Diagnostic Cardiac CT for the Improvement of Cardiovascular Event Prediction.

BACKGROUND: The aim of the long-term Heinz Nixdorf Recall Study (observation period 20 years) was to establish the extent to which computed tomography (CT) improves the predictability of cardiovascular events relative to determination of risk factors alone. METHODS: In the period 2000-2003, study staff examined 4355 probands (53% of them female) aged 45-75 years with no signs of cardiovascular disease. The Atherosclerotic Cardiovascular Disease (ASCVD) score was calculated on the basis of demographic data and cardiovascular risk factors. Cardiac CT was carried out over the same period and coronary artery calcification (CAC) was graded according to the Agatston score. RESULTS: The median duration of follow-up was 18.2 years for men and 17.8 years for women. Myocardial infarction or stroke occurred in 458 (11%) of the 4154 participants with complete data. Overall, estimation of risk using a combination of ASCVD score and CAC grade was superior to the ASCVD score alone-even after 10 and 20 years. Classification into established risk categories improved by 12.2% (95% confidence interval: [5.3%; 18.1%]). In the highest ASCVD risk category, we observed occurrence of a cardiovascular event over 20 years for 14% [5.0%; 23.1%] of probands with a CAC score = 0 but for 34.2% [27.5%; 41.4%] of those with a CAC score ≥ 400. In the lowest ASCVD risk category, an event occurred in 2.4% [1.4%; 3.7%] of probands with a CAC score = 0 and in 23.5% [2.3%; 35.8%] of those with a CAC score ≥ 400. CONCLUSION: Even after 20 years, individual risk prediction is improved by addition of CT-based determination of coronary artery calcification to the ASCVD score. Therefore, assessment of ASCVD risk factors should be complemented more widely by cardiac CT in the primary prevention of cardiovascular disease.

Imaging of clinically silent rectoprostatic hematoma in MRI guided in-bore prostate biopsy.

MR imaging provides awareness for rectoprostatic hematomas as a complication in prostate biopsy. We evaluated the frequency and size of clinically silent bleeding after in-bore MRI-guided prostate biopsy according to documentation in MRI. From 2007 until 2020 in-bore MRI-guided prostate biopsy was performed in 283 consecutive patients with suspected prostate cancer. Interventional image documentation was reviewed for rectoprostatic hematomas and rectal blood collections in this retrospective observational single-center study. Correlation to patient characteristics was analyzed using a multivariable logistic regression model. 283 consecutive patients with a mean age of 66 ± 8 years were included. We diagnosed bleeding complications in 41 (14.5%) of the patients. Significant rectoprostatic hematomas were found in 24 patients. Intra-rectal blood collections were observed in 16 patients and one patient showed bleeding in the urinary bladder. The volume of rectoprostatic hematomas was determined with a median of 7.5 ml (range 2-40 ml, IQR 11.25). We found no correlation between the presence of a rectoprostatic hematoma and malignant findings, patient position in biopsy, number of cores, age, prostate volume nor PSA density (p > 0.05). Rectoprostatic hematomas and rectal blood collections are rare complications after in-bore MR-guided prostate biopsy. MR imaging provides benefits not only for lesion detection in prostate biopsy but also for the control of bleeding complications, which can be overlooked in standard TRUS biopsy. Their significance in pain, erectile dysfunction, and urinary retention remains to be investigated.

Coronary computed tomography angiography and endocardial leads - Image quality in 320-row CT using iterative reconstruction.

