British Journal of Radiology最新文献

Objectives: To evaluate the size-specific dose estimates (SSDE) in adult patients undergoing kidneys, ureters, and bladder (CT KUB) scans using 2 approaches: water-equivalent diameter (Dw) and effective diameter (Deff). The study also aimed to assess the accuracy of using a single central image slice for SSDE estimation.

Methodology: Ethical approval was obtained to collect patient data from a local hospital. CT images from 203 adult patients were retrieved and processed using IndoseCT software to calculate patient size metrics and corresponding SSDE values.

Results: SSDE values calculated using the Dw,mean and Deff,mean were comparable: 10.3 ± 2.9 mGy and 10.2 ± 2.9 mGy, respectively. When using a single central slice, the mean percentage differences were -1.8 ± 3.9% for Dw and -1.1 ± 4.6% for Deff, with all values falling within ±11%. A strong correlation was observed between SSDE values derived from single-slice and full-slice measurements (R2 > 0.97), showing slightly better agreement for Dw.

Conclusion: While Dw offers a more accurate estimation of patient size, the minimal differences observed suggest that Deff is a suitable alternative when Dw specific tools are unavailable. Additionally, using a single central slice is a practical and efficient method to estimate SSDE, significantly reducing computational demands.

Advances in knowledge: This study provides clinical validation that SSDE can be reliably estimated using a single-slice method in CT KUB examinations, offering a substantial reduction in processing time. It also demonstrates that Deff is a viable substitute for Dw when access to advanced imaging analysis tools is limited.

Objective: This study aimed to evaluate the inter-reader agreement of visual background parenchymal enhancement (BPE) assessment on contrast-enhanced mammography (CEM) and determine whether training can improve this assessment.

Methods: Five hundred and forty-eight women who underwent contrast-enhanced mammography from 2018 through 2022 were included. A total of 2135 images were read by six radiologists (Group A) independently and rated BPE with the ordinal scale: minimal, mild, moderate, or marked. After a dedicated training, the same cases were reread in a new random order within two weeks. To further verify the effectiveness of training, four radiologists (Group B) from four different institutions were invited to assess BPE in the same way with 800 images. The accuracy of each reader and agreement on BPE categorization between radiologists and the reference standard were evaluated.

Results: The percentage of correct BPE assignments increased from 62.3% (range, 48.6%-73.6%) to 75.5% (range, 69.0%-79.7%) after training in Group A and increased from 55.7% (range, 52.0%-58.9%) to 66.9% (range, 62.0%-71.0%) after training in Group B. With training, inter-reader agreement increased from fair to moderate in both Group A (κ = 0.32-0.52) and Group B (κ = 0.40-0.53), indicating that readers learned and the training can be rolled out to different institutions.

Conclusion: The initial inter-reader agreement in assessing BPE among radiologists was fair but showed enhancement following training, highlighting the necessity of training and standard sets of reference images that should be made available for training.

Advances in knowledge: This study demonstrates that dedicated training improves inter-reader agreement in BPE assessment on CEM, highlighting the need for standardized training programs to enhance consistency in clinical practice and research.

Crohn's disease (CD) is a chronic inflammatory bowel disease that affects the entire gastrointestinal (GI) tract from the mouth to anus and has an estimated incidence of up to 20 cases per 100 000. It is a chronic remitting disease associated with significant morbidity and increasing incidence worldwide. While endoscopy and biopsy form the cornerstone of diagnosis, cross-sectional imaging modalities such as ultrasound (US), CT, and MRI play a pivotal role in assessing disease extent and treatment response. Luminal complications such as stenoses, strictures, and complications such as fistula and abscesses are accurately detected and characterized non-invasively with these modalities. The appropriate use of imaging in CD, therefore, facilitates identification and localization of diseased bowel segments and detection of complications and associations such as sclerosing cholangitis and sacroiliitis. Due to undisputed value of cross-sectional imaging combined with the chronic remitting and relapsing nature of CD, patients often undergo large numbers of imaging studies throughout their lifetime for diagnostic and surveillance purposes. This includes plain radiography and CT scanning, both of which involve exposure to ionizing radiation. While the diagnostic information obtained from imaging is crucial for appropriate patient management, over a lifetime, patients with CD may be cumulatively exposed to high levels of ionizing radiation. Therefore, consideration of patient radiation safety is of great importance and should form part of the risk-benefit analysis preceding each imaging study in CD patients. Given the increasing incidence of Crohn's disease, and the development and optimization of alternative imaging modalities in CD, which avoid radiation exposure, as well as the sustained advances in CT technology which facilitate radiation dose reduction, the preparation of this article is timely. This article aims to deliver an up-to-date overview of the role of imaging in Crohn's disease and how consideration of radiation safety and radiation dose optimization impacts choice of imaging modality in CD.

Objectives: Precise preoperative localization of parathyroid gland lesion is essential for guiding surgery in primary hyperparathyroidism (PHPT). The aim of our study was to investigate the contrast-enhanced ultrasound (CEUS) characteristics of parathyroid gland adenoma (PGA) and to evaluate whether PGA can be differentiated from central cervical lymph nodes (CCLN).

