases MR mammography helps to make the diagnosis more accurate, how does it influence the therapy. We also studied, whether the number of surgical interventions because of benign breast lesions decreases due to MR mammography. PATIENTS AND METHODS - In 65 patients MR mammography was performed using non-contrast axial and coronal T1W and STIR sequences. After the injection of gadolinium four series of 3D FLASH (fast low angle shot) dynamic gradiens echo sequences were also applied. Subtraction of the non-contrast and contrast enhanced series were evaluated in addition to the intensity curves of the postcontrast series. RESULTS - MR mammography helped to evaluate dense breasts in 21 cases, to identify multifocal lesions in 6 cases and to differentiate the malignant-benign processes. In the course of the 65 post-screening examinations, malignant processes [BI-RADS IV-V (Breast Imaging Reporting and Data System)] were diagnosed in 21 cases, benign processes (BI-RADS II-III) or negative results were found in 44 patients. CONCLUSION - MR mammography increased diagnostic accuracy, decreased the number of benign lesion-related surgical procedures and increased the accuracy in determining surgical radicality and establishing a therapeutic plan.]

Hungarian Radiology

[The force transmission of the distal endings of stent delivery systems]

SZIKRA Péter, VÖRÖS Erika, SZTRIHA László, SZÓLICS Alex, CSIKÁSZ Tamás

[INTRODUCTION - In cases of endovascular treatment of internal carotid artery stenosis, one of the most important aspects is to minimise embolic complications. Dislodging emboli may be influenced by the shape and size of tapered endings of stent delivery systems. Our team performed measurements and calculations on the emergence of force of the various tapered endings. MATERIAL AND METHOD - Five different commercially available stent dilivery systems were investigated. The thickness of the devices were measured and taking 5 mm normal artery diameter, the lumen size was calculated, above which the delivery system should dilate the lumen mechanically. By means of geometrical computer-constructions and measurements, we analysed the forces directed ahead and laterally, emerging on the surface of tapered endings during the passing through the stenosis. RESULTS - The stent delivery systems were between 5.0 and 5.9 F in diameter, and even the stent delivery system of lowest profile would dilate a stenosis of over 89%. The different endings are tapered with variable lengths. The force transmission on the vessel wall of different directions was distinct at the various points of the cone surfaces. The forces directed ahead were less than those directed laterally on the larger part of a cone surface. Irregularity of the cone surfaces distributed the forces unfavorably. Considering the features of tapered endings, the atraumatic introduction of the devices required a range of upper limits of stenoses between 89.76-98.04%, which are more feasible values than those deternined by shaft sizes. CONCLUSIONS - Our experimental work suggests, that the shape and size of the endings of stent delivery systems influence the forces affecting vessel wall plaques, and in this manner, embolic complications, during carotid stenting. The lowest risk of embolisation could be induced by using the longest and smoothest tapered endings.]

Hungarian Radiology

[Acromesomelic dysplasia du Pan]

KAISSI Al Ali, GHACHEM Ben Maher, CHEHIDA Ben Farid, KOZLOWSKI Kazimierz

[INTRODUCTION - Cartilage derived morphogenic protein (CDMP1) mutations account for several related disorders, ranging from prenatal lethal to very mild entities such as brachydactyly C. Two similar severe manifestations of CDMP1 mutations are du Pan and Hunter-Thompson syndromes. CASE REPORTS - We report two second degree relatives with du Pan syndrome. Clinical history and full skeletal surveys were analysed and compared with the data from the literature. Frequent spontaneous abortions - probably manifestation of the lethal forms of CDMP1 mutations - were present in both families. Skeletal surveys of the patients showed similar acromesomelic abnormalities consistent with du Pan syndrome. CONCLUSION - The rare publications of du Pan syndrome present usually insufficient radiographic documentation. Better radiographic imaging is necessary to establish clear-cut criteria of differentiation between du Pan and Hunter-Thompson syndrome.]