PURPOSE: To investigate whether the presence of endocardial leads has an impact on image quality in coronary computed tomography angiography (CCTA), when current technique is employed using a 320-row computed tomography and iterative reconstruction. MATERIALS AND METHODS: CCTA was performed in 1641 patients, from these we identified 51 patients (study group) with endocardial leads and 51 matched partners (control group) without endocardial leads. Noise was determined in the ascending aorta and the left ventricle; signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were determined in the left and right coronary artery. Subjective image quality was rated separately for the 15 segments of the coronary arteries by 2 radiologists. RESULTS: Current CCTA technique still shows slight impairment of objective image quality in patients with endocardial leads with inferior SNR in the aorta (median 15.04 versus 16.6; p = 0.004) and inferior SNR in the left/right coronary artery (median 15.3/13.81 versus 16.1/15.41; p = 0.013/0.002). CNR of the left/right coronary artery was also inferior (median 17.4/16.46 versus 19.26/19.24; p = 0.002/<0.001). The subjective image quality was rated significantly inferior only in segment 8 (p = 0.001) compared to the control group. Artifacts by ventricular leads were found in 65% of the patients in segment 8 with non-diagnostic rating in 9 cases (18%). Atrial leads resulted in artifacts predominantly in segment 1 (45%) with non-diagnostic rating in only 2 cases (4%). CONCLUSION: CCTA is feasible with slight restrictions for patients in the presence of implanted cardiac devices when current technique is used.

Assessment of Systemic Adenosine Effect Using Color Doppler Ultrasound of the Splenic Artery-Feasibility and Potential Clinical Utility for Coronary Interventions.

Adenosine induces coronary vasodilation and simultaneously reduces splanchnic perfusion. This effect can be absent in adenosine non-responders. Imaging of splanchnic arteries under adenosine assessing this effect has not been performed in humans previously. In 26 patients, splenic artery color Doppler was performed during an infusion of adenosine. Peak velocity in the splenic artery was measured before the infusion and at 2 min. Results were compared qualitatively with perfusion imaging in magnetic resonance. A total of 24 patients showed a drop of splenic artery peak velocity from 62.3 ± 18.1 to 40.4 ± 15.7 cm/s (p <0.001), which corresponded to perfusion restriction in magnetic resonance. Two patients with constant splenic artery velocity did not show perfusion restriction. We showed feasibility of assessing changes in splenic artery velocity under adenosine for the first time in humans. Further studies are needed to investigate whether this novel application is a robust tool to rule out inadequate adenosine effect during measurement of fractional flow reserve in coronary catheterization.

Sleep characteristics and progression of coronary artery calcification: Results from the Heinz Nixdorf Recall cohort study.

BACKGROUND AND AIMS: Sleep characteristics are associated with incident cardiovascular diseases (CVD), but there is a lack of studies on the association between sleep characteristics and incidence/progression of coronary artery calcification (CAC). METHODS: In the Heinz Nixdorf Recall Study, a population-based cohort study in Germany, CAC was assessed by electron-beam tomography at baseline and at 5-year follow-up. In an analysis set of 3043 subjects (age at baseline 45-74 years; 47% men), we fitted logistic and linear regression models to assess associations between self-rated sleep characteristics (nocturnal and total sleep duration; napping; various sleep disorders) and CAC incidence/CAC progression. Progression was measured as 5-year progression factor, as categories of absolute CAC change, and additionally characterized as rapid or slow compared to an extrapolation of baseline CAC values. RESULTS: We observed barely any association between sleep characteristics and CAC progression regardless of the chosen statistical approach; associations between sleep and CAC incidence were slightly larger, e.g., the geometric mean of the 5-year CAC progression factor was 6.8% (95% confidence interval: -9.5; 25.9) larger for ≤5 h, 2.9% (-7.3; 14.3) larger for 5.1-6.9 h and 7.1% (-2.4; 15.7) smaller for ≥7.5 h total sleep compared to 7- <7.5 h total sleep. For subjects with any regular sleep disorder, the geometric mean of the 5-year CAC progression was 3.5% (-4.7; 11.2) smaller compared to subjects without any regular sleep disorder. CONCLUSIONS: In this German cohort study, sleep characteristics were barely associated with CAC progression.

An Integrated Maximum Current Density Approach for Noninvasive Detection of Myocardial Infarction.

We present a new approach of integrated maximum current density (IMCD) for the noninvasive detection of myocardial infarction (MI) using magnetocardiography (MCG) data acquired from a superconducting quantum interference device (SQUID) system. In this paper, we investigated the relationship of the maximum current density (MCD) in the current density map and the underlying equivalent current dipole (ECD) based on a novel method of reconstructing the ECD in the extremum circle of the magnetic field map. The performance of IMCD and the integrated ECD (IECD) approaches were also evaluated by using 61-channel MCG data from 39 healthy subjects and 102 patients with ST elevation myocardial infarction (STEMI). Statistical analysis of the healthy and STEMI groups demonstrate that the IMCD approach obtains sensitivity and specificity up to 91.2% and 84.6%, somewhat higher than that of IECD, respectively. The results indicate that IMCD provides spatiotemporal information regarding cardiac electrical activity during ventricular repolarization. This approach may be helpful to diagnose MI in clinic application. The physical concept of the approach is also explained in this paper.

