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Imaging Methods in the Evaluation of the Effects of Liver Tumours Therapy
Ludvík, Jaroslav ; Ferda, Jiří (advisor) ; Mechl, Marek (referee) ; Ungermann, Leoš (referee)
Imaging methods in the evaluation of the effects of liver tumours therapy Objectives. Liver resection is the only potential curative therapy of liver tumours today. Small future liver remnant volume (FLRV) after the resection is a limitation with the risk of hepatic failure. The increase of FLRV after portal vein embolization (PVE) is often inadequate. PVE with contralateral application of hematopoietic stem cells (HCS) can facilitate the regeneration of liver. CT liver volumetry enables to evaluate the increase of FLRV and the safety of liver resection. By automatic CT liver volumetry it is possible to determine the size of liver segments, the volume of the tumour and to make a 3D reconstruction of liver vessels. The aim of the first prospective study was to verify the effect of HSC on the liver growth. The impact of both HSC derived from peripheral blood and from bone marrow was compared. The second, retrospective study aimed to evaluate the accuracy and the speed of the automatic CT liver volumetry in comparison to manual CT volumetry. Material and methods. 20 patients (the group I) underwent PVE with the contralateral application of HSC in the 1st study. In the control group II (n = 20) was performed PVE only. By the manual CT volumetry (Syngo Volume, Siemens Healthineers, Forchheim, Germany)...
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Correlation between in vivo quantitative MR parameters in various tissues (MR spectroscopic imaging, MR diffusometry, MR relaxometry)
Wagnerová, Dita ; Hájek, Milan (advisor) ; Krššák, Martin (referee) ; Mechl, Marek (referee)
Coregistration of MR spectroscopic (SI), diffusion (DTI), relaxation images and their subsequent correlations based on pixel-by-pixel quantitative analysis have the potential to distinguish between pathological states and healthy tissue and therefore can help assessing brain pathology extent. Patients with brain tumours and temporal lobe epilepsy (TLE) were involved in the study to validate the use of this method in clinical practice. 30 patients with a new diagnosed brain lesion, 22 patients with a treated tumour (diagnosis assessed by histology or by radiological follow-up), 20 TLE patients and 59 healthy subjects were examined on a 3T system. The measurement protocol consisted of T2-weighted MR images, SI, DTI and T2 relaxometry. Correlations were analysed with the CORIMA programme with automatic identification of pixels in the normal tissue according to control data. Brain lesions: Specific correlation patterns between metabolites, MD and T2 relaxation times (T2) were found for a given lesion localisation and tumour type. The patterns depend on different tissue states involved in the examined area. Recurrent tumours exhibited the same patterns as untreated ones but with changed parameter values caused by therapy. Metabolic values did not correlate with MD and T2 in radiation necrosis. TLE: MR...
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31P MR Spectroscopy of Human Kidney Grafts Monitoring of MR parameters of human grafts and their comparison with clinical parameters of patients
Vyhnanovská, Pavlína ; Hájek, Milan (advisor) ; Teplan, Vladimír (referee) ; Mechl, Marek (referee)
The aim of this work was to evaluate the possibility of using in vivo phosphorus magnetic resonance spectroscopy (31P MRS) for diagnosis of kidney graft dysfunction after transplantation. In vivo 31P MRS is noninvasive imaging method which make possible to assess energy metabolism. A total of 68 patients with kidney grafts were examined on a 1.5T MR scanner. 31P MRS was performed using the 2D-chemical shift imaging method. The patients were divided into four groups: acute rejection; acute tubular necrosis; late graft dysfunction; and patients with good renal function after transplantation. We measured the signal intensities of phosphomonoesters (PME), inorganic phosphate (Pi), phosphodiesters (PDE) and -, -- adenosine triphosphate (with contribution of -, -adenosine diphosphate) and their ratios. Patients with acute rejection episodes showed significantly elevated PME/ß-ATP, PME/Pi and PDE/Pi signal ratios compared to the control group. The group with acute tubular necrosis has decreased these ratios: PDE/-ATP a PDE/Pi compared to the control group. Patients with late graft dysfunction revealed only significant decrease of PME/Pi ratio. The group of AR patients display higher ratios of PME/Pi and PDE/Pi compared to the group of ATN patients and display higher ratios of PME/Pi compared to the group of LGD....
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Detection and characterization of hepatocellular liver lesions by using MRI with hepatospecific contrast agent Gd-EOB-DTPA
Mrklovský, Milan ; Žižka, Jan (advisor) ; Mechl, Marek (referee) ; Ferda, Jiří (referee)
Detection and characterization of hepatocellular liver lesions by using MRI with hepatospecific contrast agent Gd-EOB-DTPA Aim: To prospectively compare contrast properties of extracelullar (gadobutrol) and hepatospecific (gadoxetic acid) contrast agents in upper abdominal MRI studies. To prospectively evaluate the possibilities of detection and characterization of hepatocellular liver lesions by means of MRI using hepatospecific contrast agent Gd-EOB-DTPA. Materials and methods: Standardized (0,1 ml/kg) dose of gadobutrol (56 subjects) and gadoxetic acid (51 subjects) was administered intravenously by MRI-compatible injector at 2 ml/s, followed by 20 ml saline flush. MR signal intensity changes (SIC) between precontrast scans and arterial phase, portal venous phase, equilibrium, and delayed scans at 10 and 20 minutes were measured in abdominal aorta, portal vein, common bile duct, liver, and spleen. Mean SIC values for gadobutrol and gadoxetic acid were compared by a two-sample t-test with p-value < 0,05 considered significant. A total of 78 subjects with known arterial hypervascularized liver lesion (other than haemangioma) were examined on MRI with administration of liver specific contrast agent Gd-EOB-DTPA. All studies were performed before and after contrast agent injection in arterial, portal...
