This study aimed to establish and validate CT-based radiomics models combined with clinical data to identify Fungal Co-Infections (FCI) in immunocompromised patients with Viral Pneumonia (VP). A total of 406 patients (VP: 283; FCI: 123) from two hospitals were retrospectively enrolled and divided into training (n = 218), testing (n = 96), and external validation (n = 92) cohorts. Radiomics features were extracted from chest CT images. Feature selection was performed using the Least Absolute Shrinkage And Selection Operator (LASSO), and logistic regression models were built with clinical, radiomics, and combined inputs. Model performance was assessed using the Area Under the Receiver Operating Characteristic Curve (AUC), calibration, and Decision Curve Analysis (DCA). The combined model achieved AUCs of 0.981 (95% CI: 0.959 - 0.992), 0.845 (95% CI: 0.762 - 0.950), and 0.835 (95% CI: 0.715 - 0.937) in the training, testing, and external validation cohorts, respectively, and consistently outperformed clinical-only and radiomics-only models. The model identified characteristic clinical and imaging differences between VP and FCI, including higher neutrophil counts, lower lymphocyte counts, and imaging markers such as reversed halo sign and solid nodules in FCI. These findings support the potential of radiomics as a noninvasive tool for early detection and risk stratification. CT-based radiomics provides an effective approach for differentiating VP and FCI in immunocompromised patients, with potential to improve diagnosis and clinical management.

Sacral Insufficiency Fractures (SIFs) are a common yet frequently misdiagnosed late complication following pelvic radiotherapy for cervical cancer. Accurate differentiation from bone metastases is crucial to avoid unnecessary interventions. While MRI is sensitive for early marrow edema, integrated 18F-FDG PET/CT offers a unique simultaneous assessment of bone metabolism and systemic tumor status. However, comprehensive studies detailing the qualitative and quantitative PET/CT characteristics of post-radiotherapy SIFs are lacking. This study aims to systematically define these features and establish their discriminative value. In this retrospective study, we analyzed 32 cervical cancer patients who developed SIFs following pelvic radiotherapy and underwent 18F-FDG PET/CT imaging between January 2018 and January 2024. Diagnosis was based on characteristic radiologic findings, clinical correlation, and a minimum 12-month follow-up. Qualitative (fracture patterns, FDG uptake morphology) and quantitative (SUVmax, SUR-BP ratio, CT densitometry) parameters on 18F-FDG PET/CT were evaluated. SIFs predominantly occurred in postmenopausal women (93.7%, 30/32) at a median of 14 months post-radiotherapy. Sacral involvement was observed as follows: unilateral ala (53.1%, 17/32), bilateral alae (37.5%, 12/32), and extension to the sacral body (9.4%, 3/32). The affected segments were primarily located at S1-S3. Concomitant pelvic fractures were also frequently identified, including pubic (28.1%, 9/32), iliac (25%, 8/32), and bilateral L5 transverse process fractures (6.2%, 2/32). Common CT findings included ill-defined osteosclerosis near the sacroiliac joint (87.5%, 28/32) and linear or curvilinear hypoattenuating fracture lines (68.7%, 22/32). PET revealed characteristic mild, diffuse/patchy FDG uptake parallel to the sacroiliac joint (96.8%, 31/32) with low metabolic activity (mean SUVmax 2.45±0.74, mean SUR-BP 1.46±0.38). Quantitative CT confirmed significant osteopenia within the radiation field (mean HU 36.8±28.6 vs. 78.0±37.3 outside, p<0.001). Post-radiation SIFs predominantly affect postmenopausal cervical cancer patients due to radiotherapy-induced osteoporosis and bone vulnerability. These fractures often present with nonspecific pain and require differentiation from bone metastases, for which 18F-FDG PET/CT is essential due to its ability to detect characteristic metabolic patterns and associated osteoporotic changes. Key diagnostic features include linear or curvilinear hypoattenuating fracture lines, mild diffuse/patchy FDG uptake parallel to the sacroiliac joint, and background osteoporotic changes within radiation fields. Integrated PET/CT outperformed single-modality imaging by enabling simultaneous assessment of bone metabolism and systemic tumor status, a critical advantage over MRI (superior for marrow edema but unable to evaluate systemic disease) and standalone CT (lacking metabolic discrimination of benign vs malignant lesions). Early recognition of SIFs through integrated imaging is critical to avoid misdiagnosis and unnecessary invasive procedures, thereby guiding appropriate conservative management. SIFs represent a prevalent post-radiotherapy complication in cervical cancer patients, with a particular predilection for postmenopausal women. 18F-FDG PET/CT demonstrates high diagnostic reliability for diagnosing SIFs, which typically present as linear fractures parallel to the sacroiliac joints on a background of osteoporotic changes, accompanied by mild diffuse or patchy FDG uptake and frequently co-occurring with pelvic fractures at other sites. Integrated PET/CT is crucial for early recognition, preventing misdiagnosis as metastasis, and guiding appropriate conservative management.

