BACKGROUND: The current requirement is to establish the preoperative diagnosis accurately as possible and to achieve an adequate extent of surgery. The aim of this study was to define the preoperative clinical and molecular genetic risks of malignancy in indeterminate thyroid nodules (Bethesda III and IV) and to determine their impact on the surgical strategy. METHODS: Prospectively retrospective analysis of 287 patients provided the basis of preoperative laboratory examination, sonographic stratification of malignancy risks and cytological findings. Molecular tests focused on pathogenic variants of genes associated with thyroid oncogenesis in cytologically indeterminate nodules (Bethesda III and IV). The evaluation included clinical risk factors: positive family history, radiation exposure and growth in size and/or number of nodules. RESULTS: Preoperative FNAB detected 52 cytologically indeterminate nodules (28.7%) out of 181 patients. Postoperative histopathological examination revealed malignancy in 12 cases (23.7%) and there was no significant difference between Bethesda III and IV categories (P=0.517). Clinical risk factors for malignancy were found in 32 patients (61.5%) and the presence of at least one of them resulted in a clearly higher incidence of malignancy than their absence (31.3% vs. 10.0%, respectively). Pathogenic variants of genes were detected in 12/49 patients in Bethesda III and IV, and in 4 cases (33.3%) thyroid carcinoma was revealed. The rate of malignancies was substantially higher in patients with pathogenic variants than in those without (33.3% vs. 16.2%, respectively). CONCLUSIONS: Our experience implies that molecular genetic testing is one of several decision factors. We will continue to monitor and enlarge our patient cohort to obtain long-term follow-up data.

• MeSH
• dospělí MeSH
• genetické testování MeSH
• lidé středního věku MeSH
• lidé MeSH
• nádory štítné žlázy * genetika   MeSH
• retrospektivní studie MeSH
• rizikové faktory MeSH
• senioři MeSH
• tenkojehlová biopsie MeSH
• uzly štítné žlázy * genetika   patologie   MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH

OBJECTIVES: This study aims to identify factors possibly contributing to complications in children with acute leukaemia. Despite diverse etiological causes, similar processes trigger the process of cell malignancy. Genomic instability has received considerable attention in this context. METHOD: We conducted chromosomal analysis of bone marrow cells and measured the micronuclei (Mn) level in buccal cells over time. Statistical reliability assessment was performed using Analysis of variance (ANOVA), and the data were analyzed and visualized using the SPSS 12 statistical analysis software package. RESULTS: On the 15th day of treatment, our findings confirmed a statistically significant correlation (χ2=3.88, P=0.04) between the number of blasts in the bone marrow and unfavourable outcome in patients with a near-tetraploid chromosome clone. Additionally, on the 33rd day of treatment, we observed a correlation between an elevated number of Mn and relapses. DISCUSSION: While it is commonly believed that a hyperdiploid clone with >50 chromosomes in childhood acute lymphoblastic leukaemia confers favorable outcome, our study revealed partially heterogeneous results and poor prognosis in patients with a near-tetraploid clone. We have also identified a correlation between the Mn level on the 33rd day of treatment and the development of complications. It is possible that the increased Mn values and the occurrence of relapses were influenced by the individual patient's sensitivity to the genotoxic effect of the medication.

• MeSH
• akutní lymfatická leukemie * genetika   MeSH
• buňky kostní dřeně patologie   MeSH
• dítě MeSH
• lidé MeSH
• mikrojaderné testy MeSH
• mikrojádra chromozomálně defektní * MeSH
• mladiství MeSH
• předškolní dítě MeSH
• prognóza MeSH
• tetraploidie MeSH
• Check Tag
• dítě MeSH
• lidé MeSH
• mladiství MeSH
• mužské pohlaví MeSH
• předškolní dítě MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH

PURPOSE: The aim of this study was to develop a simple, robust, and easy-to-use calibration procedure for correcting misalignments in rosette MRI k-space sampling, with the objective of producing images with minimal artifacts. METHODS: Quick automatic calibration scans were proposed for the beginning of the measurement to collect information on the time course of the rosette acquisition trajectory. A two-parameter model was devised to match the measured time-varying readout gradient delays and approximate the actual rosette sampling trajectory. The proposed calibration approach was implemented, and performance assessment was conducted on both phantoms and human subjects. RESULTS: The fidelity of phantom and in vivo images exhibited significant improvement compared with uncorrected rosette data. The two-parameter calibration approach also demonstrated enhanced precision and reliability, as evidenced by quantitative T2*$$ {\mathrm{T}}_2^{\ast } $$ relaxometry analyses. CONCLUSION: Adequate correction of data sampling is a crucial step in rosette MRI. The presented experimental results underscore the robustness, ease of implementation, and suitability for routine experimental use of the proposed two-parameter rosette trajectory calibration approach.

