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Optimization of the amount of iodine contrast agent (ICU) in CT scan examinations on a multislice CT scanner (64-detector row)
KRAJÍČEK, Ondřej
In my work, I focused on the optimization of the amount of iodine contrast agent during CT scan examinations by comparing various amounts of the contrast agent per kilogram of a patient{\crq}s body weight. I compared three groups of weight amounts: 1 mL/kg vs. 1.25 mL/kg vs. 1.5 mL/kg. I measured the differences in the enhancement of organs and blood vessels of the abdominal cavity. Their enhancement levels were compared quantitatively in the areas of interest by determining Hounsfield units in the aorta and parenchyma of the abdominal organs, and qualitatively by using an independent evaluation by a radiologist. Measurements were made on the GE Lightspeed 64-detector row CT scanner with pressure injector. No parameters were changed during the entire study, enabling the maintenance of standard conditions for high-quality comparisons in all examinations. Patients with any significant lesion in the organ to be measured were excluded from the study measurements, and patients at risk of circulation disorder (patients with severe conditions, such as heart failure, shock, and others) were also not enrolled. A contrast agent with a constant amount of iodine amounting to 300 mg/mL was used for the measurements. The study population comprised 120 patients, of which 51 were women and 69 men. The following data were recorded for each measurement: examination number, age, sex, body weight, HU values, and radiologist{\crq}s evaluation. The data were recorded in tables and further analyzed. Various HU enhancement levels were compared and evaluated and subsequently correlated with the radiologist{\crq}s evaluation. Optimal values of the amount of contrast agent were also compared with those routinely used at the facility concerned. This work provided optimal values of the amount of contrast agent for the examination of abdominal organs and adjusted standards for a CT scan facility. I believe my bachelor{\crq}s thesis contributed to a more precise dosing of the contrast agent during CT scan examinations.
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Influence of the contrast medium iodine concentration on quality of the CT examination
RANŠOVÁ, Pavlína
Our work focused on determining absolute and relative density of various contrast agents in relation to iodine contents using in vitro and in vivo methods. It was documented that the relative density of contrast agents increases with the decreasing contents of iodine, i.e. density absolute values vary inversely as iodine content in these substances. Four various agents, bearing commercial names Visipaque 270, Visipaque 320, Ultravist 370 and Iomeron 400, in their original glass packing were used for our in vitro measurements. The measurements were carried out using CT equipment Emotion Duo (Siemens, Forchheim, Germany). Individual packing of the contrast agents were scanned by means of a standard protocol and under standard conditions. The obtained data were entered into tables. A retrospectively selected array of patients with standard scan of their stomachs was used for our in vivo measurements with a defined standard protocol using the same CT equipment and pressure injector CT 9000 Advantage (Liebel-Flarsheim, Mallinckrodt, the U.S.A.). The following data from 258 patients were recorded: age, sex, blood density after administering contrast agent in vitro on the level of diaphragm hiatus and on the bifurcation level, AP dimension of the patients on the hiatus level. Mean densities of the individual kinds of contrast agents were compared and a good correlation with the in vitro measurements was found out. The measured values were then analysed. The interdependence was studied in the measured densities and age, density changes measured on the hiatus level and on the bifurcation level for the individual contrast agents. The interdependence of the blood density on the AP dimension of the patients was also studied due to its practical use and it was documented that there is a good correlation of the decreasing density with the AP dimension as a simple parameter used instead of finding out patients{\crq} weights.
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Small bowel´s examination methods
NAGY, Markéta
Imaging methods play an essential role in the diagnostic algorithm by determining the disease character in any part of the human body. For the diagnostic small intestine diseases we use as classic X-ray methods as modern modalities. In introduce I mention history, morphology and physiology of small intestine. Than I describe summary about X-ray and non X-ray examination methods of small intestine (from basic methods to those special). Among basic examination methods of small intestine belong for example X-ray of abdomen, ultrasonography, passage throw small intestine and enteroclyse. Special examinations are CT enteroclyse, nuclear medicine examination, MR enteroclyse, angiography, enteroscopy and capsle endoscopy (CE). After compendium indications, contraindications, contrast agents and preparation patient for examination, in the finish of my work I worked up a collection of patient which were examined between the years 2002 {--} 2006 on our clinic {--} Institut of clinical and experimental medicine (IKEM), in Prague.