Mandibular third molars are the most frequently impacted teeth. The proximity of impacted third molars to the inferior alveolar canal requires particular consideration during extraction. Hence, we aimed to compare the diagnostic accuracy of CBCT and OPG using radiographic signs of Rood and Shebab's and find out the risk of mandibular nerve injury. A prospective study was conducted in 50 subjects. All patients underwent digital OPG evaluation based on Winter's classification of impacted teeth and Rood and Shehab's classification of seven radiographic signs. Cases with any positive finding were examined using CBCT to assess the positioning of the mandibular canal and alveolar ridge. Horizontal and mesioangular impactions were at higher risk of inferior alveolar nerve damage (p< 0.01 and p < 0.05) along with lingual position of canal (p<0.001), Darkening of roots, interruption of the mandibular canal (p<0.001), and diversion of the mandibular canal (p< 0.04) were associated with a higher risk of damage during extractions. The current study confirmed that horizontal and mesioangular impactions showed a significant association with the absence of cortication between the mandibular canal and third molar roots, indicating a high risk of nerve injury, similar to other studies. Also, CBCT has been proven to be the best imaging modality owing to its high diagnostic accuracy. In the current study, CBCT was considered the gold standard, and diagnostic accuracy was higher than OPG. There was fair agreement about the mesioangular and horizontal impaction and their proximity to the mandibular nerve.

Colorectal tumors are common, and magnetic resonance imaging (MRI) with diffusion-weighted imaging (DWI), apparent diffusion coefficient (ADC), and contrast-enhanced sequences can assist in distinguishing benign from malignant lesions. However, certain atypical cases exist in which malignancies do not exhibit restricted water molecule diffusion. We present the case of a 66-year-old male with moderately differentiated rectal adenocarcinoma showing heterogeneous diffusion restriction on MRI. The tumor surface demonstrated diffusion restriction (hyperintense on DWI, hypointense on ADC), whereas the base did not. Quantitative ADC analysis showed mean values of 0.82 × 10-3 mm2/s at the surface and 1.36 × 10-3 mm2/s at the base. This case highlights that regions with lower cellularity in moderately differentiated adenocarcinoma may lack diffusion restriction. Correlating imaging findings with histopathological results is essential to prevent diagnostic misinterpretation.

MR-HSG offers radiation-free multiplanar visualization for evaluating fallopian tube patency, but persistent challenges in achieving consistent high-quality visualization, particularly in smaller-diameter segments, limit clinical adoption. Previous studies modifying contrast viscosity achieved only partial improvements. This study aimed to use standardized phantom models simulating the female pelvis to systematically explore factors affecting MR-HSG image quality and provide evidence-based guidance for protocol optimization. Nine standardized phantoms were constructed using agar gel with embedded tubes of three inner diameters (4mm, 2mm, and 1.4mm) representing ampullary, isthmic, and interstitial segments. Three contrast agents with different viscosities were tested: gadolinium-saline (2.6 mPa·s), gadolinium-iopromide (7.9 mPa·s), and gadolinium-iodixanol (8.7 mPa·s) at 37°C. T1-weighted 3D-mDIXON sequences with keyhole technology were employed on a 1.5T MRI scanner. Signal intensity measurements and qualitative assessment (good/fair/poor) were performed by blinded evaluators. No significant differences in signal intensity were found between contrast agents of different viscosities (P>0.05). However, tube diameter significantly affected imaging quality (P<0.001). The 4 mm tubes showed the highest SI (5554.49±1042) with 100% good imaging, the 2 mm tubes showed intermediate SI (733.65±78.76) with 100% fair imaging, and the 1.4 mm tubes showed the lowest SI (444.55±34.70) with 100% poor imaging across all contrast agents. Fallopian tube inner diameter is the primary determinant of MR-HSG imaging quality, while contrast agent viscosity (within 2.6-8.7 mPa·s range) shows no significant effect under controlled conditions. This study provides foundational data for understanding physical factors affecting MRHSG quality and suggests that anatomical factors may be more critical than contrast properties for clinical protocol optimization, potentially reducing procedure costs while maintaining diagnostic quality. Optimizing spatial resolution to minimize partial volume effects may be more beneficial than modifying contrast agent properties for improving visualization of narrow fallopian tube segments. Clinical validation studies are warranted to confirm these findings in the complex in vivo environment.

