Diagnostic accuracy of contrast-enhanced diffusion-weighted MRI for liver metastases of pancreatic cancer: towards adequate staging and follow-up of pancreatic cancer - DIA-PANC study: study protocol for an international, multicenter, diagnostic trial.

BACKGROUND: At the time of surgery, approximately 10-20% of the patients with pancreatic cancer are considered unresectable because of unexpected liver metastasis, peritoneal carcinomatosis or locally advanced disease. This leads to futile surgical treatment with all the associated morbidity, mortality and costs. More than 50% of all liver metastases develop in the first six months postoperatively. These (subcentimeter) liver metastases are most likely already present at the time of diagnosis and have not been identified pre-operatively, due to the poor sensitivity of routine preoperative contrast-enhanced CT (CECT). METHODS: The DIA-PANC study is a prospective, international, multicenter, diagnostic cohort study investigating diffusion-weighted, contrast-enhanced MRI for the detection of liver metastases in patients with all stages of pancreatic cancer. Indeterminate or malignant liver lesions on MRI will be further investigated histopathologically. For patients with suspected liver lesions without histopathological proof, follow up imaging with paired CT and MRI at 3-, 6- and 12-months will serve as an alternative reference standard. DISCUSSION: The DIA-PANC trial is expected to report high-level evidence of the diagnostic accuracy of MRI for the detection of liver metastases, resulting in significant value for clinical decision making, guideline development and improved stratification for treatment strategies and future trials. Furthermore, DIA-PANC will contribute to our knowledge of liver metastases regarding incidence, imaging characteristics, their number and extent, and their change in time with or without treatment. It will enhance the worldwide implementation of MRI and consequently improve personalized treatment of patients with suspected pancreatic ductal adenocarcinoma. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT03469726 . Registered on March 19th 2018 - Retrospectively registered.

Incidental perifissural nodules on routine chest computed tomography: lung cancer or not?

OBJECTIVES: Perifissural nodules (PFNs) are a common finding on chest CT, and are thought to represent non-malignant lesions. However, data outside a lung cancer-screening setting are currently lacking. METHODS: In a nested case-control design, out of a total cohort of 16,850 patients ≥ 40 years of age who underwent routine chest CT (2004-2012), 186 eligible subjects with incident lung cancer and 511 controls without were investigated. All non-calcified nodules ≥ 4 mm were semi-automatically annotated. Lung cancer location and subject characteristics were recorded. RESULTS: Cases (56 % male) had a median age of 64 years (IQR 59-70). Controls (60 % male) were slightly younger (p<0.01), median age of 61 years (IQR 51-70). A total of 262/1,278 (21 %) unique non-calcified nodules represented a PFN. None of these were traced to a lung malignancy over a median follow-up of around 4.5 years. PFNs were most often located in the lower lung zones (72 %, p<0.001). Median diameter was 4.6 mm (range: 4.0-8.1), volume 51 mm3 (range: 32-278). Some showed growth rates < 400 days. CONCLUSIONS: Our data show that incidental PFNs do not represent lung cancer in a routine care, heterogeneous population. This confirms prior screening-based results. KEY POINTS: • One-fifth of non-calcified nodules represented a perifissural nodule in our non-screening population. • PFNs fairly often show larger size, and can show interval growth. • When morphologically resembling a PFN, nodules are nearly certainly not a malignancy. • The assumed benign aetiology of PFNs seems valid outside the screening setting.

[Lung cancer screening. What have we learnt for the practice so far?]. / Bronchialkarzinomscreening. Was haben wir für die Praxis bisher gelernt?

