Early evaluation of a screen-and-treat strategy using high-risk HPV testing for Uganda: Implications for screening coverage and treatment.

Background: Uganda has a high burden of cervical cancer and its current coverage of screening based on visual inspection with acetic acid (VIA) is low. High-risk HPV (hrHPV) testing is recommended by the World Health Organization as part of the global elimination strategy for cervical cancer. In this context, country-specific health economic evaluations can inform national-level decisions regarding implementation.

Visceral adipose tissue volume is associated with premature atherosclerosis in early type 2 diabetes mellitus independent of traditional risk factors.

Background And Aims: Type 2 diabetes mellitus (T2DM) is commonly associated with abdominal obesity, predominantly with high visceral adipose tissue (VAT), and is accompanied by premature atherosclerosis. However, the association between VAT and subcutaneous adipose tissue (SAT) with premature atherosclerosis and (i.e.

Performance Evaluation of a Semi-automated Method for [F]FDG Uptake in Abdominal Visceral Adipose Tissue.

Purpose: Severity of abdominal obesity and possibly levels of metabolic activity of abdominal visceral adipose tissue (VAT) are associated with an increased risk for cardiovascular disease (CVD). In this context, the purpose of the current study was to evaluate the reproducibility and repeatability of a semi-automated method for assessment of the metabolic activity of VAT using 2-deoxy-2-[F]fluoro-D-glucose ([F]FDG) positron emission tomography (PET)/x-ray computed tomography (CT).

Procedures: Ten patients with lung cancer who underwent two baseline whole-body [F]FDG PET/low-dose (LD) CT scans within 1 week were included.

Assessment of coronary calcification using calibrated mass score with two different multidetector computed tomography scanners in the Copenhagen General Population Study.

Objective: Population studies have shown coronary calcium score to improve risk stratification in subjects suspected for cardiovascular disease. The aim of this work was to assess the validity of multidetector computed tomography (MDCT) for measurement of calibrated mass scores (MS) in a phantom study, and to investigate inter-scanner variability for MS and Agaston score (AS) recorded in a population study on two different high-end MDCT scanners.

Materials And Methods: A calcium phantom was scanned by a first (A) and second (B) generation 320-MDCT.

Feasibility of spectral shaping for detection and quantification of coronary calcifications in ultra-low dose CT.

Objectives: To evaluate detectability and quantification of coronary calcifications for CT with a tin filter for spectral shaping.

Methods: Phantom inserts with 100 small and 9 large calcifications, and a moving artificial artery with 3 calcifications (speed 0-30 mm/s) were placed in a thorax phantom simulating different patient sizes. The phantom was scanned in high-pitch spiral mode at 100 kVp with tin filter (Sn100 kVp), and at a reference of 120 kVp, with electrocardiographic (ECG) gating.

Quantitative comparison of commercial and non-commercial metal artifact reduction techniques in computed tomography.

Objectives: Typical streak artifacts known as metal artifacts occur in the presence of strongly attenuating materials in computed tomography (CT). Recently, vendors have started offering metal artifact reduction (MAR) techniques. In addition, a MAR technique called the metal deletion technique (MDT) is freely available and able to reduce metal artifacts using reconstructed images.

The Use of CT Scan in Hemodynamically Stable Children with Blunt Abdominal Trauma: Look before You Leap.

We set out to determine the diagnostic value of computed tomographic (CT) scans in relation to the radiation dose, tumor incidence, and tumor mortality by radiation for hemodynamically stable pediatric patients with blunt abdominal injury. We focused on the changes in management because of new information obtained by CT. CT scans for suspected pediatric abdominal injury performed in our accident and emergency department were retrieved from the radiology registry and analyzed for: injury and hemodynamic parameters, changes in therapy, and radiological interventions.

Circumference as an alternative for diameter measurement in endovascular aneurysm repair.

Appropriate sizing of endografts for endovascular aneurysm repair has traditionally been performed by one standardized method. By measuring the average of the minor and major axes in the sealing zone, the endograft size is traditionally calculated. However, no adequate scientific evaluation has been performed to validate this method.