• MeSH
• algoritmy * MeSH
• artefakty * MeSH
• fantomy radiodiagnostické * MeSH
• kalibrace MeSH
• lidé MeSH
• magnetická rezonanční tomografie * metody   MeSH
• mozek diagnostické zobrazování   MeSH
• počítačové zpracování obrazu * metody   MeSH
• reprodukovatelnost výsledků MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

PURPOSE: Dual velocity encoding PC-MRI can produce spurious artifacts when using high ratios of velocity encoding values (VENCs), limiting its ability to generate high-quality images across a wide range of encoding velocities. This study aims to propose and compare dual-VENC correction methods for such artifacts. THEORY AND METHODS: Two denoising approaches based on spatiotemporal regularization are proposed and compared with a state-of-the-art method based on sign correction. Accuracy is assessed using simulated data from an aorta and brain aneurysm, as well as 8 two-dimensional (2D) PC-MRI ascending aorta datasets. Two temporal resolutions (30,60) ms and noise levels (9,12) dB are considered, with noise added to the complex magnetization. The error is evaluated with respect to the noise-free measurement in the synthetic case and to the unwrapped image without additional noise in the volunteer datasets. RESULTS: In all studied cases, the proposed methods are more accurate than the Sign Correction technique. Using simulated 2D+T data from the aorta (60 ms, 9 dB), the Dual-VENC (DV) error 0.82±0.07$$ 0.82\pm 0.07 $$ is reduced to: 0.66±0.04$$ 0.66\pm 0.04 $$ (Sign Correction); 0.34±0.04$$ 0.34\pm 0.04 $$ and 0.32±0.04$$ 0.32\pm 0.04 $$ (proposed techniques). The methods are found to be significantly different (p-value <0.05$$ <0.05 $$ ). Importantly, brain aneurysm data revealed that the Sign Correction method is not suitable, as it increases error when the flow is not unidirectional. All three methods improve the accuracy of in vivo data. CONCLUSION: The newly proposed methods outperform the Sign Correction method in improving dual-VENC PC-MRI images. Among them, the approach based on temporal differences has shown the highest accuracy.

• MeSH
• algoritmy * MeSH
• aorta * diagnostické zobrazování   MeSH
• artefakty * MeSH
• fantomy radiodiagnostické MeSH
• interpretace obrazu počítačem metody   MeSH
• intrakraniální aneurysma diagnostické zobrazování   MeSH
• lidé MeSH
• magnetická rezonanční tomografie * metody   MeSH
• mozek diagnostické zobrazování   MeSH
• počítačová simulace MeSH
• počítačové zpracování obrazu * metody   MeSH
• poměr signál - šum * MeSH
• reprodukovatelnost výsledků MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

The topic of the diagnosis of phaeochromocytomas remains highly relevant because of advances in laboratory diagnostics, genetics, and therapeutic options and also the development of imaging methods. Computed tomography still represents an essential tool in clinical practice, especially in incidentally discovered adrenal masses; it allows morphological evaluation, including size, shape, necrosis, and unenhanced attenuation. More advanced post-processing tools to analyse digital images, such as texture analysis and radiomics, are currently being studied. Radiomic features utilise digital image pixels to calculate parameters and relations undetectable by the human eye. On the other hand, the amount of radiomic data requires massive computer capacity. Radiomics, together with machine learning and artificial intelligence in general, has the potential to improve not only the differential diagnosis but also the prediction of complications and therapy outcomes of phaeochromocytomas in the future. Currently, the potential of radiomics and machine learning does not match expectations and awaits its fulfilment.

• MeSH
• feochromocytom * diagnostické zobrazování   MeSH
• lidé MeSH
• nádory nadledvin * diagnostické zobrazování   MeSH
• paragangliom * diagnostické zobrazování   MeSH
• počítačová rentgenová tomografie metody   MeSH
• počítačové zpracování obrazu metody   MeSH
• radiomika MeSH
• strojové učení MeSH
• umělá inteligence MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH

BACKGROUND: This study aims to evaluate the feasibility of generating pseudo-normal single photon emission computed tomography (SPECT) data from potentially abnormal images. These pseudo-normal images are primarily intended for use in an on-the-fly data harmonization technique. MATERIAL AND METHODS: The methodology was tested on brain SPECT with [123I]Ioflupane. The proposed model for generating a pseudo-normal image was based on a variational autoencoder (VAE) designed to process 2D sinograms of the brain [123I]-FP-CIT SPECT, potentially exhibiting abnormal uptake. The model aimed to predict SPECT sinograms with corresponding normal uptake. Training, validation, and testing datasets were created by SPECT simulator from 45 brain masks segmented from real patient's magnetic resonance (MR) scans, using various uptake levels. The training and validation datasets each comprised 612 and 360 samples, respectively, drawn from 36 brain masks. The testing dataset contained 153 samples based on 9 brain masks. VAE performance was evaluated through brain dimensions, Dice similarity coefficient (DSC) and specific binding ratio. RESULTS: Mean DSC was 80% for left basal ganglia and 84% for right basal ganglia. The proposed VAE demonstrated excellent consistency in predicting basal ganglia shape, with a coefficient of variation of DSC being less than 1.1%. CONCLUSIONS: The study demonstrates that VAE can effectively estimate an individualized pseudo-normal distribution of the radiotracer [123I]-FP-CIT SPECT from abnormal SPECT images. The main limitations of this preliminary research are the limited availability of real brain MR data, used as input for the SPECT data simulator, and the simplified simulation setup employed to create the synthetic dataset.

• MeSH
• jednofotonová emisní výpočetní tomografie * MeSH
• lidé MeSH
• mozek * diagnostické zobrazování   MeSH
• počítačové zpracování obrazu * MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

PURPOSE: This study aimed to compare the image quality of the Siemens Biograph mCT40 (photomultiplier-based system - PMT) and the Siemens Vision600 (silicon photomultiplier-based system - SiPM) using a modified NEMA IEC Body phantom (Data Spectrum). METHODS: SiPM-based Vision600 has a smaller crystal size (3.2 × 3.2 mm vs. 4.0 × 4.0 mm in the PMT-based mCT40), resulting in better spatial resolution. Enhanced time-of-flight (TOF) timing and higher sensitivity leads to nearly four times higher effective sensitivity. The standard NEMA IEC Body phantom was modified with a 3D-printed holder to accommodate also Hollow and Micro Hollow Spheres of 15.4 mm, 12.4 mm, 7.9 mm, 6.2 mm, 5.0 mm, and 4.0 mm. Each of the three acquisition sessions per scanner included 18 time points and spanned 5.6 half-lives to assess system performance at varying activity concentrations in the field of view. RESULTS: Recovery curves for both systems were similar when identical post-reconstruction filters were applied. The SiPM-based Vision600 system detected smaller sources at significantly lower activity concentrations, and the variations in standardized uptake value (SUVmax, SUVA50) measurements were generally smaller compared to those of the PMT-based system. The two smallest sources became undetectable below 63 MBq and 16 MBq on the PMT system, versus 20 MBq and 6.5 MBq on the SiPM system. CONCLUSIONS: SiPM technology demonstrated superior performance compared to PMT in detecting small sources in low-activity scenarios and provided more robust quantification results. It is recommended to use averaged SUV metrics, such as SUVA50 or SUVpeak.

• MeSH
• fantomy radiodiagnostické * MeSH
• křemík MeSH
• počítačové zpracování obrazu metody   MeSH
• pozitronová emisní tomografie * přístrojové vybavení   MeSH
• Publikační typ
• časopisecké články MeSH
• srovnávací studie MeSH

The integration of 3D printing into the pharmaceutical sciences opens new possibilities for personalized medicine. Poly(lactide) (PLA), a biodegradable and biocompatible polymer, is highly suitable for biomedical applications, particularly in the context of 3D printing. However, its processability often requires the addition of plasticizers. This study investigates the use of phase diagram modeling as a tool to guide the rational selection of plasticizers and to assess their impact on the thermodynamic and kinetic stability of PLA-based amorphous solid dispersions (ASDs) containing active pharmaceutical ingredients (APIs). Thermodynamic stability against API recrystallization was predicted based on the API solubility in PLA and Plasticizer-PLA carriers using the Conductor-like Screening Model for Real Solvents (COSMO-RS), while the kinetic stability of the ASDs was evaluated by modeling the glass transition temperatures of the mixtures. Two APIs, indomethacin (IND) and naproxen (NAP), with differing glass-forming abilities (i.e., recrystallization tendencies), and three plasticizers, triacetin (TA), triethyl citrate (TEC), and poly(L-lactide-co-caprolactone) (PLCL), were selected for investigation. The physical stability of ASD formulations containing 9 wt% API and plasticizer to PLA in two ratios, 10:81 and 20:71 w/w %, was monitored over time using differential scanning calorimetry and X-ray powder diffraction and compared with phase diagram predictions. All formulations were predicted to be thermodynamically unstable; however, those containing no plasticizer or with TEC and TA at 10 wt% were predicted to exhibit some degree of kinetic stability. Long-term physical studies corroborated these predictions. The correlation between the predicted phase behavior and long-term physical stability highlights the potential of phase diagram modeling as a tool for the rational design of ASDs in pharmaceutical 3D printing.