Methods: Fifty-four consecutive patients with PHPT were retrospectively enrolled and underwent preoperative imaging with high-resolution ultrasound (US) and CEUS, and underwent subsequent parathyroidectomy. One hundred seventy-four lymph nodes of papillary thyroid carcinomas (PTC) patients were examined by high-resolution US and CEUS, and underwent unilateral, subtotal, or total thyroidectomy with central neck dissection were enrolled. By incorporating US and CEUS characteristics, a predictive model presented as a nomogram was developed, and their performance and utility were evaluated by plotting receiver operating characteristic (ROC) curves, calibration curves and decision curve analysis (DCA).

Results: Three US characteristics and 2 CEUS characteristics were independent characteristics related to PGA for their differentiation from CCLN, and were obtained for machine learning model construction. The area under the receiver characteristic curve (AUC) of the US + CEUS model was 0.915, was higher than the other US model (0.874) and CEUS model (0.791).

Conclusion: It is recommended that CEUS techniques be used to enhance the diagnostic utility of US in cases of suspected parathyroid lesions.

Advances in knowledge: This is the first study to use a combination of US + CEUS to build a nomogram to distinguish between PGA and CCLN, filling a gap in the existing literatures.

Objectives: The aim of this systematic review and meta-analysis is to evaluate the diagnostic accuracy of artificial intelligence (AI) based algorithms in detecting pneumoperitoneum on medical imaging.

Methods: Online databases were searched until June 2024. Statistical analyses were conducted using Open Meta-Analyst software and STATA 17.0. The analysis included overall sensitivity, specificity, diagnostic odds ratio (DOR), and area under the curve (AUC). Meta-regression and subgroup analyses were conducted to identify sources of heterogeneity among the included studies.

Results: Among the 14 AI-based radiograph models analysed, AI demonstrated high diagnostic accuracy for pneumoperitoneum, with a sensitivity of 83.6% (95% CI: 80.2%-86.4%), specificity of 92.9% (95% CI: 88.3%-95.8%), negative likelihood ratio of 0.18, and positive likelihood ratio of 11.76 (all P < .001). Deep learning models showed higher sensitivity (83.7%) but slightly lower specificity (91.2%) compared to machine learning models (sensitivity 77%, specificity 98%). The AUC was 0.93, with a DOR of 76. Meta-regression revealed larger sample sizes significantly improved specificity. Deeks' funnel plot showed no publication bias.

Conclusions: AI models are effective in diagnosing pneumoperitoneum. The high accuracy of these models enhances the potential for rapid and precise detection, thereby improving patient management. Future prospective multicentre studies with larger sample sizes and comparisons of various models are highly anticipated.

Advances in knowledge: This is the first meta-analysis to evaluate AI's diagnostic accuracy for pneumoperitoneum, revealing high sensitivity and specificity, comparing deep learning and machine learning performance, and highlighting AI's potential to enhance early diagnosis and prioritization in clinical workflows.

Objectives: To predict histologic grade of soft tissue sarcoma (STS) with preoperative ultrasound images, aiding in the selection of personalized treatment plans and improving long-term prognosis.

Methods: In total, 238 patients with histologically proven STS were retrospectively enrolled from April 2016 to December 2023 and divided into the training and internal validation cohorts. Seventy patients were prospectively enrolled from 3 centers between January 2024 and December 2024 as the external validation cohort. Radiomics features were extracted from preoperative grayscale ultrasound images. The dynamic nomogram (DynNom) was developed by using multivariable logistic regression analysis. Predictive performance was evaluated with the receiving operating characteristic curve, calibration curve, Hosmer-Lemeshow test, decision curve analysis (DCA), and clinical impact curve (CIC).

Results: The DynNom based on clinical-US characteristics (metastasis status, echogenicity, fascia layer, and vascularity) and radiomics features yielded an optimal AUC of 0.915 (95% CI, 0.873-0.947), 0.87 (95% CI, 0.79-0.93), and 0.90 (95% CI, 0.80-0.96) for predicting the STS histologic grade in the training, internal, and external validation cohorts, respectively. The DynNom outperformed the conventional model and radiomics model (P < .05). Calibration curves and Hosmer-Lemeshow tests indicated its satisfactory calibration ability. DCA confirmed that the DynNom outperformed other models in overall net benefit, meanwhile CIC suggested that the DynNom had great clinical applicability in predicting histologic grade.

Conclusions: The dynamic nomogram is a practical tool that could predict the histologic grade of STS, which might help clinicians to screen histologic high-grade STSs as neoadjuvant treatment candidates.

Advances in knowledge: The dynamic nomogram had the potential to accurately predict histologic grade in STS patients before surgery. High-risk patients defined by the dynamic nomogram were potential candidates for preoperative radiotherapy and neoadjuvant chemotherapy.

