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    Wyświetlanie 1-4 z 4
    Tytuł:
    Contribution of diffusion weighted MRI to the differential diagnosis of renal masses
    Autorzy:
    Kış, Naciye
    Gülden Düzkalır, Hanife
    Oğuzhan Ağaçlı, Mehmet
    Erok, Berrin
    Gamze Kılıçoğlu, Zeynep
    Powiązania:
    https://bibliotekanauki.pl/articles/2049180.pdf
    Data publikacji:
    2022-03-30
    Wydawca:
    Uniwersytet Rzeszowski. Wydawnictwo Uniwersytetu Rzeszowskiego
    Tematy:
    apparent diffusion coefficient
    diffusion weighted imaging
    renal neoplasms
    Opis:
    Introduction and aim. We aimed to assess the usefulness of diffusion weighted imaging (DWI) and apparent diffusion coefficients (ADCs) for characterizing renal masses. Material and methods. In this retrospective study we measured the ADC values of renal masses at b=0, b=500 and b=1000. Measurements were made by placing a circular region of interest with a diameter of 1 cm. ADC values from normal renal parenchyma were taken to define the ADC and to compare with the ADC values of the lesions. Results. A total of 72 lesions of 54 patients were included.40 of the masses were benign and 32 were malignant. The ADC values of benign lesions at both b values were significantly higher than malignant lesions. We found the lowest values in angiomyolipomas (AMLs) and oncocytomas and the highest values in Bosniac type I cysts. Similarities was found between the ADC values of some AMLs and the RCCs. In terms of statistical results, the inclusion of AMLs in the analysis did not significantly affect the difference between malignant and benign lesions. Conclusion. In our study, the ADC values of benign renal masses were higher than those of normal renal parenchyme, which is higher than those of malignant renal masses.The lowest ADC values were observed in AMLs and oncocytomas.
    Źródło:
    European Journal of Clinical and Experimental Medicine; 2022, 1; 44-48
    2544-2406
    2544-1361
    Pojawia się w:
    European Journal of Clinical and Experimental Medicine
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Diffusion weighted imaging in differentiation of the clear cell RCC from the major non-clear cell RCC subtypes
    Autorzy:
    Kış, Naciye
    Erok, Berrin
    Powiązania:
    https://bibliotekanauki.pl/articles/2040173.pdf
    Data publikacji:
    2021-09-30
    Wydawca:
    Uniwersytet Rzeszowski. Wydawnictwo Uniwersytetu Rzeszowskiego
    Tematy:
    apparent diffusion coefficient
    diffusion weighted imaging
    renal cell carcinoma
    Opis:
    Introduction. Renal cell carcinoma (RCC) is the most common malignant renal tumor in adults accounting for 80-90% of primary malignant adult renal neoplasms. RCC represents a very heterogenous groups of tumors with a number of distinct histological varieties, of which the major 3 subtypes are clear cell RCC (70-80%), papillary RCC (13-20%), and chromophobe RCC (5%). Imaging features are varied from solid and relatively homogenous appearance to markedly heterogenous appearance with cystic changes, hemorrhage and necrosis. The use of diffusion weighted imaging (DWI) for RCC subtyping and also for differentiation of high grade and low grade tumors has been showed to be useful in many studies in the literature. Aim. In this study, we aimed to determine the comparative contribution of DWI in differentiation of the clear cell RCC from the major non-clear cell RCC subtypes at standard high b-value (1000 s/mm2) versus low b-value (500 s/mm2). In addition, we also aimed to assess the diagnostic performance of DWI for differentiating high grade clear cell RCC from low grade clear cell RCC based on Fuhrman grades in our patients. Material and methods. 62 cases with a prediagnosis of RCC according to MRI findings including DWI sequence with histological verification and subtyping of renal cortical tumor following a total or partial nephrectomy were included in the study. Results. Among 62 cases, 46 were male and 16 were female, with mean age of 59.5±15.7. Pathological diagnoses of 62 cases were as follows, clear cell RCC, (44) papillary cell RCC (14) and chromophobe cell RCC (4). They were divided into two groups as clear cell RCC group (44 cases) and non-clear cell RCC group (18 cases). There was no statistically significant difference between the mean ADC values of clear cell and non-clear cell groups at b-value of 1000 s/mm2 (p>0.05). However, the mean ADC level for clear cell RCC group at b-value of 500 s/mm2 were significantly higher than for non-clear cell RCC group (p<0.05). When a value of 0.99x10-3 mm2/s was set as cut-off for ADC at b-factor of 500 s/mm2, differentiation was achieved with a high sensitivity (91%) and specificity (56%). Regarding the diagnostic performance of DWI for differentiating high from low Fuhrman grades clear cell RCCs, there was no statistically significant difference between the ADC values of Grade I-II clear cell RCC cases and Grade III-IV clear cell RCC cases at b-factor of 1000 s/mm2 (p>0.05). However, ADC values for grade III-IV group was statistically significantly lower than ADC values for Grade I-II group at b-factor of 500 s/mm2 level. Conclusion. ADC measurements at moderate b-value of 500 s/mm2 were more sensitive in subtyping and grading of RCC cases. This technique can be used in clinical practice as a fast and additional sequence in abdominal MRI.