Effects of Preoperative Simulation on Minimally Invasive Hybrid Lumbar Interbody Fusion.

OBJECTIVE: The main focus of this study was to evaluate how preoperative simulation affects the surgical work flow, radiation exposure, and outcome of minimally invasive hybrid lumbar interbody fusion (MIS-HLIF). METHODS: A total of 132 patients who underwent single-level MIS-HLIF were enrolled in a cohort study design. Dose area product was analyzed in addition to surgical data. Once preoperative simulation was established, 66 cases (SIM cohort) were compared with 66 patients who had previously undergone MIS-HLIF without preoperative simulation (NO-SIM cohort). RESULTS: Dose area product was reduced considerably in the SIM cohort (320 cGy·cm2 NO-SIM cohort: 470 cGy·cm2; P < 0.01). Surgical time was shorter for the SIM cohort (155 minutes; NO-SIM cohort, 182 minutes; P < 0.05). SIM cohort had a better outcome in Numeric Rating Scale back at 6 months follow-up compared with the NO-SIM cohort (P < 0.05). CONCLUSIONS: Preoperative simulation reduced radiation exposure and resulted in less back pain at the 6 months follow-up time point. Preoperative simulation provided guidance in determining the correct cage height. Outcome controls enabled the surgeon to improve the procedure and the software algorithm.

Deactivation vs. asynchronous pacing - prospective evaluation of a protocol for rhythm management in patients with magnetic resonance conditional pacemakers undergoing adenosine stress cardiovascular magnetic resonance imaging.

BACKGROUND: Cardiovascular Magnetic Resonance (CMR) imaging with adenosine stress is an important diagnostic tool in patients with known or suspected coronary artery disease (CAD). However, the method is not yet established for CAD patients with pacemakers (PM) in clinical practice. A possible reason is that no recommendations exist for PM setting (paused pacing or asynchronous mode) during adenosine stress. We elaborated a protocol for rhythm management in clinical routine for PM patients that considers heart rate changes under adenosine using a test infusion of adenosine in selected patients. METHODS: 47 consecutive patients (mean age 72.3 ± 10,0 years) with MR conditional PM and known or suspected CAD who underwent CMR in clinical routine were studied in this prospective observational study. PM indications were sinus node dysfunction (SND, n = 19; 40,4%), atrioventricular (AV) block (n = 26; 55.3%) and bradyarrhythmia in permanent atrial fibrillation (AF, n = 2; 4.3%). In patients with SND, normal AV-conduction and resting HR >45 bpm at the time of CMR and in AF the PM was deactivated for the scan. In intermittent AV-block a test infusion of adenosine was given prior to the scan. All patients with permanent higher degree sinuatrial or AV-block or deterioration of AV-conduction in the adenosine test were paced asynchronously during CMR, in patients with preserved AV-conduction under adenosine the pacemaker was deactivated. CMR protocol included cine imaging, adenosine stress perfusion and late gadolinium enhancement. RESULTS: The adenosine test was able to differentiate between mandatory PM stimulation during CMR and safe deactivation of the device. In patients with permanent sinuatrial or AV-block (n = 11; 23.4%) or deterioration of AV conduction in the adenosine test (n = 5, 10.6%) asynchronous pacing above resting heart rate did not interfere with intrinsic rhythm, no competitive stimulation was seen during the scan. 10 of 15 (66,7%) patients with intermittent AV-block showed preserved AV-conduction under adenosine. As in SND and AF deactivation of the PM showed to be safe during CMR, no bradycardia was observed. CONCLUSION: Our protocol for rhythm management during adenosine stress CMR showed to be feasible and safe and may be recommended for pacemaker patients undergoing routine CMR.

