Morphologic perfusion patterns and PI-RADSv2.1 in transition zone prostate cancer.

PURPOSE: To evaluate morphologic perfusion patterns in transition zone prostate cancer in multiparametric MRI controlled by in-bore MRI-guided prostate biopsy. METHODS: Two experienced radiologists evaluated MRI perfusion patterns in consensus from 321 biopsy cores from the transition zone in 141 patients. Transition zone cancer was present in 77 cores in 36 patients. Single early-phase perfusion images were evaluated separately for the presence of a transition zone prostate cancer (consensus tumor early perfusion). The proposed criteria for the perfusion pattern (asymmetry, signal strength, and homogeneity) were rated in consensus for each biopsy position in the presence of the T2w images including the markers of the biopsy trace. We analyzed receiver operating characteristic curves for the PI-RADSv2.1 score and the proposed perfusion pattern. RESULTS: A logistic regression model with PI-RADSv2.1 and perfusion patterns in early perfusion imaging improved the model fit significantly compared to a model containing only PI-RADSv2.1 (Likelihood Ratio Test, LR = 14.5, p < .001). The AUC was 0.96 for the multiple regression model compared to 0.92 for the PI-RADSv2.1 alone. The evaluation of homogeneity in single early-enhancement images is not inferior compared to the conventional DCE parameter of PI-RADSv2.1 (AUC 0.84 versus 0.83). CONCLUSION: Morphologic perfusion patterns significantly improve the diagnostic performance of PI-RADSv2.1 in TZ prostate cancer.

Imaging of cardiac electrical excitation conduction.

We present a multiple time windows beamformer (MTWB) method of solving the inverse problem of magnetic field and non-invasively imaging the cardiac electrical excitation conduction using the magnetocardiac signals acquired by a 61-channel superconducting quantum interference device (SQUID). The MTWB constructs spatial filters for each location in source space, one for each component of the source moment based on the distributed source model, and estimates the cardiac equivalent current sources. The output of spatial filters is the source strength estimated in three-dimensional space and the weight matrix calculated with magnetocardiac signals in multiple time windows. A signal subspace projection technique is used to suppress noise. Then, the characteristics of cardiac electrical excitation conduction among two healthy subjects and two coronary vessel stenosis (CVS) patients are extracted from reconstructed current sources with maximum strength at each instant during QRS complex and ST-T segment, and a series of two-dimensional cardiac electrical excitation conduction maps (EECM) are obtained. It is demonstrated that two healthy subjects are of similar and the stronger electrical activities than those of two CVS patients. This technique can be used as an effective tool for the diagnosis of heart diseases.

[Biotechnological therapies for the treatment of back pain: alternatives to corticosteroids]. / Biotechnologische Konzepte zur Behandlung von Rückenschmerzen : Erste Erfahrungen mit Alternativen zu Glukokortikoiden.

In recent years, it is increasingly clear that back pain is not only caused by biomechanical problems. Currently, biologically-based local therapy concepts for the treatment of affected spinal regions as an alternative to the standard treatment with steroids are in development or in early stages of clinical application. The common features of these new therapies are to intervene in the regulation of homeostasis at various key points at the affected region and specifically to suppress or block catabolic influences as well as to provide with anti-inflammatory substances and growth factors. These include on one hand the genetically produced Biologicals such as TNF-α inhibitors and cytokine antagonists and on the other hand therapies with autologous blood preparations (Autologous Conditioned Serum [ACS], and Platelet Rich Plasma formulations [PRP]). This article presents the individual methods, gives an overview of developments and results of various studies and discusses current recommendations.

Changes in neuronal correlates of body image processing by means of cognitive-behavioural body image therapy for eating disorders: a randomized controlled fMRI study.

