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In coronary computed tomography (CT) angiography (CTA) prospective electrocardiography triggering requires less radiation dose than retrospective electrocardiography gating but provides less cardiac phases for interpretation. This meta-analysis presents a concise and comprehensive head-to-head comparison of image quality, diagnostic accuracy, and radiation dose of prospectively triggered coronary CTA vs retrospectively gated CTA in patients with suspected or known coronary artery disease (CAD). In patients with CAD and without tachyarrhythmia, eligible studies (selected from 4 databases) compared prospectively triggered vs retrospectively gated CTA (performed with ≥64-slice CT or dual-source CT) in 2 groups having approximately similar patient characteristics, scored CTA image quality, and/or assessed how accurately CTA diagnoses ≥50% coronary stenoses compared with catheter angiography and reported the radiation dose. The data were meta-analyzed by random-effects models, with CIs provided in the text. Among 3,330 patients from 20 included studies, 91.3% of CTAs (segments: 97.8%) had diagnostic quality with prospective triggering and 93.3% of CTAs (segments: 98.4%) with retrospective gating (P > .05). Among 664 patients from 5 studies, the pooled sensitivity/specificity of diagnostic CTAs was 98.7%/91.3% (segment level: 91.3%/97.7%) with prospective triggering and 96.9%/95.8% (segment level: 93.1%/97.6%) with retrospective gating (P > .05). The pooled effective dose was 3.5 mSv with prospective triggering and thus, by a factor of 3.5, lower than the pooled effective dose of retrospective gating, which was 12.3 mSv (P < .01). In patients with CAD and without tachyarrhythmia, prospectively triggered coronary CTA provides image quality and diagnostic accuracy comparable with retrospectively gated CTA, but at a much lower radiation dose.

Background Cardiovascular Magnetic Resonance myocardial feature tracking (CMR-FT) is a quantitative technique tracking tissue voxel motion on standard steady-state free precession (SSFP) cine images to assess ventricular myocardial deformation. The importance of left atrial (LA) deformation assessment is increasingly recognized and can be assessed with echocardiographic speckle tracking. However atrial deformation quantification has never previously been demonstrated with CMR. We sought to determine the feasibility and reproducibility of CMR-FT for quantitative derivation of LA strain and strain rate (SR) myocardial mechanics. Methods 10 healthy volunteers, 10 patients with hypertrophic cardiomyopathy (HCM) and 10 patients with heart failure and preserved ejection fraction (HFpEF) were studied at 1.5 Tesla. LA longitudinal strain and SR parameters were derived from SSFP cine images using dedicated CMR-FT software (2D CPA MR, TomTec, Germany). LA performance was analyzed using 4- and 2-chamber views including LA reservoir function (total strain [ε s ], peak positive SR [SRs]), LA conduit function (passive strain [ε e ], peak early negative SR [SRe]) and LA booster pump function (active strain [ε a ], late peak negative SR [SRa]). Results In all subjects LA strain and SR parameters could be derived from SSFP images. There was impaired LA reservoir function in HCM and HFpEF (ε s [%]: HCM 22.1 ± 5.5, HFpEF 16.3 ± 5.8, Controls 29.1 ± 5.3, p < 0.01; SRs [s -1 ]: HCM 0.9 ± 0.2, HFpEF 0.8 ± 0.3, Controls 1.1 ± 0.2, p < 0.05) and impaired LA conduit function as compared to healthy controls (ε e [%]: HCM 10.4 ± 3.9, HFpEF 11.9 ± 4.0, Controls 21.3 ± 5.1, p < 0.001; SRe [s -1 ]: HCM -0.5 ± 0.2, HFpEF -0.6 ± 0.1, Controls -1.0 ± 0.3, p < 0.01). LA booster pump function was increased in HCM while decreased in HFpEF (ε a [%]: HCM 11.7 ± 4.0, HFpEF 4.5 ± 2.9, Controls 7.8 ± 2.5, p < 0.01; SRa [s -1 ]: HCM -1.2 ± 0.4, HFpEF -0.5 ± 0.2, Controls -0.9 ± 0.3, p < 0.01). Observer variability was excellent for all strain and SR parameters on an intra- and inter-observer level as determined by Bland-Altman, coefficient of variation and intraclass correlation coefficient analyses. Conclusions CMR-FT based atrial performance analysis reliably quantifies LA longitudinal strain and SR from standard SSFP cine images and discriminates between patients with impaired left ventricular relaxation and healthy controls. CMR-FT derived atrial deformation quantification seems a promising novel approach for the study of atrial performance and physiology in health and disease states.

