Quantitative Imaging in Medicine and Surgery最新文献

Background: While standard clinical magnetic resonance (MR) enterography can detect inflammatory bowel disease, it is of limited value in deciding between medical versus surgical treatment. Alternatively, intestinal MR elastography has the potential to contribute additional information to therapeutic decision-making; however, the influence of bowel distension by oral contrast agent on viscoelastic tissue properties remains elusive. Therefore, we aimed to investigate the influence of oral contrast agent-induced bowel distension on the viscoelastic properties of the terminal ileum in healthy volunteers.

Methods: In this prospective pilot study, 20 healthy volunteers (33.2±8.2 years; 10 men, 10 women) underwent multifrequency MR elastography using a single-shot spin-echo echo planar imaging sequence at 1.5 Tesla and drive frequencies of 40, 50, 60 and 70 Hz. Maps of shear wave speed (c in ms^-1) and loss angle (φ in rad), representing stiffness and viscous properties, respectively, were generated using tomoelastography data processing. The volunteers were scanned before and after ingestion of 1,000 mL of 2% mannitol solution as oral contrast agent.

Results: There was no significant difference in terminal ileum biomechanical properties before vs. after ingestion of an oral contrast agent (mean c: 1.47±0.24 vs. 1.40±0.25 ms^-1 with P=0.37; mean φ: 0.70±0.12 rad vs. 0.68±0.12 rad with P=0.61). Moreover, there was no statistically significant correlation between MR elastography parameters before and after the ingestion of oral contrast (c: r=0.22, P=0.36; φ: r=0.24, P=0.30).

Conclusions: The results of this study suggest that bowel distension for intestinal MR elastography has no systematic effect on the biomechanical tissue properties of the terminal ileum determined by MR elastography. Therefore, future study protocols appear feasible with or without oral contrast agents.

Background: Lymphoma is a common malignant tumor in children. The pathologic subtyping of lymphoma is high complex, and the treatment options vary. The different pathologic subtypes of lymphomas have no significant differences on computed tomography (CT) images. As it is a hematologic disease, patients with lymphoma often show abnormalities in the spleen, and so the aim of this study was to construct a model for differentiating Burkitt lymphoma (BL) from lymphoblastic lymphoma through the extraction of radiomic features of the spleen from CT images. This could provide an efficient, noninvasive method that can differentiate the common pathological subtypes in patients with pediatric lymphoma.

Methods: The clinical data and imaging data of 48 patients with lymphoblastic lymphoma and 61 patients with BL were retrospectively analyzed. The dataset was divided into a training set (n=76) and a test set (n=33) through complete randomization. Radiomics features of the spleen were separately extracted from CT images in the noncontrast enhanced, arterial, and venous phases. These phase-specific features were integrated to construct fusion models. Three classifiers, quadratic discriminant analysis (QDA), logistic regression (LR), and support vector machine (SVM), were employed to build the models.

Results: The fusion model exhibited superior performance compared to individual models. There was no significant difference between the fusion models constructed by QDA and LR in either the training set or the test set. Among the four fusion models constructed with the SVM classifier, SVM_4 emerged as the best performing model. The area under the curve, sensitivity, specificity, and F1-score of the SVM_4 model were 0.967 [95% confidence interval (CI): 0.935-0.998], 0.86, 0.97, and 0.913 in the training set, respectively, and 0.754 (95% CI: 0.584-0.924), 0.611, 0.867, and 0.71 in the test set, respectively.

Conclusions: The radiomics features of the spleen demonstrated the capability to distinguish between the two most common lymphoma subtypes in pediatric patients. This noninvasive approach holds promise for efficient and accurate discrimination.

Background: Complete bundle branch block in individuals without structural heart disease is known as isolated complete bundle branch block. Isolated complete left bundle branch block (CLBBB) is correlated with ventricular dysfunction secondary to dyssynchrony; however, few studies have investigated isolated complete right bundle branch block (CRBBB), which was previously considered benign but was recently found to be associated with adverse cardiovascular outcomes. This study aimed to evaluate cardiac mechanical synchrony, and systolic and diastolic function in patients with isolated CRBBB and compare cardiac synchrony and function to patients with isolated CLBBB.

