Preference-Based Implementation of Video Consultations in Urban and Rural Regions in Outpatient Care in Germany: Protocol for a Mixed Methods Study

BACKGROUND

Particularly in rural regions, factors such as lower physician density and long travel distances complicate adequate outpatient care. However, urban regions can also be affected by deficits in care, for example, long waiting times. One model of care intending to improve the situation is the implementation of video consultations. The study protocol presents the methodology of the research project titled "Preference-based implementation of the video consultation in urban and rural regions" funded by the German Federal Joint Committee (funding number 01VSF20011).

OBJECTIVE

This study aims to identify existing barriers to the use of video consultation and the preferences of insured individuals and physicians as well as psychotherapists in order to optimize its design and thus increase acceptance and use of video consultations in urban and rural regions.

METHODS

Built on a mixed methods approach, this study first assesses the status quo of video consultation use through claims data analysis and carries out a systematic literature review on barriers and promoting factors for the use of video consultations. Based on this preliminary work, focus groups are conducted in order to prepare surveys with insureds as well as physicians and psychotherapists in the second study phase. The central element of the survey is the implementation of discrete choice experiments to elicit relevant preferences of (potential) user groups and service providers. The summarized findings are discussed in a stakeholder workshop and translated into health policy recommendations.

RESULTS

The methodological approach used in this study is the focus of this paper. The study is still ongoing and will continue until March 2024. The first study phase has already been completed, in which preliminary work has been done on potential applications and hurdles for the use of video consultations. Currently, the survey is being conducted and analyses are being prepared.

CONCLUSIONS

This study is intended to develop a targeted strategy for health policy makers based on actual preferences and perceived obstacles to the use of video consultations. The results of this study will contribute to further user-oriented development of the implementation of video consultations in German statutory health insurance. Furthermore, the iterative and mixed methods approach used in this study protocol is also suitable for a variety of other research projects.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/50932.

Iopromide for Contrast-Enhanced Mammography: A Systemic Review and Meta-Analysis of Pertinent Literature

Background

Contrast-enhanced mammography (CEM) is an emerging breast imaging modality. Clinical data is scarce.

Objectives

To summarize clinical evidence on the use of iopromide in CEM for the detection or by systematically analyzing the available literature on efficacy and safety.

Design

Systematic review and meta-analysis.

Data sources and methods

Iopromide-specific publications reporting its use in CEM were identified by a systematic search within Bayer's Product Literature Information (PLI) database and by levering a recent review publication. The literature search in PLI was performed up to January 2023. The confirmatory-supporting review publication was based on a MEDLINE/EMBASE + full text search for publications issued between September 2003 and January 2019. Relevant literature was selected based on pre-defined criteria by 2 reviewers. The comparison of CEM vs traditional mammography (XRM) was performed on published results of sensitivity and specificity. Differences in diagnostic parameters were assessed within a meta-analysis.

Results

Literature search: A total of 31 studies were identified reporting data on 5194 patients. Thereof, 19 studies on efficacy and 3 studies on safety. Efficacy: in 11 studies comparing iopromide CEM vs XRM, sensitivity was up to 43% higher (range 1%-43%) for CEM. Differences in specificity were found to be in a range of -4% to 46% for CEM compared with XRM. The overall gain in sensitivity for CEM vs XRM was 7% (95% CI [4%, 11%]) with no statistically significant loss in specificity in any study assessed. In most studies, accuracy, positive predictive value, and negative predictive value were found to be in favor of CEM. In 2 studies comparing CEM with breast magnetic resonance imaging (bMRI), both imaging modalities performed either equally well or CEM tended to show better results with respect to sensitivity and specificity. Safety: eight cases of iopromide-related adverse drug reactions were reported in 1022 patients (0.8%).

Conclusions

Pertinent literature provides evidence for clinical utility of iopromide in CEM for the detection or confirmation of breast cancer. The overall gain in sensitivity for iopromide CEM vs XRM was 7% with no statistically significant loss in specificity.

Long-term cardiac pathology in individuals with mild initial COVID-19 illness

Cardiac symptoms are increasingly recognized as late complications of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in previously well individuals with mild initial illness, but the underlying pathophysiology leading to long-term cardiac symptoms remains unclear. In this study, we conducted serial cardiac assessments in a selected population of individuals with Coronavirus Disease 2019 (COVID-19) with no previous cardiac disease or notable comorbidities by measuring blood biomarkers of heart injury or dysfunction and by performing magnetic resonance imaging. Baseline measurements from 346 individuals with COVID-19 (52% females) were obtained at a median of 109 days (interquartile range (IQR), 77-177 days) after infection, when 73% of participants reported cardiac symptoms, such as exertional dyspnea (62%), palpitations (28%), atypical chest pain (27%) and syncope (3%). Symptomatic individuals had higher heart rates and higher imaging values or contrast agent accumulation, denoting inflammatory cardiac involvement, compared to asymptomatic individuals. Structural heart disease or high levels of biomarkers of cardiac injury or dysfunction were rare in symptomatic individuals. At follow-up (329 days (IQR, 274-383 days) after infection), 57% of participants had persistent cardiac symptoms. Diffuse myocardial edema was more pronounced in participants who remained symptomatic at follow-up as compared to those who improved. Female gender and diffuse myocardial involvement on baseline imaging independently predicted the presence of cardiac symptoms at follow-up. Ongoing inflammatory cardiac involvement may, at least in part, explain the lingering cardiac symptoms in previously well individuals with mild initial COVID-19 illness.

Combined Analysis of Two Parallel Randomized Trials of Sirolimus-Coated and Paclitaxel-Coated Balloons in Coronary In-Stent Restenosis Lesions

BACKGROUND

Paclitaxel-coated balloons (PCBs) are a preferred treatment option for coronary in-stent restenosis. To date, data from randomized trials of alternative drug coatings are lacking. The aim of the randomized Malaysian and German-Swiss randomized trials was to investigate a novel sirolimus-coated balloon (SCB) compared with a PCB in in-stent restenosis.

METHODS

One hundred one patients with drug-eluting stent in-stent restenosis were enrolled in 2 identical randomized trials comparing the novel SCB (SeQuent SCB, 4 μg/mm²) with the clinically proven PCB (SeQuent Please, 3 μg/mm²). Primary end point was angiographic late lumen loss at 6 months. Secondary end points included procedural success, major adverse cardiac events, and individual clinical end points such as stent thrombosis, cardiac death, target lesion myocardial infarction, clinically driven target lesion revascularization, and binary restenosis.

RESULTS

Quantitative coronary angiography revealed no differences in baseline parameters. After 6 months, in-segment late lumen loss was 0.25±0.57 mm in the PCB group versus 0.26±0.60 mm in the SCB group. Mean difference between SCB and PCB was 0.01 (95% CI, -0.23 to 0.24). Noninferiority at a predefined margin of 0.35 was shown. Clinical events up to 12 months did not differ between the groups.

CONCLUSIONS

This first-in man comparison of a novel SCB with a crystalline coating showed similar angiographic and clinical outcomes in the treatment of coronary drug-eluting stent in-stent restenosis compared with PCB.

REGISTRATION

URL: https://www.

CLINICALTRIALS

gov; Unique identifier: NCT02996318, NCT03242096.

A phase I study assessing the safety, tolerability, immunogenicity, and low-density lipoprotein cholesterol-lowering activity of immunotherapeutics targeting PCSK9

Purpose

AT04A and AT06A are two AFFITOPE® peptide vaccine candidates being developed for the treatment of hypercholesterolemia by inducing proprotein convertase subtilisin/kexin type 9 (PCSK9)-specific antibodies. This study aimed to investigate safety, tolerability, antibody development, and reduction of low-density lipoprotein cholesterol (LDLc) following four subcutaneous immunizations.

Methods

This phase I, single-blind, randomized, placebo-controlled study was conducted in a total of 72 healthy subjects with a mean fasting LDLc level at baseline of 117.1 mg/dL (range 77–196 mg/dL). Each cohort enrolled 24 subjects to receive three priming immunizations at weeks 0, 4, and 8 and to receive a single booster immunization at week 60 of either AT04A, AT06A, or placebo. In addition to safety (primary objective), the antigenic peptide- and PCSK9-specific antibody response and the impact on LDLc were evaluated over a period of 90 weeks.