• MeSH
• 3D tisk * MeSH
• citráty chemie   MeSH
• diferenciální skenovací kalorimetrie metody   MeSH
• farmaceutická chemie metody   MeSH
• farmaceutická technologie metody   MeSH
• indomethacin * chemie   MeSH
• krystalizace MeSH
• naproxen chemie   MeSH
• polyestery * chemie   MeSH
• rozpouštědla chemie   MeSH
• rozpustnost * MeSH
• stabilita léku MeSH
• termodynamika MeSH
• tranzitní teplota MeSH
• triacetin chemie   MeSH
• změkčovadla * chemie   MeSH
• Publikační typ
• časopisecké články MeSH

The evaluation of large experimental datasets is a fundamental aspect of research in every scientific field. Streamlining this process can improve the reliability of results while making data analysis more efficient and faster to execute. In biomedical research it is often very important to determine the type of cell death after various treatments. Thus, differentiating between viable, apoptotic, and necrotic cells provide critical insights into the treatment efficacy, a key aspect in the field of drug development. Fluorescent microscopy is perceived as a widely used technique for cell metabolism assessment and can therefore be used to investigate treatment outcomes after staining samples with cell death detection kit. However, accurate evaluation of therapeutic results requires quantitative analysis, often necessitating extensive postprocessing of imaging data. In this study, we introduce a complementary tool designed as a macro for the Fiji platform, enabling the automated postprocessing of fluorescent microscopy images to accurately distinguish and quantify viable, apoptotic, and necrotic cells.

• MeSH
• apoptóza MeSH
• buněčná smrt MeSH
• fluorescenční mikroskopie * metody   MeSH
• lidé MeSH
• nekróza MeSH
• počítačové zpracování obrazu * metody   MeSH
• software MeSH
• viabilita buněk MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

BACKGROUND: Large vessel carotid stenosis is a significant cause of ischaemic stroke. Indications for surgical revascularisation depend on the severity of the stenosis and clinical symptoms. However, mild symptoms such as TIA (Transient ischaemic attack), amaurosis fugax or minor stroke precede large strokes in only 15% of cases. AIM: The aim of this prospective study is to evaluate whether retinal perfusion is impacted in significant carotid stenosis. Automated retinal oximetry will be used to better assess perfusion in the post-stenotic basin. We presume the more stenotic the blood vessel, the more reduced the retinal perfusion is, resulting in adaptive changes such as greater arteriovenous saturation difference due to greater oxygen extraction. This could broaden the indication spectrum for revascularisation for carotid stenosis. METHODS: We plan to enroll yearly 50 patients with significant carotid stenosis and cross-examine them with retinal oximetry. The study group will provide stenotic vessels and, non-stenotic vessels will form the control group. Patients with significant carotid stenosis will undergo an MRI (Magnetic Resonnance imaging) examination to determine the presence of asymptomatic recent ischaemic lesions in the stenotic basin, and the correlation to oximetry parameters. STATISTICS: The stenosis severity and retinal oximetry parameters will be compared for study and control groups with a threshold of 70%, respectively 80% and 90% stenosis. Results will be then reevaluated with emphasis on MRI findings in the carotid basin. CONCLUSION: This prospective case control study protocol will be used to launch a multicentre trial assessing the relationship between significant carotid stenosis and retinal perfusion measured with automated retinal oximetry. Despite these differences, the findings indicate the potential of retinal oximetry for noninvasive real-time measurements of oxyhaemoglobin saturation in central nervous system vessels. Following calibration upgrade and technological improvement, verification retinal oximetry may potentially be applied to critically ill and anaesthesia care patients. The study on combined scanning laser ophthalmoscope and retinal oximetry supports the feasibility of the technique for oximetry analysis in newly born babies. TRIAL REGISTRATION: ClinicalTrials.gov, ID: NCT06085612.

• MeSH
• lidé středního věku MeSH
• lidé MeSH
• oxymetrie * metody   MeSH
• prospektivní studie MeSH
• retina diagnostické zobrazování   patofyziologie   MeSH
• retinální cévy diagnostické zobrazování   patofyziologie   MeSH
• senioři MeSH
• stenóza arteria carotis * patofyziologie   chirurgie   komplikace   MeSH
• studie případů a kontrol MeSH
• Check Tag
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• protokol klinické studie MeSH