The Rotterdam Scan Study: design update 2016 and main findings

Imaging plays an essential role in research on neurological diseases in the elderly. The Rotterdam Scan Study was initiated as part of the ongoing Rotterdam Study with the aim to elucidate the causes of neurological disease by performing imaging of the brain in a prospective population-based setting. Initially, in 1995 and 1999, random subsamples of participants from the Rotterdam Study underwent neuroimaging, whereas from 2005 onwards MRI has been implemented into the core protocol of the Rotterdam Study. In this paper, we discuss the background and rationale of the Rotterdam Scan Study. Moreover, we describe the imaging protocol, image post-processing techniques, and the main findings to date. Finally, we provide recommendations for future research, which will also be topics of investigation in the Rotterdam Scan Study

Tissue-Specific T2* Biomarkers in Patellar Tendinopathy by Subregional Quantification Using 3D Ultrashort Echo Time MRI

Background: Quantitative MRI of patellar tendinopathy (PT) can be challenging due to spatial variation of T2* relaxation times. Purpose: 1) To compare T2* quantification using a standard approach with analysis in specific tissue compartments of the patellar tendon. 2) To evaluate test–retest reliability of different methods for fitting ultrashort echo time (UTE)-relaxometry data. Study Type: Prospective. Subjects: Sixty-five athletes with PT. Field Strength/Sequence: 3D UTE scans covering the patellar tendon were acquired using a 3.0T scanner and a 16-channel surface coil. Assessment: Voxelwise median T2* was quantified with monoexponential, fractional-order, and biexponential fitting. We applied two methods for T2* analysis: first, a standard approach by analyzing all voxels covering the proximal patellar tendon. Second, within subregions of the patellar tendon, by using thresholds on biexponential fitting parameter percentage short T2* (0–30% for mostly long T2*, 30–60% for mixed T2*, and 60–100% for mostly short T2*). Statistical Tests: Average test–retest reliability was assessed in three athletes using coefficients-of-variation (CV) and coefficients-of-repeatability (CR). Results: With standard image analysis, we found a median [interquartile range, IQR] monoexponential T2* of 6.43 msec [4.32–8.55] and fractional order T2* 4.39 msec [3.06–5.78]. The percentage of short T2* components was 52.9% [35.5–69.6]. Subregional monoexponential T2* was 13.78 msec [12.11–16.46], 7.65 msec [6.49–8.61], and 3.05 msec [2.52–3.60] and fractional order T2* 11.82 msec [10.09–14.44], 5.14 msec [4.25–5.96], and 2.19 msec [1.82–2.64] for 0–30%, 30–60%, and 60–100% short T2*, respectively. Biexponential component short T2* was 1.693 msec [1.417–2.003] for tissue with mostly short T2* and long T2* of 15.79 msec [13.47–18.61] for mostly long T2*. The average CR (CV) was 2 msec (15%), 2 msec (19%) and 10% (22%) for monoexponential, fractional order and percentage short T2*, respectively. Data Conclusion: Patellar tendinopathy is characterized by regional variability in binding states of water. Quantitative multicompartment T2* analysis in PT can be facilitated using a voxel selection method based on using biexponential fitting parameters. Level of Evidence: 1. Technical Efficacy Stage: 1

Pulmonary pathology of pandemic influenza A/H1N1 virus (2009)-infected ferrets upon longitudinal evaluation by computed tomography

We investigated the development of pulmonary lesions in ferrets by means of computed tomography (CT) following infection with the 2009 pandemic A/H1N1 influenza virus and compared the scans with gross pathology, histopathology and immunohistochemistry. Ground-glass opacities observed by CT scanning in all infected lungs corresponded to areas of alveolar oedema at necropsy. These areas were most pronounced on day 3 and gradually decreased from days 4 to 7 post-infection. This pilot study shows that the non-invasive imaging procedure allows quantification and characterization of influenza-induced pulmonary lesions in living animals under biosafety level 3 conditions and can thus be used in pre-clinical pharmaceutical efficacy studies

Decreased static and dynamic postural control in children with autism spectrum disorders

The purpose of this study was to investigate postural control in children with Autism Spectrum Disorders (ASD) during static and dynamic postural challenges. We evaluated postural sway during quiet standing and the center of pressure (COP) shift mechanism during gait initiation for thirteen children with ASD and twelve age matched typically developing (TD) children. Children with ASD produced 438% greater normalized mediolateral sway (p<0.05) and 104% greater normalized anteroposterior sway (p<0.05) than TD children. Consequently, normalized sway area was also significantly greater (p<0.05) in the group with ASD. Similarly, the maximum separation between the COP and center of mass (COM) during quiet stance was 100% greater in the anteroposterior direction (p<0.05) and 146% greater in the resultant direction (p<0.05) for children with ASD. No significant difference was observed in the mediolateral direction, in spite of the 123 % greater separation detected in children with ASD. During gait initiation, no group differences were detected in the posterior COP shift mechanism, suggesting the mechanism for generating forward momentum is intact. However, significantly smaller lateral COP shifts (p<0.05) were observed in children with ASD, suggesting instability or an alternative strategy for generating momentum in the mediolateral direction. These results help clarify some discrepancies in the literature, suggesting an impaired or immature control of posture, even under the most basic conditions when no afferent or sensory information have been removed or modified. Additionally, these findings provide new insight into dynamic balance in children with ASD

Added value of 18F-FDG-PET/CT and cardiac CTA in suspected transcatheter aortic valve endocarditis