CLINICAL/METHODICAL ISSUE: Lung cancer is the most frequent cause of tumor-associated death and only has a good prognosis if detected at a very early tumor stage. METHODICAL INNOVATIONS: For the first time the American National Lung Screening Trial (NLST) could prove that low-dose computed tomography (CT) screening is able to reduce lung cancer mortality by 20 %. PERFORMANCE: To date, however, three much smaller and therefore statistically underpowered European trials could not confirm the positive results of the NLST. The results of the largest European trial NELSON are expected within the next 2 years. In addition, there are a number of open or not yet satisfactorily answered questions, such as the definition of the appropriate screening population, the management of nodules detected by screening, the effects of over-diagnosis and the risk of cumulative radiation exposure. PRACTICAL RECOMMENDATIONS: The success of the NLST prompted several predominantly American professional societies to issue a positive recommendation about the implementation of lung cancer screening in a population at risk. However, potentially conflicting results of European studies and a number of not yet optimized issues justify caution and call for a pooled analysis of European studies in order to provide statistically sound results and to ensure a high efficiency of screening with respect to the radiation applied, mental and physical patient burden and, last but not least, the financial efforts.

Impact of different dimethyl sulphoxide concentrations on cell recovery, viability and clonogenic potential of cryopreserved peripheral blood hematopoietic stem and progenitor cells.

BACKGROUND AND OBJECTIVES: The procedure of autologous hematopoietic stem/progenitor cell transplantation requires cryopreservation. Addition of DMSO is necessary to secure the viability of such cells, but this solvent is potentially toxic to stem cells' recipient. 10% DMSO solution is used by the majority of transplant centres. The aim of our study was to test if DMSO concentration might be reduced without negative impact on cell recovery and clonogenicity. MATERIALS AND METHODS: Samples were prospectively collected from 20 patients. Small volumes of leukapheresis products were frozen with different cryoprotective mixtures, containing 10%, 7·5%, 5% and 2·5% DMSO, respectively. The quality of cryoprotective mixtures was evaluated based on recovery, viability and clonogenic potential of hematopoietic stem cells after defreezing. RESULTS: Reduction in DMSO concentration to 7·5% or lower was associated with decreased recovery of nucleated cells. In contrast, the number of colonies was highest for 7·5% DMSO with significant differences when compared to 10% DMSO solution. CONCLUSION: Reduction in DMSO concentration from 10% to 7·5% may have favourable impact on hematopoietic recovery after autologous transplantation. The findings require confirmation in a clinical setting.

Inter- and intraobserver reliability for diagnosing levator ani changes on magnetic resonance imaging.

OBJECTIVES: To assess the inter- and intraobserver reliability of the diagnosis of pubovisceral muscle avulsions and measurements of the levator hiatus on magnetic resonance imaging (MRI). METHODS: Women with recurrent pelvic organ prolapse or in whom there was a discrepancy between clinical signs and symptoms of pelvic floor dysfunction underwent MRI and were eligible for inclusion. MRI datasets of the pelvic floor of 262 women were obtained and evaluated by two observers, who scored the presence and extent of pubovisceral muscle avulsions on each side using a scale from 0 to 3 and obtained measurements of the anteroposterior and transverse diameters and area of the levator hiatus. A random sample of 100 patients was reviewed a second time by one of the observers. Intraclass correlation coefficients (ICCs) with their 95% CI were calculated for all measurements. Mean differences with accompanying limits of agreement were calculated to estimate agreement between pairs of measurements and to detect possible systematic bias. RESULTS: Good interobserver reliability was found for the assessment of pubovisceral muscle avulsions (ICC = 0.76-0.79) and excellent agreement for measurements of the levator hiatus (ICC = 0.85-0.89). The intraobserver reliability for pubovisceral muscle avulsions and other levator hiatus measurements was also excellent (ICC = 0.80-0.97). A significant interobserver systematic bias was observed in the measurement of levator hiatus transverse diameter; however, narrow limits of agreement were observed. CONCLUSIONS: Pubovisceral muscle avulsions and levator hiatus measurements can be assessed with good to excellent reliability on MRI.

The relationship between lung function impairment and quantitative computed tomography in chronic obstructive pulmonary disease.