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Indications of individual imaging femoropatellar joint investigations
KOLÁŘ, Jiří
The main theme of this bachelor work is to evaluate the indication of single imaging methods for examinations in the area of the patellofemoral joint. The work contains shortly summarized anatomy-physiology conditions in this area, including anatomy variations of the patella and the patellofemoral joint pathology. The work continues with a description of single indicated imaging methods. The basic is a skiagraphy examination, every single projection is described in details, including a historical overview of the axial patella projection. Other methods which are mentioned are the artrography, the magnetic resonance imaging, the computed tomography and the scintigraphy. Issues of contraindications and risks for patients related to examinations are mentioned, too. A level of suitability how to use other examination methods, especially MRI, is considered on a chosen patient sample. At first plain pictures were done, some patients undertook ultrasonography examination and finally a magnetic resonance imaging examination was indicated. The computed tomography and the scintigraphy are not usually used for patellofemoral joint indications. The author compares financial and time demands of each method. The cheapest seem to be plain pictures and the sonography, on the other hand the most expensive is the magnetic resonance imaging, which is also the best way in the diagnostics at the same time. The magnetic resonance imaging method is the most contributory for a valuation of cartilages and tender joint parts. The time demands make a part of the comparison, too.
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The role of individual imaging methods in neuroradiology - development, the use and limitations
PEKÁREK, Vlastimil
Neuroradiology is the branch of radiodiagnostics dealing with the diagnosis of brain and spinal cord diseases. Morphological methods as X-rays, CT, MRI, ultrasound, DSA are emloyed. Recently examination procedure have made a rapid development. Some methods once frequently used were put down. Other methods were abandoned as they were invasive, demanding and diagnostically less efficient. They were replaced by new methods that are diagnostcally more precise, patient friendly and recently available qite well. These are primarily CT and MRI that dominate in diagnostic imaging of central nervous system.
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The thoracic and lumbar spine injury - role of imaging modalities in diagnostic and therapy
DOLEŽALOVÁ, Martina
This article provides information about thoracic and lumbar spine injury with reflection to the role of radiologic assistants. Spine injury belongs to the most serious injuries and its incidence is rising. These injuries are diagnosed using imaging methods like plain X-ray, computed tomography and magnetic resonance imaging. Radiologic assistant himself is the person, who is responsible for the correct examination. If these injuries are treated surgically, radiologic assistant meets them at operating theatres too. Here the assistant manipulates with fluoroscopy machines and helps the operator with procedure navigation. Important is that the radiologic assistant should know all the steps of each procedure and should take care of radiation protection. If the procedure is done inadequately, the patient can be misdiagnosed and the radiation dose for him and for the staff may be increased. Since 1st January 2006 to 31st December 2006, 84 patients (48 women, 36 men) were hospitalised at the Neurosurgery departement of University Hospital Hradec Králové under diagnosis of thoracic or lumbar spine fracture. The age, frequency of vertebral fractures in thoracic and lumbar region and percentual use of various therapeutic methods are noted. But the most important aim of the study are imaging methods used in these patients and mistakes done during these examinations.
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Nové kritérium pro stanovení poškození hlavy
Jiroušek, Ondřej ; Jírová, Jitka ; Brichtová, E.
Detailed Finite Element Model of human head used for head injury assessment is presented in the article. Development of the model based on a series of postoperative CT images of high resolution is shortly described. The model is used in a model situation of a sport accident involving a 12-year old boy on whom a handball cage fell during a sport activity causing a serious injury of the boy’s head. An approach to quantify the injuries caused is described in the paper.
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Explicitní MKP analýza nárazu lidské lebky na tuhou podložku
Jiroušek, Ondřej
Article deals with explicit finite element modelling of contact conditions of human head impacting a flat rigid surface. For this purpose, detailed 3-D model of human skull and brain was developed based on a series of computer tomography scans of resolution 512x512 pixels taken at 1 mm distances. The FE model of human skull was filled with simplified model of human brain. The brain is modelled as a homogeneous viscoelastic material. A case study of low-velocity impact to different regions of the human head (e.g. frontal impact and impact in the occipital region) is also modelled.
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Experimentální vyšetřování závislosti mezi mechanickými vlastnostmi spongiózní kosti a její relativní hustotou
Jiroušek, Ondřej ; Jírová, Jitka ; Jíra, J.
Finite element models of parts of human skeletal system are nowadays constructed on basis of data obtained from Computed Tomography or Magnetic Resonance images. Material properties of cancellous bone have been found to be strongly dependent on apparent density of the tissue. Experimental procedures used for evaluation of mechanical properties of cancellous bone using small samples of cylindrical shape will be described and relationship between the apparent density and Young's modulus of elasticity as well as ultimate strength are proposed. Compressive and tensile specimens are used while for the strains are measured using an optical method utilizing CCD camera of high resolution
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