Coronary calcium scores are systematically underestimated at a large chest size: A multivendor phantom study.

Objective: To evaluate the effect of chest size on coronary calcium score (CCS) as assessed with new-generation CT systems from 4 major vendors.

Methods: An anthropomorphic, small-sized (300 × 200 mm) chest phantom containing 100 small calcifications (diameters, 0.5-2.

Simulation models in population breast cancer screening: A systematic review.

The aim of this review was to critically evaluate published simulation models for breast cancer screening of the general population and provide a direction for future modeling. A systematic literature search was performed to identify simulation models with more than one application. A framework for qualitative assessment which incorporated model type; input parameters; modeling approach, transparency of input data sources/assumptions, sensitivity analyses and risk of bias; validation, and outcomes was developed.

Relative electron density determination using a physics based parameterization of photon interactions in medical DECT.

Radiotherapy and particle therapy treatment planning require accurate knowledge of the electron density and elemental composition of the tissues in the beam path to predict the local dose deposition. We describe a method for the analysis of dual energy computed tomography (DECT) images that provides the electron densities and effective atomic numbers of tissues. The CT measurement process is modelled by system weighting functions, which apply an energy dependent weighting to the parameterization of the total cross section for photon interactions with matter.

Leukemia and brain tumors among children after radiation exposure from CT scans: design and methodological opportunities of the Dutch Pediatric CT Study.

Computed tomography (CT) scans are indispensable in modern medicine; however, the spectacular rise in global use coupled with relatively high doses of ionizing radiation per examination have raised radiation protection concerns. Children are of particular concern because they are more sensitive to radiation-induced cancer compared with adults and have a long lifespan to express harmful effects which may offset clinical benefits of performing a scan. This paper describes the design and methodology of a nationwide study, the Dutch Pediatric CT Study, regarding risk of leukemia and brain tumors in children after radiation exposure from CT scans.

Influence of iterative image reconstruction on CT-based calcium score measurements.

Iterative reconstruction techniques for coronary CT angiography have been introduced as an alternative for traditional filter back projection (FBP) to reduce image noise, allowing improved image quality and a potential for dose reduction. However, the impact of iterative reconstruction on the coronary artery calcium score is not fully known. In 112 consecutive stable patients with suspected coronary artery disease, the coronary calcium scores were assessed.

The cumulative risk of multiple CT exposures using two different methods.

The aim of this study was to compare the summing method (A) with the complement method (B) for calculating the cumulative lifetime-attributable-risk (LAR(tot)) of tumor incidence and mortality of multiple CT exposures. Method A defines LAR(tot) as the summation of the risk of each separate exposure. Method B was defined as the complement of the probability of inducing no cancer in N separate exposures.

Small irregular pulmonary nodules in low-dose CT: observer detection sensitivity and volumetry accuracy.

Objective: The purpose of this study is to evaluate observer detection and volume measurement of small irregular solid artificial pulmonary nodules on 64-MDCT in an anthropomorphic thoracic phantom.

Materials And Methods: Forty in-house-made solid pulmonary nodules (lobulated and spiculated; actual volume, 5.1-88.

Can nontriggered thoracic CT be used for coronary artery calcium scoring? A phantom study.

Purpose: Coronary artery calcium score, traditionally based on electrocardiography (ECG)-triggered computed tomography (CT), predicts cardiovascular risk. However, nontriggered CT is extensively utilized. The study-purpose is to evaluate the in vitro agreement in coronary calcium score between nontriggered thoracic CT and ECG-triggered cardiac CT.

Optimisation of volume-doubling time cutoff for fast-growing lung nodules in CT lung cancer screening reduces false-positive referrals.

Objective: To retrospectively investigate whether optimisation of volume-doubling time (VDT) cutoff for fast-growing nodules in lung cancer screening can reduce false-positive referrals.