Results

The most common systemic treatment-related adverse events (AEs) reported were fatigue, headache, and myalgia in 75% of subjects in the AT06A group and 58% and 46% of subjects in the placebo and AT04A groups, respectively. Injection site reactions (ISR) representing 63% of all treatment-emergent adverse events (TEAEs), were transient and mostly of mild or moderate intensity and rarely severe (3%). Both active treatments triggered a robust, long-lasting antibody response towards the antigenic peptides used for immunization that optimally cross-reacted with the target epitope on PCSK9. In the AT04A group, a reduction in serum LDLc was observed with a mean peak reduction of 11.2% and 13.3% from baseline compared to placebo at week 20 and 70 respectively, and over the whole study period, the mean LDLc reduction for the AT04A group vs. placebo was −7.2% (95% CI [−10.4 to −3.9], P < 0.0001). In this group, PCSK9 target epitope titers above 50 were associated with clinically relevant LDLc reductions with an individual maximal decrease of 39%.

Conclusions

Although both AT04A and AT06 were safe and immunogenic, only AT04A demonstrated significant LDLc-lowering activity, justifying further development.

Trial registration

EudraCT: 2015-001719-11. ClinicalTrials.gov Identifier: NCT02508896.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00228-021-03149-2.

Assessing the Quality and Coherence of Network Meta-Analyses of Biologics in Plaque Psoriasis: What Does All This Evidence Synthesis Tell Us?

INTRODUCTION

A range of treatments are available for moderate-to-severe psoriasis; however, there remains a paucity of direct comparisons of these in head-to-head trials. Network meta-analyses (NMA) allow comparisons of these to support clinical decision making. This systematic literature review assesses the methodological quality of NMAs available for moderate-to-severe psoriasis and compares their methods and results. Their validity and applicability for current practice is also assessed.

METHODS

A systematic review of published NMAs of at least two biologics for moderate-to-severe psoriasis was undertaken. Embase, MEDLINE, MEDLINE In-Process, and the Cochrane Library were last searched on 19 February 2020. The quality of NMAs was assessed using the International Society of Pharmacoeconomics and Outcomes Research (ISPOR) criteria. NMA methodology, funding, and results were compared and differences in results explored.

RESULTS

Twenty-five analyses evaluating up to 19 different treatments at 8-24 weeks, and two analyses at 1 year, were included. Psoriasis Area Severity Index (PASI) response was assessed in 23, facilitating comparisons between NMAs. All NMAs met at least half of the ISPOR criteria. The major limitations were explaining the rationale for methodology, exploring effect modifiers, and consistency between direct and indirect estimates. The analyses differed in model type (Bayesian or frequentist), analysis of PASI response (binomial or multinomial), and analysis of different treatment doses (separate or pooled). PASI results were broadly similar, except for the Cochrane Collaboration NMA which provided lower estimates of treatment efficacy versus placebo. This analysis differed methodologically from others, including pooling data for different doses.

CONCLUSIONS

Based on PASI 90 at induction, the majority of recent NMAs came to similar conclusions: interleukin (IL) 17 inhibitors (brodalumab, ixekizumab, secukinumab), IL-23 inhibitors (guselkumab and risankizumab) and infliximab were most efficacious, supporting the validity of NMAs in this clinical area. Decisions should be made using high-quality, up-to-date NMAs with assumptions relevant to clinical practice.

Non-contrast-enhanced MR-angiography (MRA) of lower extremity peripheral arterial disease at 3 tesla: Examination time and diagnostic performance of 2D quiescent-interval single-shot MRA vs. 3D fast spin-Echo MRA

PURPOSE

Non-contrast enhanced MRA is a promising diagnostic alternative to contrast-enhanced (CE-) MRA or CT in patients with lower extremity peripheral arterial disease (PAD) but potentially associated with prolonged examination times and inferior diagnostic performance. We aimed to compare examination times and diagnostic performance of non-contrast enhanced quiescent-interval slice-selective (QISS)-MRA and fast-spin-echo (FSE)-MRA at 3.0 T.

MATERIALS AND METHODS

Forty-five patients with PAD were recruited for this IRB approved prospective study. Subjects underwent lower extremity MRA with 1) QISS-MRA, 2) FSE-MRA, and 3) CE-MRA (continuous table movement MRA and time-resolved MRA of the calf), which served as the standard of reference. Scan times for each examination step and total examination times for each of the three techniques was determined. Image quality and degree of stenosis were rated by two readers on a 5-point Likert scale. Sensitivity, specificity and diagnostic accuracy for relevant (>50%) stenosis were calculated.

RESULTS

Median total examination time was 27:02 min for QISS-MRA (IQR, 25:13-31:01 min), 28:37 min for FSE-MRA (IQR, 25:51-33:12 min), and 31:22 min for CE-MRA (IQR, 26:41-33:23 min). Acquisition time for QISS-MRA was significantly longer compared to FSE-MRA and CE-MRA (p ≤ 0.0001), while time for localizers, scouts and planning of the MRA sequence was significantly shorter for QISS-MRA compared to FSE-MRA and CE-MRA (p ≤ 0.0001). QISS-MRA had significantly better image quality compared to FSE-MRA with less segments classified as non-diagnostic (Reader 1: 3% vs. 35%; Reader 2: 3% vs. 50%, p ≤ 0.0001). Overall, QISS-MRA showed significantly better diagnostic performance than FSE-MRA (sensitivity, 85% vs. 54%; specificity, 90% vs. 47%, diagnostic accuracy, 89% vs. 48%; p ≤ 0.0001).

CONCLUSION

Total examination time of QISS-MRA and FSE-MRA was comparable with a conventional CE-MRA protocol. QISS-MRA showed significantly higher diagnostic performance than FSE-MRA.

Safety and immunogenicity of the α-synuclein active immunotherapeutic PD01A in patients with Parkinson's disease: a randomised, single-blinded, phase 1 trial

BACKGROUND

Robust evidence supports the role of α-synuclein pathology as a driver of neuronal dysfunction in Parkinson's disease. PD01A is a specific active immunotherapy with a short peptide formulation targeted against oligomeric α-synuclein. This phase 1 study assessed the safety and tolerability of the PD01A immunotherapeutic in patients with Parkinson's disease.

METHODS

We did a first-in-human, randomised, phase 1 study of immunisations with PD01A, followed by three consecutive study extensions. Patients aged 45-65 years with a clinical diagnosis of Parkinson's disease (≤4 years since diagnosis and Hoehn and Yahr Stage 1 to 2), imaging results (dopamine transporter single photon emission CT and MRI) consistent with their Parkinson's disease diagnosis, and on stable doses of Parkinson's disease medications for at least 3 months were recruited at a single private clinic in Vienna, Austria. Patients were randomly assigned (1:1), using a computer-generated sequence with varying block size, to receive four subcutaneous immunisations with either 15 μg or 75 μg PD01A injected into the upper arms and followed up initially for 52 weeks, followed by a further 39 weeks' follow-up. Patients were then randomly assigned (1:1) again to receive the first booster immunisation at 15 μg or 75 μg and were followed up for 24 weeks. All patients received a second booster immunisation of 75 μg and were followed up for an additional 52 weeks. Patients were masked to dose allocation. Primary (safety) analyses included all treated patients. These four studies were registered with EU Clinical Trials Register, EudraCT numbers 2011-002650-31, 2013-001774-20, 2014-002489-54, and 2015-004854-16.

FINDINGS

32 patients were recruited between Feb 14, 2012, and Feb 6, 2013, and 24 were deemed eligible and randomly assigned to receive four PD01A priming immunisations. One patient had a diagnosis change to multiple system atrophy and was withdrawn and two patients withdrew consent during the studies. 21 (87%) of 24 patients received all six immunisations and completed 221-259 weeks in-study (two patients in the 15 μg dose group and one patient in the 75 μg dose group discontinued). All patients experienced at least one adverse event, but most of them were considered unrelated to study treatment (except for transient local injection site reactions, which affected all but one patient). Serial MRI assessments also ruled out inflammatory processes. Systemic treatment-related adverse events were fatigue (n=4), headache (n=3), myalgia (n=3), muscle rigidity (n=2), and tremor (n=2). The geometric group mean titre of antibodies against the immunising peptide PD01 increased from 1:46 at baseline to 1:3580 at week 12 in the 15 μg dose group, and from 1:76 to 1:2462 at week 12 in the 75 μg dose group. Antibody titres returned to baseline over 2 years, but could be rapidly reactivated after booster immunisation from week 116 onwards, reaching geometric group mean titres up to 1:20218.