Functional magnetic resonance imaging (fMRI) hypothesis testing based on the blood oxygenation level dependent (BOLD) contrast mechanism typically involves a search for a positive effect during a specific task relative to a control state. However, aside from positive BOLD signal changes there is converging evidence that neuronal responses within various cortical areas also induce negative BOLD signals. Although it is commonly believed that these negative BOLD signal changes reflect suppression of neuronal activity direct evidence for this assumption is sparse. Since the somatosensory system offers the opportunity to quantitatively test sensory function during concomitant activation and has been well-characterized with fMRI in the past, the aim of this study was to determine the functional significance of ipsilateral negative BOLD signal changes during unilateral sensory stimulation. For this, we measured BOLD responses in the somatosensory system during unilateral electric stimulation of the right median nerve and additionally determined the current perception threshold of the left index finger during right-sided electrical median nerve stimulation as a quantitative measure of sensory function. As expected, positive BOLD signal changes were observed in the contralateral primary and bilateral secondary somatosensory areas, whereas a decreased BOLD signal was observed in the ipsilateral primary somatosensory cortex (SI). The negative BOLD signal changes were much more spatially extensive than the representation of the hand area within the ipsilateral SI. The negative BOLD signal changes in the area of the index finger highly correlated with an increase in current perception thresholds of the contralateral, unstimulated finger, thus supporting the notion that the ipsilateral negative BOLD response reflects a functionally effective inhibition in the somatosensory system.

In addition to a contralateral activation of the primary and secondary somatosensory cortices, peripheral sensory stimulation has been shown to elicit responses in the ipsilateral primary somatosensory cortex (SI). In particular, evidence is accumulating that processes of interhemispheric inhibition as depicted by negative blood oxygenation level dependent (BOLD) signal changes are part of somatosensory processes. The aim of the study was to analyze age-related differences in patterns of cerebral activation in the somatosensory system in general and processes of interhemispheric inhibition in particular. For this, a functional magnetic resonance imaging (fMRI) study was performed including 14 younger (mean age 23.3±0.9years) and 13 healthy older participants (mean age 73.2±8.3years). All subjects were scanned during peripheral electrical median nerve stimulation (40Hz) to obtain BOLD responses in the somatosensory system. Moreover, the individual current perception threshold (CPT) as a quantitative measure of sensory function was determined in a separate psychophysical testing. Significant increases in BOLD signal across the entire group could be measured within the contralateral SI, in the bilateral secondary somatosensory cortex (SII), the contralateral supplementary motor area and the insula. Negative BOLD signal changes were delineated in ipsilateral SI/MI as well as in the ipsilateral thalamus and basal ganglia. After comparing the two groups, only the cortical deactivation in ipsilateral SI in the early stimulation phase as well as the activation in contralateral SI and SII in the late stimulation block remained as statistically significant differences between the two groups. The psychophysical experiments yielded a significant age-dependent effect of CPT change with less difference in the older group which is in line with the significantly smaller alterations in maximal BOLD signal change in the contra- and ipsilateral SI found between the two groups. Healthy aging seems to be associated with a decrease in intracerebral inhibition as reflected by smaller negative BOLD signal changes during fMRI tasks. This finding could constitute an important link between age-related neurophysiological changes and behavioral alterations in humans. ► Peripheral somatosensory stimulation in young and old subjects during fMRI ► Contralateral positive and ipsilateral negative BOLD signal changes ► Lower negative and positive BOLD signals in old subjects indicating age-dependence ► Psychophysical testing with less change in current perception threshold in aging ► Healthy aging seems to be associated with a decrease in intracerebral inhibition.

This meta-analysis summarizes the accuracy of magnetic resonance angiography (MRA) for diagnosing residuals in coiled cerebral aneurysms by using the threefold Roy classification (residuals: none, neck, or sac). Four databases were searched from 2000 to June 2013 for eligible studies that compared MRA to digital subtraction angiography (DSA) and reported 3 × 3 count data of threefold Roy classification, or a reduced scheme of 2 × 2 count data. Bivariate and trivariate Bayesian random-effects models were used for meta-analysis. Among 27 included studies (2,119 coiled aneurysms in 1,809 patients) the average prevalence of DSA-confirmed sac residuals was 18.2 % (range 0–43 %). The pooled sensitivity was 88.0 % (95 % CI 81.4−94.0) and specificity was 97.2 % (94.6−99.0 %) for assessing sac residuals by MRA. In the trivariate meta-analysis, a “sac residual” finding at MRA had a high positive likelihood ratio of 28.2 (14.0–79.0). A “neck residual” finding had a moderate negative likelihood ratio of 0.246 (0.111–0.426), and the MRA finding of “no residual” had a good negative likelihood ratio of 0.044 (0.013–0.096). Subgroup analyses identified no significant influence of covariates on diagnostic accuracy ( P  > 0.05). In conclusion, in coiled cerebral aneurysms MRA with application of the threefold Roy classification is well suited for detecting or excluding sac residuals that might require retreatment.