Methods: This cross-sectional study was conducted at The First Hospital of China Medical University in Shenyang, China, from 2020 to 2021. A total of 44 isolated CRBBB patients, 44 isolated CLBBB patients, and 42 healthy subjects were enrolled in the study. Transthoracic echocardiography was performed in all subjects. Synchrony parameters, including the mechanical dispersion of the right ventricle [the standard deviation of time to the peak longitudinal strain of six right ventricular (RV) segments] and atrioventricular dyssynchrony parameter [the ratio of left ventricular (LV) diastolic filling time to the time interval between two adjacent R waves (RR interval) measured by tissue Doppler imaging]. RV and LV function were assessed by the global longitudinal strain (GLS) of six RV segments and 18 LV segments, and the ratio of the peak early diastolic flow velocity to annular velocity (E/e') of the tricuspid valve and mitral valve. Statistical analyses were performed, including an analysis of variance, Pearson correlation analysis, and linear regression analysis.

Results: Compared with the healthy subjects, the mechanical dispersion of the right ventricle was significantly increased, and ventricular function was impaired as evidenced by the decreased RV GLS and LV GLS, and the increased E/e' of the tricuspid valve and mitral valve in the isolated CRBBB patients (all P<0.001). Moreover, compared with the isolated CLBBB patients, the mechanical dispersion of the right ventricle and E/e' of the tricuspid valve were increased, and RV GLS was significantly reduced in the isolated CRBBB patients (all P<0.001). Mechanical dispersion of the right ventricle was independently associated with RV GLS [coefficient, 0.13; 95% confidence interval (CI): 0.004-0.26; P=0.04] in the isolated CRBBB patients. RV GLS (coefficient, 0.10; 95% CI: 0.01-0.20; P=0.03) and the ratio of the LV diastolic filling time to the RR interval measured (coefficient, -0.30; 95% CI: -0.53 to -0.07; P=0.01) were independent factors of LV GLS.

Conclusions: The isolated CRBBB patients had impaired cardiac mechanical synchrony and ventricular function, and more decreased RV synchrony and function than the isolated CLBBB patients. Right intrave

Background: Minimally invasive glaucoma surgery (MIGS) has become an important treatment approach for primary open angle glaucoma. Restoration of aqueous humour drainage by means of alloplastic implants represents a promising treatment option and is itself subject of methodological development. An adequate positioning in the targeted tissue regions is essential is important for the performance of our in-house developed Rostock glaucoma microstent (RGM). The aim of this study was to evaluate the applicability of two animal models and human donor eyes regarding RGM placement.

Methods: Eyes were obtained from rabbits, pigs, and human body donations. After orbital exenterations, RGMs were placed in the anterior chamber draining in the subconjunctival space. X-ray contrast was increased by incubation in aqueous iodine solution for subsequent detailed micro-computed tomography (micro-CT)-based visualization and analysis.

Results: In contrast to the human and porcine eyes, the stent extended far to the posterior pole with a more pronounced curvature along the globe in the rabbit eyes due to their smaller size. However, dysfunctional deformations were not depicted. Adequate positioning of the stent's inflow area in the anterior chamber and the outflow area in the Tenon space was achieved in both the animal models and the human eye.

Conclusions: Micro-CT has proven to be a valuable tool for postoperative ex vivo evaluation of glaucoma drainage devices in its entire complexity. With regard to morphology, the porcine eye is the ideal animal model to test implantation procedures of the RGM. Nevertheless, rabbit eye morphology facilitates successful implantation results and provides all prerequisites for preclinical animal studies.

Background: Liver cirrhosis, as the terminal phase of chronic liver disease fibrosis, is associated with high morbidity and mortality. Traditional methods for assessing liver function, such as clinical scoring systems, offer only a global evaluation and may not accurately reflect regional liver function variations. This study aimed at evaluating the diagnostic potential of whole-liver histogram analysis of gadobenate dimeglumine (Gd-BOPTA)-enhanced magnetic resonance imaging (MRI) for predicting the progression of cirrhosis.

Methods: In this retrospective study, 265 consecutive patients with cirrhosis admitted to the Department of Radiology, Shandong Provincial Hospital Affiliated to Shandong First Medical University from August 2012 to September 2019 were enrolled. After the exclusion criteria were applied, 117 patients (84 males and 33 females) were divided into Child-Pugh A cirrhosis (n=43), Child-Pugh B cirrhosis (n=49), and Child-Pugh C cirrhosis (n=25). After correction for liver signal intensity with the spleen was completed, 19 histogram features of the whole liver were extracted and modeled to evaluate liver function, with the Child-Pugh class being incorporated as a clinical parameter. Receiver operating characteristic (ROC) curves were used to assess the diagnosis capability and determine the optimal cutoffs after a mean follow-up of 42.3±19.1 (range, 8-93) months. The association between significant histogram features and the cumulative incidence of hepatic insufficiency was analyzed with the adjusted Kaplan-Meier curve model.