INTERPRETATION

Repeated administrations of PD01A were safe and well tolerated over an extended period. Specific active immunotherapy resulted in a substantial humoral immune response with target engagement. Phase 2 studies are needed to further assess the safety and efficacy of PD01A for the treatment of Parkinson's disease.

FUNDING

AFFiRiS, Michael J Fox Foundation.

Comparability of compressed sensing-based gradient echo perfusion sequence SPARSE and conventional gradient echo sequence in assessment of myocardial ischemia

PURPOSE

Stress perfusion imaging plays a major role in non-invasive detection of coronary artery disease. We compared a compressed sensing-based and a conventional gradient echo perfusion sequence with regard to image quality and diagnostic performance.

METHOD

Patients sent for coronary angiography due to pathologic stress perfusion CMR were recruited. All patients underwent two adenosine stress CMR using conventional TurboFLASH and prototype SPARSE sequence as well as quantitative coronary angiography with fractional flow reserve (FFR) within 6 weeks. Coronary angiography was considered gold standard with FFR < 0.75 or visual stenosis >90 % for identification of myocardial ischemia. Diagnostic performance of perfusion imaging was assessed in basal, mid-ventricular and apical slices by quantification of myocardial perfusion reserve (MPR) analysis utilizing the signal upslope method and a deconvolution technique using the fermi function model.

RESULTS

23 patients with mean age of 69.6 ± 8.9 years were enrolled. 46 % were female. Image quality was similar in conventional TurboFLASH sequence and SPARSE sequence (2.9 ± 0.5 vs 3.1 ± 0.7, p = 0,06). SPARSE sequence showed higher contrast-to-noise ratio (52.1 ± 27.4 vs 40.5 ± 17.6, p < 0.01) and signal-to-noise ratio (15.6 ± 6.2 vs 13.2 ± 4.2, p < 0.01) than TurboFLASH sequence. Dark-rim artifacts occurred less often with SPARSE (9 % of segments) than with TurboFLASH (23 %). In visual assessment of perfusion defects, SPARSE sequence detected less false-positive perfusion defects (n = 1) than TurboFLASH sequence (n = 3). Quantitative perfusion analysis on segment basis showed equal detection of perfusion defects for TurboFLASH and SPARSE with both upslope MPR analysis (TurboFLASH 0.88 ± 0.18; SPARSE 0.77 ± 0.26; p = 0.06) and fermi function model (TurboFLASH 0.85 ± 0.24; SPARSE 0.76 ± 0.30; p = 0.13).

CONCLUSIONS

Compressed sensing perfusion imaging using SPARSE sequence allows reliable detection of myocardial ischemia.

Impact of sequence type and field strength (1.5, 3, and 7T) on 4D flow MRI hemodynamic aortic parameters in healthy volunteers

PURPOSE

4D flow magnetic resonance imaging (4D-MRI) allows time-resolved visualization of blood flow patterns, quantification of volumes, velocities, and advanced parameters, such as wall shear stress (WSS). As 4D-MRI enters the clinical arena, standardization and awareness of confounders are important. Our aim was to evaluate the equivalence of 4D flow-derived aortic hemodynamics in healthy volunteers using different sequences and field strengths.

METHODS

4D-MRI was acquired in 10 healthy volunteers at 1.5T using three different prototype sequences, at 3T and at 7T (Siemens Healthineers). After evaluation of diagnostic quality in three segments (ascending-, descending aorta, aortic arch), peak velocity, flow volumes, and WSS were investigated. Equivalence limits for comparison of field strengths/sequences were based on the limits of Bland-Altman analyses of the intraobserver variability.

RESULTS

Non-diagnostic quality was found in 10/144 segments, 9/10 were obtained at 7T. Apart for the comparison of forward flow between sequence 1 and 3, the differences in measurements between field strengths/sequences exceeded the range of agreement. Significant differences were found between field strengths/sequences for forward flow (1.5T vs. 3T, 3T vs. 7T, sequence 1 vs. 3, 2 vs. 3 [P < .001]), WSS (1.5T vs. 3T [P < .05], sequence 1 vs. 2, 1 vs. 3, 2 vs. 3 [P < .001]), and peak velocity (1.5T vs. 7T, sequence 1 vs. 3 [P > .001]). All parameters at all field strengths/with all sequences correlated moderately to strongly (r ≥ 0.5).

CONCLUSION

Data from all sequences could be acquired and resulting images showed sufficient quality for further analysis. However, the variability of the measurements of peak velocity, flow volumes, and WSS was higher when comparing field strengths/sequences as the equivalence limits defined by the intraobserver assessments.

Comparison of 2 CT Contrast Media Injection Systems: Visual Air Identification and Injector Face Cleaning

PURPOSE

To compare the MEDRAD Stellant and MEDRAD Stellant FLEX computed tomography contrast media injection systems in terms of radiologic technologists' ability to visually identify air in the syringes at various distances and under different lighting conditions, as well as the ease of cleaning contrast media spills on the injector faces.

METHODS

Ten experienced radiologic technologists performed 104 tests (52 per injector) in normal light and in ambient light conditions. The tests were randomized for the radiologic technologists' distance from the injector at 2 ft (61 cm), 8 ft (244 cm), and 16 ft (488 cm). In addition, the authors tested the cleaning efficiency of the Stellant injector face with raised buttons and the Stellant FLEX injector face with buttons on a flush surface by applying a mixture of contrast media and invisible ultraviolet ink. Radiologic technologists followed 2 cleaning protocols: a quick clean (5 seconds) and a full clean (1 minute). Residual contrast mixture was measured.

RESULTS

The Stellant FLEX injector had an overall higher rate of correct air identification than did the Stellant injector, 97.5% vs 86.9%, respectively (P < .001), with improvement seen at greater distances. The rates for the Stellant FLEX injector remained stable for all distances (99.4%-93.9%; P < .003). A similar result was seen with ambient lighting: The visibility of air in the Stellant FLEX injector remained stable (P < .001). During cleaning, the Stellant FLEX injector required less time to reach a greater level of cleanliness and showed less contrast mixture residue, especially after the quick clean procedure (16% and 59%, respectively; P < .001).

DISCUSSION

Injector manufacturers provide various technologies to assist radiologic technologists in visualizing the presence of air in a syringe. The Stellant injector features clear syringes with FluiDots as an air identification technology. The Stellant FLEX injector incorporates an added feature called Beacon technology. This study's results are highly clinically relevant because unintentional iatrogenic air injection occurs in clinical practice and can, in rare cases, severely harm patients.

CONCLUSION

Radiologic technologists showed an improved ability to identify air in the syringes in the Stellant FLEX system. In addition, radiologic technologists were confident about their identification, specifically at greater distances and in ambient lighting conditions. The Stellant FLEX injector face also enabled quicker and more efficient cleaning.

Magnetic Resonance Perfusion or Fractional Flow Reserve in Coronary Disease

BACKGROUND

In patients with stable angina, two strategies are often used to guide revascularization: one involves myocardial-perfusion cardiovascular magnetic resonance imaging (MRI), and the other involves invasive angiography and measurement of fractional flow reserve (FFR). Whether a cardiovascular MRI-based strategy is noninferior to an FFR-based strategy with respect to major adverse cardiac events has not been established.

METHODS

We performed an unblinded, multicenter, clinical-effectiveness trial by randomly assigning 918 patients with typical angina and either two or more cardiovascular risk factors or a positive exercise treadmill test to a cardiovascular MRI-based strategy or an FFR-based strategy. Revascularization was recommended for patients in the cardiovascular-MRI group with ischemia in at least 6% of the myocardium or in the FFR group with an FFR of 0.8 or less. The composite primary outcome was death, nonfatal myocardial infarction, or target-vessel revascularization within 1 year. The noninferiority margin was a risk difference of 6 percentage points.