Purpose Aim of the study was to investigate diagnostic accuracy of cardiac computed tomography angiography (CCTA) between left ventricular end-systolic (LVES) and left ventricular end-diastolic (LVED) cardiac phase for thrombus detection in patient’s prior to pulmonary vein isolation (PVI). Materials and methods 182 consecutive Patients with drug refractory AF scheduled for PVI (62.6% male, mean age 64.1 ± 10.2 years) underwent routine pre-procedural evaluation including transesophageal echocardiography (TEE) and CCTA for evaluation of left atrial (LA)/left atrial appendage (LAA) anatomy and thrombus formation. Qualitative and quantitative analysis (using aorta ascendens (AA)/LAA ratio) was performed. Measurements of the LA/LAA in LVES and LVED cardiac phase were obtained. Results End-systolic volumes (LA/LAA) measured in 30 patients without filling defects as control group and all 14 with filling defects of 182 patients were significantly larger (p < 0.01) than in end-diastolic phase. Qualitative analysis was inferior to quantitative analysis using LA/LAA ratio (<0.5; accuracy: 100%, 88%,100%, 99% vs 100%). 5 out of 182 patients (2.7%) showed thrombus formation of the LAA in CCTA confirmed by TEE and quantitative analysis. Intra/-interobserver variability was lower in end-systolic vs end-diastolic reconstruction interval. Conclusion For evaluating CCTA datasets in patients prior PVI, the LVES reconstruction interval is recommended due to significantly larger LA/LAA volumes and lower intra/- interobserver variability’s.

Functional magnetic resonance imaging, based on the BOLD effect, typically involves looking for positive cortex activation during a specific task in a controlled state. Tactile stimulation via peripheral electrical nerve stimulation results in measurable activation of the somatosensory system in fMRI studies. In addition to the positive BOLD signal changes in the contralateral, primary cortex (Figure 25), there is increasing evidence that negative BOLD responses can also occur during this stimulation (Figure 26). Although the general opinion in the literature is that these neuronal BOLD signal changes represent a suppression of neuronal activity, direct evidence for this hypothesis in different age groups is rare. For the somatosensory system, it has long been possible to carry out quantitative measurements of sensory function during simultaneous activation and stimulation. In the past, this system was very well characterized and represented using fMRI technology.With this study, we were able to demonstrate the effect of aging on functional deactivation in the somatosensory system in connection with ipsilateral NBR and neuronal inhibition during unilateral sensory stimulation. We selected a younger and older group of subjects in order to be able to observe and understand possible potential aging processes. For this reason, we took measurements of positive and negative BOLD responses in the somatosensory system as well as other important cortical areas during unilateral electrical stimulation of the right median nerve at a frequency of 40 Hz. In addition, we determined the perception threshold CPT of the left index finger during right-sided electrical stimulation of the median nerve as a quantitative measurement of sensory function. Furthermore, we had the subjects actively compare their fingers on the hand where we had previously performed the passive stimulation during the FT. The FT showed that the older subjects did not generally show a worse hemodynamic response, but at least an equivalent response compared to the younger ones (Figures 18 to 22). As previously suspected, significant increases in the BOLD signal (PBR) were observed in contralateral, primary (Figure 25) and bilateral, secondary, somatosensory areas (Figure 27) in the younger and older subjects, whereas a decrease in the BOLD signal (NBR) in the ipsilateral, primary, somatosensory cortex (Figure 26) during electrical median nerve stimulation was more pronounced mainly in the younger subjects. In contrast to the older subjects, these NBRs correlated very closely with an increase in the CPT of the contralateral, left and unstimulated index finger (Figures 43 and 44). This finding supports the hypothesis that the ipsilateral NBR reflects a functional and effective inhibition in the somatosensory system, which is largely lost in old age. Active motor-induced tasks using FT showed that the older subjects, compared to the younger ones, do not necessarily activate hemodynamically less, but in some cases more clearly (Figures 20 and 21), expanding and undifferentiated cortical areas with in some cases higher maximum values. There is a change from lateralized, inhibited and differentiated activities in the younger subjects in mainly primary and secondary sensorimotor cortex areas to a compensatory recruitment of additional cortex areas with a reduction in inhibition in older age in order to possibly ensure the same outcome under controlled stimulation as in younger age.Based on our results and those of previous studies, we hypothesize that electrical stimulation of the median nerve leads to reduced transcallosal inhibition of ipsilateral sensorimotor cortex areas in older age. This suggests that older age may play an important role in processing in the human cortex in relation to various peripheral stimuli and should be increasingly taken into account when interpreting fMRI data with BOLD signals, especially in studies that find increased activation of cortical areas in older subjects and deactivation in younger subjects.