OBJECTIVES: To determine the relationship between lung function impairment and quantitative computed tomography (CT) measurements of air trapping and emphysema in a population of current and former heavy smokers with and without airflow limitation. METHODS: In 248 subjects (50 normal smokers; 50 mild obstruction; 50 moderate obstruction; 50 severe obstruction; 48 very severe obstruction) CT emphysema and CT air trapping were quantified on paired inspiratory and end-expiratory CT examinations using several available quantification methods. CT measurements were related to lung function (FEV(1), FEV(1)/FVC, RV/TLC, Kco) by univariate and multivariate linear regression analysis. RESULTS: Quantitative CT measurements of emphysema and air trapping were strongly correlated to airflow limitation (univariate r-squared up to 0.72, p < 0.001). In multivariate analysis, the combination of CT emphysema and CT air trapping explained 68-83% of the variability in airflow limitation in subjects covering the total range of airflow limitation (p < 0.001). CONCLUSIONS: The combination of quantitative CT air trapping and emphysema measurements is strongly associated with lung function impairment in current and former heavy smokers with a wide range of airflow limitation.

Routine contrast-enhanced CT is insufficient for TNM-staging of duodenal adenocarcinoma.

PURPOSE: Adequate TNM-staging is important to determine prognosis and treatment planning of duodenal adenocarcinoma. Although current guidelines advise contrast-enhanced CT (CECT) for staging of duodenal adenocarcinoma, literature about diagnostic tests is sparse. METHODS: In this retrospective single-center cohort study, we analyzed the real life performance of routine CECT for TNM-staging and the assessment of resectability of duodenal adenocarcinoma. Intraoperative findings and pathological staging served as reference standard for resectability, T-, and N-staging. Biopsies, 18FDG-PET-CT, and follow-up were used as the reference standard for M-staging. RESULTS: Fifty-two consecutive patients with duodenal adenocarcinoma were included, 26 patients underwent resection. Half of the tumors were isodense to normal duodenum on CECT. The tumor was initially missed in 7/52 patients (13%) on CECT. The correct T-stage was assigned with CECT in 14/26 patients (54%), N-stage in 11/26 (42%), and the M-stage in 42/52 (81%). T-stage was underestimated in (27%). The sensitivity for detecting lymph node metastases was only 24%, specificity was 78%. Seventeen percent of patients had indeterminate liver or lung lesions on CECT. Surgery with curative intent was started in 32 patients, but six patients (19%) could not be resected due to unexpected local invasion or metastases. CONCLUSION: Radiologists and clinicians have to be aware that routine CECT is insufficient for staging and determining resectability in patients with duodenal adenocarcinoma. CECT underestimates T-stage and N-stage, and M-stage is often unclear, resulting in futile surgery in 19% of patients. Alternative strategies are required to improve staging of duodenal adenocarcinoma. We propose to combine multiphase hypotonic duodenography CT with MRI.

Radiological evidence of lymphangioleiomyomatosis in female and male patients with tuberous sclerosis complex.

AIM: To determine the gender-specific prevalence of pulmonary cysts typical for lymphangioleiomyomatosis (LAM) in adult patients with known tuberous sclerosis complex (TSC). MATERIALS AND METHODS: A retrospective, cross-sectional study in a cohort of 206 adult TSC patients was performed. Institutional review board approval was obtained, and patient informed consent was waived. Patients had routinely undergone abdominal CT scanning between 1996 and 2006. All 186 patients (mean age 38 years; range 19-72 years; 91 (49%) male patients) in whom at least the lung bases were depicted on computed tomography (CT) were included. Images were reviewed for the presence of pulmonary thin-walled cysts. Descriptive statistics, two sample t-test to compare means, and χ(2)-test to compare proportions were applied. RESULTS: CT demonstrated pulmonary thin-walled cysts in the lung bases in 52 (28%) of 186 patients. Size varied from 2mm in diameter to more than 2 cm. Pulmonary cysts were detected in 40 (42%) of 95 female patients and in 12 (13%) of 91 male patients (p<0.001). In general, cysts were larger and more numerous in women than in men. Only minimal cystic changes were found in four women and two men, moderate cystic changes were seen in three women and seven men, but considerable cystic changes were seen almost exclusively in women (33 women versus three men). CONCLUSION: CT demonstrated thin-walled pulmonary cysts in the lung bases in 28% of 186 included patients with tuberous sclerosis complex. Female patients were more affected than male patients.