BACKGROUND: Previous neuroimaging studies have demonstrated abnormalities in visual body image processing in anorexia and bulimia nervosa, possibly underlying body image disturbance in these disorders. Although cognitive behavioural interventions have been shown to be successful in improving body image disturbance in eating disorders, no randomized controlled study has yet analysed treatment-induced changes in neuronal correlates of visual body image processing. METHOD: Altogether, 32 females with eating disorders were randomly assigned either to a manualized cognitive behavioural body image therapy consisting of 10 group sessions, or to a waiting list control condition. Using functional magnetic resonance imaging, brain responses to viewing photographs of one's own and another female's body taken from 16 standardized perspectives while participants were wearing a uniform bikini were acquired before and after the intervention and the waiting time, respectively. RESULTS: Data indicate a general blood oxygen level dependent signal enhancement in response to looking at photographs of one's own body from pre- to post-treatment, whereas exclusively in the control group activation decreases from pre- to post-waiting time were observed. Focused activation increases from pre- to post-treatment were found in the left middle temporal gyrus covering the coordinates of the extrastriate body area and in bilateral frontal structures including the middle frontal gyrus. CONCLUSIONS: Results point to a more intense neuronal processing of one's own body after the cognitive behavioural body image therapy in cortical regions that are responsible for the visual processing of the human body and for self-awareness.

Influence of brain tumors on the MR spectra of healthy brain tissue.

The neurochemical environment of nontumorous white matter tissue was investigated in 135 single voxel spectra of "healthy" white matter regions of 43 tumor patients and 129 spectra of 52 healthy subjects. Spectra were acquired with short TE and TR values. With the data of tumor patients, it was examined whether differences were caused by the tumor itself or aggressive tumor therapies as confounding factors. Comparing the spectra of both classes, an excellent differentiation was possible based on the metabolite peak of N-acetylaspartate (P ≈ 0) and myoinositol (P < 0.03). The area under curve of the receiver operating characteristic was calculated as 0.86 and 0.62, respectively. With linear discriminant analysis using combinations of integrals, a prediction was possible, whether a spectrum belonged to the patient or the healthy subject class with an overall accuracy above 80%. The confounding factors could be ruled out as source of the differences. The results show strong evidence for an influence of malignant growth on the biochemical environment of nontumorous white matter tissue. Because of the T(1) weighting, the measured differences between both classes were most likely concentration changes interfered by T(1) effects. The underlying processes will be subject of future studies.

Influence of paced maternal breathing on fetal-maternal heart rate coordination.

Pregnant mothers often report a special awareness of and bonding with their unborn child. Little is known about this relationship although it may offer potential for the assessment of the fetal condition. Recently we found evidence of short epochs of fetal-maternal heart rate synchronization under uncontrolled conditions with spontaneous maternal breathing. Here, we examine whether the occurrence of such epochs can be influenced by maternal respiratory arrhythmia induced by paced breathing at several different rates (10, 12, 15, and 20 cycles per minute). To test for such weak and nonstationary synchronizations among the fetal-maternal subsystems, we apply a multivariate synchronization analysis technique and test statistics based on twin surrogates. We find a clear increase in synchronization epochs mostly at high maternal respiratory rates in the original but not in the surrogate data. On the other hand, fewer epochs are found at low respiratory rates both in original and surrogate data. The results suggest that the fetal cardiac system seems to possess the capability to adjust its rate of activation in response to external--i.e., maternal--stimulation. Hence, the pregnant mothers' special awareness to the unborn child may also be reflected by fetal-maternal interaction of cardiac activity. Our approach opens up the chance to examine this interaction between independent but closely linked physiological systems.

[Fetal heart rate variation in magnetocardiography and cardiotocography--a direct comparison of the two methods]. / Die fetale Herzfrequenzvariation in der Magnetokardiografie und der Kardiotokografie--direkter Vergleich beider Verfahren.