Early detection of breast cancer and accurate assessment of lesions are key goals of imaging evaluation. Ultrasound is widely used, but its diagnostic performance is influenced by complex image features, noise, and operator experience. Reducing operator dependence and improving accuracy are critical clinical issues. In this retrospective study, 7,025 breast ultrasound images from our center were annotated based on pathology and split into training, validation, and internal test sets (8:1:1). The Dataset of Breast Ultrasound Images was used as the external test set. YOLO-v7 and YOLO-v8 models were trained through transfer learning after data augmentation and balancing the classes. Performance was compared on internal and external test sets and was evaluated against a reader study. YOLO-v7 and YOLO-v8 reached optimal performance at epochs 294 and 135, respectively. YOLO-v7 slightly outperformed YOLO-v8 on the internal test set, while YOLO-v8 achieved higher accuracy, recall, specificity, precision, and F1 score on the external test set. Both models showed significantly higher accuracy, specificity, and precision than the senior radiologist, with YOLO-v8 achieving a significantly higher F1 score. YOLO-v8 demonstrated better generalization due to its anchor-free mechanism and deeper architecture, while YOLO-v7 showed signs of overfitting. Both models outperformed the junior radiologist and approached or exceeded the diagnostic performance of the senior radiologist, indicating potential to assist less experienced readers. YOLO-v7 and YOLO-v8 effectively classified breast lesions. YOLO-v8 showed faster convergence and higher diagnostic efficiency, suggesting strong potential for clinical application.

Pseudomyogenic Hemangioendothelioma (PMHE), also known as epithelioid sarcoma-like hemangioendothelioma, is a rare, indolent, low-grade vascular tumor. It typically presents as firm cutaneous nodules, with a predilection for the lower extremities and a male predominance. While numerous cases have been reported in pathology literature, detailed radiologic descriptions, particularly of soft tissue origins, are scarce. This report aims to bridge this gap by presenting a rare case of PMHE with comprehensive imaging findings. We report on a 67-year-old male who presented with painful, palpable papules on his right buttock. MRI revealed multifocal dermal nodules demonstrating low signal intensity on T1-weighted images and high signal intensity with a distinctive peripheral high-signal halo on T2-weighted images. Notably, T1 gadolinium fat-saturated sequences exhibited marked enhancement with a characteristic peripheral rim enhancement pattern. The lesions were confined to the cutaneous layer. Initial radiological differentials included post-inflammatory granuloma and sarcoma. Histopathological examination confirmed PMHE. PET/CT demonstrated no evidence of systemic metastasis, and the patient has remained recurrence-free for two years following surgery. This report highlights a rare case of cutaneous PMHE and details its distinctive MRI features, particularly the peripheral rim enhancement. Given its rarity and often non-specific clinical and imaging presentations, there is a significant potential for misdiagnosis. Therefore, it is crucial for radiologists to be aware of PMHE and familiarize themselves with its characteristic radiological patterns to facilitate accurate, timely diagnosis and ensure appropriate patient management.