The impact and challenges of implementing CTCA according to the 2019 ESC guidelines on chronic coronary syndromes: a survey and projection of CTCA services in the Netherlands.

BACKGROUND: The 2019 ESC-guidelines on chronic coronary syndromes (ESC-CCS) recommend computed tomographic coronary angiography (CTCA) or non-invasive functional imaging instead of exercise ECG as initial test to diagnose obstructive coronary artery disease. Since impact and challenges of these guidelines are unknown, we studied the current utilisation of CTCA-services, status of CTCA-protocols and modeled the expected impact of these guidelines in the Netherlands. METHODS AND RESULTS: A survey on current practice and CTCA utilisation was disseminated to every Dutch hospital organisation providing outpatient cardiology care and modeled the required CTCA capacity for implementation of the ESC guideline, based on these national figures and expert consensus. Survey response rate was 100% (68/68 hospital organisations). In 2019, 63 hospital organisations provided CTCA-services (93%), CTCA was performed on 99 CTCA-capable CT-scanners, and 37,283 CTCA-examinations were performed. Between the hospital organisations, we found substantial variation considering CTCA indications, CTCA equipment and acquisition and reporting standards. To fully implement the new ESC guideline, our model suggests that 70,000 additional CTCA-examinations would have to be performed in the Netherlands. CONCLUSIONS: Despite high national CTCA-services coverage in the Netherlands, a substantial increase in CTCA capacity is expected to be able to implement the 2019 ESC-CCS recommendations on the use of CTCA. Furthermore, the results of this survey highlight the importance to address variations in image acquisition and to standardise the interpretation and reporting of CTCA, as well as to establish interdisciplinary collaboration and organisational alignment.

Short-term health-related quality of life consequences in a lung cancer CT screening trial (NELSON).

BACKGROUND: In lung cancer CT screening, participants often have an indeterminate screening result at baseline requiring a follow-up CT. In subjects with either an indeterminate or a negative result after screening, we investigated whether health-related quality of life (HRQoL) changed over time and differed between groups in the short term. METHODS: A total of 733 participants in the NELSON trial received four questionnaires: T0, before randomisation; T1, 1 week before the baseline screening; T2, 1 day after the screening; and T3, 2 months after the screening results but before the 3-month follow-up CT. HRQoL was measured as generic HRQoL (the 12-item Short Form, SF-12; the EuroQol questionnaire, EQ-5D), anxiety (the Spielberger State-Trait Anxiety Inventory, STAI-6), and lung-cancer-specific distress (the Impact of Event Scale, IES). For analyses, repeated-measures analysis of variance was used, adjusted for covariates. RESULTS: Response to each questionnaire was 88% or higher. Scores on SF-12, EQ-5D, and STAI-6 showed no clinically relevant changes over time. At T3, IES scores that were clinically relevant increased after an indeterminate result, whereas these scores showed a significant decrease after a negative result. At T3, differences in IES scores between the two baseline result groups were both significant and clinically relevant (P<0.01). CONCLUSION: This longitudinal study among participants of a lung cancer screening programme showed that in the short term recipients of an indeterminate result experienced increased lung-cancer-specific distress, whereas the HRQoL changes after a negative baseline screening result may be interpreted as a relief.

Lung nodule volumetry: segmentation algorithms within the same software package cannot be used interchangeably.