Objective: To evaluate the auxiliary role of contrast-enhanced ultrasound (CEUS) in the etiological diagnosis of pathological nipple discharge (PND) and compare its effectiveness with dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI).

Methods: In this prospective study conducted from March 2021 to February 2024, PND patients underwent breast ultrasound and DCE-MRI after initial history and physical examination. Lesions were categorized as mass or non-mass-like on baseline US and assessed for vascularity using colour Doppler. CEUS was utilized to refine the breast imaging reporting and data system (BI-RADS) classification. Logistic regression identified risk factors, and diagnostic performance was evaluated using receiver operating characteristic curve analysis.

Results: A total of 116 lesions from 112 PND patients were analysed. CEUS-assisted ultrasound showed increased specificity (ranging from 50.0%-80.0% compared to US alone, P = .009) while maintaining sensitivity. Of the 81 patients who underwent DCE-MRI, CEUS demonstrated a higher positive predictive value (83.3% vs 75.5%), with comparable negative predictive values (97.0% vs 96.4%). CEUS was particularly effective in accurately diagnosing benign lesions that were overestimated by DCE-MRI and in identifying ductal carcinoma in situ with greater precision than US alone.

Conclusion: The auxiliary use of CEUS with ultrasound improves the specificity and positive predictive value in diagnosing PND-associated malignancies and serves as a valuable secondary imaging method to DCE-MRI, potentially reducing unnecessary biopsies of benign lesions.

Advances in knowledge: CEUS can enhance the diagnostic accuracy of PND, effectively differentiating benign from malignant lesions, and its integration into clinical practice could offer significant benefits in patient management.

Objectives: Ultra-high dose rate irradiation (UHDR) has been shown to spare normal tissue in various model systems. This study evaluates its potential to sterilize cancer cells using spheroid tumor models.

Methods: Spheroids from glioblastoma (U87), hypopharyngeal squamous cell carcinoma (2 sizes, FaDusmall and FaDularge) and breast adenocarcinoma (T47D) cells were irradiated with electron beams using UHDR (>200 Gy/s) or conventional dose rate (CONV, ∼0.1 Gy/s) exposures under ambient or reduced oxygen (1%) conditions. U87 and FaDusmall were also irradiated with protons. Spheroids were monitored using imaging for up to 100 days to determine the dose required to cure 50% of spheroids (SCD50). These data were used to calculate dose-modifying factor estimates for UHDR at the 50% survival level (DMFSCD50).

Results: A total of 3230 spheroids were analyzed. Under ambient oxygen tension, UHDR and CONV showed no significant differences in U87 (DMFSCD50 = 0.98, P = .47), FaDusmall (DMFSCD50 = 1.01, P = .75), and T47D (DMFSCD50 = 1.04, P = .25), regardless of electron or proton irradiation. Under reduced oxygen levels, significantly higher UHDR doses were required to sterilize the spheroids, with DMFSCD50 1.14 (U87, P < .01), 1.07 (FaDusmall, P = .02), and 1.13 (T47D, P < .01). FaDularge-spheroids irradiated under ambient oxygen showed a DMFSCD50 of 1.66 (P < .001).

Conclusion: Using spheroid tumor models with long follow-up, we demonstrate that efficacy of UHDR varies across cancer types and conditions. Whereas small spheroids exhibit iso-efficacy, both reduced oxygen tension and increased spheroid size lead to higher DMF.

Advances in knowledge: This preclinical study suggests that tumor iso-efficacy with UHDR may not hold true for all cancer types and is associated with oxygen level.

Objective: Ultra-high-dose rate (UHDR) radiotherapy has become a large area of research due to observed normal tissue sparing without sacrificing tumour control, termed the FLASH effect. The purpose of this study was to compare reactive oxygen species (ROS) production and DNA damage across various O2 levels at UHDR and conventional dose rates (CDR) in solutions without repair enzymes and radical scavengers.

Methods: Solution assays of both ROS and DNA damage assessed dose rate and oxygen dependent (0%-20% O2) changes between UHDR and CDR from an IntraOp Mobetron. For ROS reporters Amplex UltraRed (H2O2), and CellROX Deep Red (non-H2O2) were quantified via intensity per unit dose. DNA damage assayed plasmid pBR322 gel electrophoresis, to differentiate both single (SSB) and double strand breaks (DSB).

Results: For ROS assays, a significant reduction was noted from CDR to UHDR across all measured oxygen levels. The generation of H2O2 decreased when departing from physiologically relevant oxygen levels (1%-5%), with generation 30%-40% lower at UHDR. The DNA damage assay showed no trends in the SSB or DSB values with O2.

Conclusion: Examination of trends between ROS and DNA damage from factors such as oxygen can help elucidate FLASH mechanisms. The H2O2 yield has maximum yield at physiological oxygenation levels (1%-5%), and UHDR further diminishes yield. In DNA damage no trend was observed. It is possible that these mechanisms have underlying effects on the FLASH effect in vivo.

Advances in knowledge: This study is the first to directly compare radiation chemistry differences caused by UHDR to biologically relevant DNA damage in identical solutions.