Results: Among 117 patients (12%), 14 developed hepatic insufficiency through a period of follow-up. Five features, including the median (P<0.01), 90th percentile (P<0.01), root mean squared (P<0.01), mean (P<0.01), and 10th percentile (P<0.05), were significantly different between the groups with and without hepatic insufficiency according to the Kruskal-Wallis test; in the ROC curve analysis, the area under the curve (AUC) of these features was 0.723 [95% confidence interval (CI): 0.653-0.793], 0.722 (95% CI: 0.652-0.792), 0.722 (95% CI: 0.652-0.792), 0.721 (95% CI: 0.651-0.791), and 0.674 (95% CI: 0.600-0.748) after correction, respectively (all P values <0.05). Median, 90th percentile, root mean squared, and mean were found to be significant factors in predicting liver insufficiency. The adjusted Kaplan-Meier curves revealed that patients with a feature level less than the cutoff, as compared to those with a level above the cutoff, showed a statistically shorter progression-free survival and higher incidences of hepatic insufficiency for significant features of median (cutoff =26.001; 21.28% versus 5.71%; P=0.02), 90th percentile (cutoff =86.263; 20.41% versus 5.88%; P<0.01), root mean squared (cutoff =1,028.477; 19.15% versus 7.14%; P=0.049), and mean (cutoff =27.484; 19.15% versus 7.14%; P=0.049). Patients with a 10th percentile less than -3

Background: Contrast-enhanced ultrasound (CEUS) technology has been developed for decades, and its application is becoming increasingly more extensive. In this study, bibliometrics was used to characterize the development status of CEUS over the past 20 years and to identify future research hotspots.

Methods: We collected data from the Web of Science and analyzed the literature related to CEUS published from 2002 to 2022. We examined 6,382 publications and analyzed the publication year, country of origin, affiliated institutions, authors, journal, categories, keywords, and research frontiers within the relevant literature. Using bibliometric analysis, we aimed to determine the general research direction and current publication trends. This allowed us to identify the most prolific and outstanding authors, institutions, countries, and keywords in CEUS research. For data collection, analysis, and visualization, we employed VOSviewer (Leiden University, Leiden, the Netherlands), Excel (Microsoft Corp., Redmond, WA, USA), CiteSpace, and biblioshiny. These tools helped us gather, analyze, and visualize the data effectively.

Results: The analyzed publications indicated a consistent upward trend in the number of works published between 2002 and 2022. Notably, China and Sun Yat-sen University emerged as the most prolific countries and institutions, respectively. China published 391 articles with 5,817 citations and was the leader in terms of international cooperation. Moreover, pediatrics-related keywords have surged in frequency in recent years.

Conclusions: The amount of research on CEUS has increased rapidly and continues to grow, with China being at the forefront of this research field. The application of CEUS in some pediatric diseases is a recent research hotspot and perhaps warrants close attention.

Background: Myocardial microcirculation dysfunction is the most potent predictor of adverse cardiovascular events in hypertension. The current study aimed to apply intravoxel incoherent motion diffusion-weighted imaging (IVIM-DWI) to assess hypertension-related microcirculation dysfunction.

Methods: In this prospective study, 102 participants were recruited from our hospital and underwent cardiac magnetic resonance (CMR) examination on a 3T scanning system. Hypertensive patients were divided into 3 subgroups based on blood pressure (BP) types. Two experienced CMR radiologists independently analyzed all images, and Bland-Altman analysis was applied to assess intra- and inter-observer reproducibility. Cardiac function indexes and IVIM-DWI parameters were compared between the hypertension and healthy control groups, as well as among the three hypertension subgroups.

Results: Totally 62 participants with hypertension and 27 healthy controls were included. 13 participants were excluded for poor quality of IVIM-DWI images. Significantly higher maximal left ventricular wall thickness (10.3±2.0 vs. 8.6±1.4 mm, P<0.001) and left ventricular mass index (49.0±9.1 vs. 42.1±7.5 g/m², P<0.05) were observed inhypertension group compared with healthy control group. There were significant statistical differences in pseudo diffusion (D*) between them (81.3±16.3 vs. 111.8±18.9 mm²/s, P<0.001), as well as among the three hypertension subgroups (99.4±13.9 vs. 79.7±10.6 vs. 67.1±6.6 mm²/s, P<0.001). Participants with poor quality of IVIM-DWI images had higher heart rates (72.2±10.0 vs. 62.0±8.1 bpm, P<0.001).

Conclusions: IVIM-DWI is feasible for quantitatively evaluating myocardial microcirculation dysfunction in hypertension. The D* parameter has a potential value for assessing the severity of microcirculation dysfunction in different BP categories.