Progression of coronary artery calcification is stronger in poorly than in well controlled diabetes: Results from the Heinz Nixdorf Recall Study.

AIM: To assess associations between HbA1c and progression of coronary artery calcification (CAC) in persons with and without diabetes. METHODS: In the Heinz Nixdorf Recall Study, a population-based cohort study in Germany (N=3453, aged 45-74years), CAC was assessed by electron-beam tomography at baseline and at 5-year follow-up. At baseline, participants were divided into five groups: poorly (HbA1c≥7.0%) and well (HbA1c<7.0%) controlled previously known diabetes (group I/II); no previously known diabetes with HbA1c ≥6.5% (group III), HbA1c 5.7-6.4% (group IV), and HbA1c <5.7% (group V). We fitted linear, logistic and robust Poisson regression models to assess associations between diabetes group and PF5 (factor by which CAC after 5-year follow-up is larger than baseline CAC), and categories of CAC change, respectively. RESULTS: Relative to group V, adjusted percentage increase of the geometric mean of PF5 (95% CI) was: 69.1% (33.9%;113.6%), 15.4% (-5.6%;41.1%), -4.1% (-22.2%;18.2%), 4.2% (-5.4%;14.8%) for groups I-IV, respectively. The corresponding odds ratios for annual CAC increase ≥100 Agatston units (reference: <10) were 10.0 (4.8;20.6), 4.0 (2.1;7.6), 1.5 (0.7;3.2), and 1.1 (0.7;1.8). CONCLUSIONS: In known diabetes, CAC progression was stronger in poor diabetes control. For newly detected diabetes diagnosed by HbA1c ≥6.5%, associations with CAC progression were weak.

Cardiovascular magnetic resonance in patients with magnetic resonance conditional pacemaker systems at 1.5 T: influence of pacemaker related artifacts on image quality including first pass perfusion, aortic and mitral valve assessment, flow measurement, short tau inversion recovery and T1-weighted imaging.

There are only limited data on the impact of device-related artifacts on image quality in cardiovascular magnetic resonance imaging (CMR) in patients with pacemakers (PM). Adenosine stress perfusion, T1-weighted imaging and flow measurement as well as valve characterization have not been evaluated previously concerning artifact burden. We aimed to assess image quality in all routinely used CMR sequences. We analyzed 2623 myocardial segments in CMR scans of 61 patients with MR conditional PM (mean age 72.1 ± 11.5 years), 23 (37.7%) with right sided, 38 (62.3%) with left-sided devices. There were no relevant artifacts in patients with right-sided devices irrespective of the imaging sequence. In left-sided implants no PM-induced artifacts were found in first pass perfusion sequence, flow analysis and T1 weighted imaging. Only few patients with left-sided devices showed significant PM-artifacts in aortic (3/38, 7.9%)/mitral (n = 2/38, 5.3%) valve imaging and STIR (n = 3/35, 8.6%). In STIR only 14/805 (1.7%) segments were involved. In left-sided PM SSFP cine sequences had more artifact burden than LGE with 377/1505 (25.0%) vs. 162/1505 (10.8%) myocardial segments involved by relevant artifacts respectively (p < 0.001). Apart from cine and LGE imaging in anterior myocardial segments with left-sided implants presence of MRI conditional pacemakers does not affect CMR image quality in multimodal CMR examinations to a significant extent. Our data supports evidence that reduced image quality does not need to be a major concern in PM patients undergoing CMR.

Accelerated progression of coronary artery calcification in hypertension but also prehypertension.

