Search Results (505)

Lymphatic complications are becoming increasingly identified in cancer patients. Chylous ascites, chylothorax, lymphoceles, and lymphorrhea are common in cancer patients and can occur due to traumatic injury during surgeries or infiltrative effects of the tumors themselves. Recently, some anti-neoplastic medications are also thought to result in lymphatic complications. Management options range from conservative options to minimally invasive interventions, to surgical interventions with no standardized management strategy. Imaging techniques such as dynamic contrast-enhanced magnetic resonance lymphangiography and intranodal computed tomography or fluoroscopic lymphangiography are becoming more valuable in diagnosis and treatment planning. Minimally invasive interventions are rapidly evolving and have become the first-line intervention in most cases. Current research, however, faces limitations due to study design and variability. Standardized reporting and prospective studies are needed to advance the field. This review summarizes some of the latest literature on lymphatic interventions in cancer patients and provides reporting recommendations for future studies on lymphatic interventions. Full article

The Bawean deer (Axis kuhlii) is a small deer species endemic to the island of Bawean in Indonesia. The species is listed as critically endangered by the IUCN Red List. The current population is assessed to be less than 500 adults living in the wild. The cerebral arterial circle (also called the circle of Willis) is an anastomosis of arteries that supply the brain. The aim of this study was to describe the arterial vascularization of the brain in this species. Three different methods were used to obtain a complete arterial pattern of this region—latex injection, corrosion cast, and contrast-enhanced computed tomography. The arterial vascularization of the brain was described. The pattern of the arterial vessels supplying the brain in this species was similar to that described previously by ruminants. The vessel with the biggest lumen branching off from the circle of Willis was the medial cerebral artery. The basilar artery is a vessel with a narrow lumen and does not mediate the delivery of blood to the encephalon from the caudal side. The results of the study may be useful in creating veterinary protocols for treating vascular diseases in this species and further studies from the field of pathophysiology or pathology. Full article

Bacterial liver parenchymal infections in dogs are rarely documented, and their imaging characteristics are scarce in the veterinary literature, especially in Computed Tomography (CT). This retrospective multicentric study aimed to describe the CT characteristics of parenchymal bacterial liver infection and abscessation in dogs and compare them with the human literature. Twenty dogs met the inclusion criteria. All dogs, except one, showed discrete hepatic lesions consistent with pyogenic liver abscess (19/20). A single case showed diffuse liver changes, which was diagnosed with granulomatous bacterial hepatitis (1/20). Multifocal lesions were associated with the presence of abdominal pain (p = 0.023). CT characteristics of pyogenic liver abscesses in our study resemble those described in the human literature, with multifocal (14/19) or single (5/19), round or ovoid (19/19), hypoattenuating hepatic lesions, which are better visualised in post-contrast images. Pyogenic liver abscesses can also show features such as the “cluster sign” (8/19), transient arterial segmental enhancement (6/10), rim enhancement (6/19), and intralesional gas (4/19). Additional CT findings, such as local lymphadenomegaly (18/20), peritoneal fat stranding (14/20), and peritoneal fluid (13/20), are also commonly observed. Full article

Background/Objectives: Spinal metastases are a frequent and serious complication in cancer patients, often causing severe pain, instability, and neurological deficits. Thermal ablation techniques such as radiofrequency ablation (RFA), microwave ablation (MWA), and cryoablation (CA) have emerged as minimally invasive treatments. These techniques rely on precise imaging guidance to effectively target lesions while minimizing complications. This systematic review aims to compare the efficacy of different imaging modalities—computed tomography (CT), magnetic resonance imaging (MRI), fluoroscopy, and mixed techniques—in guiding thermal ablation for spinal metastases, focusing on success rates and complications. Methods: A systematic literature search was conducted across PubMed, OVID, Google Scholar, and Web of Science databases, yielding 3733 studies. After screening, 51 studies met the eligibility criteria. Data on success rates, tumor recurrence, complications, and patient outcomes were extracted. Success was defined as no procedure-related mortality, tumor recurrence or expansion, or nerve injury. This systematic review followed PRISMA guidelines and was registered with PROSPERO (ID: CRD42024567174). Results: CT-guided thermal ablation demonstrated high success rates, especially with RFA (75% complete success). Although less frequently employed, MRI guidance showed lower complication rates and improved soft-tissue contrast. Fluoroscopy-guided procedures were effective but had a higher incidence of nerve injury and incomplete tumor control. Mixed imaging techniques, such as CBCT-MRI fusion, showed potential for reducing complications and improving targeting accuracy. Conclusions: CT remains the most reliable imaging modality for guiding thermal ablation in spinal metastases, while MRI provides enhanced safety in complex cases. Fluoroscopy, although effective for real-time guidance, presents limitations in soft-tissue contrast. Mixed imaging techniques like CBCT-MRI fusion offer promising solutions by combining the advantages of both CT and MRI, warranting further exploration in future studies. Full article