RESULTS

A total of 184 of 454 patients (40.5%) in the cardiovascular-MRI group and 213 of 464 patients (45.9%) in the FFR group met criteria to recommend revascularization (P = 0.11). Fewer patients in the cardiovascular-MRI group than in the FFR group underwent index revascularization (162 [35.7%] vs. 209 [45.0%], P = 0.005). The primary outcome occurred in 15 of 421 patients (3.6%) in the cardiovascular-MRI group and 16 of 430 patients (3.7%) in the FFR group (risk difference, -0.2 percentage points; 95% confidence interval, -2.7 to 2.4), findings that met the noninferiority threshold. The percentage of patients free from angina at 12 months did not differ significantly between the two groups (49.2% in the cardiovascular-MRI group and 43.8% in the FFR group, P = 0.21).

CONCLUSIONS

Among patients with stable angina and risk factors for coronary artery disease, myocardial-perfusion cardiovascular MRI was associated with a lower incidence of coronary revascularization than FFR and was noninferior to FFR with respect to major adverse cardiac events. (Funded by the Guy's and St. Thomas' Biomedical Research Centre of the National Institute for Health Research and others; MR-INFORM ClinicalTrials.gov number, NCT01236807.).

DCE-MR imaging of orbital lesions: diagnostic performance of the tumor flow residence time τ calculated by a multi-compartmental pharmacokinetic tumor model based on individual factors

BACKGROUND

Differentiating benign from malignant orbital lesions by imaging and clinical presentation can be challenging.

PURPOSE

To differentiate benign from malignant orbital masses using dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) based on tumor flow residence time τ calculated with the aid of a pharmacokinetic tumor model.

MATERIAL AND METHODS

Sixty patients with orbital masses were investigated by 3-T MRI including dynamic sequences. The signal intensity-time curve after i.v. contrast medium administration within lesions was approximated by Gd-concentration profiles on the basis of model calculations where the tumor is embedded in a whole-body kinetic model. One output of the model was tumor flow residence time τ, defined as the ratio of the tumor volume and the tumor blood flow rate. Receiver operating characteristic (ROC) curves were used to analyze the diagnostic performance of τ. The results were compared with those of K^trans, k_ep, v_e, iAUC, and ADC.

RESULTS

Thirty-one benign and 29 malignant orbital masses were identified (reference standard: histopathology, clinical characteristics). Mean τ was significantly longer for benign masses (94 ± 48 s) than for malignant masses (21 ± 19 s, P < 0.001). ROC analysis revealed the highest area under the curve (AUC = 0.94) for τ in orbital masses compared to standard methods.

CONCLUSION

Tumor flow residence times τ of benign and malignant orbital masses are valuable in the diagnostic work-up of orbital tumors. Measures of diagnostic accuracy were superior for τ compared to ADC, K^trans, v_e, and iAUC.

On estimands and the analysis of adverse events in the presence of varying follow-up times within the benefit assessment of therapies

The analysis of adverse events (AEs) is a key component in the assessment of a drug's safety profile. Inappropriate analysis methods may result in misleading conclusions about a therapy's safety and consequently its benefit-risk ratio. The statistical analysis of AEs is complicated by the fact that the follow-up times can vary between the patients included in a clinical trial. This paper takes as its focus the analysis of AE data in the presence of varying follow-up times within the benefit assessment of therapeutic interventions. Instead of approaching this issue directly and solely from an analysis point of view, we first discuss what should be estimated in the context of safety data, leading to the concept of estimands. Although the current discussion on estimands is mainly related to efficacy evaluation, the concept is applicable to safety endpoints as well. Within the framework of estimands, we present statistical methods for analysing AEs with the focus being on the time to the occurrence of the first AE of a specific type. We give recommendations which estimators should be used for the estimands described. Furthermore, we state practical implications of the analysis of AEs in clinical trials and give an overview of examples across different indications. We also provide a review of current practices of health technology assessment (HTA) agencies with respect to the evaluation of safety data. Finally, we describe problems with meta-analyses of AE data and sketch possible solutions.

Diagnostic Efficacy and Safety of Gadoxetate Disodium vs Gadobenate Dimeglumine in Patients With Known or Suspected Focal Liver Lesions: Results of a Clinical Phase III Study

Purpose:

The aim of this study is to evaluate the diagnostic efficacy and safety of gadoxetate disodium vs gadobenate dimeglumine in patients with known or suspected focal liver lesions.

Methods:

This was a prospective, multicenter, double-blind, randomized, inter-individual Phase III study. The primary target—technical efficacy—was already published. Here, secondary efficacy parameters—sensitivity and specificity—and safety in specific patient populations are presented. Patients with suspected or known focal liver lesions scheduled for contrast-enhanced liver magnetic resonance imaging (MRI) were recruited and categorized in 4 a priori specified subgroups: (1) all patients, (2) patients with liver cancer (hepatocellular carcinoma [HCC]), (3) patients with cirrhosis, and (4) patients with HCC + cirrhosis. Dual multi-detector liver computed tomography (CT) served as standard of reference.

Results:

A total of 295 patients were included. While the overall increase in sensitivity across all 4 patient groups was comparable for gadoxetate disodium (increase from pre- to post-contrast ranging from 6.2% to 9.9%) and gadobenate dimeglumine (ranging from −2.9% to 10.0%), significant differences were seen for some of the subgroups. There was a significantly higher increase in sensitivity for gadoxetate disodium in patients with HCC (7%) and HCC + cirrhosis (12.8%) in comparison with gadobenate dimeglumine. Specificity decreased for both agents: gadoxetate disodium by −2.8% to −6.3% and gadobenate dimeglumine by −3.3% to −8.7%. Gadoxetate showed a significantly lower loss of specificity in all subgroups. Safety was comparable in both groups.

Conclusions:

Gadoxetate disodium proved to be an effective liver-specific MRI contrast agent. Some distinct advantages over gadobenate dimeglumine were demonstrated in patients with HCC and patients with HCC + liver cirrhosis for sensitivity and specificity in liver lesion detection.

Detection of Sacroiliitis by Short-tau Inversion Recovery and T2-weighted Turbo Spin Echo Sequences: Results from the SIMACT Study

Objective.

To compare proton density–weighted short-tau inversion recovery (PD-STIR) and T2-weighted fat-suppressed turbo spin echo (T2-FS) sequences for detecting osteitis lesions of the sacroiliac joints (SIJ) in patients with chronic low back pain (CLBP).

Methods.

This prospective study included 110 patients with CLBP and suspected spondyloarthritis and 18 healthy controls. All 128 participants (age range: 19–57 yrs) underwent 3.0 Tesla magnetic resonance imaging (MRI) of the SIJ including PD-STIR and T2-FS. Two readers independently scored PD-STIR and T2-FS images for osteitis in separate sessions. Sum scores and signal-to-noise (SNR) and contrast-to-noise (CNR) ratios were calculated. Images were further analyzed as to whether they fulfilled the Assessment of SpondyloArthritis international Society (ASAS) criterion of a positive MRI (MRI+). Interreader agreement was calculated using intraclass correlation coefficients.

Results.

Average osteitis sum scores were higher for T2-FS images (mean sum score of 4.10 in T2-FS vs 2.55 in PD-STIR, p = 0.017). Mean SNR was 16.54 for PD-STIR and 37.30 for T2-FS (p = 0.0289). Mean CNR was 4.14 for PD-STIR and 20.20 for T2-FS (p = 0.0212). For both readers, the ASAS MRI+ definition was more often fulfilled by T2-FS than by PD-STIR images, resulting in more patients being classified as having axial spondyloarthritis (axSpA): 68 patients using T2-FS versus 58 patients using PD-STIR. Interreader intraclass correlation coefficients were very good for both PD-STIR (0.91) and T2-FS (0.86).

Conclusion.

T2-FS sequences improve image quality and hence the detection of osteitis compared to the PD-STIR sequence. More patients were classified as axSpA based on a positive MRI by T2-FS.

