Hungarian Radiology

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


OCTOBER 10, 2005

Hungarian Radiology - 2005;79(05)

[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.]



Further articles in this publication

Hungarian Radiology



Hungarian Radiology

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


[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

[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.]

Hungarian Radiology

[Calcification of the tentorium cerebelli]

BILONKA Viola, BENDE Mariann

[A 16-year-old female patient with high temperature and headache was hospitalized because of suspicion of meningitis. Cranial CT showed a mild hydrocephalus, massive falx calcification and calcification in the projection of the tentorium. Excluding several well known reasons of the calcification the findings was thought to be a physiological variation. The child recovered after some days and left the hospital. The authors based on prior publications on tentorium calcification consider this finding a physiological-phylogenetic origin.]

All articles in the issue

Related contents

Hungarian Radiology

[Forces exerted on the plaques during in vitro measurements by various carotid stent delivery systems and embolic protection devices]


[PURPOSE - During the endovascular treatment of internal carotid artery stenosis, one of the most important aspects is reducing of embolic complications. Degree of embolization may be influenced by the force exerted by stent delivery systems and embolic protection devices. We assessed the force emersion produced by various devices on vessel walls and plaques. MATERIAL AND METHOD - Six different commercially available devices were investigated. The force load on vessel wall was measured in a carotid model with vessel angulations of 25, 50 and 75 degree, respectively. The IDTE 2000 CE marked measurement system was used. A transparent, flexible PVC tube was used as a model of the carotid bifurcation, which was 6 mm in width, 1.5 mm wall thickness and 12 mm length. 75-85% stenosis were created in it. The measured data were evaluated and different conclusions were drawn. RESULTS - Forces exerted on vessel walls varied widely among different stent delivery systems. The magnitude of force exertion caused by stent delivery systems significantly exceeded that caused by protecting devices. Protecting devices showed only 30% increase in vessel load at angulation of 75 degrees compared to those at 25-50 degrees. Above 50 degrees of vessel angulation the forces exerted by stent delivery systems considerably increases. CONCLUSIONS - Our results showed that selection of the most proper stent can contribute to decrease in the load of vessel wall. Protecting devices exert significantly lower forces than stent delivery systems, therefore, it seems to be a better choice to advance a protecting device before introducing a stent delivery system. If the vessel angulation exceeds 50 degrees, endarterectomy should be considered, because the vessel wall load will increase radically in that case.]

Lege Artis Medicinae

[Second game, 37th move and Fourth game 78th move]

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

Simultaneous subdural, subarachnoideal and intracerebral haemorrhage after rupture of a peripheral middle cerebral artery aneurysm


The cause of intracerebral, subarachnoid and subdural haemorrhage is different, and the simultaneous appearance in the same case is extremely rare. We describe the case of a patient with a ruptured aneurysm on the distal segment of the middle cerebral artery, with a concomitant subdural and intracerebral haemorrhage, and a subsequent secondary brainstem (Duret) haemorrhage. The 59-year-old woman had hypertension and diabetes in her medical history. She experienced anomic aphasia and left-sided headache starting one day before admission. She had no trauma. A few minutes after admission she suddenly became comatose, her breathing became superficial. Non-contrast CT revealed left sided fronto-parietal subdural and subarachnoid and intracerebral haemorrhage, and bleeding was also observed in the right pontine region. The patient had leucocytosis and hyperglycemia but normal hemostasis. After the subdural haemorrhage had been evacuated, the patient was transferred to intensive care unit. Sepsis developed. Echocardiography did not detect endocarditis. Neurological status, vigilance gradually improved. The rehabilitation process was interrupted by epileptic status. Control CT and CT angiography proved an aneurysm in the peripheral part of the left middle cerebral artery, which was later clipped. Histolo­gical examination excluded mycotic etiology of the aneu­rysm and “normal aneurysm wall” was described. The brain stem haemorrhage – Duret bleeding – was presumably caused by a sudden increase in intracranial pressure due to the supratentorial space occupying process and consequential trans-tentorial herniation. This case is a rarity, as the patient not only survived, but lives an active life with some residual symptoms.

Clinical Neuroscience

Electrophysiological investigation for autonomic dysfunction in patients with myasthenia gravis: A prospective study


Myasthenia gravis (MG) is an autoimmune disorder of neuromuscular transmission. Autonomic dysfunction is not a commonly known association with MG. We conducted this study to evaluate autonomic functions in MG & subgroups and to investigate the effects of acetylcholinesterase inhibitors. This study comprised 30 autoimmune MG patients and 30 healthy volunteers. Autonomic tests including sympathetic skin response (SSR) and R-R interval variation analysis (RRIV) was carried out. The tests were performed two times for patients who were under acetylcholinesterase inhibitors during the current assessment. The RRIV rise during hyperventilation was better (p=0.006) and Valsalva ratio (p=0.039) was lower in control group. The SSR amplitudes were lower thereafter drug intake (p=0.030). As much as time went by after drug administration prolonged SSR latencies were obtained (p=0.043).Valsalva ratio was lower in the AchR antibody negative group (p=0.033). The findings showed that both ocular/generalized MG patients have a subclinical parasympathetic abnormality prominent in the AchR antibody negative group and pyridostigmine has a peripheral sympathetic cholinergic noncumulative effect.