Hungarian Radiology

[Quality cost in radiology: the cost of repeated examinations]

KIS Zsuzsanna

[INTRODUCTION - The aim of the author is to describe the definition and types of quality cost in the health care services especially in the field of radiology. The proportion of the quality cost is based on the author's data and data from the literature. The ways of reduction of the quality cost is also discussed. MATERIAL AND METHODS - The author made a research based on a prior multicentric study to determine the loss derived from the excessive use of films used during the repeated radiological examination. The cost of wrong services nationwide is calculated on the basis of the loss per 1000 German point. RESULTS - Our short research showed that 300 000 Ft HUF + VAT per year was paid because of the excessive use of the films during the repeated examination points within the given period of time. The loss percentage per 1000 German points can be calculated based on the points generated during a given time. In this way there was more than 300 million HUF spent on defective services nationwide in 2002. CONCLUSION - The cost of defective services and resulting moral and financial losses justify the need for finding and reducing the costs. Quality control and quality improvement can be used to achieve the aims of controlling the processes by the right indicators. By discussing them the processes will improve, the costs will be lower and quality also improves. The patients and insurance companies who buy our services also have the same expectations.]

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VOKÓ Zoltán

[What has Go to do with making clinical decisions? One of the greatest intellectual challenges of bedside medicine is making decisions under uncertainty. Besides the psychological traps of traditionally intuitive and heuristic medical decision making, lack of information, scarce resources and characteristics of doctor-patient relationship contribute equally to this uncertainty. Formal, mathematical model based analysis of decisions used widely in developing clinical guidelines and in health technology assessment provides a good tool in theoretical terms to avoid pitfalls of intuitive decision making. Nevertheless it can be hardly used in individual situations and most physicians dislike it as well. This method, however, has its own limitations, especially while tailoring individual decisions, under inclusion of potential lack of input data used for calculations, or its large imprecision, and the low capability of the current mathematical models to represent the full complexity and variability of processes in complex systems. Nevertheless, clinical decision support systems can be helpful in the individual decision making of physicians if they are well integrated in the health information systems, and do not break down the physicians’ autonomy of making decisions. Classical decision support systems are knowledge based and rely on system of rules and problem specific algorithms. They are utilized widely from health administration to image processing. The current information revolution created the so-called artificial intelligence by machine learning methods, i.e. machines can learn indeed. This new generation of artificial intelligence is not based on particular system of rules but on neuronal networks teaching themselves by huge databases and general learning algorithms. This type of artificial intelligence outperforms humans already in certain fields like chess, Go, or aerial combat. Its development is full of challenges and threats, while it presents a technological breakthrough, which cannot be stopped and will transform our world. Its development and application has already started also in the healthcare. Health professionals must participate in this development to steer it into the right direction. Lee Sedol, 18-times Go world champion retired three years after his historical defeat from AlphaGo artificial intelligence, be­cause “Even if I become the No. 1, there is an entity that cannot be defeated”. It is our great luck that we do not need to compete or defeat it, we must ensure instead that it would be safe and trustworthy, and in collaboration with humans this entity would make healthcare more effective and efficient. ]

Clinical Neuroscience

Neuroscience highlights: Main cell types underlying memory and spatial navigation

KRABOTH Zoltán, KÁLMÁN Bernadette

Interest in the hippocampal formation and its role in navigation and memory arose in the second part of the 20th century, at least in part due to the curious case of Henry G. Molaison, who underwent brain surgery for intractable epilepsy. The temporal association observed between the removal of his entorhinal cortex along with a significant part of hippocampus and the developing severe memory deficit inspired scientists to focus on these regions. The subsequent discovery of the so-called place cells in the hippocampus launched the description of many other functional cell types and neuronal networks throughout the Papez-circuit that has a key role in memory processes and spatial information coding (speed, head direction, border, grid, object-vector etc). Each of these cell types has its own unique characteristics, and together they form the so-called “Brain GPS”. The aim of this short survey is to highlight for practicing neurologists the types of cells and neuronal networks that represent the anatomical substrates and physiological correlates of pathological entities affecting the limbic system, especially in the temporal lobe. For that purpose, we survey early discoveries along with the most relevant neuroscience observations from the recent literature. By this brief survey, we highlight main cell types in the hippocampal formation, and describe their roles in spatial navigation and memory processes. In recent decades, an array of new and functionally unique neuron types has been recognized in the hippocampal formation, but likely more remain to be discovered. For a better understanding of the heterogeneous presentations of neurological disorders affecting this anatomical region, insights into the constantly evolving neuroscience behind may be helpful. The public health consequences of diseases that affect memory and spatial navigation are high, and grow as the population ages, prompting scientist to focus on further exploring this brain region.