Comparing the EQ-5D-5L utility index based on value sets of different countries: impact on the interpretation of clinical study results

Objective

To compare the country-specific value sets of the EQ-5D-5L utility index and to evaluate the impact on the interpretation of clinical study results. Six country value sets from Canada, England, Japan, Korea, Netherlands and Uruguay were obtained from literature. In addition, ten crosswalk value sets were downloaded from the EuroQol.org website.

Results

For each of the 3125 possible health states the difference between the country with the highest index and the country with the lowest index was calculated. The median difference was 0.417 across the health states. When analyzing multinational clinical studies, country-specific value sets should be used to evaluate treatment effects. Additional country-specific analyses are needed.

Electronic supplementary material

The online version of this article (10.1186/s13104-019-4067-9) contains supplementary material, which is available to authorized users.

Critical appraisal of RCTs by 3rd year undergraduates after short courses in EBM compared to expert appraisal

Introduction: An essential aim of courses in evidence-based medicine (EBM) is to improve the skills for reading and interpreting medical literature adequately. Regarding the conceptual framework, it is important to consider different educational levels. Aim: Our primary aim was to investigate the applicability of different instruments for the assessment of methodological study quality by 3rd grade students after short courses in EBM. Our secondary outcomes were agreement with expert assessments and student's knowledge and competences. Methods: We conducted four short courses in EBM of 90 minutes each for health care management and medical students focused on critical appraisal of the literature. At the end, the students assessed five publications about randomized controlled trials (RCTs) using five different instruments; the results were compared to expert assessments. Results: In total, 167 students participated in our EBM courses. Students' assessments showed a non-systematic over- and underestimation of risk of bias compared to expert assessments with no clear direction. Agreement with expert assessments ranged between 66% to over 80%. Across RCTs, evidence was found that the choice of instrument had an impact on agreement rates between expert and student assessments (p=0.0158). Three RCTs showed an influence of the instrument on the agreement rate (p<0.05 each). Discussion: Our results contrast sharply with those of many other comparable evaluations. Reasons may be a lack of students' motivation due to the compulsory courses, and the comparison to a reference standard in addition to self-ratings causing objectivity. Conclusion: Undergraduates should become familiar with the principles of EBM, including research methods, and the reading of scientific papers as soon as possible. For a deeper understanding, clinical experience seems to be an indispensable precondition. Based on our results, we would recommend an integration of lectures about EBM and critical appraisal at least twice during studies and with greater intensity shortly before graduation.

Analysis of Proportions from Clustered Data with Missing Observations in a Matched-pair Design

Objectives: Typically, methods for the estimation of differences in proportions from clustered data are based on complete cases with no missing information [1, 2]. In this paper we propose an extension to the method of Rao and Scott [3] and Obuchowski [2] to allow for the explicit computation of the variance of the estimator for the difference in presence of incomplete cases.

Methods: We divided the full analysis set into a set of complete cases and a set of incomplete cases. The differences in proportions of correct diagnoses were estimated for each set by taking into consideration the clustering effect for both sets and the correlation between the procedures in the set with complete cases. Then the estimates of the two parts were combined by appropriate weights, which then allowed the explicit calculation of the variance. The performance of the extension as compared to the original method and generalized estimation equations model (GEEs) was examined by simulations.

Results: The results of the examples suggest that the extended approach is superior to the complete-case method and is therefore appropriate when all data are to be used. In comparison to GEEs, the extended method appears to be slightly inferior, when the number of observations per patient is high, but of similar efficiency with a low number of observations per patient.

Conclusions: With the extension of the method by Rao and Scott [3] and Obuchowski [2] we make use of all available data. Therefore, we follow the intent-to-treat principle as close as possible.

Image quality of low-radiation dose left atrial CT using filtered back projection and an iterative reconstruction algorithm: intra-individual comparison in unselected patients undergoing pulmonary vein isolation

Background Computed tomography (CT) of the left atrium (LA) is performed prior to pulmonary vein isolation (PVI) to improve success of circumferential ablation for atrial fibrillation. The ablation procedure itself exposes patients to substantial radiation doses, therefore radiation dose reduction in pre-ablational imaging is of concern. Purpose To assess and compare diagnostic performance of low-radiation dose preprocedural CT in patients scheduled for PVI using two types of reconstruction algorithms. Material and Methods Forty-six patients (61 ± 10 years) scheduled for PVI were enrolled in this study irrespective of body-mass-index or cardiac rhythm at examination. An electrocardiographically triggered dual-source CT scan was performed. Filtered back projection (FBP) and iterative reconstruction (IR) algorithms were applied. Images were integrated into an electroanatomic mapping (EAM) system. Subjective image quality was scored independently by two readers on a five-point scale for both reconstruction algorithms (1 = excellent to 5 = non-diagnostic). Signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and effective radiation dose were calculated. Results Data acquisition and EAM integration were successful in all patients. Median image quality score was 1 for both FBP (quartiles = 1, 1.62; range = 1-3) and IR (quartiles = 1, 1.5; range = 1-3). Mean SNR was 7.61 ± 2.14 for FBP and 9.02 ± 2.69 for IR. Mean CNR was 5.92 ± 1.80 for FBP and 6.95 ± 2.29 for IR. Mean effective radiation dose was 0.3 ± 0.1 mSv. Conclusion At a radiation dose of 0.3 ± 0.1 mSv, high-pitch dual-source CT yields LA images of consistently high quality using both FBP and IR. IR raises SNR and CNR without significantly improving subjective image quality.

Quantification of the left atrium applying cardiovascular magnetic resonance in clinical routine

OBJECTIVES

In recent years the impact of the left atrium (LA) has become more evident in different cardiovascular pathologies. We aim to provide LA parameters in healthy volunteers for cardiovascular magnetic resonance (CMR) using a fast approach.

DESIGN

We analyzed 203 healthy volunteers (mean age 44.6 years (y), range 19y-76y) at 1.5 and 3.0 Tesla (T) using steady-state free precession (SSFP) cine in routine long axis view. Left atrial enddiastolic volume (LA-EDV), endsystolic volume (LA-ESV), stroke volume (LA-SV) and ejection fraction (LA-EF) were quantified and indexed to body-surface-area (BSA). Dependency on age and sex was analyzed.

RESULTS

21 subjects had to be excluded. In the remaining, there was no significant difference between 1.5 T and 3.0 T. Absolut LA-EDV and LA-ESV were larger in men than in women (LA-EDV: male 70 ± 19 ml vs. female 61 ± 16 ml (p = .001); LA-ESV: male 24 ± 9 ml vs. female 21 ± 8 ml (p = .01)). These differences disappeared after indexing to BSA (LA-EDV/BSA: male 34 ± 10 ml/m² vs. female 33 ± 9 ml/m² (p = .65) and LA-ESV/BSA: male 12 ± 4 ml/m² vs. female 11 ± 4 ml/m² (p = .71)). LA-EDV/BSA decreased with older age.

CONCLUSIONS

Reference values for LA size and function based on a fast approach are provided. LA size decreases with older age. Normalization to body size overcomes sex-dependency. Reports should be related to body size.

Safety profile of gadoxetate disodium in elderly patients (≥65 years)

Background

Safety data on routine clinical use of gadoxetate disodium in elderly patients is not reported yet.

Purpose

To assess the safety of liver specific gadoxetate disodium in contrast enhanced magnetic resonance imaging in elderly patients (≥65 years) in comparison to adults (18–64 years).

Material and Methods

Safety data on gadoxetate disodium were analyzed from 12 clinical phase II–III studies and from our pharmacovigilance database. A comparison between elderly (≥65 years) versus adults (18–64 years) was performed with respect to the frequency of drug-related adverse events (AEs) in clinical phase II–III studies and adverse drug reactions (ADRs) in the pharmacovigilance database.

Results

In clinical studies, 1989 patients were enrolled: 675 elderly and 1314 adults. Twenty-three elderly patients (3.4%) suffered at least one drug-related AE in contrast to 58 patients (4.4%) in the group of adults (odds ratio = 0.76; 95% confidence interval = 0.45–1.27). Since marketing authorization in 2004, more than 3.5 million patients have been exposed to gadoxetate disodium worldwide: 1.7 million (48.6%) in elderly and 1.8 million (51.4%) in adults. The number of patients with post-marketing ADRs (total n = 793) was 354 (0.021%) in the elderly group and 439 (0.024%) in the adult group. Thus, there were significantly fewer patients with ADRs reported in the group of elderly versus adults (P = 0.028). Hypersensitivity/immune system disorders, gastrointestinal disorders, and respiratory disorders were the most frequent ADRs in both groups, elderly and adults.

