Utility of diffusion tensor imaging and generalized q-sampling imaging for predicting short-term clinical effect of deep brain stimulation in Parkinson's disease.

PURPOSE: To assess whether diffusion tensor imaging (DTI) and generalized q-sampling imaging (GQI) metrics could preoperatively predict the clinical outcome of deep brain stimulation (DBS) in patients with Parkinson's disease (PD). METHODS: In this single-center retrospective study, from September 2021 to March 2023, preoperative DTI and GQI examinations of 44 patients who underwent DBS surgery, were analyzed. To evaluate motor functions, the Unified Parkinson's Disease Rating Scale (UPDRS) during on- and off-medication and Parkinson's Disease Questionnaire-39 (PDQ-39) scales were used before and three months after DBS surgery. The study population was divided into two groups according to the improvement rate of scales: ≥ 50% and < 50%. Five target regions, reported to be affected in PD, were investigated. The parameters having statistically significant difference were subjected to a receiver operating characteristic (ROC) analysis. RESULTS: Quantitative anisotropy (qa) values from globus pallidus externus, globus pallidus internus (qa_Gpi), and substantia nigra exhibited significant distributional difference between groups in terms of the improvement rate of UPDRS-3 scale during on-medication (p = 0.003, p = 0.0003, and p = 0.0008, respectively). In ROC analysis, the best parameter in predicting DBS response included qa_Gpi with a cut-off value of 0.01370 achieved an area under the ROC curve, accuracy, sensitivity, and specificity of 0.810, 73%, 62.5%, and 85%, respectively. Optimal cut-off values of ≥ 0.01864 and ≤ 0.01162 yielded a sensitivity and specificity of 100%, respectively. CONCLUSION: The imaging parameters acquired from GQI, particularly qa_Gpi, may have the ability to non-invasively predict the clinical outcome of DBS surgery.

Reproducibility of rCBV in glioblastomas using T2*-weighted perfusion MRI: an evaluation of sampling, normalization, and experience.

PURPOSE: The reproducibility of relative cerebral blood volume (rCBV) measurements among readers with different levels of experience is a concern. This study aimed to investigate the inter-reader reproducibility of rCBV measurement of glioblastomas using the hotspot method in dynamic susceptibility contrast perfusion magnetic resonance imaging (DSC-MRI) with various strategies. METHODS: In this institutional review board-approved single-center study, 30 patients with glioblastoma were retrospectively evaluated with DSC-MRI at a 3.0 Tesla scanner. Three groups of reviewers, including neuroradiologists, general radiologists, and radiology residents, calculated the rCBV based on the number of regions of interest (ROIs) and reference areas. For statistical analysis of feature reproducibility, the intraclass correlation coefficient (ICC) and Bland-Altman plots were used. Analyses were made among individuals, reader groups, reader-group pooling, and a population that contained all of them. RESULTS: For individuals, the highest inter-reader reproducibility was observed between neuroradiologists [ICC: 0.527; 95% confidence interval (CI): 0.21-0.74] and between residents (ICC: 0.513; 95% CI: 0.20-0.73). There was poor reproducibility in the analyses of individuals with different levels of experience (ICC range: 0.296-0.335) and in reader-wise and group-wise pooling (ICC range: 0.296-0.335 and 0.397-0.427, respectively). However, an increase in ICC values was observed when five ROIs were used. In an analysis of all strategies, the ICC for the centrum semiovale was significantly higher than that for contralateral white matter (P < 0.001). CONCLUSION: The inter-reader reproducibility of rCBV measurement was poor to moderate regardless of whether it was calculated by neuroradiologists, general radiologists, or residents, which may indicate the need for automated methods. Choosing five ROIs and using the centrum semiovale as a reference area may increase reliability for all users.

Influence of image preprocessing on the segmentation-based reproducibility of radiomic features: in vivo experiments on discretization and resampling parameters.

PURPOSE: To systematically investigate the impact of image preprocessing parameters on the segmentation-based reproducibility of magnetic resonance imaging (MRI) radiomic features. METHODS: The MRI scans of 50 patients were included from the multi-institutional Brain Tumor Segmentation 2021 public glioma dataset. Whole tumor volumes were manually segmented by two independent readers, with the participation of eight readers. Radiomic features were extracted from two sequences: T2-weighted (T2) and contrast-enhanced T1-weighted (T1ce). Two methods were considered for discretization: bin count (i.e., relative discretization) and bin width (i.e., absolute discretization). Ten discretization (five for each method) and five resampling parameters were varied while other parameters were fixed. The intraclass correlation coefficient (ICC) was used for reliability analysis based on two commonly used cut-off values (0.75 and 0.90). RESULTS: Image preprocessing parameters had a significant impact on the segmentation-based reproducibility of radiomic features. The bin width method yielded more reproducible features than the bin count method. In discretization experiments using the bin width on both sequences, according to the ICC cut-off values of 0.75 and 0.90, the rate of reproducible features ranged from 70% to 84% and from 35% to 57%, respectively, with an increasing percentage trend as parameter values decreased (from 84 to 5 for T2; 100 to 6 for T1ce). In the resampling experiments, these ranged from 53% to 74% and from 10% to 20%, respectively, with an increasing percentage trend from lower to higher parameter values (physical voxel size; from 1 x 1 x 1 to 2 x 2 x 2 mm3). CONCLUSION: The segmentation-based reproducibility of radiomic features appears to be substantially influenced by discretization and resampling parameters. Our findings indicate that the bin width method should be used for discretization and lower bin width and higher resampling values should be used to allow more reproducible features.

