New ct contrast

The latest X-ray photon-counting computed tomography (PCCT) for extremity allows multi-energy high-resolution (HR) imaging for tissue characterization and material decomposition. However, both radiation dose and imaging speed need improvement for contrast-enhanced and other studies. Despite the success of deep learning methods for 2D few-view reconstruction, applying them to HR volumetric reconstruction of extremity scans for clinical diagnosis has been limited due to GPU memory constraints, training data scarcity, and domain gap issues...

BACKGROUND: Contrast-enhanced mammography (CEM) is a promising technique. We evaluated the diagnostic potential of CEM performed immediately after contrast-enhanced computed tomography (CE-CT). METHODS: Fifty patients with breast cancer underwent first CE-CT and then CEM without additional contrast material injection. Two independent radiologists evaluated CEM images. The sensitivity of CEM for detecting index and additional malignant lesions was compared with that of mammography/ultrasonography by the McNemar test, using histopathology as a reference standard...

BACKGROUND: The use of 3D planning to guide corrective osteotomies of the lower extremity is increasing in clinical practice. The use of computer-tomography (CT) data acquired in supine position neglects the weight-bearing (WB) state and the gold standard in 3D planning involves the manual adaption of the surgical plan after considering the WB state in long-leg radiographs (LLR). However, this process is subjective and dependent on the surgeons experience. A more standardized and automated method could reduce variability and decrease costs...

PURPOSE: To evaluate the potential of volumetric imaging in predicting survival of advanced hepatocellular carcinoma (HCC) patients receiving immunotherapy. METHODS: Retrospective analysis included 40 patients with advanced HCC who received targeted immunotherapy. Baseline and follow-up contrast-enhanced abdominal computed tomography (CT) scans were analyzed. The largest tumor was chosen as the index lesion. Viable tumor volume (qViable) and percentage tumor viability (%Viability) were calculated...

We herein report an extremely rare case of intratumoral metastasis of colon cancer to chromophobe renal cell carcinoma. A 71-year-old woman was diagnosed with lung metastasis of sigmoid colon cancer and underwent sigmoid colon resection with D3 lymph node dissection. Preoperative contrast-enhanced computed tomography (CT) revealed a left renal tumor; however, colon resection was prioritized, and the renal tumor was placed under observation. Two years later, CT revealed enlargement of the left renal tumor, and laparoscopic partial left nephrectomy was performed 1 month later...

PURPOSE: Accurate staging of ovarian cancer is critical to guide optimal management pathways. North American guidelines recommend contrast-enhanced CT as the primary work-up for staging ovarian cancer. This meta-analysis aims to compare the diagnostic accuracy of contrast-enhanced CT alone to PET/CT for detecting abdominal metastases in patients with a new or suspected diagnosis of ovarian cancer. MATERIALS AND METHODS: A systematic review of MEDLINE, EMBASE, Scopus, the Cochrane Library, and the gray literature from inception to October 2022 was performed...

BACKGROUND AND PURPOSE: Balloon test occlusion (BTO) evaluates cerebral ischemic tolerance before internal carotid artery (ICA) sacrifice but carries risks like dissection and thrombosis. This study introduces a new approach using a patient-specific circle of Willis (COW) blood flow model, based on non-invasive quantitative MR angiography (qMRA) measurements, to predict the outcomes of BTO. METHODS: We developed individualized COW blood flow models for 43 patients undergoing BTO...

A new generation cone-beam computed tomography (CBCT) system with new hardware design and advanced image reconstruction algorithms is available for radiation treatment simulation or adaptive radiotherapy (HyperSight CBCT imaging solution, Varian Medical Systems-a Siemens Healthineers company). This study assesses the CBCT image quality metrics using the criteria routinely used for diagnostic CT scanner accreditation as a first step towards the future use of HyperSight CBCT images for treatment planning and target/organ delineations...

Neuroendocrine neoplasms (NENs) may be challenging to diagnose due to their small size and diverse anatomical locations. Hybrid imaging techniques, specifically positron emission tomography/computed tomography (PET/CT) and positron emission tomography/magnetic resonance imaging (PET/MRI), represent the current state-of-the-art for evaluating NENs. The preferred radiopharmaceuticals for NEN PET imaging are gallium-68 (68Ga) DOTA-peptides, which target somatostatin receptors (SSTR) overexpressed on NEN cells...

Plants are able to naturally graft or inosculate their trunks, branches and roots together, this mechanism is used by humans to graft together different genotypes for a range of purposes. Grafts are considered successful if functional vascular connections between the two genotypes occur. Various techniques can evaluate xylem connections across the graft interface. However, these methods are generally unable to assess the heterogeneity and three-dimensional (3D) structure of xylem vessel connections. Here we present the use of X-ray micro-computed tomography to characterize the 3D morphology of grafts of grapevine...