Conclusion

The incidence of drug-related AEs in clinical studies was similar and that of patients with ADRs in the post-marketing setting was lower in elderly (≥65 years) compared with younger adults aged 18–64 years. Overall, gadoxetate disodium shows a favorable safety profile in both age groups.

Comparison of MRI with radiography for detecting structural lesions of the sacroiliac joint using CT as standard of reference: results from the SIMACT study

OBJECTIVE

Radiographs of sacroiliac (SI) joints are used for the detection of structural damage in patients with axial spondyloarthritis (axSpA), but are often difficult to interpret. Here, we address the question how the T1-weighted MRI (T1w MRI) sequence compares with radiography for SI joints' structural lesions using low-dose CT as the standard of reference.

METHODS

Radiographs, T1w MRI and low-dose CT of the SI joints from 110 patients (mean age 36.1 (19-57) years, 52% males and 48% females; 53% with axSpA, 21 non-radiographic axSpA and 32% radiographic axSpA, 47% with non-SpA) referred to the rheumatologist because of unclear chronic back pain, but possible axSpA, were scored for structural lesions (erosions, sclerosis, joint space changes and an overall impression of positivity).

RESULTS

Using low-dose CT as the standard of reference, T1w MRI showed markedly better sensitivity with significantly more correct imaging findings compared with radiography for erosions (79% vs 42%; p=0.002), joint space changes (75% vs 41%; p=0.002) and overall positivity (85% vs 48%; p=0.001), respectively, while there were no differences between X-rays and MRI-T1 sequence regarding specificity (>80% for all scores). Only for sclerosis, MRI-T1 was inferior to radiography (sensitivity 30% vs 70%, respectively), however, not statistically significant (p=0.663).

CONCLUSIONS

T1w MRI was superior to radiography in the detection of structural lesion of the SI joints in patients with axSpA. Future studies should focus on finding an agreement on the definition of MRI-T1 positivity.

Effects of heart valve prostheses on phase contrast flow measurements in Cardiovascular Magnetic Resonance - a phantom study

BACKGROUND

Cardiovascular Magnetic Resonance is often used to evaluate patients after heart valve replacement. This study systematically analyses the influence of heart valve prostheses on phase contrast measurements in a phantom trial.

METHODS

Two biological and one mechanical aortic valve prostheses were integrated in a flow phantom. B0 maps and phase contrast measurements were acquired at a 1.5 T MR scanner using conventional gradient-echo sequences in predefined distances to the prostheses. Results were compared to measurements with a synthetic metal-free aortic valve.

RESULTS

The flow results at the level of the prosthesis differed significantly from the reference flow acquired before the level of the prosthesis. The maximum flow miscalculation was 154 ml/s for one of the biological prostheses and 140 ml/s for the mechanical prosthesis. Measurements with the synthetic aortic valve did not show significant deviations. Flow values measured approximately 20 mm distal to the level of the prosthesis agreed with the reference flow for all tested all prostheses.

CONCLUSIONS

The tested heart valve prostheses lead to a significant deviation of the measured flow rates compared to a reference. A distance of 20 mm was effective in our setting to avoid this influence.

Individual selection of X-ray tube settings in computed tomography coronary angiography: Reliability of an automated software algorithm to maintain constant image quality

OBJECTIVES

To evaluate a software tool that claims to maintain a constant contrast-to-noise ratio (CNR) in high-pitch dual-source computed tomography coronary angiography (CTCA) by automatically selecting both X-ray tube voltage and current.

METHODS

A total of 302 patients (171 males; age 61±12years; body weight 82±17kg, body mass index 27.3±4.6kg/cm(2)) underwent CTCA with a topogram-based, automatic selection of both tube voltage and current using dedicated software with quality reference values of 100kV and 250mAs/rotation (i.e., standard values for an average adult weighing 75kg) and an injected iodine load of 222mg/kg.

RESULTS

The average radiation dose was estimated to be 1.02±0.64mSv. All data sets had adequate contrast enhancement. Average CNR in the aortic root, left ventricle, and left and right coronary artery was 15.7±4.5, 8.3±2.9, 16.1±4.3 and 15.3±3.9 respectively. Individual CNR values were independent of patients' body size and radiation dose. However, individual CNR values may vary considerably between subjects as reflected by interquartile ranges of 12.6-18.6, 6.2-9.9, 12.8-18.9 and 12.5-17.9 respectively. Moreover, average CNR values were significantly lower in males than females (15.1±4.1 vs. 16.6±11.7 and 7.9±2.7 vs. 8.9±3.0, 15.5±3.9 vs. 16.9±4.6 and 14.7±3.6 vs. 16.0±4.1 respectively).

CONCLUSION

A topogram-based automatic selection of X-ray tube settings in CTCA provides diagnostic image quality independent of patients' body size. Nevertheless, considerable variation of individual CNR values between patients and significant differences of CNR values between males and females occur which questions the reliability of this approach.

MRI-guided core needle biopsy of the prostate: acceptance and side effects

PURPOSE

We aimed to study side effects, complications, and patient acceptance of magnetic resonance imaging-guided real-time biopsy (MRI-GB) of the prostate.

METHODS

Fifty-four men (49-78 years) with elevated prostate-specific antigen after at least one negative systematic transrectal ultrasound-guided biopsy (TRUS-GB) were included in a prospective clinical study. Suspicious areas on images were selectively sampled by obtaining a median of four specimens (range, 1-9 specimens) using MRI-GB. In TRUS-GB, a median of 10 specimens (range, 6-14 specimens) were obtained. Telephone interviews were conducted one week after outpatient MRI-GB, asking patients about pain and side effects (hematuria, hemospermia, rectal bleeding, fever, and chills) of the two biopsy procedures and which of the two procedures they preferred. Multinomial regression analysis and Fisher's exact test was used to test for differences.

RESULTS

MRI-GB was preferred by 65% (35/54), and 82% (44/54) would undergo MRI-GB again. Pain intensity (P = 0.005) and bleeding duration (P = 0.004) were significantly lower for MRI-GB compared with TRUS-GB. Hematuria was less common after MRI-GB compared with TRUS-GB (P = 0.006). A high correlation was given between bleeding intensity and bleeding duration for TRUS-GB (r=0.77) and pain intensity and pain duration for MRI-GB (r=0.65). Although hemospermia, rectal hemorrhage, fever, and chills were less common in MRI, they showed no statistically significant difference.

CONCLUSION

MRI-GB of the prostate seems to have fewer side effects and less pain intensity than TRUS-GB and was preferred by the majority of patients.

Effect of Application and Intensity of Bevacizumab-based Maintenance After Induction Chemotherapy With Bevacizumab for Metastatic Colorectal Cancer: A Meta-analysis

BACKGROUND

The administration and intensity of bevacizumab-based maintenance therapy after induction treatment with bevacizumab is still a matter of debate. Thus, the present meta-analysis and an indirect comparison were performed to clarify these issues.

PATIENTS AND METHODS

Trials evaluating a separately defined "maintenance phase," with randomization after the induction phase, were selected. Three trials of maintenance with bevacizumab with or without a fluoropyrimidine (CAIRO3, SAKK 41/06, and AIO KRK 0207) were analyzed regarding the effect on progression-free survival (PFS) and overall survival (OS) of any maintenance therapy compared with observation alone and different maintenance intensities (bevacizumab with or without fluoropyrimidine) compared with observation alone and between each other.

RESULTS

Maintenance with bevacizumab with or without fluoropyrimidine after bevacizumab-based induction treatment for 4 to 6 months significantly improved PFS (hazard ratio [HR], 0.57; 95% confidence interval [CI], 0.43-0.75; P = .0004) and showed a trend toward prolonged OS (HR, 0.89; 95% CI, 0.78-1.02; P = .09) compared with observation alone. The effect on PFS increased with the intensity of the maintenance regimen (HR, 0.72; 95% CI, 0.60-0.85 for single-agent bevacizumab vs. HR, 0.45; 95%, CI 0.39-0.51 for combination therapy, both compared to observation alone). In contrast, the HRs for OS remained in the same range. A similarly improved PFS (HR, 0.63; 95% CI, 0.50-0.79) was shown for the more intensive maintenance therapy (bevacizumab and fluoropyrimidine) compared with bevacizumab alone.

CONCLUSION

Bevacizumab-based maintenance therapy after induction chemotherapy with bevacizumab significantly improves PFS and showed a trend toward prolonged OS and should thus be considered, in particular, in patients with a response to induction treatment.

Impact of surgical correction of pectus excavatum on cardiac function: insights on the right ventricle. A cardiovascular magnetic resonance study†

OBJECTIVES

Pectus excavatum (PE) is often regarded as a cosmetic disease, while its effect on cardiac function is under debate. Data regarding cardiac function before and after surgical correction of PE are limited. We aimed to assess the impact of surgical correction of PE on cardiac function by cardiovascular magnetic resonance (CMR).

METHODS

CMR at 1.5 T was performed in 38 patients (mean age 21 ± 8.3; 31 men) before and after surgical correction to evaluate thoracic morphology, indices and its relation to three-dimensional left and right ventricular cardiac function.

RESULTS

Surgery was successful in all patients as shown by the Haller Index ratio of maximum transverse diameter of the chest wall and minimum sternovertebral distance [pre: 9.64 (95% CI 8.18-11.11) vs post: 3.0 (2.84-3.16), P < 0.0001]. Right ventricular ejection fraction (RVEF) was reduced before surgery and improved significantly at the 1-year follow-up [pre: 45.7% (43.9-47.4%) vs 48.3% (46.9-49.5%), P = 0.0004]. Left ventricular ejection fraction was normal before surgery, but showed a further improvement after 1 year [pre: 61.0% (59.3-62.7%) vs 62.7% (61.3-64.2%), P = 0.0165]. Cardiac compression and the asymmetry index changed directly after surgery and were stable at the 1-year follow-up [3.93 (3.53-4.33) vs 2.08 (1.98-2.19) and 2.36 (2.12-2.59) vs 1.38 (1.33-1.44), respectively; P < 0.0001 for both]. None of the obtained thoracic indices were predictors of the improvement of cardiac function. A reduced preoperative RVEF was predictive of RVEF improvement.

CONCLUSIONS

PE is associated with reduced RVEF, which improves after surgical correction. CMR has the capability of offering additional information prior to surgical correction.

MRI in multiple sclerosis: an intra-individual, randomized and multicentric comparison of gadobutrol with gadoterate meglumine at 3 T

OBJECTIVES

To compare contrast effects of gadobutrol with gadoterate meglumine for brain MRI in multiple sclerosis (MS) in a multicentre, randomized, prospective, intraindividual study at 3 T.

METHODS

Institutional review board approval was obtained. Patients with known or suspected active MS lesions were included. Two identical MRIs were performed using randomized contrast agent order. Four post-contrast T1 sequences were acquired (start time points 0, 3, 6 and 9 min). If no enhancing lesion was present in first MRI, second MRI was cancelled. Quantitative (number and signal intensity of enhancing lesions) and qualitative parameters (time points of first and all lesions enhancing; subjective preference regarding contrast enhancement and lesion delineation; global preference) were evaluated blinded.

RESULTS

Seventy-four patients (male, 26; mean age, 35 years) were enrolled in three centres. In 45 patients enhancing lesions were found. Number of enhancing lesions increased over time for both contrast agents without significant difference (median 2 for both). Lesions signal intensity was significantly higher for gadobutrol (p < 0.05 at time points 3, 6 and 9 min). Subjective preference rating showed non-significant tendency in favour of gadobutrol.

CONCLUSION

Both gadobutrol and gadoterate meglumine can be used for imaging of acute inflammatory MS lesions. However, gadobutrol generates higher lesion SI.

KEY POINTS

Contrast-enhanced MRI plays a key role in the management of multiple sclerosis. Different gadolinium-based contrast agents are available. Number of visibly enhancing lesions increases over time after contrast injection. Gadobutrol and gadoterate meglumine do not differ in number of visible lesions. Gadobutrol generates higher signal intensity than gadoterate meglumine.

Intraindividual, randomized comparison of the macrocyclic contrast agents gadobutrol and gadoterate meglumine in breast magnetic resonance imaging

OBJECTIVES

To compare intraindividually two macrocyclic contrast agents - gadobutrol and gadoterate meglumine (Gd-DOTA) - for dynamic and quantitative assessment of relative enhancement (RE) in benign and malignant breast lesions.

METHODS

This was an ethically approved, prospective, single-centre, randomized, crossover study in 52 women with suspected breast lesions referred for magnetic resonance imaging (MRI). Each patient underwent one examination with gadobutrol and one with Gd-DOTA (0.1 mmol/kg BW) on a 1.5 T system 1 - 7 days apart. Dynamic, T1-weighted, 3D gradient echo sequences were acquired under identical conditions. Quantitative evaluation with at least three regions of interest (ROI) per lesion was performed. Primary endpoint was RE during the initial postcontrast phase after the first and second dynamic acquisition, and peak RE. All lesions were histologically proven; differences between the examinations were evaluated.

RESULTS

Forty-five patients with a total of 11 benign and 34 malignant lesions were assessed. Mean RE was significantly higher for gadobutrol than Gd-DOTA (p < 0.0001). Gadobutrol showed significantly less washout (64.4 %) than Gd-DOTA (75.4 %) in malignant lesions (p = 0.048) CONCLUSIONS: Gadobutrol has higher RE values compared with Gd-DOTA, whereas Gd-DOTA shows more marked washout in malignant lesions. This might improve the detection of breast lesions and influence the specificity of breast MRI-imaging.

High-pitch dual-source CT coronary angiography with low volumes of contrast medium

OBJECTIVES

To assess the effect of lower volumes of contrast medium (CM) on image quality in high-pitch dual-source computed tomography coronary angiography (CTCA).

METHODS

One-hundred consecutive patients (body weight 65-85 kg, stable heart rate ≤65 bpm, cardiac index ≥2.5 L/min/m(2)) referred for CTCA were prospectively enrolled. Patients were randomly assigned to one of five groups of different CM volumes (G30, 30 mL; G40, 40 mL; G50, 50 mL; G60, 60 mL; G70, 70 mL; flow rate 5 mL/s each, iodine content 370 mg/mL). Attenuation within the proximal and distal coronary artery segments was analysed.

RESULTS

Mean attenuation for men and women ranged from 345.0 and 399.1 HU in G30 to 478.2 and 571.8 HU in G70. Mean attenuation values were higher in groups with higher CM volumes (P < 0.0001) and higher in women than in men (P < 0.0001). The proportions of segments with attenuation of at least 300 HU in G30, G40, G50, G60 and G70 were 89 %, 95 %, 98 %, 98 % and 99 %. CM volume of 30 mL in women and 40 mL in men proved to be sufficient to guarantee attenuation of at least 300 HU.

CONCLUSIONS

In selected patients high-pitch dual-source CTCA can be performed with CM volumes of 40 mL in men or 30 mL in women.

KEY POINTS

• High-pitch dual-source coronary angiography is feasible with low contrast media volumes. • Traditional injection rules still apply: higher volumes result in higher enhancement. • The patient's gender is a co-factor determining the level of contrast enhancement. • Volumes can be reduced down to 30-40 mL in selected patients.

Dynamic contrast enhanced MRI of the prostate: comparison of gadobutrol and Gd-DTPA

PURPOSE

To evaluate the enhancement profile of the macrocyclic contrast medium (CM) gadobutrol in comparison to linear CM Gd-DTPA in DCE-MRI of the prostate.

MATERIALS AND METHODS

In total 53 patients with prostata cancer (PCa) were included, who received a radical prostatectomy after multiparametric MRI of the prostate including DCE-MRI. Using circular regions of interests normal peripheral zone (PZ) and PCa foci > 5 mm in diameter (42 and 34 foci in Gd-DTPA and gadobutrol group, respectively) were analysed in DCE-MRI. Enhancement curves (Type I, II and III) and pharmacokinetic parameters were analyzed qualitatively and quantitatively and compared using mixed linear models (two sided p-values < 0.05 were regarded significant).