Backgrounds: Transcatheter-implanted aortic valve infective endocarditis (TAVI-IE) is difficult to diagnose when relying on the Duke Criteria. Our aim was to assess the additional diagnostic value of 18F-fluorodeoxyglucose (18F-FDG) positron emission/computed tomography (PET/CT) and cardiac computed tomography angiography (CTA) in suspected TAVI-IE. Methods: A multicenter retrospective analysis was performed in all patients who underwent 18F-FDG-PET/CT and/or CTA with suspected TAVI-IE. Patients were first classified with Duke Criteria and after adding 18F-FDG-PET/CT and CTA, they were classified with European Society of Cardiology (ESC) criteria. The final diagnosis was determined by our Endocarditis Team based on ESC guideline recommendations. Results: Thirty patients with suspected TAVI-IE were included. 18F-FDG-PET/CT was performed in all patients and Cardiac CTA in 14/30. Using the Modified Duke Criteria, patients were classified as 3% rejected (1/30), 73% possible (22/30), and 23% definite (7/30) TAVI-IE. Adding 18F-FDG-PET/CT and CTA supported the reclassification of 10 of the 22 possible cases as “definite TAVI-IE” (5/22) or “rejected TAVI-IE” (5/22). This changed the final diagnosis to 20% rejected (6/30), 40% possible (12/30), and 40% definite (12/30) TAVI-IE. Conclusions: Addition of 18F-FDG-PET/CT and/or CTA changed the final diagnosis in 33% of patients and proved to be a valuable diagnostic tool in patients with suspected TAVI-IE

Comparison of 1.0 M gadobutrol and 0.5 M gadopentate dimeglumine-enhanced MRI in 471 patients with known or suspected renal lesions: Results of a multicenter, single-blind, interindividual, randomized clinical phase III trial

The purpose of this phase III clinical trial was to compare two different extracellular contrast agents, 1.0 M gadobutrol and 0.5 M gadopentate dimeglumine, for magnetic resonance imaging (MRI) in patients with known or suspected focal renal lesions. Using a multicenter, single-blind, interindividual, randomized study design, both contrast agents were compared in a total of 471 patients regarding their diagnostic accuracy, sensitivity, and specificity to correctly classify focal lesions of the kidney. To test for noninferiority the diagnostic accuracy rates for both contrast agents were compared with CT results based on a blinded reading. The average diagnostic accuracy across the three blinded readers ('average reader') was 83.7% for gadobutrol and 87.3% for gadopentate dimeglumine. The increase in accuracy from precontrast to combined precontrast and postcontrast MRI was 8.0% for gadobutrol and 6.9% for gadopentate dimeglumine. Sensitivity of the average reader was 85.2% for gadobutrol and 88.7% for gadopentate dimeglumine. Specificity of the average reader was 82.1% for gadobutrol and 86.1% for gadopentate dimeglumine. In conclusion, this study documents evidence for the noninferiority of a single i.v. bolus injection of 1.0 M gadobutrol compared with 0.5 M gadopentate dimeglumine in the diagnostic assessment of renal lesions with CE-MRI

A clinical prediction rule for the diagnosis of coronary artery disease: validation, updating, and extension

Aims The aim was to validate, update, and extend the Diamond-Forrester model for estimating the probability of obstructive coronary artery disease (CAD) in a contemporary cohort. Methods and results Prospectively collected data from 14 hospitals on patients with chest pain without a history of CAD and referred for conventional coronary angiography (CCA) were used. Primary outcome was obstructive CAD, defined as ≥50% stenosis in one or more vessels on CCA. The validity of the Diamond-Forrester model was assessed using calibration plots, calibration-in-the-large, and recalibration in logistic regression. The model was subsequently updated and extended by revising the predictive value of age, sex, and type of chest pain. Diagnostic performance was assessed by calculating the area under the receiver operating characteristic curve (c-statistic) and reclassification was determined. We included 2260 patients, of whom 1319 had obstructive CAD on CCA. Validation demonstrated an overestimation of the CAD probability, especially in women. The updated and extended models demonstrated a c-statistic of 0.79 (95% CI 0.77-0.81) and 0.82 (95% CI 0.80-0.84), respectively. Sixteen per cent of men and 64% of women were correctly reclassified. The predicted probability of obstructive CAD ranged from 10% for 50-year-old females with non-specific chest pain to 91% for 80-year-old males with typical chest pain. Predictions varied across hospitals due to differences in disease prevalence. Conclusion Our results suggest that the Diamond-Forrester model overestimates the probability of CAD especially in women. We updated the predictive effects of age, sex, type of chest pain, and hospital setting which improved model performance and we extended it to include patients of 70 years and olde

Costs and effectiveness of a brief MRI examination of patients with acute knee injury

The aim of this study was to assess the costs and effectiveness of selective short magnetic resonance imaging (MRI) in patients with acute knee injury. A model was developed to evaluate the selective use of MRI in patients with acute knee injury and no fracture on radiography based on the results of a trial in which 208 patients were randomized between radiography only and radiography plus MRI. We analyzed medical (diagnostic and therapeutic) costs, quality of life, duration of diagnostic workup, number of additional diagnostic examinations, time absent from work, and time to convalescence during a 6-month follow-up period. Quality of life was lowest (EuroQol at 6 weeks 0.61 (95% CI 0.54–0.67)); duration of diagnostic workup, absence from work, and time to convalescence were longest; and the number of diagnostic examinations was largest with radiography only. These outcomes were more favorable for both MRI strategies (EuroQol at 6 weeks 0.72 (95% CI 0.67–0.77) for both). Mean total costs were 2,593 euros (95% CI 1,815–3,372) with radiography only, 2,116 euros (95% CI 1,488–2,743) with radiography plus MRI, and 1,973 euros (95% CI 1,401–2,543) with selective MRI. The results suggest that selective use of a short MRI examination saves costs and potentially increases effectiveness in patients with acute knee injury without a fracture on radiography