This study aimed to evaluate the clinical usefulness of zero-echo time(ZTE)-based magnetic resonance imaging(MRI)in planning an optimal surgical approach and applying ZTE for anatomical guidance during transcranial surgery. P atients who underwent transcranial surgery and carotid endarterectomy and for whom ZTE-based MRI and magnetic resonance angiography(MRA)data were obtained, were analyzed by creating ZTE/MRA fusion images and 3D-ZTE-based MRI models. We examined whether these images and models could be substituted for computed tomography imaging during neurosurgical procedures...

OBJECTIVE: To assess the safety and efficacy of percutaneous microwave ablation (MWA) in treating high-risk localized liver tumors in patients unable to undergo deep anesthesia because of comorbid lung diseases. METHODS: Between January 2019 and January 2022, percutaneous MWA procedures were performed for 50 liver tumors. These lesions were situated in close proximity to anatomically essential structures, with a maximum distance to surrounding structures being 10 mm...

BACKGROUND: Esophageal cancer is the seventh most frequently diagnosed cancer with a high mortality rate and the sixth leading cause of cancer deaths in the world. Early detection of esophageal cancer is very vital for the patients. Traditionally, contrast computed tomography (CT) was used to detect esophageal carcinomas, but with the development of deep learning (DL) technology, it may now be possible for non-contrast CT to detect esophageal carcinomas. In this study, we aimed to establish a DL-based diagnostic system to stage esophageal cancer from non-contrast chest CT images...

BACKGROUND: In radiotherapy, real-time tumor tracking can verify tumor position during beam delivery, guide the radiation beam to target the tumor, and reduce the chance of a geometric miss. Markerless kV x-ray image-based tumor tracking is challenging due to the low tumor visibility caused by tumor-obscuring structures. Developing a new method to enhance tumor visibility for real-time tumor tracking is essential. PURPOSE: To introduce a novel method for markerless kV image-based tracking of lung tumors via deep learning-based target decomposition...

OBJECTIVES: An evaluation of the effectiveness of a new computational system proposed for automatic classification, developed based on a Siamese network combined with Convolutional Neural Networks (CNNs), is presented. It aims to identify endodontic technical errors using Cone Beam Computed Tomography (CBCT). The study also aims to compare the performance of the automatic classification system with that of dentists. METHODS: One thousand endodontically treated maxillary molars sagittal and coronal reconstructions were evaluated for the quality of the endodontic treatment and the presence of periapical hypodensities by three board-certified dentists and by an oral and maxillofacial radiologist...

Kounis Syndrome (KS), a seldom-seen adverse reaction to iodine contrast agents, has an incidence that remains unclear. At present, there are no unified guidelines for managing KS either nationally or internationally. Ioversol, a new triiodinated hypotonic nonionic contrast agent, is commonly used in cardiovascular Computed Tomography (CT) and vascular imaging for diagnostic purposes. Its principal adverse reactions encompass fever, dermatological responses, convulsions, respiratory distress, hypersensitivity reactions including KS, and acute renal injury...

This study aims to investigate the maximum achievable dose reduction for applying a new deep learning-based reconstruction algorithm, namely the artificial intelligence iterative reconstruction (AIIR), in computed tomography (CT) for hepatic lesion detection. A total of 40 patients with 98 clinically confirmed hepatic lesions were retrospectively included. The mean volume CT dose index was 13.66 ± 1.73 mGy in routine-dose portal venous CT examinations, where the images were originally obtained with hybrid iterative reconstruction (HIR)...

OBJECTIVES: This study aimed to investigate radiomics based on primary nonsmall-cell lung cancer (NSCLC) and distant metastases to predict epidermal growth factor receptor (EGFR) mutation status. METHODS: A total of 290 patients (mean age, 58.21 ± 9.28) diagnosed with brain (BM, n = 150) or spinal bone metastasis (SM, n = 140) from primary NSCLC were enrolled as a primary cohort. An external validation cohort, consisting of 69 patients (mean age, 59.87 ± 7...

This study involves the synthesis, characterization, and spectral photon counting CT (SPCCT) imaging of gold nanoparticles tailored for enhancing the contrast of small cancer lesions. We used the modified Turkevich method to produce thiol-capped gold nanoparticles (AuNPs) at different concentrations (20, 15, 10, 5, 2.5, 1.25, 0.6 mg/ml). We thoroughly characterized the AuNPs using Transmission Electron Microscopy (TEM), X-ray diffraction spectroscopy (XRD), Dynamic Light Scattering (DLS), and UV-visible absorption spectroscopy...

A 2D plane strain extended finite element method (XFEM) model was developed to simulate three-point bending fracture toughness tests for human bone conducted in hydrated and dehydrated conditions. Bone microstructures and crack paths observed by micro-CT imaging were simulated using an XFEM damage model. Critical damage strains for the osteons, matrix, and cement lines were deduced for both hydrated and dehydrated conditions and it was found that dehydration decreases the critical damage strains by about 50%...