Catheter ablation therapy, which is a treatment for atrial fibrillation (AF), has a higher recurrence rate as AF duration increases. Compared to paroxysmal AF (PAF), sustained AF is known to cause progressive anatomic remodeling of the left atrium, resulting in enlargement and shape changes. In this study, we used contrast-enhanced computed tomography (CT) to classify atrial fibrillation (AF) into paroxysmal atrial fibrillation (PAF) and long-term persistent atrial fibrillation (LSAF), which have particularly different recurrence rates after catheter ablation. Contrast-enhanced CT images of 30 patients with PAF and 30 patients with LSAF were input into six pretrained convolutional neural networks (CNNs) for the binary classification of PAF and LSAF. In this study, we propose a method that can recognize information regarding the body axis direction of the left atrium by inputting five slices near the left atrium. The classification was visualized by obtaining a saliency map based on score-class activation mapping (CAM). Furthermore, we surveyed cardiologists regarding the classification of AF types, and the results of the CNN classification were compared with the results of physicians’ clinical judgment. The proposed method achieved the highest correct classification rate (81.7%). In particular, models with shallow layers, such as VGGNet and ResNet, are able to capture the overall characteristics of the image and therefore are likely to be suitable for focusing on the left atrium. In many cases, patients with an enlarged left atrium tended to have long-lasting AF, confirming the validity of the proposed method. The results of the saliency map and survey of physicians’ basis for judgment showed that many patients tended to focus on the shape of the left atrium in both classifications, suggesting that this method can classify atrial fibrillation more accurately than physicians, similar to the judgment criteria of physicians. Full article

Background/Objective: Orbital diseases often require precise measurements of eyeball volume, optic nerve sheath diameter (ONSD), and apex-to-eyeball distance (AED) for accurate diagnosis and treatment planning. This study aims to automate and optimize these measurements using advanced deep learning segmentation techniques on orbital Computed Tomography (CT) scans. Methods: Orbital CT datasets from individuals of various age groups and genders were used, with annotated masks for the eyeball and optic nerve. A 2D attention U-Net architecture was employed for segmentation, enhanced with slice-level information embeddings to improve contextual understanding. After segmentation, the relevant metrics were calculated from the segmented structures and evaluated for clinical applicability. Results: The segmentation model demonstrated varying performance across orbital structures, achieving a Dice score of 0.8466 for the eyeball and 0.6387 for the optic nerve. Consequently, eyeball-related metrics, such as eyeball volume, exhibited high accuracy, with a root mean square error (RMSE) of 1.28–1.90 cm³ and a mean absolute percentage error (MAPE) of 12–21% across different genders and age groups. In contrast, the lower accuracy of optic nerve segmentation led to less reliable measurements of optic nerve sheath diameter (ONSD) and apex-to-eyeball distance (AED). Additionally, the study analyzed the automatically calculated measurements from various perspectives, revealing key insights and areas for improvement. Conclusions: Despite these challenges, the study highlights the potential of deep learning-based segmentation to automate the assessment of ocular structures, particularly in measuring eyeball volume, while leaving room for further improvement in optic nerve analysis. Full article