Cardiovascular magnetic resonance feature tracking (CMR-FT) offers quantification of myocardial deformation from routine cine images. However, data using CMR-FT to quantify left ventricular (LV) torsion and diastolic recoil are not yet available. We therefore sought to evaluate the feasibility and reproducibility of CMR-FT to quantify LV torsion and peak recoil rate using an optimal anatomical approach. Short-axis cine stacks were acquired at rest and during dobutamine stimulation (10 and 20 µg · kg(-1) · min(-1)) in 10 healthy volunteers. Rotational displacement was analysed for all slices. A complete 3D-LV rotational model was developed using linear interpolation between adjacent slices. Torsion was defined as the difference between apical and basal rotation, divided by slice distance. Depending on the distance between the most apical (defined as 0% LV distance) and basal (defined as 100% LV distance) slices, four different models for the calculation of torsion were examined: Model-1 (25-75%), Model-2 (0-100%), Model-3 (25-100%) and Model-4 (0-75%). Analysis included subendocardial, subepicardial and global torsion and recoil rate (mean of subendocardial and subepicardial values). Quantification of torsion and recoil rate was feasible in all subjects. There was no significant difference between the different models at rest. However, only Model-1 (25-75%) discriminated between rest and stress (Global Torsion: 2.7 ± 1.5° cm(-1), 3.6 ± 2.0° cm(-1), 5.1 ± 2.2° cm(-1), p<0.01; Global Recoil Rate: -30.1 ± 11.1° cm(-1) s(-1),-46.9 ± 15.0° cm(-1) s(-1),-68.9 ± 32.3° cm(-1) s(-1), p<0.01; for rest, 10 and 20 µg · kg(-)1 · min(-1) of dobutamine, respectively). Reproducibility was sufficient for all parameters as determined by Bland-Altman analysis, intraclass correlation coefficients and coefficient of variation. CMR-FT based derivation of myocardial torsion and recoil rate is feasible and reproducible at rest and with dobutamine stress. Using an optimal anatomical approach measuring rotation at 25% and 75% apical and basal LV locations allows effective quantification of torsion and recoil dynamics. Application of these new measures of deformation by CMR-FT should next be explored in disease states.

Purpose In children and adolescents, preoperative planning for a semi-implantable bone conduction device (SIBCD) is crucial. The geometric changes of the new version of a common SIBCD should enable a higher rate of successful implantation due to its flatter actuator. Thus, this radioanatomic study compared the rate of successful implantation of both device versions at the traditional mastoidal localization and two alternative sites, retrosigmoidal, and parietal, and investigated parameters helping to estimate the feasibility. Methods A retrospective analysis of 136 CT scans of 0 to 20-year-old patients, evaluation of demographic parameters, radioanatomy, and assessment of head diameter was conducted. The feasibility was investigated for certain age groups at three implantation sites. Prediction of feasible implantation by means of different parameters was calculated. Results A significant higher implantation rate was observed with the new device for all three sites and age groups. The age group of 6–8 years ( n  = 19) had most striking differences with a 58.1% rate of successful implantation with the new device without spacer (80% with spacer) at the mastoidal localization, whereas none with the old implant. Head diameter was identified as the most predictive parameter regarding all implantation sites (mastoidal: p  = 0.030; retrosigmoidal: p  = 0.006; parietal: p  < 0.0001), age for the mastoidal ( p  < 0.0001) and retrosigmoidal ( p  < 0.0001), and gender for the parietal site ( p  = 0.001). Conclusion The geometric changes of the actuator lead to a higher rate of successful implantation in all age-groups and all three localizations with reducing the requirement for spacers. Parameters age and head diameter might aid in estimating the rate of successful implantation in young patients and may be a novel tool to assist in the decision-making process for a SIBCD.

There have been few reports of ingestion of bottlecaps worldwide. However, all of these seemed to be unlikely accidental ingestions with a comic side effect. In contrast to this, the authors of this study found an accumulation of bottlecap ingestions in a small university town. Hence, we conducted a study to investigate the nature of these ingestions. We conducted a retrospective cohort study in a tertiary referral center in a small German university town (Göttingen). All patients that were admitted for esophageal foreign bodies were screened for accidental ingestion of bottlecaps and included in the study at hand. Overall, there were 14 cases of bottlecap ingestion within 12 years. Patients were exclusively male, average age was 23.0 ± 4.2 years, ranging from 18.3 to 35.6 years. In 13 out of 14 cases, association to a fraternity was found. Young men, particularly those belonging to a fraternity, should be beware of bottlecap ingestion when consuming beer in risky rituals in small university towns. Alternatively, competitive beer drinking may generally be avoided.