Methods: Screening participants of the NELSON study underwent low-dose CT. For indeterminate nodules (volume 50-500 mm(3)), follow-up CT was performed 3 months after baseline.

Non-calcified coronary atherosclerotic plaque visualization on CT: effects of contrast-enhancement and lipid-content fractions.

Computed tomography (CT) may characterize lipid-rich and presumably rupture-prone non-calcified coronary atherosclerotic plaque based on its Hounsfield-Unit (HU), but still inconclusively. This study aimed to evaluate factors influencing the HU-value of non-calcified plaque using software simulation. Several realistic virtual plaqueburdened coronary phantoms were constructed at 5 μm resolution.

Improving the reproducibility of MR-derived left ventricular volume and function measurements with a semi-automatic threshold-based segmentation algorithm.

To validate a novel semi-automatic segmentation algorithm for MR-derived volume and function measurements by comparing it with the standard method of manual contour tracing. The new algorithms excludes papillary muscles and trabeculae from the blood pool, while the manual approach includes these objects in the blood pool. An epicardial contour served as input for both methods.

Breast Cancer Incidence After Risk-Reducing Salpingo-Oophorectomy in BRCA1 and BRCA2 Mutation Carriers.

Premenopausal risk-reducing salpingo-oophorectomy (RRSO) in BRCA1/2 mutation carriers effectively reduces ovarian cancer risk, but also reduces breast cancer risk. Breast cancer risk reductions up to 50% have been reported for both BRCA1 and BRCA2 mutation carriers, but recent prospective studies were not able to reproduce this finding for BRCA1 mutation carriers. Breast cancer incidence after RRSO was assessed in a consecutive series of 104 BRCA1 and 58 BRCA2 mutation carriers.

Sensitivity and accuracy of volumetry of pulmonary nodules on low-dose 16- and 64-row multi-detector CT: an anthropomorphic phantom study.

Objective: To assess the sensitivity of detection and accuracy of volumetry by manual and semi-automated quantification of artificial pulmonary nodules in an anthropomorphic thoracic phantom on low-dose CT.

Methods: Fifteen artificial spherical nodules (diameter 3, 5, 8, 10 and 12 mm; CT densities -800, -630 and +100 HU) were randomly placed inside an anthropomorphic thoracic phantom. The phantom was examined on 16- and 64-row multidetector CT with a low-dose protocol.

CT-based temperature monitoring during hepatic RF ablation: feasibility in an animal model.

Purpose: The aim of this paper was to establish non-invasive CT-based temperature monitoring during hepatic radiofrequency (RF) ablation in an ex vivo porcine model followed by transfer of the technique into a feasibility in vivo experiment.

Materials And Methods: Bipolar RF ablations were performed in 10 specimens of porcine liver. Parallel to the needle-shaped RF applicator three optical temperature probes were inserted into the liver specimens at fixed distances of 5, 10 and 15 mm from the RF probe.

Automated bone removal in CT angiography: comparison of methods based on single energy and dual energy scans.

Purpose: To evaluate dual energy based methods for bone removal in computed tomography angiography (CTA) images and compare these with single energy based methods that use an additional, nonenhanced, CT scan.

Methods: Four different bone removal methods were applied to CT scans of an anthropomorphic thorax phantom, acquired with a second generation dual source CT scanner. The methods differed by the way information on the presence of bone was obtained (either by using an additional, nonenhanced scan or by scanning with two tube voltages at the same time) and by the way the bone was removed from the CTA images (either by masking or subtracting the bone).

Feasibility of noninvasive temperature assessment during radiofrequency liver ablation on computed tomography.

Purpose: The purpose of this study was to assess the feasibility of noninvasive thermometry using high-resolution computer tomography (CT) for the monitoring of bovine liver during radiofrequency (RF) ablation.

Methods: Radiofrequency probes were used to ablate bovine livers from 20°C to 98°C. During the heating process, images were acquired using a multidetector CT scanner with simultaneous measurement of temperature using calibrated thermal sensors.