Background and Objective: High-flow pancreaticoduodenal artery (PDA) aneurysms secondary to celiac trunk occlusion or stenosis have a high risk of rupture. Embolization offers a less invasive alternative to surgery. We evaluated the effectiveness and safety of retrograde embolization via the superior mesenteric artery of high-flow PDA aneurysms without celiac trunk revascularization. Methods: This retrospective bicentric study included patients who underwent embolization of high-flow PDA aneurysms due to significant celiac trunk stenosis or occlusion. All patients underwent pre-interventional dynamic contrast-enhanced computed tomography. Retrograde embolization was performed using microcoils and/or liquid agents without celiac trunk revascularization. Follow up involved clinical and radiological assessment at one month. Technical and clinical success were evaluated, and complications were categorized as minor or major. Results: Twenty-three patients (mean age 65 ± 14 years; 52% male) were included. Emergency embolization was required in 12 patients (52%). The technical success rate was 100%. Patients were monitored for a median of 16 months. Clinical success was 87%. No hemorrhagic recurrences were observed. Minor complications occurred in two cases. One major complication involved splenic infarction due to glue migration, requiring splenectomy and intensive unit care admission. Conclusions: Retrograde embolization of high-flow PDA aneurysms is effective and safe without needing celiac trunk revascularization. Full article

Background/Objectives: Photon-counting detector computed tomography (PCD-CT) offers energy-resolved CT data with enhanced resolution, reduced electronic noise, and improved tissue contrast. This study aimed to evaluate the visibility of intracranial perforating arteries on ultra-high-resolution (UHR) CT angiography (CTA) on PCD-CT. Methods: A retrospective analysis of intracranial UHR PCD-CTA was performed for 30 patients. The image quality from four UHR PCD-CTA reconstruction methods [kernel Hv40 and Hv72, with and without quantum iterative reconstruction (QIR)] was assessed for the lenticulostriate arteries (LSAs) and pontine arteries (PAs). A subjective evaluation included peripheral visibility, vessel sharpness, and image noise, while objective analysis focused on the signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR). Results: Peripheral LSAs were well visualized across all reconstruction methods, with no significant differences between them. Vessel sharpness and image noise varied significantly (p < 0.0001); sharper LSAs and more noise were seen with kernel Hv72 compared to kernel Hv40 (p < 0.05). A similar pattern was observed for PAs, though peripheral visibility was lower than that for LSAs. The SNR and CNR were the highest in the presence of kernel Hv72 with QIR, and lowest with kernel Hv72 without QIR, compared to kernel Hv40 (p < 0.05). Conclusions: UHR PCD-CTA provided a good visualization of the intracranial perforating arteries, particularly LSAs. The vessel sharpness and image noise varied by reconstruction method, in which kernel Hv72 with QIR offered the optimal visualization. Full article

Background: Recent advancements in computed tomography (CT), notably in photon-counting CT (PCCT), are revolutionizing the medical imaging field. PCCT’s spectral imaging can better visualize tissues based on their material properties. This research aims to establish a fundamental approach for the in vivo visualization of intracranial cerebrospinal fluid (CSF) using PCCT. Methods: PCCT was integrated to distinguish the CSF within the intracranial space with spectral imaging. In this study, we analyzed monoenergetic +67 keV reconstructions alongside virtual non-contrast and iodine phase images. This approach facilitated the assessment of the spectral characteristics of CSF in patients who did not present with intra-axial pathology or inflamation. Results: Our findings illustrate PCCT’s effectiveness in providing distinct and clear visualizations of intracranial CSF structures, building a foundation. The signal-to-noise ratio was quantified across all measurements, to check in image quality. Conclusions: PCCT serves as a robust, non-invasive platform for the detailed visualization of intracranial CSF. This technology is promising in enhancing diagnostic accuracy through different conditions. Full article