BACKGROUND: Heart rate variability (HRV) is becoming increasingly important in the analysis of prepartal cardiotocography (CTG). Dawes and Redmann have developed a computer algorithm which can calculate short-term variability on the basis of CTG data. In dealing with artefacts, CTG monitors average heart rate values over several beats which makes the use of standard measures of HRV such as the root mean square of successive differences (RMSSD) inappropriate. Fetal magnetocardiography (FMCG) enables the registration of signals similar to the electrocardiogram and this permits the precise determination of heart beat duration and, in consequence, of measures of fetal HRV. METHODS: In this study we applied both methods--CTG and FMCG--sequentially and simultaneously in healthy pregnancies. Fetal short-term HRV was estimated on the basis of RMSSD values for both methods. RESULTS: The RMSSD values of the FMCG data were generally higher and showed a wider dynamic range than those of the CTG. The direct comparison of the simultaneously acquired data demonstrated that the data processing of the CTG signal leads to a suppression of essential aspects of short-term HRV. CONCLUSION: FMCG permits a substantially more differentiated examination of fetal HRV and offers new possibilities in the analysis of fetal cardiac activity.

Influence of gestational age, heart rate, gender and time of day on fetal heart rate variability.

From adult data, it is known that numerous factors, such as age, state of the autonomic nervous system, diurnal rhythms or mean R-R interval mRR, influence heart rate variability (HRV). The aim of this study was the examination of the influence of gestational age, mRR, gender and time of day on fetal HRV. The analysis was based on 66 fetal magnetocardiograms (FMCGs) of 22 healthy fetuses between the 16th and 42nd week. FMCGs were recorded for 5 min using a multichannel biomagnetometer. On the basis of the time series of fetal R-R intervals, mRR as well as the standard deviation sdRR, root mean square of successive differences rmssdRR and approximate entropy ApEn were calculated. The influence of gestational age, mRR and gender on sdRR, rmssdRR and ApEn was determined by regression analysis. The relationship between time of day and HRV was evaluated by visual inspection of scatterplots. The logarithmised HRV measures increased significantly with the logarithm of gestational age (regression coefficients: sdRR = 1.28, rmssdRR = 1.12, ApEn = 1.30) and mRR (regression coefficients: sdRR = 0.008, rmssdRR = 0.011, ApEn = 0.012) There was no significant influence of gender. With respect to time of day (between 0800 h and 1800 h), no dependency of the HRV measures was apparent. In summary, when fetal HRV is assessed, it is essential to take gestational age and mRR into account. In contrast, time of day, with respect to daytime, and gender need not be considered. In future studies, the influence of fetal activity state on HRV should be examined.

Prognostic value of electron-beam computed tomography-derived coronary calcium scores compared with clinical parameters in patients evaluated for coronary artery disease. Prognostic value of EBCT in symptomatic patients.

OBJECTIVE: The electron-beam computed tomography-(EBCT-)derived calcium score provides a measure of coronary atherosclerotic plaque disease which may allow for more precise risk stratification in symptomatic patients. However, it remains unclear if EBCT can add prognostic information compared with the clinical information derived from risk factor assessment, exercise stress testing, and coronary angiography. METHODS AND RESULTS: A cohort of 300 consecutive patients with recent (<3 months) onset of symptoms was retrospectively identified who were examined for possible coronary artery disease (CAD) and who all underwent EBCT. Successful follow-up after 3.5 years was obtained in 255 (85%) patients whose mean age at baseline was 58+/-11 years (n = 181 (71%), males). Four clinical categories with increasing evidence of CAD were constructed on the basis of risk factor assessment, exercise stress testing, coronary angiographic anatomy, and coronary revascularization at baseline. During follow-up, major adverse cardiac events (MACE: myocardial infarction, cardiac death, revascularization) were observed in 40 (16%) patients, including myocardial infarction and cardiac death in 5 patients. The 4 clinical categories were highly predictive of MACE, with a relative risk estimate of 28.3 (95% CI, 6.7-119.1) in the upper vs. the reference category. In univariate analysis, the relative risk estimate of MACE associated with a calcium score > or =100 was 12.0 (95% CI, 4.7-30.6). After adjustment for the clinical categories and for age, this estimate decreased in multivariate analysis, but remained predictive at 4.4 (95% CI, 1.5-12.6). CONCLUSION: In patients with first-time evaluation of possible CAD, EBCT-derived coronary calcium is suggested to provide for independent and additional information compared with the clinically available information.