    Źródło:
    European Journal of Clinical and Experimental Medicine; 2021, 3; 215-220
    2544-2406
    2544-1361
    Pojawia się w:
    European Journal of Clinical and Experimental Medicine
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Diffusion of lead ions trough the Poznan Clay (Neogene) and through glacial clay
    Autorzy:
    Mieszkowski, R.
    Powiązania:
    https://bibliotekanauki.pl/articles/2059620.pdf
    Data publikacji:
    2003
    Wydawca:
    Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
    Tematy:
    apparent diffusion coefficient
    diffusion in clays
    Fick's Law
    Opis:
    Two main kinds of migration through clays can be distinguished: advection and diffusion. The main force for advective flow is the water pressure gradient, while ionic concentration gradients drive diffusion. In compacted clays the hydraulic permeability is very low, therefore the diffusion process predominates. Clays can be considered as waste repositories. This paper shows characteristics of the diffusion process and the application of this process to modelling of waste migration in clays. Additionally, a new calculation method for the apparent diffusion coefficient using the finite-difference method is given. Experimental, values of the apparent diffusion coefficient Dapp for Poznan Clay and glacial clay are respectively 2.2_2.6 _ 10-12 m2/s and 2.6_4.4 _ 10-12 m2/s.
    Źródło:
    Geological Quarterly; 2003, 47, 1; 111-118
    1641-7291
    Pojawia się w:
    Geological Quarterly
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Diffusion-weighted MRI of kidney in the diagnosis of clear cell renal cell carcinoma of various grades of differentiation
    Autorzy:
    Mytsyk, Y.
    Dutka, I.
    Komnastka, I.
    Gorecki, A.
    Yuriy, B.
    Shatynska-Mytsyk, I.
    Powiązania:
    https://bibliotekanauki.pl/articles/3241.pdf
    Data publikacji:
    2015
    Wydawca:
    Instytut Medycyny Wsi
    Tematy:
    diffusion-weighted imaging
    kidney
    diagnosis
    clear cell
    renal cell
    renal carcinoma
    carcinoma
    magnetic resonance imaging
    apparent diffusion coefficient
    Opis:
    Introduction. Renal cell carcinoma (RCC) is the most common malignant epithelial tumour of the kidney, accounting for 85–90% of all solid renal tumours in adults and comprising 1–3% of all malignant visceral neoplasms. Recently, computed tomography (CT) has been considered the ‘gold standard’ in the diagnostic imaging of RCC; however, the use of CT is always associated with radiation exposure and consequently carries a significant increase in the risk of malignancy for patients with neoplastic processes. In recent years, magnetic resonance imaging (MRI) is increasingly attracting the attention of clinicians as the method of choice for the diagnosis and staging of RCC, due to several advantages over CT. Materials and method. The study involved 62 adult patients with a pathologically verified clear cell subtype of the renal cell carcinoma (ccRCC) and 15 healthy volunteers. All patients underwent renal MRI which included diffusion-weighted imaging (DWI) with subsequent apparent diffusion coefficient (ADC) measurement. Results. A significant difference was observed in the mean ADC value of the normal renal parenchyma and ccRCC – 1.82 ± 0.16 × 10– 3 mm2/s vs 2.15 ± 0.12 × 10– 3 mm2/s, respectively (р < 0,05). Additionally, statistically reliable differences in ADC values in patients with high and low ccRCC grades were obtained: in patients with the I grade, the mean ADC value was 1.92 ± 0.12 × 10– 3 mm2/s, in patients with the II grade, this value was 1.84 ± 0.14 × 10– 3 mm2/s, in patients with the III grade, the mean ADC value was 1.79 ± 0.12 × 10– 3 mm2/s, and in patients with the IV grade of nuclear polymorphism the mean ADC value was 1.72 ± 0.11 × 10– 3 mm2/s (p <0.05). Conclusions. The data obtained in the survey show a significant restriction in the diffusion of hydrogen molecules in tissues of ccRCC, compared to the healthy renal parenchyma due to the tumour’s greater density. A statistically significant difference was observed in the mean ADC values of ccRCC tumours with different Fuhrman nuclear grades: tumours with a low grade of differentiation demonstrated higher mean ADC values compared to highly differentiated tumours. Application of DWI modality of MR imaging with ADC calculation allows to obtain valuable information that is vital for the diagnosis of ccRCC and differentiation of its degree of malignancy.
    Źródło:
    Journal of Pre-Clinical and Clinical Research; 2015, 09, 1
    1898-2395
    Pojawia się w:
    Journal of Pre-Clinical and Clinical Research
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
      Wyświetlanie 1-4 z 4

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