Head and neck cancer represents the seventh most common neoplasm worldwide, with squamous cell carcinoma being the most represented histologic variant. The rising incidence of the neoplastic pathology of this district, coupled with the drastic changes in its epidemiology over the past decades, have posed significant challenges to physicians worldwide in terms of diagnosis, prognosis, and treatment. In order to meet these challenges, a considerable amount of effort has been spent by the authors of the recent literature to explore new technologies and their possible employment for the better diagnostic and prognostic definition of head and neck squamous cell carcinoma (HNSCC). Among these technologies, a growing interest has been gathering around the possible applications of dual-energy computed tomography (DECT) in head and neck pathology. Dual-energy computed tomography (DECT) utilizes two distinct X-ray energy spectra to obtain two datasets in a single scan, allowing for material differentiation based on unique attenuation profiles. DECT offers key benefits such as enhanced contrast resolution, reduced beam-hardening artifacts, and precise iodine quantification through monochromatic reconstructions. It also creates material decomposition images, like iodine maps, aiding in tumor characterization and therapy assessment. This paper aims to summarize recent findings on the use of DECT in HNSCC, providing a comprehensive overview to aid further research and exploration in the field. Full article

Objectives: This study aimed to analyze the usage patterns and hypersensitivity reaction (HSR) profiles of six nonionic iodinated contrast media (ICMs) used in computed tomography (CT) to enhance patient safety and inform evidence-based contrast agent selection. Methods: We retrospectively reviewed 248,209 CT scans obtained between January 2020 and December 2022. Six ICMs (iomeprol, iohexol, ioversol, iopromide, iodixanol, and iobitridol) were compared on the basis of their usage rates, HSR incidence, and severity. This study also evaluated the impact of premedication protocol reinforcement and assessed the quarterly HSR rates. Results: Among the 248,209 CT scans, 1603 (0.65%) were associated with HSRs. Most HSRs were mild (86.2%), with moderate (10.9%) and severe (2.9%) reactions being less common. Four ICMs were used as first-line agents and two ICMs were used as second-line agents. The second-line agents, iobitridol and iodixanol, exhibited 7–8 times higher HSR rates compared to the first-line agents. A modified premedication protocol implemented in mid-2022 significantly reduced the incidence of moderate HSRs (p = 0.0075). The quarterly analysis indicated a trend in higher HSR rates in the first quarter and a statistically significant increase in severe HSRs in the third quarter (p = 0.033). Conclusions: These findings highlight the importance of tailored premedication protocols and a 7–8 times higher rate of HSR with second-line agents in contrast-enhanced imaging. Future research should focus on elucidating the mechanisms underlying these variations to further refine contrast agent selection and management strategies. Full article

Evaluating masses of mesenchymal and epithelial origin accurately using computed tomography (CT) has several limitations in dogs. This study aimed to present dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) parameters to aid in improving the diagnostic accuracy for masses of mesenchymal and epithelial origin in veterinary medicine. Four dogs diagnosed with benign and malignant soft tissue sarcoma (STS), cholesteatoma, or squamous cell carcinoma underwent CT, conventional MRI, and DCE-MRI. K^trans is a quantitative DCE-MRI parameter representing vascular permeability and tissue perfusion and is related to the potential for malignancy. Hemangiopericytomas (Grade II, STS) showed a higher K^trans than normal muscle tissue and myxosarcoma (Grade I, STS). Squamous cell carcinoma (a malignant epithelial tumor) also showed a higher K^trans than normal muscle tissue and cholesteatoma (a mass originating from keratinized squamous epithelium). These results suggest that higher K^trans values may indicate a greater likelihood that a lesion is more malignant. In conclusion, K^trans might be useful as a biomarker for evaluating the malignancy of a mass and as an indicator of lesion characteristics in dogs. Full article