OBJECTIVE: To determine the role of hypertension for coronary artery calcification (CAC) progression. METHODS: The population-based Heinz Nixdorf Recall study recruited 4814 participants from a German urban population in 2000-2003. CAC was measured using electron-beam computed tomography at baseline and after 5 years. The present analyses refer to 3481 participants with repeat scan (coronary heart disease until 5 years excluded, age at baseline 45-74 years, and 53.1% women). Blood pressure (BP), Framingham risk factors, and antihypertensive medication were recorded at baseline. BP was staged according to Joint National Committee 7 guidelines. Participants under antihypertensive medication were classified as stage 2. CAC at 5 years was predicted from baseline using our dedicated, publicly available algorithm. CAC progression was accordingly classified as slow, expected, or rapid. RESULTS: Normotension was found in 20.5%, prehypertension in 27.2%, stage 1 hypertension in 15.8%, and stage 2 (ST2) in 36.5%. The frequency of rapid progression increases with BP stage (normotension: 16.7% to ST2: 21.1%, P = 0.004). Risk factor adjusted relative risk [RR (95% confidence interval), reference: normotension] of rapid progression was for prehypertension: 1.22 (0.98;1.51), stage 1: 1.29 (1.01;1.65), and ST2: 1.45 (1.17;1.79). Risk factor adjusted measures of CAC progression per 10 mmHg SBP were already elevated in women with BP below 140/90 mmHg: CAC onset, RR = 1.22 (1.07;1.40), rapid progression, RR = 1.17 (1.05;1.31), 5-year CAC progression, 6.7% (0.5;13.4). In men below 140/90 mmHg, only RR of rapid progression was considerably increased [RR = 1.11 (0.96;1.29)]. CONCLUSION: CAC progression, a sign of ongoing target organ damage, is already accelerated in prehypertensive patients, a substantial proportion of our urban population.

A novel cross-sector telemedical approach to detect arrhythmia in primary care patients with palpitations using a patient-activated event recorder.

BACKGROUND: Patient-activated event recorders (ER) can facilitate diagnosis in unclear palpi-tations, however impact of ER screening on further treatment in clinical routine is unknown. We investigated the feasibility and clinical value of a network-based telemetric monitoring using a patient activated ER. METHODS: The network consisted of 12 general practitioners (GP) and a department of car-diology (DC). GP-patients sent electrocardiograms (ECGs) twice daily and in case of palpitations. ECGs were transferred by email to GP and DC and analyzed independently by both. The therapeutic strategy was discussed between GP and DC. The monitoring period ended after 4 weeks or in case of detected arrhythmia. RESULTS: A group of 184 consecutive patients were retrospectively analyzed. Mean age was 57.5 ± 14.4 years (range 17-82), 104 (56.5%) were female. Significant arrhythmia occurred in 71 (38.5%) patients: Recurrence of known paroxysmal atrial fibrillation (AF; n = 27, 14.7%), de novo AF (n = 19, 10.3%), premature complexes/bigeminus (n = 13, 7.1%), sinus tachycar-dia (n = 7, 3.8%), atrioventricular nodal reentrant tachycardia (n = 3, 1.6%), and ventricular tachycardia (n = 2, 1.1%). A therapeutic consequence resulted in 63 (88.7%) patients with de-tected arrhythmia: new oral anticoagulation (n = 29, 40.8%), new antiarrhythmic medication (n = 27, 38.0%), behavioral intervention (n = 19, 26.8%), electrophysiology-study/catheter ablation (n = 4, 5.6%), cardioversion (n = 2, 2.8%), implantable cardioverter-defibrillator- -implantation (n = 1, 1.4%), and left atrial appendage occluder (n = 1, 1.4%). CONCLUSIONS: The investigated cross-sector telemetric network is a feasible approach to detect arrhythmia in patients with palpitations and may have high impact on further treatment, notably in those at risk for stroke due to AF.

Assessment of fetal development by HRV and chaotic global techniques

INTRODUCTION: Fetal heart rate and its variability during the course of gestation have been extensively researched. The overall reduction in heart rate and increase in fetal HRV is associated with fetal growth and the increase in neural integration. The increased complexity of the demands on the cardiovascular system leads to more variation in the temporal course of the heart rate which has been shown to be reflected in measures of complexity. The aim of this work was to investigate novel complexity measures with respect to their ability to quantify changes over gestational age in individual fetuses consistently and in a stable manner. METHODS: We examined 215 fetal magnetocardiograms (FMCG), each of 5 min duration, in 11 fetuses during the second and third trimesters (at least 10 data sets per fetus). From the FMCG we determined the fetal RR beat durations. For each 5 min time-series of RR intervals we then calculated Shannon entropy, high spectral entropy, high spectral Detrended Fluctuation Analysis, spectral Multi-Taper Method as well as the standard deviation and two commonly used complexity measures: Approximate Entropy and Sample Entropy. For each subject and HRV measure, we performed regression analysis with respect to gestational age. The coefficient of determination R² was used to estimate 'goodness-of-fit', the slope of the regression indicated the strength of the individual dependency on gestational age. RESULTS: We found that the new complexity measures do not outperform ApEn. CONCLUSION: This study has now rejected the hypothesis that the spectral complexity measures outperform those applied previously.