OBJECTIVE: We examined the reproducibility of lung nodule volumetry software that offers three different volumetry algorithms. METHODS: In a lung cancer screening trial, 188 baseline nodules >5 mm were identified. Including follow-ups, these nodules formed a study-set of 545 nodules. Nodules were independently double read by two readers using commercially available volumetry software. The software offers readers three different analysing algorithms. We compared the inter-observer variability of nodule volumetry when the readers used the same and different algorithms. RESULTS: Both readers were able to correctly segment and measure 72% of nodules. In 80% of these cases, the readers chose the same algorithm. When readers used the same algorithm, exactly the same volume was measured in 50% of readings and a difference of >25% was observed in 4%. When the readers used different algorithms, 83% of measurements showed a difference of >25%. CONCLUSION: Modern volumetric software failed to correctly segment a high number of screen detected nodules. While choosing a different algorithm can yield better segmentation of a lung nodule, reproducibility of volumetric measurements deteriorates substantially when different algorithms were used. It is crucial even in the same software package to choose identical parameters for follow-up.

Simultaneous aortic and coronary assessment in abdominal aortic aneurysm patients by thoraco-abdominal 64-detector-row CT angiography: estimate of the impact on preoperative management: a pilot study.

OBJECTIVES: To estimate the influence of information on the coronary arteries obtained from routine thoraco-abdominal CT angiography (CTA) on pre-operative clinical management in abdominal aortic aneurysm (AAA) patients. METHODS: Twenty-eight AAA patients underwent pre-operative thoraco-abdominal electrocardiography (ECG)-gated 64-detector-row CTA to evaluate aortic pulsatility for prosthesis size matching. Retrospectively, the coronaries were reconstructed from the same data set and scored on a per segment basis for stenosis (0%, 50%) and grading confidence (poor, adequate or high). An experienced cardiologist was presented information on patient characteristics obtained from patient records and CTA findings. Suggested changes in European Society of Cardiology guidelines based patient management based on CTA information were scored. RESULTS: On CTA, 17 patients (61%) had significant coronary disease (>50% stenosis) including left main (n=4), single (n=7) and multiple (n=6) vessel disease. Grading confidence was adequate or high in 86% of proximal and middle segments. Based on CTA findings, patient management would have been changed in 4 out of the 28 patients (14%; 95% CI 1-27%) by adding coronary angiography (n=4). In five patients who underwent coronary artery bypass grafting previously, CT did not change management but confirmed graft patency. CONCLUSIONS: Information on coronary pathology and coronary bypass graft patency can be readily obtained from thoraco-abdominal CTA and may alter pre-operative patient management, as shown in 14% of AAA patients in our study.

Scanning gate microscopy mapping of edge current and branched electron flow in a transition metal dichalcogenide nanoribbon and quantum point contact.

We study scanning gate microscopy conductance mapping of a [Formula: see text] zigzag ribbon exploiting tight-binding and continuum models. We show that, even though the edge modes of a pristine nanoribbon are robust to backscattering on the potential induced by the tip, the conductance mapping reveals presence of both the edge modes and the quantized spin- and valley-current carrying modes. By inspecting the electron flow from a split gate quantum point contact (QPC) we find that the mapped current flow allows to determine the nature of the quantization in the QPC as spin-orbit coupling strength affects the number of branches in which the current exits the constriction. The radial conductance oscillation fringes found in the conductance mapping reveal the presence of two possible wavevectors for the charge carriers that correspond to spin and valley opposite modes. Finally, we show that disorder induced valley mixing leads to a beating pattern in the radial fringes.

Grading of carotid artery stenosis with multidetector-row CT angiography: visual estimation or caliper measurements?