Purpose: The current guidelines for initial cross-sectional imaging in pediatric lymphomas involve computed tomography (CT) of the chest, abdomen, and pelvis. However, whole-body magnetic resonance imaging (MRI) can be favored over CT for diagnosing and staging the disease, given its lack of ionizing radiation and its higher tissue contrast. Imaging characteristics of lymphoid tissue on MRI include a high T2/short tau inversion recovery (STIR) signal. A low or intermediate signal of lymphadenopathy on T2 and STIR images is an unexpected finding, noted anecdotally in nodular sclerosing Hodgkin lymphoma. This signal may be characteristic of a histological subtype of the disease and, if confirmed, could potentially be used to avoid biopsy. In this study, we aimed to review signal characteristics of lymphadenopathy in patients with biopsy-confirmed nodular sclerosing Hodgkin lymphoma. Methods: We undertook a retrospective review of relevant MR studies of patients with nodular sclerosing Hodgkin lymphoma. Studies were reviewed by an experienced pediatric radiologist regarding lymph node signal, especially on T2/STIR. Results: Eleven children with nodular sclerosing Hodgkin lymphoma were included. Median age at the time of MRI was 14.3 (IQR: 13.9–16.1) years, and nine were boys. Five patients showed some lymphadenopathy with a low T2/STIR signal, and six showed an intermediate T2/STIR signal. Central gadolinium non-enhancement was observed in four patients. Conclusions: All eleven patients (100%) with a diagnosis of nodular sclerosing Hodgkin lymphoma showed some lymphadenopathy with a low or intermediate T2/STIR signal, and five children (45.5%) showed a frank low signal of some lymphadenopathy, a feature which may prove to be a biomarker for this histology. Full article

Cardiovascular diseases (CVD) are a leading cause of death. The most notable cause of CVD is an atherosclerotic plaque. The aim of this review is to provide an overview of different diagnostic methods for atherosclerotic plaque relevant to the assessment of cardiovascular risk. The methods can be divided into invasive and non-invasive. This review focuses on non-invasive with attention paid to ultrasonography, contrast-enhanced ultrasonography, intravascular ultrasonography, and assessment of intima-media complex, coronary computed tomography angiography, and magnetic resonance. In the review, we discuss a number of Artificial Intelligence technologies that support plaque imaging. Full article

Objectives: Subarachnoid Hemorrhage (SAH) is a serious neurological emergency case with a higher mortality rate. An automatic SAH detection is needed to expedite and improve identification, aiding timely and efficient treatment pathways. The existence of noisy and dissimilar anatomical structures in NCCT images, limited availability of labeled SAH data, and ineffective training causes the issues of irrelevant features, overfitting, and vanishing gradient issues that make SAH detection a challenging task. Methods: In this work, the water waves dynamic factor and wandering strategy-based Sand Cat Swarm Optimization, namely DWSCSO, are proposed to ensure optimum feature selection while a Parametric Rectified Linear Unit with a Stacked Convolutional Neural Network, referred to as PRSCNN, is developed for classifying grades of SAH. The DWSCSO and PRSCNN surpass current practices in SAH detection by improving feature selection and classification accuracy. DWSCSO is proposed to ensure optimum feature selection, avoiding local optima issues with higher exploration capacity and avoiding the issue of overfitting in classification. Firstly, in this work, a modified region-growing method was employed on the patient Non-Contrast Computed Tomography (NCCT) images to segment the regions affected by SAH. From the segmented regions, the wide range of patterns and irregularities, fine-grained textures and details, and complex and abstract features were extracted from pre-trained models like GoogleNet, Visual Geometry Group (VGG)-16, and ResNet50. Next, the PRSCNN was developed for classifying grades of SAH which helped to avoid the vanishing gradient issue. Results: The DWSCSO-PRSCNN obtained a maximum accuracy of 99.48%, which is significant compared with other models. The DWSCSO-PRSCNN provides an improved accuracy of 99.62% in CT dataset compared with the DL-ICH and GoogLeNet + (GLCM and LBP), ResNet-50 + (GLCM and LBP), and AlexNet + (GLCM and LBP), which confirms that DWSCSO-PRSCNN effectively reduces false positives and false negatives. Conclusions: the complexity of DWSCSO-PRSCNN was acceptable in this research, for while simpler approaches appeared preferable, they failed to address problems like overfitting and vanishing gradients. Accordingly, the DWSCSO for optimized feature selection and PRSCNN for robust classification were essential for handling these challenges and enhancing the detection in different clinical settings. Full article