Reproducibility and reliability of fetal cardiac time intervals using magnetocardiography.

We investigated several factors which may affect the accuracy of fetal cardiac time intervals (CTI) determined in magnetocardiographic (MCG) recordings: observer differences, the number of available recording sites and the type of sensor used in acquisition. In 253 fetal MCG recordings, acquired using different biomagnetometer devices between the 15th and 42nd weeks of gestation, P-wave, QRS complex and T-wave onsets and ends were identified in signal averaged data sets independently by different observers. Using a defined procedure for setting signal events, interobserver reliability was high. Increasing the number of registration sites led to more accurate identification of the events. The differences in wave morphology between magnetometer and gradiometer configurations led to deviations in timing whereas the differences between low and high temperature devices seemed to be primarily due to noise. Signal-to-noise ratio played an important overall role in the accurate determination of CTI and changes in signal amplitude associated with fetal maturation may largely explain the effects of gestational age on reproducibility. As fetal CTI may be of value in the identification of pathologies such as intrauterine growth retardation or fetal cardiac hypertrophy, their reliable estimation will be enhanced by strategies which take these factors into account.

Assessment of fetal growth on the basis of signal strength in fetal magnetocardiography.

Fetal magnetocardiography has shown that fetal P wave and QRS complex durations increase with gestational age, reflecting change in cardiac muscle mass. The latter should, in principle, be associated with an increase in signal strength. We examined two approaches for determining QRS signal strength in a healthy fetus on a weekly basis in the second and third trimester. Twenty-two fetal magnetocardiograms of the same fetus were obtained using a 61 channel Magnes 1300 biomagnetometer (20th-42nd week of gestation). In the signal averaged fetal beat produced at each week, signal strength was assessed on the basis of 1) peak-to-peak QRS signal amplitudes and 2) strength of an equivalent current dipole (ECD) computed at R peak. The results were assessed on the basis of correlation to week of gestation and by comparison to changes in QRS interval duration. All values increased with advancing gestation and regression analysis suggested a nonlinear dependency on age. ECD strength reflected gestational age slightly more reliably (r2=0.93) than signal amplitude values (mean, median, maximum: r2=089, 0.88, 0.85, respectively). ECD strength and mean signal amplitude also correlated well (r=0.97, p<0.0005) Values calculated from QRS complexes determined immediately before and after a clear change in fetal position (acquisition week 24) demonstrated a certain instability in both approaches. Nonetheless, the overall correlation of the amplitude to gestational age compared favorably with that of QRS complex duration. This indicates that not only magnetocardiographically determined fetal cardiac time intervals but also signal strength may be used to assess fetal growth.

Image-guided percutaneous laser disk decompression for herniated lumbar disks: a 4-year follow-up in 200 patients.

OBJECTIVE: The purpose of this study was to describe the long-term effect of image-guided percutaneous laser disk decompression (PLDD). BACKGROUND DATA: PLDD has been reported to be an alternative method to treat herniated lumbar disks. It has proved to be effective on a short-term basis. Although the procedure has been used for several years, few articles report on the long-term effect of the intervention. MATERIALS AND METHODS: Two hundred patients, who were treated with image-guided PLDD for herniated lumbar disks, were observed over a period of 4 +/- 1.3 years. Treatments were carried out under CT/fluoroscopy guidance with local anesthesia on an outpatient basis with an Nd:YAG laser of 1064 nm. RESULTS: At follow-up, back pain was eliminated or reduced in 73% of the patients. Regarding sensorimotor impairment, PLDD did have a positive effect on 74% of the patients. In the majority of patients, the number of sick days and consumption of pain medication was reduced. In one patient, diskitis occurred as a complication of PLDD; 74% of the patients said they were satisfied with the outcome of the therapy; and 81.5% of the patients would have required another PLDD in cases of disk herniation. CONCLUSION: From our clinical results, we conclude that image-guided PLDD is an effective and secure method to treat contained herniated lumbar disks. Advantages of the procedure include the minimally invasive approach on an out-patient basis and the low complication rate.