This study aimed to evaluate the prognostic significance of dynamic cadmium-zinc-telluride (CZT) cardiac-dedicated single photon emission computed tomography (SPECT)-derived myocardial flow reserve (MFR) in patients with suspected or confirmed coronary artery disease (CAD) and normal myocardial perfusion. A consecutive cohort of patients who completed dynamic myocardial perfusion imaging and routine myocardial perfusion imaging (MPI) using CZT cardiac-dedicated SPECT were selected and followed up for at least 24 months to determine the occurrence of major adverse cardiac events (MACEs). Patients were divided into groups with no MACEs and MACEs. Differences between the two groups in baseline characteristics, semiquantitative, and quantitative parameters were compared. Cox regression analysis was performed to identify predictive factors associated with MACEs. Kaplan-Meier survival curves were plotted, and log-rank tests were performed to compare the incidence of MACEs between the normal MFR group and the reduced MFR group. A total of 369 patients with negative routine MPI results were included in this study, with an average age of 61.82±8.68 years (113 males and 256 females). The median follow-up duration was 30 months [IQR (25, 34)], during which 73 patients experienced MACEs. The incidence of MACEs was significantly higher in patients with reduced MFR than in those with normal MFR (P<0.05). Cox regression analysis identified reduced MFR as an independent predictor of MACEs (HR: 2.076, 95%CI: 1.174-3.669, P=0.012). The proportion of patients diagnosed with obstructive coronary artery disease (OCAD) was significantly higher in the MACE group compared to the no MACE group (P<0.05). These findings provide critical clinical insights, particularly for patients in whom myocardial ischemia is not detected via traditional semiquantitative MPI analysis. CZT cardiac-dedicated SPECT, which enables quantitative assessment of myocardial blood flow, serves as a more precise tool for early CAD diagnosis and prognostic evaluation. This underscores the role of CZT cardiac-dedicated SPECT in assessing myocardial ischemia and prognosis among patients with negative conventional MPI, helping to identify high-risk individuals that conventional MPI may overlook. By leveraging CZT cardiac-dedicated SPECT to obtain absolute quantitative myocardial blood flow (MBF) and MFR, myocardial perfusion is quantified more accurately, thereby overcoming the limitations of traditional MPI and providing a more reliable basis for early clinical diagnosis and treatment. MFR measured with CZT cardiac-dedicated SPECT can effectively predict the prognosis of patients with suspected or confirmed CAD and normal MPI. Reduced MFR is significantly associated with a higher incidence of MACEs, and MFR reduction is an independent predictor of MACEs.

Life-threatening respiratory conditions such as COVID-19 and pneumonia demand rapid and accurate diagnosis. Chest X-rays (CXR) are widely used due to their accessibility and cost-effectiveness, but interpreting them remains clinically challenging, especially with overlapping radiological features. The proposed VSAG-HDL Net, a novel hybrid deep learning framework designed to enhance the accuracy and interpretability of CXR-based diagnosis. The architecture integrates a Variational Spatial Attention Fusion U-Net (VSA-FU-Net) for lesion segmentation and a Sharpened Cosine Similarity (SCS) Network for disease classification. A dataset of 21,165 CXR images from the Radiography Database was used. Segmentation performance was evaluated using Dice Similarity Coefficient (DSC) and Intersection over Union (IoU), while classification performance was assessed via accuracy metrics. The VSA-FU-Net achieved a DSC of 90% and an IoU of 95%, indicating high precision in localizing lesions of varying shapes and sizes. The classification module reached an overall accuracy of 95.5%, outperforming traditional CNN-based methods such as CoroDet (+4.3%), CovXNet (+5.3%), and ShuffleNet (+3.9%). Although slightly less accurate than DenseNet+VIT (-2.0%) and DenseNet+VIT+GAP (-2.3%), the proposed framework offers competitive accuracy with significantly reduced model complexity. The elimination of redundant feature extraction and the integration of spatial attention enhance both the diagnostic performance and computational efficiency, making the framework suitable for real-world clinical settings. VSAG-HDL Net provides a robust, interpretable, and resource-efficient solution for chest disease detection in CXR. Its clinical integration can support early and accurate diagnostic decision-making, particularly in resource-limited environments.

Anterior Inferior Cerebellar Artery (AICA) aneurysms are rare, accounting for 0.1% to 0.5% of posterior circulation aneurysms. They often present with diverse morphologies and clinical symptoms, challenging diagnosis and management. We report three cases of AICA aneurysms with distinct clinical presentations and management strategies. Case 1: A 56-year-old male presented with chronic headache and left hemiparesis. MRI and 3D TOF MRA revealed a fusiform AICA aneurysm compressing the pons, treated with microsurgical clipping via anterior petrosectomy, resulting in a favorable outcome (mRS score of 0). Case 2: A 26-year-old female with a sudden-onset sentinel headache had a wide-neck saccular aneurysm of the right AICA confirmed by DSA. A posterior petrosectomy approach with clipping was performed, achieving complete aneurysm exclusion without complications (mRS score of 0). Case 3: A 21-year-old male with an incidentally detected saccular aneurysm underwent DSA and 3D angio-CT, confirming a wide-neck saccular aneurysm in the AICA territory. Microsurgical clipping via anterior petrosectomy was successful, with no residual lesion (mRS score of 0). Microsurgical clipping remains a viable option for managing wide-neck and fusiform AICA aneurysms, particularly those unsuitable for endovascular techniques. Advanced imaging modalities and tailored cranial base approaches are crucial for optimizing outcomes. Further studies are needed to refine management strategies for these rare aneurysms.