To assess the optimal method for grading carotid artery stenosis with computed tomographic angiography (CTA), we compared visual estimation to caliper measurements, and determined inter-observer variability and agreement relative to digital subtraction angiography (DSA). We included 46 patients with symptomatic carotid stenosis for whom CTA and DSA of 55 carotids was available. Stenosis quantification by CTA using visual estimation (CTA(VE)) (method 1) was compared with caliper measurements using subjectively optimized wide window settings (method 2) or predefined contrast-dependent narrow window settings (method 3). Measurements were independently performed by two radiologists and two residents. To determine accuracy and inter-observer variability, we calculated linear weighted kappa, performed a Bland-Altman analysis and calculated mean difference (bias) and standard deviation of differences (SDD). For inter-observer variability, kappa analysis was "very good" (0.85) for expert observers using CTA(VE) compared with "good" (0.61) for experts using DSA. Compared with DSA, method 1 led to overestimation (bias 5.8-8.0%, SDD 10.6-14.4), method 3 led to underestimation (bias -6.3 to -3.0%, SDD 13.0-18.1). Measurement variability between DSA and visual estimation on CTA (SDD 11.5) is close to the inter-observer variability of repeated measurements on DSA that we found in this study (SDD 11.6). For CTA of carotids, stenosis grading based on visual estimation provides better agreement to grading by DSA compared with stenosis grading based on caliper measurements.

Prevalence of subependymal giant cell tumors in patients with tuberous sclerosis and a review of the literature.

BACKGROUND AND PURPOSE: To investigate the prevalence of subependymal giant cell ependymomas (SEGA) in patients with tuberous sclerosis complex (TSC). METHODS: We performed a retrospective cross-sectional study in a cohort of 285 patients with known TSC. Institutional review board approval was obtained. We included all 214 TSC-patients who had received a contrast-enhanced computed tomography (CT) scan of the brain. The most recent scan was evaluated for SEGA and presence of hydrocephalus. Additionally, a literature search was performed, and pooled estimates of SEGA prevalence in TSC were calculated. We used descriptive statistics, two sample t-test, chi-squared-test, and meta-analysis as appropriate. RESULTS: Computed tomography showed radiological evidence of SEGA in 43 of the 214 TSC-patients (20%); 23 of 105 men (22%) and 20 of 109 women (18%; P = .52). Average maximum tumor size was 11.4 mm (range, 4-29 mm). Patients with SEGA (mean, 31 years; range, 16-58 years) were on average younger than patients without SEGA (mean, 37 years; range, 10-72 years; P = 0.007). No association between tumor size and patient age was detected. Nine patients had bilateral SEGA. Hydrocephalus was present in six of the 43 patients (14%). Meta-analysis of reported prevalence and our current study showed that studies using radiological evidence to diagnose SEGA gave a higher pooled estimate of the prevalence of SEGA in TSC (0.16; 95% CI: 0.12, 0.21) than studies using mainly histopathological evidence of SEGA (0.09; 95% CI: 0.07, 0.12). CONCLUSIONS: In our cohort, CT demonstrated evidence of SEGA in 20% of TSC-patients. Prevalence of SEGA in TSC is higher in studies using radiological evidence to diagnose SEGA than in studies using histopathological evidence.

Dynamics of the aorta before and after endovascular aneurysm repair: a systematic review.

OBJECTIVE: An overview of the knowledge of thoracic (TAA), and abdominal aortic aneurysm (AAA) dynamics, before and after endovascular repair, is given. METHODS: Medline, EMBASE and the Cochrane database were searched for relevant articles. After inclusion and exclusion, 25 relevant articles reporting on aneurysm dynamics remained, allowing for comparison. Results provided in the included studies were assumed (statistically) significant if they were larger than the repeatability of the used method. RESULTS: The sample size of dynamic studies is limited and translational studies are missing. Magnetic resonance angiography (MRA) and computed tomographic angiography (CTA) were shown to have lower inter-observer variabilities than ultrasonography (US). The distension of several relevant stent-graft-landing zones during the cardiac cycle in both the abdominal and thoracic aorta are significant (mean diameter change of the AAA neck in the included studies ranged from 0.9 mm to 2.4 mm; mean area change of the thoracic aorta ranged from 4.8% to 12.7% at various levels). This distension remained preserved after stent-graft placement. Preoperatively, the renal arteries displace per heartbeat. Significant movement of the aorta in the anteroposterior (AP) and lateral direction, during the cardiac cycle, was observed. CONCLUSION: The aorta exhibits a wide variety of morphologic changes throughout the cardiac cycle. CTA and MRA are reliable modalities to investigate aortic shape changes during the cardiac cycle. Significant changes per heartbeat are reported in the AAA neck and thoracic aorta. The renal artery displaces per heartbeat. The clinical relevance of dynamic imaging has not been proven yet, but dynamic changes of the aorta have to be taken into account in stent-graft selection and future stent-graft design.

