An Exploratory Pilot Study on the Application of Radiofrequency Ablation for Atrial Fibrillation Guided by Computed Tomography-Based 3D Printing Technology.

Radiofrequency ablation (RFA) is the treatment of choice for atrial fibrillation (AF). Additionally, the utilization of 3D printing for cardiac models offers an in-depth insight into cardiac anatomy and cardiovascular diseases. The study aims to evaluate the clinical utility and outcomes of RFA following in vitro visualization of the left atrium (LA) and pulmonary vein (PV) structures via 3D printing (3DP). Between November 2017 and April 2021, patients who underwent RFA at the First Affiliated Hospital of Xinxiang Medical University were consecutively enrolled and randomly allocated into two groups: the 3DP group and the control group, in a 1:1 ratio. Computed tomography angiography (CTA) was employed to capture the morphology and diameter of the LA and PV, which facilitated the construction of a 3D entity model. Additionally, surgical procedures were simulated using the 3D model. Parameters such as the duration of the procedure, complications, and rates of RFA recurrence were meticulously documented. Statistical analysis was performed using the t-test or Mann-Whitney U test to evaluate the differences between the groups, with a P-value of less than 0.05 considered statistically significant. In this study, a total of 122 patients were included, with 53 allocated to the 3DP group and 69 to the control group. The analysis of the morphological measurements of the LA and PV taken from the workstation or direct entity measurement showed no significant difference between the two groups (P > 0.05). However, patients in the 3DP group experienced significantly shorter RFA times (97.03 ± 28.39 compared to 120.51 ± 44.76 min, t = 3.05, P = 0.003), reduced duration of radiation exposure (2.55 [interquartile range 2.01, 3.24] versus 3.20 [2.28, 3.91] min, Z = 3.23, P < 0.001), and shorter modeling times (7.68 ± 1.03 compared to 8.89 ± 1.45 min, t = 5.38, P < 0.001). 3DP technology has the potential to enhance standard RFA practices by reducing the time required for intraoperative interventions and exposure to radiation.

Evaluating the consistency in different methods for measuring left atrium diameters.

BACKGROUND: The morphological information of the pulmonary vein (PV) and left atrium (LA) is of immense clinical importance for effective atrial fibrillation ablation. The aim of this study is to examine the consistency in different LA diameter measurement techniques. METHODS: Retrospective imaging data from 87 patients diagnosed with PV computed tomography angiography were included. The patients consisted of 50 males and 37 females, with an average age of (60.74 ± 8.70) years. Two physicians independently measured the anteroposterior diameter, long diameter, and transverse diameter of the LA using six different methods. Additionally, we recorded the post-processing time of the images. Physician 1 conducted measurements twice with a one-month interval between the measurements to assess intra-rater reliability. Using the intraclass correlation coefficient (ICC), the consistency of each LA diameter measurement by the two physicians was evaluated. We compared the differences in the LA diameter and the time consumed for measurements using different methods. This was done by employing the rank sum test of a randomized block design (Friedman M test) and the q test for pairwise comparisons among multiple relevant samples. RESULTS: (1) The consistency of the measured LA diameter by the two physicians was strong or very strong. (2) There were statistical differences in the anteroposterior diameter, long diameter, and transverse diameter of LA assessed using different methods (χ2 = 222.28, 32.74, 293.83, P < 0.001). (3) Different methods for measuring the diameters of LA required different amounts of time (χ2 = 333.10, P < 0.001). CONCLUSION: The results of left atrium (LA) diameter measurements conducted by different physicians were found to be reliable. However, the LA diameters obtained through various techniques exhibited variations. It was observed that measuring LA long diameters using only the VR (volume rendering) picture was the most clinically applicable method.

An interpretable machine learning model for stroke recurrence in patients with symptomatic intracranial atherosclerotic arterial stenosis.

Background and objective: Symptomatic intracranial atherosclerotic stenosis (SICAS) is the most common etiology of ischemic stroke and one of the main causes of high stroke recurrence. The recurrence of stroke is closely related to the prognosis of ischemic stroke. This study aims to develop a machine learning model based on high-resolution vessel wall imaging (HR-VWI) to predict the risk of stroke recurrence in SICAS. Methods: This study retrospectively collected data from 180 SICAS stroke patients treated at the hospital between 2020.01 and 2022.01. Relevant imaging and clinical data were collected, and follow-up was conducted. The dataset was divided into a training set and a validation set in a ratio of 7:3. We employed the least absolute shrinkage and selection operator (LASSO) regression to perform a selection on the baseline data, laboratory tests, and neuroimaging data generated by HR-VWI scans collected from the training set. Finally, five machine learning techniques, including logistic regression model (LR), support vector machine (SVM), Gaussian naive Bayes (GNB), Complement naive Bayes (CNB), and k-nearest neighbors algorithm (kNN), were employed to develop a predictive model for stroke recurrence. Shapley Additive Explanation (SHAP) was used to provide visualization and interpretation for each patient. The model's effectiveness was evaluated using average accuracy, sensitivity, specificity, precision, f1 score, PR curve, calibration curve, and decision curve analysis. Results: LASSO analysis revealed that "history of hypertension," "homocysteine level," "NWI value," "stenosis rate," "intracranial hemorrhage," "positive remodeling," and "enhancement grade" were independent risk factors for stroke recurrence in SICAS patients. In 10-fold cross-validation, the area under the curve (AUC) ranged from 0.813 to 0.912 in ROC curve analysis. The area under the precision-recall curve (AUPRC) ranged from 0.655 to 0.833, with the Gaussian Naive Bayes (GNB) model exhibiting the best ability to predict stroke recurrence in SICAS. SHAP analysis provided interpretability for the machine learning model and revealed essential factors related to the risk of stroke recurrence in SICAS. Conclusion: A precise machine learning-based prediction model for stroke recurrence in SICAS has been established to assist clinical practitioners in making clinical decisions and implementing personalized treatment measures.