INTRODUÇÃO: A freqüência cardíaca fetal e da sua variabilidade durante o curso da gestação têm sido extensivamente pesquisada. A redução global da frequência cardíaca e aumento da VFC fetal está associada com o crescimento fetal e aumento da integração neural. O aumento da complexidade das exigências sobre o sistema cardiovascular conduz a uma maior variação no decurso temporal da frequência cardíaca o que foi mostrado para reflectir-se medidas de complexidade. O objetivo deste trabalho foi investigar medidas de complexidade novos em relação à sua capacidade de quantificar as mudanças ao longo da idade gestacional em fetos individuais de forma consistente e de forma estável. MÉTODO: Foram examinados 215 magnetocardiograms fetais (FMCG), cada um dos 5 min de duração, em 11 fetos durante o segundo e terceiro trimestres (pelo menos 10 conjuntos de dados por feto). A partir do grande consumo determinamos as durações RR batimento fetais. Para cada série temporal 5 min dos intervalos RR então calculada Shannon entropia, alta entropia espectral, alta espectral Destendenciada Análise Flutuação, espectral Multi-Taper Método, bem como o desvio padrão e duas medidas de complexidade comumente utilizados: aproximado Entropia e Amostra Entropia. Para cada medida assunto e HRV, foi realizada análise de regressão em relação à idade gestacional. O coeficiente de determinação R² foi usada para estimar a "o bem-of-fit", a inclinação da regressão indicou a força do indivíduo dependência da idade gestacional. RESULTADOS: Verificou-se que as novas medidas de complexidade não superar ApEn. CONCLUSÃO: Este estudo agora rejeitou a hipótese de que as medidas de complexidade espectrais superar os aplicados anteriormente.

Feasibility and safety of adenosine cardiovascular magnetic resonance in patients with MR conditional pacemaker systems at 1.5 Tesla.

BACKGROUND: Cardiovascular Magnetic Resonance (CMR) with adenosine stress is a valuable diagnostic tool in coronary artery disease (CAD). However, despite the development of MR conditional pacemakers CMR is not yet established in clinical routine for pacemaker patients with known or suspected CAD. A possible reason is that adenosine stress perfusion for ischemia detection in CMR has not been studied in patients with cardiac conduction disease requiring pacemaker therapy. Other than under resting conditions it is unclear whether MR safe pacing modes (paused pacing or asynchronous mode) can be applied safely because the effect of adenosine on heart rate is not precisely known in this entity of patients. We investigate for the first time feasibility and safety of adenosine stress CMR in pacemaker patients in clinical routine and evaluate a pacing protocol that considers heart rate changes under adenosine. METHODS: We retrospectively analyzed CMR scans of 24 consecutive patients with MR conditional pacemakers (mean age 72.1 ± 11.0 years) who underwent CMR in clinical routine for the evaluation of known or suspected CAD. MR protocol included cine imaging, adenosine stress perfusion and late gadolinium enhancement. RESULTS: Pacemaker indications were sinus node dysfunction (n = 18) and second or third degree AV block (n = 6). Under a pacing protocol intended to avoid competitive pacing on the one hand and bradycardia due to AV block on the other no arrhythmia occurred. Pacemaker stimulation was paused to prevent competitive pacing in sinus node dysfunction with resting heart rate >45 bpm. Sympatho-excitatory effect of adenosine led to a significant acceleration of heart rate by 12.3 ± 8.3 bpm (p < 0.001), no bradycardia occurred. On the contrary in AV block heart rate remained constant; asynchronous pacing above resting heart rate did not interfere with intrinsic rhythm. CONCLUSION: Adenosine stress CMR appears to be feasible and safe in patients with MR conditional pacemakers. Heart rate response to adenosine has to be considered for the choice of pacing modes during CMR.