[Magnetoneurographic registration of evoked summation action fields over lumbar vertebrae following transcutaneous tibial nerve stimulation]. / Magnetoneurographische Darstellung evozierter Summenaktionsfelder über der lumbalen Wirbelsäule nach transkutaner N. Tibialis Stimulation.

Goal of this study was the development of a protocol for the registration of evoked magnetic fields over the lumbar spine using off-the-shelf equipment. Three subjects in a sitting position with their torso bent slightly forward were stimulated at the tibial nerve with a commercially available stimulator. Neuromagnetic fields were registered over a circular, 800 cm2 area of the lumbosacral spine using a 61-channel 4D-Neuroimaging biomagnetometer. After appropriate signal processing, dipolar magnetic fields with a field strength 5-17 fT peak-to-peak amplitude were detected in three out of four registrations. Location and orientation of these fields concurred with the expected evoked compound action currents along the course of the nerve fibers.

[Simulation of coupling behavior of heart rhythms for study of phase synchronization]. / Simulation des Kopplungsverhaltens von Herzrhythmen zur Untersuchung der Phasensynchronisation.

Biological systems exhibit numerous rhythmic processes. In the human, rhythms produced by e.g. the cardiac and respiratory systems show signs of synchronisation, reflecting a physiological coupling of the underlying oscillating processes. When examining such rhythms for evidence of coupling, it is difficult to distinguish between epochs of coincidental (numerical) and real (physiological) synchronisation. The objective of this study was to simulate model rhythms in order to examine the conditions under which coupling may be recognised and the influence of noise on this recognition. Different model rhythms with adjustable noise were implemented. The synchronisation between pairs of such rhythms was examined with the help of synchrograms. Functions were used to simulate coupling. The results of the simulation were compared to real fetal-maternal cardiac rhythms. The simulation showed that heart rate variability may be an important factor in distinguishing between coincidental and real synchronisation.

Reproducibility of two coronary calcium quantification algorithms in patients with different degrees of calcification.

PURPOSE: To evaluate the reproducibility of coronary calcium quantification algorithms by electron beam CT (EBT) in patients with different amounts of calcified plaque using the conventional (Agatston) score and an area score and to demonstrate a potential application of these results for evaluation of follow-up scans. METHODS: In 50 consecutive patients. the conventional calcium score (CCS = Agatston score) and the area score (AS) were summed for each artery and patient. Data were analyzed in four groups according to degrees of calcification: 0 (absent-minimal): CCS 0-9, I (mild): CCS 10-99, II (moderate): CCS 100-399, III (severe): CCS > or = 400. We determined and compared the reproducibility for each algorithm within and among groups. RESULTS: Median percent reproducibility improved with increasing amounts of calcified plaque for the CCS and the AS (p = 0.002 and p = 0.004, respectively). We demonstrate how these reproducibility values can be used to evaluate long-term follow-up studies. The reduction of median reproducibility per patient using the AS vs. the CCS was 32% (13 vs. 19%, respectively). On a vessel-by-vessel basis, the reduction of median reproducibility was 7% (24.3 vs. 22.6%, CCS vs. AS, p < 0.02), which was attributable to a 45% reduction in reproducibility in arteries with mild scores (46.1 vs. 25.5%, CCS vs. AS, p < 0.005). CONCLUSION: The AS has an improved reproducibility compared with the CCS, especially in patients with small amounts of coronary calcifications which may prove clinically useful. Different reproducibility values in different degrees of calcification can be used for an individual assessment of changes in amounts of coronary calcification.

Prevalence and clinical significance of accidental findings in electron-beam tomographic scans for coronary artery calcification.