The effect of radiofrequency ablation on pain score and non-steroidal painkiller use in osteoid osteoma patients.

AIM: CT-guided radiofrequency ablation (RFA) is among the thermal ablative procedures and provides great benefits with a minimally invasive procedure. In this prospective study, we aimed to reveal the significance of a multidisciplinary method in reducing the recurrence and complications in osteoid osteoma patients with CT-guided RFA performed by a team of experts in the field. MATERIALS AND METHODS: A total of consecutive 40 patients with osteoid osteoma were prospectively evaluated and treated with CT-guided RFA. Before and the post ablation the visual analog scale (VAS) and use of nonsteroidal anti-inflammatory drugs (NSAIDS) were compared. RESULTS: Post-ablation VAS of the patients at the 1st week and 3rd month after the procedure decreased significantly (p < 0.01) compared to the pre-ablation. The frequency of NSAID use after the ablation decreased significantly (p < 0.01) compared to the pre-ablation time. The pre-procedure NSAID use of our patients included in the study was average 6.93 per week, the NSAID use in the 3rd month post-procedure controls was average 0.53 per week. Recurrence was detected in 4 of our patients, 36 patients had complete recovery. CONCLUSION: Radiofrequency ablation is an effective treatment method in the management of osteoid osteomas. Radiofrequency ablation has low recurrence rates and provides rapid regression in patients' pain after treatment.

Investigation of the Effectiveness of Microvascular Doppler Ultrasound and Q-Pack in the Discrimination of Malign Thyroid Nodules From Benign.

ABSTRACT: In this prospective study, the diagnostic performance of MicroV Doppler ultrasonography (US) and Q-pack application in distinguishing malignant thyroid nodules from benign nodules will be examined. Given the emerging irregular vascular structures in malignant nodules, it is thought that MicroV Doppler US and Q-pack application can help in diagnosis. One hundred sixteen nodules that were suggested a biopsy by a clinician were examined with B-mode US, color, X-flow, and MicroV Doppler US, respectively. In addition, during MicroV Doppler US examination, thyroid nodule and its adjacent thyroid parenchyma were evaluated with Q-pack application. After US examinations, biopsy was performed on the nodules and histopathological results were obtained. Eighty-nine nodules were histopathologically proven as benign, and the rest of them were malignant. In Doppler types, the thyroid findings in score 1, 2, and 3 nodule blood supply type were benign, whereas the thyroid findings in the score 4 have a possibility of malignancy between 63% and 66.7%. It was found that MicroV Doppler was significantly superior to X-flow and color Doppler ( P = 0.037 and P = 0.042, respectively). Nodule/parenchyma Q-pack mean values were statistically significantly higher in malignant findings compared with benign findings ( P < 0.001). Nodule/parenchyma Q-pack peak values were also statistically significantly higher in malignant findings compared with benign findings ( P < 0.001).As a result, although Q-pack application enables us to obtain quantitative values about vascularity, due to its ability to demonstrate slow blood flow, microvascular vessel structure, and distribution, MicroV Doppler US has promises to detect malignant thyroid nodules.

The Importance of Superb Microvascular Imaging for the Differentiation of Malignant Breast Lesions from Benign Lesions.

OBJECTIVE: In this prospective study, the diagnostic performance of the new version of superb microvascular imaging (SMI) in differentiating malignant from benign lesions was evaluated. MATERIAL AND METHODS: Ninety breast lesions were included. During color SMI examination, both free-hand region of interest (ROI) and box ROI were used. Vascular index (VI) values were obtained from the lesion using both types of ROI and from normal breast tissue via box ROI. VI values, monochrome SMI grading and histopathological results were compared. The efficacy of color SMI and monochrome SMI was investigated in differentiating between benign and malignant breast lesions. RESULTS: The cut-off value, in the differentiation of benign and malignant lesions with color SMI was 0.50 for box ROI, while it was 0.30 for free-hand ROI. The specificity of VI values obtained with box ROI was higher than that of free-hand ROI when differentiating malignant lesions from benign. Comparison of VI values from a lesion and from normal breast tissue showed that VI values in malignant lesions were significantly higher (p<0.05). The VI values of benign lesions and VI values of normal breast tissue were similar. There was a statistically significant relationship between monochrome SMI grading and the malignancy or benign status of the lesion (p<0.001). CONCLUSION: Drawing the lesion circumference free-hand using a free-shape ROI did not enhance the sensitivity and specificity. Contrary to popular belief, a more easy and practical measurement method may be more suitable for SMI examination. It is hoped that this will be one of the earliest studies to assess the clinical performance of the latest version of SMI.