Reproducibility of brain metabolite concentration measurements in lesion free white matter at 1.5 T.

BACKGROUND: Post processing for brain spectra has a great influence on the fit quality of individual spectra, as well as on the reproducibility of results from comparable spectra. This investigation used pairs of spectra, identical in system parameters, position and time assumed to differ only in noise. The metabolite amplitudes of fitted time domain spectroscopic data were tested on reproducibility for the main brain metabolites. METHODS: Proton spectra of white matter brain tissue were acquired with a short spin echo time of 30 ms and a moderate repetition time of 1500 ms at 1.5 T. The pairs were investigated with one time domain post-processing algorithm using different parameters. The number of metabolites, the use of prior knowledge, base line parameters and common or individual damping were varied to evaluate the best reproducibility. RESULTS: The protocols with most reproducible amplitudes for N-acetylaspartate, creatine, choline, myo-inositol and the combined Glx line of glutamate and glutamine in lesion free white matter have the following common features: common damping of the main metabolites, a baseline using only the points of the first 10 ms, no additional lipid/macromolecule lines and Glx is taken as the sum of separately fitted glutamate and glutamine. This parameter set is different to the one delivering the best individual fit results. DISCUSSION: All spectra were acquired in "lesion free" (no lesion signs found in MR imaging) white matter. Spectra of brain lesions, for example tumors, can be drastically different. Thus the results are limited to lesion free brain tissue. Nevertheless the application to studies is broad, because small alterations in brain biochemistry of lesion free areas had been detected nearby tumors, in patients with multiple sclerosis, drug abuse or psychiatric disorders. CONCLUSION: Main metabolite amplitudes inside healthy brain can be quantified with a normalized root mean square deviation around 5 % using CH3 of creatine as reference. Only the reproducibility of myo-inositol is roughly twice as bad. The reproducibility should be similar using other references like internal or external water for an absolute concentration evaluation and are not influenced by relaxation corrections with literature values.

Validation of functional fetal autonomic brain age score fABAS in 5 min short recordings.

With the objective of evaluating the functional maturation age and developmental disturbances we have previously introduced the fetal autonomic brain age score (fABAS) using 30 min fetal magnetocardiographic recordings (fMCG, Jena). The score is based on heart rate pattern indices that are related to universal principles of developmental biology. The present work aims at the validation of the fABAS methodology on 5 min recordings from an independent database (fMCG, Bochum).We found high agreement of fABAS obtained from Jena normal fetuses (5 min subsets, n = 364) and Bochum recordings (n = 322, normal fetuses). fABAS of 48 recordings from fetuses with intra-uterine growth restriction (IUGR, Bochum) was reduced in most of the cases, a result consistent with IUGR fetuses from Jena previously reported. fABAS calculated from 5 min snapshots only partly covers the accuracy when compared to fABAS from 30 min recordings. More precise diagnosis requires longer recordings.fABAS obtained from fMCG recordings is a strong candidate for standardized assessment of functional maturation age and developmental disturbances. Even 5 min recordings seem to be valuable for screening for maturation problems.

Accuracy of MRI-Targeted in-Bore Prostate Biopsy According to the Gleason Score with Postprostatectomy Histopathologic Control--a Targeted Biopsy-Only Strategy with Limited Number of Cores.