TRITON: graphic software for rational engineering of enzymes.

Engineering of the catalytic properties of enzymes requires knowledge about amino acid residues interacting with the transition state of the substrate. TRITON is a graphic software package for modelling enzymatic reactions for the analysis of essential interactions between the enzyme and its substrate and for in silico construction of protein mutants. The reactions are modelled using semi-empirical quantum-mechanic methods and the protein mutants are constructed by homology modelling. The users are guided through the calculation and data analysis by wizards.

Color-Mapping of 4D-CTA for the Detection of Cranial Arteriovenous Shunts.

BACKGROUND AND PURPOSE: 4D CT angiography is increasingly used in clinical practice for the assessment of different neurovascular disorders. Optimized processing of 4D-CTA is crucial for diagnostic interpretation because of the large amount of data that is generated. A color-mapping method for 4D-CTA is presented for improved and enhanced visualization of the cerebral vasculature hemodynamics. This method was applied to detect cranial AVFs. MATERIALS AND METHODS: All patients who underwent both 4D-CTA and DSA in our hospital from 2011 to 2018 for the clinical suspicion of a cranial AVF or carotid cavernous fistula were retrospectively collected. Temporal information in the cerebral vasculature was visualized using a patient-specific color scale. All color-maps were evaluated by 3 observers for the presence or absence of an AVF or carotid cavernous fistula. The presence or absence of cortical venous reflux was evaluated as a secondary outcome measure. RESULTS: In total, 31 patients were included, 21 patients with and 10 without an AVF. Arterialization of venous structures in AVFs was accurately visualized using color-mapping. There was high sensitivity (86%-100%) and moderate-to-high specificity (70%-100%) for the detection of AVFs on color-mapping 4D-CTA, even without the availability of dynamic subtraction rendering. The diagnostic performance of the 3 observers in the detection of cortical venous reflux was variable (sensitivity, 43%-88%; specificity, 60%-80%). CONCLUSIONS: Arterialization of venous structures can be visualized using color-mapping of 4D-CTA and proves to be accurate for the detection of cranial AVFs. This finding makes color-mapping a promising visualization technique for assessing temporal hemodynamics in 4D-CTA.

Multi Detector-Row Computed Tomography (MDCT) had excellent reproducibility of coronary calcium measurements.

OBJECTIVE: To assess reproducibility of coronary calcium measurements with Multi Detector-Row Computed Tomography (MDCT) imaging and to evaluate whether different measurement protocols, slice thickness, and cardiovascular risk factors affect inter and intra-observer reproducibility. STUDY DESIGN AND SETTING: In a cross-sectional design, the study population comprised 199 healthy postmenopausal women. Coronary calcium was assessed using a 16-MDCT (Philips Mx 8000 IDT 16). Images were made using 1.5 and 3.0mm slice thicknesses. To assess inter and intra-observer reproducibility, the images were read by two observers. One observer read the images of 52 subjects twice. The Agatston score, a volume, and a mass measurement were used to quantify coronary calcium. Reproducibility was determined by estimation of mean, absolute, and relative differences between scores of the observers and by estimation of intraclass correlation coefficients (ICC). RESULTS: 60.3% participants (n=120) had a positive calcium score. Median Agatston score for the first observer was 2.20 with a range of 0-2,019. The reproducibility of coronary calcium measurements between and within observers was excellent with ICC of >0.95, and small mean, absolute, and relative differences. Reproducibility findings were similar for 1.5mm slices as for 3.0mm slices, and equal for Agatston, volume, and mass measurements. CONCLUSION: Reproducibilility of coronary calcium measurement using MDCT is excellent, irrespective of slice thickness and type of calcium parameter.