CT-pathologic correlation in lung adenocarcinoma and squamous cell carcinoma.

Distinguishing lung adenocarcinoma from squamous cell carcinoma (SCC) is clinically important. Computed tomography (CT) scan is an economical, effective, noninvasive, commonly available, and quick diagnostic way for lung cancer. In this study, we aim to compare the CT characteristics in adenocarcinoma and SCC.Data from 275 cases (259 adenocarcinoma and 16 SCC) were retrospectively compared. CT characteristics, including lesion size and shape, single/multifocal lesions, location of the tumor, the margin of lobes, whether the lesion had deep lobulated margin, bronchial cut-off sign, signs of dilated bronchial arteries, signs of vascular bundle thickening, signs of short burrs, spinous processes, and pleural indentation, were compared in 148 cases (137 adenocarcinoma and 11 SCC).Patients with adenocarcinoma were more likely to be female (44.2% vs 25.0%, P = .017). Compared with SCC, adenocarcinomas were more likely to have deep lobulated margin (81.0% vs 54.5%, P = .038), less likely to have smooth lobes margin (2.7% vs 83.3%, P < .001), more likely to have vascular bundle thickening (37.2% vs 0, P = .016) and pleural indentation (59.9% vs 18.2%, P = .01), and marginally less likely to have dilated bronchial arteries (17.5% vs 45.5%, P = .064). No significant difference was observed regarding to characteristics, including tumor size, location of the tumor, signs of bronchial cut-off, dilated bronchial arteries, short burrs, or spinous processes.CT scan has the potential to help to distinguish lung adenocarcinoma and SCC in a fast and commonly available way. CT could be a rough but fast way to diagnosis, and may thus shorten the waiting time to treatment and allow more time for clinicians, patients, and their families to prepare for future treatment.

Using integrated problem- and lecture-based learning teaching modes for imaging diagnosis education.

BACKGROUND: There are two parts included in traditional imaging diagnosis teaching: theoretical lessons and experimental lessons. Most of the time, the experimental lesson is a review of the theoretical lesson. The teacher is the centre of the course and students are passive learners. Thus, in this study we included the patient problem of the imaging centre in our imaging diagnosis education. The traditional theoretical lessen was used to discuss prior knowledge, the discussion and analysis of patient problems was arranged under class, and the experimental lesson was used to synthesize and test the newly acquired information. The aim of this study is to determine whether or not integration of problem- and lecture-based learning teaching modes in imaging diagnosis education was associated with a good teaching effect. Forty-six of sixty students (76.7%) like integrated problem- and lecture-based learning teaching mode and 53 of 60 students (88.3%) think that integrated problem- and lecture-based learning teaching mode can make their ability of self-study be improved. METHODS: Sixty students participated in a prospective study with a two-phase cross-over design. All of the students were divided into 2 groups of 30 each. In the first term, the first group participated in an integration of the problem- and lecture-based learning teaching mode, whereas students in the second group underwent the lecture-based learning teaching mode alone. During the second term, the teaching modes were exchanged between the two groups. A close-exam and survey were used to evaluate the teaching effect, and the data were analysed means of analysis of variance with a two-phase cross-over design and a χ2 test with a 2-tailed α of 0.05. RESULTS: There was a statistically significant difference in the test scores between the integration of the problem- and lecture-based learning teaching mode and the lecture-based learning teaching mode alone (P < 0.05). The integration of problem- and lecture-based learning teaching mode was well-appraised. CONCLUSION: Integration of the problem- and lecture-based learning teaching modes in teaching imaging diagnosis education resulted in a good teaching effect.

Executive dysfunction in patients with cerebral hypoperfusion after cerebral angiostenosis/occlusion.

Impairment of executive functions (EFs) was investigated in patients with cerebral hypoperfusion after cerebral angiostenosis/occlusion. Several EFs were measured in patients with cerebral angiostenosis/occlusion and healthy subjects. The vascular conditions, regional cerebral blood flow (rCBF), regional cerebral blood volume (rCBV), mean transit time (MTT), time to peak (TTP), and delay time were assessed. The scores of the vascular stenosis/occlusion group were significantly lower than those of the control group. rCBV and rCBF were negatively correlated with the error response times in the Stroop test, and the persistent error responses in the Wisconsin Card Sorting Test (WCST) were positively correlated with the Montreal Cognitive Assessment (MoCA) scores. TTP was positively correlated with the reaction and error reaction times, and the persistent error response in WCST was negatively correlated with the times of sorting in WCST and MoCA scores. MTT was positively correlated with the persistent error response in WCST. In the Stroop test, delay time was positively correlated with response time, and negatively correlated with error response times, and the persistent error response in WCST and MoCA scores. Patients with cerebral hypoperfusion after cerebral angiostenosis/occlusion had executive dysfunctions in working memory, sustained attention, response inhibition, cognitive flexibility, thought organization, planning, and implementation. Moreover, their executive dysfunctions were related with the decline in rCBF and rCBV. The prolonged TTP, MTT, and delay time suggested a slow blood flow and the poor compensation of collateral circulation, resulting in impairment of the EFs.