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Coronary atherosclerosis imaging using CT coronary angiography in patients with high risk of coronary heart disease
Baxa, Jan ; Ferda, Jiří (advisor) ; Vymazal, Josef (referee) ; Mechl, Marek (referee)
Coronary atherosclerosis imaging using CT coronary angiography in patients with high risk of coronary heart disease Coronary heart disease (CHD) belongs to most frequent disorders and in industrial countries is responsible for most deaths in population. The costs of treatment of the clinical manifested CHD are high, so there is tendency to detect this disease in early phase and ideally before development of clinical symptoms. Aim of our study was to evaluate the value of coronary CT angiography (CCTA) in detecting of coronary atherosclerosis in early (preclinical) phase. Our goals were estimation of prevalence of atherosclerosis in group, influence of main risk factors on grade and character of atherosclerotic changes. In follow-up we concerned on occurrence of cardiac events. 205 patients with increased cardiovascular risk underwent CCTA using dual-source CT. Coronary findings were analyzed by character of atherosclerotic changes and degree of event. stenosis. Statistical evaluation of influence of risk factors was made using the odds ratio. The statistically important differences were tested between subgroup of type 2 diabetics and non-diabetics. All patients were under follow-up for two years. Overall prevalence of atherosclerosis in analyzed group was 73 %, calcified lesions were found in 63.9 %...
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Benefits of dynamic contrast ultrasonography for differential diagnosis focal liver lesions
Ungermann, Leoš ; Eliáš, Pavel (advisor) ; Mechl, Marek (referee) ; Mírka, Hynek (referee)
5 3. Summary Purpose: To evaluate the clinical utility of contrast enhanced ultrasonography (CEUS) for the characterisation of focal liver lesions with the emphasis on the benign entities. Our aim was to find out the accuracy of CEUS to differentiate between the malignant and benign lesions and to extend the knowledge about the typical signs of solid benignomas on CEUS. Material and methods: our material consists of 163 liver masses observed in 144 patients. The final dianosis has been stated by means of the computed tomography in 26.4 %, magnetic resonance imaging (60.4 %) and histology (25.8 %). There was a majority of women (n=90) against men (n=54); the average age was 47.6 years. The number of benign lesions (n=137) markedly exceeded the number of malignant ones (n=6). The dominant lesions were hemangiomas (n=66), the second most common was focal nodular hyperplasia (FNH, n=42). The other lesions comprised of limited numbers of entities(focal steatotic or nonsteatis regions: n=21, metastatic lesions: n=15, hepatocelullar carcinoma, n=7, regenerative nodular hyperplasia, n=5, peripheral cholangiogenic carcinoma, n=4, and others - inflemmatory pseudotumour, adenoma, epithelial angiomyolipoma). Results: The accuracy of CEUS for the differentiation of malign or benign lesion was 95, 7 %. Regarding the...
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Avascular necrosis by adults
Kunešová, Martina ; Kreuzberg, Boris (advisor) ; Šprindrich, Jan (referee) ; Mechl, Marek (referee)
The author evaluates the role of imaging methods in diagnosis of AVN of the femoral head. She foccuses especially on MRI, she finds this imaging modality the most suitable in diagnosis of early stages of AVN. In therapy of AVN, revitalizing operation on the femoral head with using surgical diamond instruments is a promising therapeutical procedure. The author summarizes short term results in group of pacients who underwent revitalizing operation. The special attention is given to pacients after renal trasplantation. In this group of renal transplant recipients the author suggests MRI as a screening method for early detection of AVN of femoral head during the first year after transplantation. In the last part of report, the author evaluates using MRI in acute fracture of proximal femur. She suggests MRI of the hip as a method of choice in concrete age group of pacients (about between 40-65 years). Considering this pacients, the method significantly helps in choosing of adequate therapy and the proper type of surgical approach.
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Methods of the Spectroscopic I maging in clinical practice and experiments
Jírů, Filip ; Hájek, Milan (advisor) ; Horký, Jaroslav (referee) ; Mechl, Marek (referee)
Spectroscopic imaging (SI) is the method which enables non-invasive studying of the metabolite composition of tissues in vivo from multiple regions simultaneously. The objective of this thesis was to develop a methodology for the reliable evaluation of in vivo SI data. The thesis addresses several aspects of the evaluation of SI data as described below. The processing of SI data represents a complex issue requiring dedicated evaluation programs. Although various spectra processing programs are provided by the vendors of MR scanners, software enabling complete SI data processing and analysis is not available. The CULICH program has been developed within the framework of this thesis to enable the comprehensive processing of SI data. The program offers advanced functionality for evaluation of SI data. The initial experience with the program shows that CULICH is suitable for evaluation of SI data measured in both clinical practice and the experiments. The accuracy of calculated concentrations is of high importance for each quantification method. SVS techniques can be taken as the gold standard for quantification of MR spectra. Therefore, to asses the accuracy of the metabolite concentrations measured by SI, the comparison of results obtained by SI and SVS was performed. The direct comparison of results obtained...
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