RATIONALE AND OBJECTIVES: Accuracy of ultrasound-guided biopsy and Gleason score is limited, and diagnosis of insignificant cancer with Gleason score ≤6 is frequent when extended biopsy schemes are used. We evaluated whether the magnetic resonance imaging (MRI)-targeted in-bore prostate biopsy correctly identifies the Gleason score of prostate cancer in histopathologic correlation after prostatectomy. Simultaneously a targeted concept is expected to keep down the rate of insignificant cancer. MATERIALS AND METHODS: We compared retrospectively the Gleason score of the MRI-targeted in-bore biopsy with prostatectomy specimens in 50 men with prostate cancer. Endorectal MRI included T2-weighted imaging, diffusion-weighted imaging, dynamic contrast-enhanced imaging, and spectroscopy. Lesions with a prostate imaging-reporting and data system (PI-RADS) score ≥3 were considered. Upgrading and downgrading of tumors was evaluated, and significant upgrading was defined as a shift in Gleason score from 6 to 7 or more. RESULTS: Gleason score was concordant in 66% of the patients, overall upgraded in 30% of patients, and downgraded in 4% of patients. Significant upgrading of the Gleason score from 6 to 7 occurred in eight patients; upgrading did not exceed one step in the Gleason score. After prostatectomy the Gleason score 6 was found in 20% of patients. The median number of cores obtained was 4 (range 2-6), and the median number of positive cores was 2 (range 1-4). CONCLUSIONS: In-bore MRI-targeted biopsy offers good accuracy in the Gleason score with postprostatectomy histopathologic control when compared to the literature. A limited number of cores are sufficient to achieve these results. The fraction of insignificant cancer identified by targeted only-biopsy is low. Upgrading is restricted to one step in the Gleason score. Clinicians should be aware of positive findings in MRI and the biopsy technique used when assessing prostate biopsy results.

Aerobic exercise during pregnancy and presence of fetal-maternal heart rate synchronization.

UNLABELLED: It has been shown that short-term direct interaction between maternal and fetal heart rates may take place and that this interaction is affected by the rate of maternal respiration. The aim of this study was to determine the effect of maternal aerobic exercise during pregnancy on the occurrence of fetal-maternal heart rate synchronization. METHODS: In 40 pregnant women at the 36th week of gestation, 21 of whom exercised regularly, we acquired 18 min. RR interval time series obtained simultaneously in the mothers and their fetuses from magnetocardiographic recordings. The time series of the two groups were examined with respect to their heart rate variability, the maternal respiratory rate and the presence of synchronization epochs as determined on the basis of synchrograms. Surrogate data were used to assess whether the occurrence of synchronization was due to chance. RESULTS: In the original data, we found synchronization occurred less often in pregnancies in which the mothers had exercised regularly. These subjects also displayed higher combined fetal-maternal heart rate variability and lower maternal respiratory rates. Analysis of the surrogate data showed shorter epochs of synchronization and a lack of the phase coordination found between maternal and fetal beat timing in the original data. CONCLUSION: The results suggest that fetal-maternal heart rate coupling is present but generally weak. Maternal exercise has a damping effect on its occurrence, most likely due to an increase in beat-to-beat differences, higher vagal tone and slower breathing rates.

Fetal electrocardiographic measurements in the assessment of fetal heart rate variability in the antepartum period.

This study examines signal availability in fetal electrocardiogram (FECG) beat-to-beat acquisition and the accuracy of fetal heart rate variability (HRV) analysis in the clinical setting using a commercially available FECG monitor. Signal availability was examined in 130 FECG recordings of 0.3-17.5 h duration collected in 63 fetuses (25th-42nd week of gestation) under uncontrolled conditions. Identification of R-peaks demonstrated a signal loss of 30% ± 24% with 3.6 ± 1.7 signal gaps per minute. Median duration of the gaps within a recording was 1.8 ± 0.2 s. Per hour of recording, 1.8 ± 2.1 episodes of 5 min of uninterrupted data were found. Signal availability improved with gestational age and was poorer in women with high body-mass index. Fetal HRV between weeks 36-42 was examined on the basis of 5 min RR-interval episodes obtained under controlled quiet conditions in 55 FECG compared to 46 high quality fetal magnetocardiograms. There were no differences in RR-interval duration, its standard deviation and low frequency power. However, various measures of short-term HRV were significantly higher in the FECG data: root mean square of successive differences (10.0 ± 1.8 versus 6.6 ± 3.0 ms, p < 0.001, high frequency spectral power (24 ± 12 versus 13 ± 13 ms(2), p < 0.001) and approximate entropy (0.86 ± 0.16 versus 0.73 ± 0.24, p = 0.007). We conclude that, in spite of considerable signal loss, FECG recordings can accurately estimate heart rate and its overall variance. However, measures that quantify short-term beat-to-beat HRV will be compromised due to possible recurring inappropriate detection of single R-peaks.