Clinical Neuroscience

[The concept of epileptic networks. Part 2.]

HALÁSZ Péter

[In this paper we investigate evidences supporting the network concept of epilepsies from different approaches. Firstly the functions of cortical networks in which most of the epileptic networks are embedded, are treated. Then the tentative characteristics of an epileptic network are enumerated and the conversion mechanisms from physiological to epileptic networks are analyzed. Later the role of neuronal oscillations in epileptic networks and aspects of epilepsies provoked by sensory and cognitive tasks is studied. Lastly new fMRI data in mapping BOLD networks underlying spike and seizure discharges are used as arguments in favour of the epileptic network hypothesis. In a second part the well-known epilepsies related, or probably related to physiological networks are shown. Finally consequences of the network approach for creating a new unified epilepsy classification are discussed.]

Clinical Neuroscience

[The concept of epileptic networks. Part 1.]

HALÁSZ Péter

[In this paper we investigate evidences supporting the network concept of epilepsies from different approaches. Firstly the functions of cortical networks in which most of the epileptic networks are embedded, are treated. Then the tentative characteristics of an epileptic network are enumerated and the conversion mechanisms from physiological to epileptic networks are analyzed. Later the role of neuronal oscillations in epileptic networks and aspects of epilepsies provoked by sensory and cognitive tasks is studied. Lastly new fMRI data in mapping BOLD networks underlying spike and seizure discharges are used as arguments in favour of the epileptic network hypothesis. In a second part the well-known epilepsies related, or probably related to physiological networks are shown. Finally consequences of the network approach for creating a new unified epilepsy classification are discussed.]

Clinical Neuroscience

[EEG-based cerebral networks in 14 neurological disorders]

DÖMÖTÖR Johanna, CLEMENS Béla, CSÉPÁNY Tünde, EMRI Miklós, FOGARASI András, HOLLÓDY Katalin, PUSKÁS Szilvia, FEKETE Klára, KOVÁCS Attila, FEKETE István

[Background - Brain networks have not been systematically investigated yet in most neurological disorders. Purpose - To investigate EEG functional connectivity (EEGfC) networks in 14 neurological disorders. Patients - Potentially eligible patients were collected from clinical and EEG databases. All the available clinical data and EEG records were critically revised. All the patients who suffered of a single neurological disorder (out of the 14) and had a good quality EEG recording entered the study. Confoundig factors as comorbidity and CNS-active drug effects were eliminated as far as possible. EEG analysis - Three minutes of resting-state, waking EEG activity were selected for analysis. Current source density (CSD) values were computed for 2394 cortical voxels by Low Resolution Electromagnetic Tomography (LORETA). Thereafter, Pearson correlation coefficients were computed between all pairs of 23 cortical regions of interest (ROI) in each hemisphere (LORETA Source Correlation, LSC software). Computation was carried out for conventional EEG broad bands and very narrow bands (1 Hz bandwidth) between 1 and 25 Hz as well. Correlation coefficients of each group were statistically compared to our normative EEG (LSC) database by two-talied t-tests. Bonferroni-corrected p<0.05 values were accepted as statistically significant, and were graphically displayed as topographical networks. Results and conclusion - Group-specific networks were demonstrated. However, non-specific networks, charasteristic for most groups, were detected as well. Common finding were: decreased connectivity in the alpha band and increased connectivity in the delta, theta bands and upper-beta band. Decreased alpha-band connectivity presumably reflected primary lesional effects and on the other hand, non-specific vulnerability of “rich club connections”. Increased connectivity in the slow bands presumably indicated adaptive-compensatory activity of brain homeostasis. ]