Background: Although small bowel bleeding is relatively rare, it is a potentially fatal disease, and its diagnosis still faces challenges. Technetium 99m-labeled red blood cell computed single photon emission computed tomography/computed tomography (^99mTc-RBC SPECT/CT) and contrast-enhanced multidetector computed tomography (MDCT) are common imaging methods for diagnosing small bowel bleeding, but there have been no studies comparing their diagnostic efficacy for this purpose. This study aims to compare the diagnostic value of ^99mTc-RBC SPECT/CT and contrast-enhanced MDCT for small bowel bleeding.

Methods: A total of 44 patients (30 males and 14 females, median age of 64 years) definitively diagnosed with small bowel bleeding and 15 non-small bowel bleeding patients (8 males and 7 females, median age of 66 years) were consecutively included in this study. All patients underwent ^99mTc-RBC SPECT/CT and contrast-enhanced MDCT examinations at Beijing Friendship Hospital of Capital Medical University between January 2020 to September 2023. The definitive diagnosis had been made through surgery or colonoscopy, or through patient history, patient management, and clinical follow-up. We collected clinical data of the participants. ^99mTc-RBC SPECT/CT and contrast-enhanced MDCT were reviewed in a blinded fashion for accuracy of detection of active bleeding as well as the active small bowel bleeding location.

Results: Among the 59 patients, the accuracy, sensitivity, and specificity of ^99mTc-RBC SPECT were 27.3%, 93.3%, and 92.3%; for ^99mTc-RBC SPECT/CT they were 76.3%, 40.5%, and 93.3%; whereas for contrast-enhanced MDCT they were 45.8%, 27.3%, and 100%, respectively. The diagnostic accuracy of ^99mTc-RBC SPECT/CT for jejunal and ileal bleeding was high, at 100% and 86.4%, respectively. Meanwhile, ^99mTc-RBC SPECT/CT had a higher accuracy in diagnosing more causes of small bowel bleeding. In 59 patients, the combination of ^99mTc-RBC SPECT/CT and contrast-enhanced MDCT accurately diagnosed small bowel bleeding and provided precise localization in 50 patients, resulting in the accuracy, sensitivity, and specificity of 84.7%, 79.5%, and 100.0%, respectively.

Conclusions: ^99mTc-RBC SPECT/CT has high diagnostic value in diagnosing small bowel bleeding and is superior to ^99mTc-RBC SPECT and contrast-enhanced MDCT. The combination of ^99mTc-RBC SPECT/CT and contrast-enhanced MDCT can further improve the diagnostic accuracy of diagnosis, and can accurately guide the diagnosis and treatment of small bowel bleeding.

Background: The automated classification of histological images is crucial for the diagnosis of cancer. The limited availability of well-annotated datasets, especially for rare cancers, poses a significant challenge for deep learning methods due to the small number of relevant images. This has led to the development of few-shot learning approaches, which bear considerable clinical importance, as they are designed to overcome the challenges of data scarcity in deep learning for histological image classification. Traditional methods often ignore the challenges of intraclass diversity and interclass similarities in histological images. To address this, we propose a novel mutual reconstruction network model, aimed at meeting these challenges and improving the few-shot classification performance of histological images.

Methods: The key to our approach is the extraction of subtle and discriminative features. We introduce a feature enhancement module (FEM) and a mutual reconstruction module to increase differences between classes while reducing variance within classes. First, we extract features of support and query images using a feature extractor. These features are then processed by the FEM, which uses a self-attention mechanism for self-reconstruction of features, enhancing the learning of detailed features. These enhanced features are then input into the mutual reconstruction module. This module uses enhanced support features to reconstruct enhanced query features and vice versa. The classification of query samples is based on weighted calculations of the distances between query features and reconstructed query features and between support features and reconstructed support features.

Results: We extensively evaluated our model using a specially created few-shot histological image dataset. The results showed that in a 5-way 10-shot setup, our model achieved an impressive accuracy of 92.09%. This is a 23.59% improvement in accuracy compared to the model-agnostic meta-learning (MAML) method, which does not focus on fine-grained attributes. In the more challenging, 5-way 1-shot setting, our model also performed well, demonstrating a 18.52% improvement over the ProtoNet, which does not address this challenge. Additional ablation studies indicated the effectiveness and complementary nature of each module and confirmed our method's ability to parse small differences between classes and large variations within classes in histological images. These findings strongly support the superiority of our proposed method in the few-shot classification of histological images.

Conclusions: The mutual reconstruction network provides outstanding performance in the few-shot classification of histological images, successfully overcoming the challenges of similarities between classes and diversity within classes. This marks a significant advancement in the automated classification of h