RESULTS

There was no significant difference in frequencies of curve types I, II or III in the normal PZ (p = 0.63) or in PCa foci (p = 0.75). PCa with a Gleason score ≥ 7 had in comparison to Gleason ≤ 6 significantly more often a Wash-Out-curve (Type III) with both CM (p = 0.02). The relative peak enhancement was in the PZ (Gd-DTPA 1.4 a. u. [1.20; 1.59], gadobutrol 1.58 a. u. [1.37; 1.78]) and in PCa foci (Gd-DTPA 1.56 a. u. [1.41; 1.71], gadobutrol 1.76 a. u. [1.59; 1.94]) significantly higher with gadobutrol (p = 0.04). The pharmacokinetic parameters Ktrans und kep were higher in PCa foci than in PZ (p < 0.0001 and p = 0.002, respectively) without significant difference of the parameter values between both CM (p = 0.65).

CONCLUSION

[corrected] This study is the first systematic comparison of gadobutrol and Gd-DTPA in DCE-MRI of the prostate. The relative peak enhancement is higher using gadobutrol compared to Gd-DTPA in DCE-MRI. There was no statistically significant difference in curve types or the pharmacokinetic parameters in PCa or normal PZ between both CM.

Intra-individual, randomised comparison of the MRI contrast agents gadobutrol versus gadoteridol in patients with primary and secondary brain tumours, evaluated in a blinded read

OBJECTIVE

To prove that 1.0 M gadobutrol provides superior contrast enhancement and MRI image characteristics of primary and secondary brain tumours compared with 0.5 M gadoteridol, thereby providing superior diagnostic information.

METHODS

Brain MRI was performed in two separate examinations in patients scheduled for neurosurgery. Independent injections of 1.0 M gadobutrol and 0.5 M gadoteridol at doses of 0.1 mmol Gd/kg body weight were administered per patient in randomised order. Evaluation was performed in an off-site blinded read.

RESULTS

Fifty-one patients in the full analysis set (FAS) were eligible for efficacy analysis and 44 for the per-protocol analysis. For the primary efficacy variable "preference in contrast enhancement for one contrast agent or the other", the rate of "gadobutrol preferred" was estimated at 0.73 (95 % confidence interval 0.61; 0.83), showing significant superiority of gadobutrol over gadoteridol. Calculated lesion-to-brain contrast and the results of all qualitative secondary efficacy variables were also in favour of gadobutrol. Keeping a sufficient time delay after contrast application proved to be essential to get optimal image quality.

CONCLUSION

Compared with 0.5 M gadoteridol, 1.0 M gadobutrol was proven to have significantly superior contrast enhancement characteristics in a routine MRI protocol of primary and secondary brain tumours.

Myocardial T1 and T2 mapping at 3 T: reference values, influencing factors and implications

BACKGROUND

Myocardial T1 and T2 mapping using cardiovascular magnetic resonance (CMR) are promising to improve tissue characterization and early disease detection. This study aimed at analyzing the feasibility of T1 and T2 mapping at 3 T and providing reference values.

METHODS

Sixty healthy volunteers (30 males/females, each 20 from 20-39 years, 40-59 years, 60-80 years) underwent left-ventricular T1 and T2 mapping in 3 short-axis slices at 3 T. For T2 mapping, 3 single-shot steady-state free precession (SSFP) images with different T2 preparation times were acquired. For T1 mapping, modified Look-Locker inversion recovery technique with 11 single shot SSFP images was used before and after injection of gadolinium contrast. T1 and T2 relaxation times were quantified for each slice and each myocardial segment.

RESULTS

Mean T2 and T1 (pre-/post-contrast) times were: 44.1 ms/1157.1 ms/427.3 ms (base), 45.1 ms/1158.7 ms/411.2 ms (middle), 46.9 ms/1180.6 ms/399.7 ms (apex). T2 and pre-contrast T1 increased from base to apex, post-contrast T1 decreased. Relevant inter-subject variability was apparent (scatter factor 1.08/1.05/1.11 for T2/pre-contrast T1/post-contrast T1). T2 and post-contrast T1 were influenced by heart rate (p < 0.0001, p = 0.0020), pre-contrast T1 by age (p < 0.0001). Inter- and intra-observer agreement of T2 (r = 0.95; r = 0.95) and T1 (r = 0.91; r = 0.93) were high. T2 maps: 97.7% of all segments were diagnostic and 2.3% were excluded (susceptibility artifact). T1 maps (pre-/post-contrast): 91.6%/93.9% were diagnostic, 8.4%/6.1% were excluded (predominantly susceptibility artifact 7.7%/3.2%).

CONCLUSIONS

Myocardial T2 and T1 reference values for the specific CMR setting are provided. The diagnostic impact of the high inter-subject variability of T2 and T1 relaxation times requires further investigation.

Intra-individual randomised comparison of gadobutrol 1.0 M versus gadobenate dimeglumine 0.5 M in patients scheduled for preoperative breast MRI

OBJECTIVE

To demonstrate non-inferiority of gadobutrol versus gadobenate dimeglumine by intra-individually comparing 0.1 mmol/kg body weight doses for contrast-enhanced breast magnetic resonance imaging (MRI) and prospectively evaluating lesion detection and characterisation in a multicentre trial.

METHODS

Two identical breast MRI examinations were performed in 72 patients with biopsy-proven breast cancer, separated by 1-7 days. Gadobutrol 1.0 M or gadobenate 0.5 M were administered in a randomised order. Lesion detection and characterisation were performed by two independent blinded readers. Lesion tracking, which compared on-site readings and histology from surgery or biopsy, was performed by a third reader. Differences in lesion detection and characterisation were compared between the two contrast agents.

RESULTS

Among 103 lesions, 96 were malignant and 7 were benign. No difference in lesion detection was identified between the contrast agents (82.33 % for gadobutrol, 81.60 % for gadobenate). Assessment of sensitivity in lesion characterisation and Breast Imaging Reporting and Data Systems showed no difference between gadobutrol (92.63 %) and gadobenate (90.53 %). Regarding morphology, there was more non-focal enhancement for gadobutrol than for gadobenate (P = 0.0057).

CONCLUSION

Non-inferiority of gadobutrol compared with gadobenate was demonstrated for breast lesion detection and sensitivity in lesion characterisation in breast MRI.

Inflammation assessment in patients with arthritis using a novel in vivo fluorescence optical imaging technology

BACKGROUND

Indocyanine green (ICG)-enhanced fluorescence optical imaging (FOI) is an established technology for imaging of inflammation in animal models. In experimental models of arthritis, FOI findings corresponded to histologically proven synovitis. This is the first comparative study of FOI with other imaging modalities in humans with arthritis.

METHODS

252 FOI examinations (Xiralite system, mivenion GmbH, Berlin, Germany; ICG bolus of 0.1 mg/kg/body weight, sequence of 360 images, one image per second) were compared with clinical examination (CE), ultrasonography (US) and MRI of patients with arthritis of the hands.

RESULTS

In an FOI sequence, three phases could be distinguished (P1-P3). With MRI as reference, FOI had a sensitivity of 76% and a specificity of 54%, while the specificity of phase 1 was 94%. FOI had agreement rates up to 88% versus CE, 64% versus greyscale US, 88% versus power Doppler US and 83% versus MRI, depending on the compared phase and parameter. FOI showed a higher rate of positive results compared to CE, US and MRI. In individual patients, FOI correlated significantly (p<0.05) with disease activity (Disease Activity Score 28, r=0.41), US (r=0.40) and RAMRIS (Rheumatoid Arthritis MRI Score) (r=0.56). FOI was normal in 97.8% of joints of controls.

CONCLUSION

ICG-enhanced FOI is a new technology offering sensitive imaging detection of inflammatory changes in subjects with arthritis. FOI was more sensitive than CE and had good agreement with CE, US in power Doppler mode and MRI, while showing more positive results than these. An adequate interpretation of an FOI sequence requires a separate evaluation of all phases. For the detection of synovitis and tenosynovitis, FOI appears to be as informative as 1.5 T MRI and US.