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

Radiomic features are usually used to predict target variables such as the absence or presence of a disease, treatment response, or time to symptom progression. One of the potential clinical applications is in patients with Parkinson's disease. Robust radiomic features for this specific imaging method have not yet been identified, which is necessary for proper feature selection. Thus, we are assessing the robustness of radiomic features in dopamine transporter imaging (DaT). For this study, we made an anthropomorphic head phantom with tissue heterogeneity using a personal 3D printer (polylactide 82% infill); the bone was subsequently reproduced with plaster. A surgical cotton ball with radiotracer (123I-ioflupane) was inserted. Scans were performed on the two-detector hybrid camera with acquisition parameters corresponding to international guidelines for DaT single photon emission tomography (SPECT). Reconstruction of SPECT was performed on a clinical workstation with iterative algorithms. Open-source LifeX software was used to extract 134 radiomic features. Statistical analysis was made in RStudio using the intraclass correlation coefficient (ICC) and coefficient of variation (COV). Overall, radiomic features in different reconstruction parameters showed a moderate reproducibility rate (ICC = 0.636, p <0.01). Assessment of ICC and COV within CT attenuation correction (CTAC) and non-attenuation correction (NAC) groups and within particular feature classes showed an excellent reproducibility rate (ICC > 0.9, p < 0.01), except for an intensity-based NAC group, where radiomic features showed a good repeatability rate (ICC = 0.893, p <0.01). By our results, CTAC becomes the main threat to feature stability. However, many radiomic features were sensitive to the selected reconstruction algorithm irrespectively to the attenuation correction. Radiomic features extracted from DaT-SPECT showed moderate to excellent reproducibility rates. These results make them suitable for clinical practice and human studies, but awareness of feature selection should be held, as some radiomic features are more robust than others.

• MeSH
• jednofotonová emisní výpočetní tomografie * MeSH
• lidé MeSH
• nortropany * MeSH
• počítačové zpracování obrazu * metody   MeSH
• radiomika MeSH
• reprodukovatelnost výsledků MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

CONTEXT: Investigate whether 123I-ioflupane SPECT (DaT SPECT) has the potential as a marker of basal ganglia damage in acute methanol poisoning. METHODS: Prospective, single-centre, cohort study of patients with confirmed methanol poisoning was conducted. DaT SPECT was performed twice with semi-quantification using DaTQUANTTM and MRI-based volumetry was calculated. Specific binding ratios (SBR) of striatum, caudate nucleus, and putamen were correlated with laboratory parameters of outcome, volumetric data, and retinal nerve fibres layer (RNFL) thickness measurements. RESULTS: Forty-two patients (mean age 46.3 ± 4.2 years; 8 females), including 15 with MRI-detected putamen lesions (group I) and 27 patients with intact putamen (group II), underwent DaT SPECT. Volumetry was calculated in 35 of the patients assessed. SBR values for the left putamen correlated with putamen volume (r = 0.665; p < 0.001). Decreased bilateral SBR values were determined for the striatum and the putamen, but not for the nucleus caudate, in group I (p < 0.05). Significant correlation was observed between the SBR of the posterior putamen and arterial blood pH (r = 0.574; p < 0.001) and other toxicological parameters of severity of poisoning/outcome including serum lactate, glucose, and creatinine concentrations (p < 0.05). The SBR of the posterior putamen positively correlated with the global RNFL thickness (p < 0.05). ROC analysis demonstrated a significant discriminatory ability of SBR of the posterior putamen with AUC = 0.753 (95%CI 0.604-0.902; p = 0.007). The multivariate regression model demonstrated that arterial blood pH, age, and gender were the most significant factors associated with SBR of the posterior putamen. CONCLUSION: DaT SPECT demonstrates significant potential for the diagnosis of methanol-induced basal ganglia damage.

• MeSH
• bazální ganglia diagnostické zobrazování   účinky léků   MeSH
• dospělí MeSH
• jednofotonová emisní výpočetní tomografie metody   MeSH
• lidé středního věku MeSH
• lidé MeSH
• longitudinální studie MeSH
• magnetická rezonanční tomografie MeSH
• methanol otrava   MeSH
• nemoci bazálních ganglií chemicky indukované   diagnostické zobrazování   MeSH
• neurozobrazování MeSH
• nortropany MeSH
• prospektivní studie MeSH
• putamen diagnostické zobrazování   účinky léků   MeSH
• radiofarmaka MeSH
• radioizotopy jodu MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• pozorovací studie MeSH

OBJECTIVES: Hyperechogenicity of the substantia nigra (SN) and abnormal dopamine transporter-single-photon emission computed tomography (DAT-SPECT) are biomarkers commonly used in the assessment of prodromal synucleinopathy. Our goals were as follows: (1) to compare echogenicity of SN in idiopathic rapid eye movement (REM) behavior disorder (iRBD), Parkinson's disease (PD) without RBD (PD-noRBD), PD with RBD (PD + RBD), and control subjects; and (2) to examine association between SN degeneration assessed by DAT-SPECT and SN echogenicity. PATIENTS/METHODS: A total of 61 subjects with confirmed iRBD were examined using Movement Disorders Society-unified PD rating scale (MDS-UPDRS), TCS (transcranial sonography) and DAT-SPECT. The results were compared with 44 patients with PD (25% PD + RBD) and with 120 age-matched healthy subjects. RESULTS AND CONCLUSION: The abnormal SN area was found in 75.5% PD, 23% iRBD and 7.3% controls. Median SN echogenicity area in PD (0.27 ± 0.22 cm2) was higher compared to iRBD (0.07 ± 0.07 cm2; p < 0.0001) and controls (0.05 ± 0.03 cm2; p < 0.0001). SN echogenicity in PD + RBD was not significantly different from PD-noRBD (0.30 vs. 0.22, p = 0.15). Abnormal DAT-SPECT was found in 16 iRBD (25.4%) and 44 PD subjects (100%). No correlation between the larger SN area and corresponding putaminal binding index was found in iRBD (r = -0.13, p = 0.29), nor in PD (r = -0.19, p = 0.22). The results of our study showed that: (1) SN echogenicity area in iRBD was higher compared to controls, but the hyperechogenicity was present only in a minority of iRBD patients; (2) SN echogenicity and DAT-SPECT binding index did not correlate in either group; and (3) SN echogenicity does not differ between PD with/without RBD.

• MeSH
• jednofotonová emisní výpočetní tomografie MeSH
• lidé MeSH
• nortropany MeSH
• porucha chování v REM spánku * diagnostické zobrazování   patofyziologie   MeSH
• radioizotopy jodu MeSH
• substantia nigra * diagnostické zobrazování   patofyziologie   MeSH
• synukleinopatie * diagnostické zobrazování   patofyziologie   MeSH
• ultrasonografie dopplerovská transkraniální MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH