Intravenous contrast-enhanced cone beam computed tomography (IVCBCT) of intrahepatic tumors and vessels.
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ABSTRACT:
SUBMITTER: Eccles CL
PROVIDER: S-EPMC5506729 | biostudies-other | 2016 Jan-Mar
REPOSITORIES: biostudies-other
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Project description:BackgroundTreatment of nasal tumors in dogs is associated with high morbidity and reliable prognostic factors are lacking. Dynamic contrast-enhanced computed tomography (DCECT) can be used to assess tumor perfusion.ObjectivesTo assess perfusion parameters of nasal tumors (correlating with tumor type) before and during radiotherapy (RT) and find potential correlation with survival.AnimalsTwenty-four client-owned dogs with nasal tumors, including 16 epithelial tumors and 8 sarcomas.MethodsProspective cross-sectional study. All dogs had baseline DCECT to assess fractional vascular volume (BV), blood flow (BF), and transit time (TT). Thirteen dogs had repeat DCECT after 12 Gy of megavoltage RT. Survival times were calculated.ResultsMedian BV was 17.83 mL/100 g (range, 3.63-66.02), median BF was 122.63 mL/100 g/minute (range, 23.65-279.99), and median TT was 8.91 seconds (range, 4.57-14.23). Sarcomas had a significantly lower BF than adenocarcinomas (P = .002), carcinomas (P = .01), and other carcinomas (P = .001), and significantly lower BV than adenocarcinomas (P = .03) and other carcinomas (P = .004). Significant associations were found between epithelial tumors and sarcoma for change in tumor volume (P = .01), width (P = .004), and length (P = .02) in that epithelial tumors decreased in volume whereas sarcomas increased in volume. Perfusion parameters were not correlated with survival.Conclusions and clinical importanceNasal sarcomas have lower BV and BF than nasal carcinomas, and sarcomas have a lower size reduction than carcinomas early on during RT. Baseline results and changes in perfusion parameters may not be correlated with survival.
| S-EPMC10229329 | biostudies-literature
Project description:ObjectiveTo present and validate an open-source fully automated landmark placement (ALICBCT) tool for cone-beam computed tomography scans.Materials and methodsOne hundred and forty-three large and medium field of view cone-beam computed tomography (CBCT) were used to train and test a novel approach, called ALICBCT that reformulates landmark detection as a classification problem through a virtual agent placed inside volumetric images. The landmark agents were trained to navigate in a multi-scale volumetric space to reach the estimated landmark position. The agent movements decision relies on a combination of DenseNet feature network and fully connected layers. For each CBCT, 32 ground truth landmark positions were identified by 2 clinician experts. After validation of the 32 landmarks, new models were trained to identify a total of 119 landmarks that are commonly used in clinical studies for the quantification of changes in bone morphology and tooth position.ResultsOur method achieved a high accuracy with an average of 1.54 ± 0.87 mm error for the 32 landmark positions with rare failures, taking an average of 4.2 second computation time to identify each landmark in one large 3D-CBCT scan using a conventional GPU.ConclusionThe ALICBCT algorithm is a robust automatic identification tool that has been deployed for clinical and research use as an extension in the 3D Slicer platform allowing continuous updates for increased precision.
| S-EPMC10440369 | biostudies-literature
Project description:PurposeTo evaluate the usefulness of cone-beam computed tomography with automated bone subtraction (CBCT-ABS) in the preoperative embolization of hypervascular tumors located in the pelvic bone.Materials and methodsThis retrospective study included 26 patients with pelvic bone tumors who underwent preoperative embolization between January 2014 and October 2016. A CBCT-ABS scan was taken in a total of 17 patients (CBCT-ABS group), and only a series of digital subtraction angiographies (DSAs) was taken in the remaining 9 patients (DSA group). The percent devascularization, number of angiographic runs, total dose-area product (DAP), fluoroscopy time, interventional procedure time, operative time, and estimated blood loss were compared between the two groups using Mann-Whitney test.ResultsThe percent devascularization, interventional procedure time, fluoroscopy time, operative time, and estimated blood loss were not statistically different between the two groups (p > 0.05). On the other hand, the number of angiographic runs in the CBCT-ABS group was significantly lower than that in the DSA group (p = 0.029). The total DAP of the CBCT-ABS group (mean, 17700.7 μGym2) was higher than that of the DSA group (mean, 8939.4 μGym2) (p = 0.002).ConclusionsThe use of CBCT-ABS during the preoperative embolization of pelvic bone tumors significantly reduces the number of angiographic runs at the cost of an increased radiation dose.
| S-EPMC5395210 | biostudies-literature
Project description: Not available
| S-EPMC9641331 | biostudies-literature
Project description:PurposeTo test radiomics for prognostication of intrahepatic mass-forming cholangiocarcinoma (IMCC) and to develop a comprehensive risk model.MethodsHistologically proven IMCC (representing the full range of stages) were retrospectively analyzed by volume segmentation on baseline hepatic venous phase computed tomography (CT), by two readers with different experience (R1 and R2). Morphological CT features included: tumor size, hepatic satellite lesions, lymph node and distant metastases. Radiomic features (RF) were compared across CT protocols and readers. Univariate analysis against overall survival (OS) warranted ranking and selection of RF into radiomic signature (RSign), which was dichotomized into high and low-risk strata (RSign*). Models without and with RSign* (Model 1 and 2, respectively) were compared.ResultsAmong 78 patients (median follow-up 262 days, IQR 73-957), 62/78 (79%) died during the study period, 46/78 (59%) died within 1 year. Up to 10% RF showed variability across CT protocols; 37/108 (34%) RF showed variability due to manual segmentation. RSign stratified OS (univariate: HR 1.37 for R1, HR 1.28 for R2), RSign* was different between readers (R1 0.39; R2 0.57). Model 1 showed AUC 0.71, which increased in Model 2: AUC 0.81 (p < 0.001) and AIC 89 for R1, AUC 0.81 (p = 0.001) and AIC 90.2 for R2.ConclusionThe use of RF into a unified RSign score stratified OS in patients with IMCC. Dichotomized RSign* classified survival strata, its inclusion in risk models showed adjunct yield. The cut-off value of RSign* was different between readers, suggesting that the use of reference values is hampered by interobserver variability.
| S-EPMC8435517 | biostudies-literature
Project description:Different cone beam computed tomography (CBCT) protocols have shown promising results for imaging furcation defects. This study evaluates the suitability of low-dose (LD)-CBCT for this purpose. Fifty-nine furcation defects of nine upper and 16 lower molars in six human cadavers were measured by a high-dose (HD)-CBCT protocol, a LD-CBCT protocol, and a surgical protocol. HD-CBCT and LD-CBCT measurements were made twice by two investigators and were compared with the intrasurgical measurements, which served as the reference. Furcation defect volumes generated from HD-CBCT and LD-CBCT imaging were segmented by one rater. Cohen's kappa and intraclass correlation coefficient (ICC) values were calculated to determine intra- and interrater reliability. The level of significance was set at α = 0.05. In total, 59 furcation defects of nine upper and 16 lower human molars were assessed. Comparing CBCT furcation defect measurements with surgical measurements revealed a Cohen's kappa of 0.5975 (HD-and LD-CBCT), indicating moderate agreement. All furcation defects identified by HD-CBCT were also detected by LD-CBCT by both raters, resulting in a Cohen's kappa of 1. For interrater agreement, linear furcation defect measurements showed an ICC of 0.992 for HD-CBCT and 0.987 for LD-CBCT. The intrarater agreement was 0.994(r1)/0.992(r2) for HD-CBCT and 0.987(r1)/0.991(r2) for LD-CBCT. The intermodality agreement was 0.988(r1)/0.991(r2). Paired t-test showed no significant differences between HD-CBCT and LD-CBCT measurements. LD-CBCT is a precise and reliable method for detecting and measuring furcation defects in mandibular and maxillary molars in this experimental setting. It has the potential to improve treatment planning and treatment monitoring with a far lower radiation dose than conventional HD-CBCT.
| S-EPMC9043180 | biostudies-literature
Project description:AimThe objective of this research was to measure the labial bone thickness (LBT) in relation to the 6 anterior maxillary teeth at different levels along the long axis and the distance between cementoenamel junction and bone crest (CEJ-BC) based on cone beam computed tomography (CBCT) scans retrieved from patients of Arab ethnicity and identify any association with patients' characteristics.Materials and methodsA total of 100 CBCT scans were evaluated by one calibrated examiner. The thickness of the labial bone was measured perpendicular to the long axis of the tooth at 1, 3, and 5 mm from the alveolar crest (LBT-1, LBT-3, and LBT-5, respectively) and CEJ-BC using a medical imaging viewer.ResultsCBCT scans of 58 female patients and 42 male patients with a mean age of 39.7 ± 9.5 years were included. A high variation of CEJ-BC was observed (range, 0.55-3.90 mm). Statistically significant higher CEJ-BC values were associated with men and increased age (>50 years). The overall means of LBT-1 were 0.76 ± 0.26, 0.79 ± 0.26, and 0.83 ± 0.37 mm; LBT-3: 0.92 ± 0.36, 1.05 ± 0.46, and 1.03 ± 0.48 mm; LBT-5: 1.17 ± 0.52, 0.80 ± 0.45, and 0.81 ± 0.40 mm for central incisors, lateral incisors, and canines, respectively. The LBT was <1 mm in 74.2% of all maxillary anterior teeth, with central incisors showing the highest predilection (85% with LBT <1 mm). No significant association between LBT and patient characteristics was observed.ConclusionsThe CEJ-BC distance is greater in men and increases with age, particularly in those aged 50 years and older. The LBT in the 6 maxillary anterior teeth is predominantly thin (<1 mm) and has no correlation to age or sex. An increased LBT was observed at a 3-mm level when compared with LBT-1 and LBT-5. Such variability should be taken into consideration when planning for implant placement.
| S-EPMC10023538 | biostudies-literature
Project description:Background and purposeRadiomics analysis extracts quantitative data (features) from medical images. These features could potentially reflect biological characteristics and act as imaging biomarkers within precision medicine. However, there is a lack of cross-comparison and validation of radiomics outputs which is paramount for clinical implementation. In this study, we compared radiomics outputs across two computed tomography (CT)-based preclinical scanners.Materials and methodsCone beam CT (CBCT) and µCT scans were acquired using different preclinical CT imaging platforms. The reproducibility of radiomics features on each scanner was assessed using a phantom across imaging energies (40 & 60 kVp) and segmentation volumes (44-238 mm3). Retrospective mouse scans were used to compare feature reliability across varying tissue densities (lung, heart, bone), scanners and after voxel size harmonisation. Reliable features had an intraclass correlation coefficient (ICC) > 0.8.ResultsFirst order and GLCM features were the most reliable on both scanners across different volumes. There was an inverse relationship between tissue density and feature reliability, with the highest number of features in lung (CBCT=580, µCT=734) and lowest in bone (CBCT=110, µCT=560). Comparable features for lung and heart tissues increased when voxel sizes were harmonised. We have identified tissue-specific preclinical radiomics signatures in mice for the lung (133), heart (35), and bone (15).ConclusionsPreclinical CBCT and µCT scans can be used for radiomics analysis to support the development of meaningful radiomics signatures. This study demonstrates the importance of standardisation and emphasises the need for multi-centre studies.
| S-EPMC11328005 | biostudies-literature
Project description:PurposeAnastomosis between posterior superior alveolar artery and infraorbital artery can go through bony canal in the lateral wall of the maxilla. This artery is called alveolar antral artery. It can complicate lateral sinus lift procedure by bleeding and hemosinus formation or bone graft wash out. The artery can also go in soft tissues where is not visible on cone beam computed tomography. In previous studies, the relation of this artery to sinus floor or alveolar process was measured. These structures are highly unstable during lifetime and after tooth loss. The aim of this study is to study presence and relations of bony canal in the lateral maxillary wall, to characterize the group of patients which is more likely to have bone canal in the lateral maxilla. The aim and the novelty of this study is the describing of the relationship of the bony canal to the more stable structure of hard palate and describing the relation of presence of bony canal on width of maxillary sinus, and to facilitate the prediction of presence of the alveolar antral artery.MaterialsThe cone beam computed tomography scans of the patients (251 in number) of the university hospital were examined for presence of alveolar antral artery (148 was fulfilled inclusion criteria), patient were characterized by gender, age, and sinus type (wide, average, narrow). The diameter of the bony canal and its relation to the level of sinus floor and hard palate were measured.ResultsThe cone beam computed tomography scans of 148 patients, out of it 55 man (37,2%) and 93 women (62,8%). Bony canal containing alveolar anastomosis was found in 69 cases (57,0%). Presence of the bony canal in the lateral wall of maxillae showed statistical probability depending on age with p = 0, 064 according to Mann-Whitney test. The older patients have more likely the bony canal. The presence of the alveolar antral artery was found more likely in the wide sinuses. The hard palate level can serve as a prediction point of alveolar antral artery only in first molar and second premolar region. In accordance with previous studies the width of bony canal is significantly higher in group of man (p = 0, 015). There was found a correlation between smaller distance of bony canal from sinus floor in the presence of teeth (p = 0, 067). After tooth loss the distance between sinus floor and bony canal increases, but the distance of bony canal to hard palate level stays constant. This can be explained hypothetically so that periodontal ligaments and root surface acts as a barrier for sinus pneumatization.ConclusionLateral sinus lifting in some cases can be unenviable, the knowledge about alveolar antral artery anatomy can reduce the risk of arterial bleeding. The cone-beam computed tomography is a routine examination prior to augmentation surgery and therefore the data obtained from it has an impact on clinical practice.
| S-EPMC10693819 | biostudies-literature
Project description:ObjectivesThis study aims to evaluate the diagnostic performance of machine-learning-based contrast-enhanced CT radiomic analysis for categorizing benign and malignant ovarian tumors.MethodsA total of 1,329 patients with ovarian tumors were randomly divided into a training cohort (N=930) and a validation cohort (N=399). All tumors were resected, and pathological findings were confirmed. Radiomic features were extracted from the portal venous phase images of contrast-enhanced CT. The clinical predictors included age, CA-125, HE-4, ascites, and margin of tumor. Both radiomics model (including selected radiomic features) and mixed model (incorporating selected radiomic features and clinical predictors) were constructed respectively. Six classifiers [k-nearest neighbor (KNN), support vector machines (SVM), random forest (RF), logistic regression (LR), multi-layer perceptron (MLP), and eXtreme Gradient Boosting (XGBoost)] were used for each model. The mean relative standard deviation (RSD) and area under the receiver operating characteristic curve (AUC) were applied to evaluate and select the best classifiers. Then, the performances of the two models with selected classifiers were assessed in the validation cohort.ResultsThe MLP classifier with the least RSD (1.21 and 0.53, respectively) was selected as the best classifier in both radiomics and mixed models. The two models with MLP classifier performed well in the validation cohort, with the AUCs of 0.91 and 0.96 and with accuracies (ACCs) of 0.83 and 0.87, respectively. The Delong test showed that the AUC of mixed model was statistically different from that of radiomics model (p<0.001).ConclusionsMachine-learning-based CT radiomic analysis could categorize ovarian tumors with good performance preoperatively. The mixed model with MLP classifier may be a potential tool in clinical applications.
| S-EPMC9395674 | biostudies-literature