AIMS: To analyse the prevalence, and diagnostic and therapeutic consequences, of accidental findings in electron-beam tomographic scans performed for evaluation of coronary artery calcification. METHODS AND RESULTS: A total of 1812 consecutive patients with known or suspected coronary artery disease underwent electron-beam tomography. In 583 (32%) of the patients, i.v. contrast was also administered for non-invasive coronary angiography. A total of 2055 non-coronary pathological findings were observed in 953 (53%) of the patients. The prevalence of extra-cardiac disease, as shown in native scans and contrast studies, was assessed separately. In 583 (32%) patients, cardiac structures or the pericardium were affected, in 423 (23%) aortic disease was found. Lung disease was found in 357 (20%), and pathology of other organs in 273 patients (15%). The most frequent findings were aortic calcium in 423 (23%) patients and heart valve calcification in 317 patients (17%). Malignant disease could be detected in three patients. Further diagnostic investigations were done in 191 (11%) patients, 141 (74%) of which concerned the heart. In 22 (1.2%) patients, specific therapy was initiated following electron-beam tomographic findings. CONCLUSION: Accidental non-coronary pathology is a frequent finding in electron-beam tomographic calcium scanning, and often requires diagnostic or therapeutic action. Profound knowledge of the radiological differential diagnosis of the thoracic organs is necessary for reporting electron-beam tomographic scans, in order to avoid misdiagnosis and to receive a high quality interpretation.

[Electron beam computed tomography of the heart before kidney transplantation. Severe coronary disease in a 21-year old woman with nephrocalcinosis due to infantile hypercalcemia syndrome]. / Elektronenstrahltomographie des Herzens vor Nierentransplantation. Schwere koronare Herzerkrankung bei einer 21-Jährigen mit Nephrokalzinose bei infantilem Hyperkalzämiesyndrom.

BACKGROUND: Cardiovascular diseases are very common in patients with end-stage renal disease and are the underlying cause of approximately half the deaths in dialysis patients. In those patients vascular calcifications are typically seen in the tunica media and therefore represent histopathological changes different to those in atherosclerosis. For the evaluation of cardiovascular risk in chronic dialysis patients, a method is needed to reliably identify patients who have to undergo invasive diagnostics. Coronary artery calcium assessed by electron beam computed tomography (EBT) has been suggested to measure the extent of coronary atherosclerosis in patients with normal renal function. It might also be of value in the stratification of cardiovascular risk in patients with renal failure. CASE REPORT: We report the case of a 21-year-old female with end-stage renal disease as a result of idiopathic infantile hypercalcemia with nephrocalcinosis and extensive vascular calcification. Due to a total atrioventricular block, a 2-chamber pacemaker had been implanted in 1998. Because of a very high calcium score in EBT, depressed left ventricular function in echocardiography, and limited physical strength she was sent to coronary angiography. Severe 2-vessel coronary artery disease was found and successfully treated by balloon angioplasty. She was then listed for renal transplantation. Angiographic 6-month follow-up showed an excellent long-term result. CONCLUSION: This case demonstrates that coronary artery disease can also be present in young dialysis patients. Discrimination of atherosclerotic vascular calcification and tunica media sclerosis typical in dialysis patients without hemodynamic effects is difficult. EBT allows for the direct detection of coronary calcium. Its extent correlates with coronary atherosclerosis and the probability of acute coronary syndromes in patients with normal renal function. This evidence has not been proved for dialysis patients, yet. However, EBT may be of value in the stratification of cardiovascular risk for patients awaiting renal transplantation.

Natural history and topographic pattern of progression of coronary calcification in symptomatic patients: An electron-beam CT study.

Electron-beam CT may assess the progression of coronary atherosclerosis by visualizing changes in calcification. The present investigation analyzes (1) the rate of progression of calcification in symptomatic patients, (2) the topographic pattern, and (3) the influence of baseline plaque burden and risk factors. Progression of calcification during a mean (median) interval of 18 (15) months was measured in 102 symptomatic outpatients (aged 59+/-9 years, 80% male) with calcification. In 4 patient groups with a baseline total score (Agatston criteria) of 1 to 30, >30 to 100, >100 to 400, and >400, the median was 3.1, 26.1, 58.9, and 109.7, respectively, for absolute annual progression of the score (P<0.05) and 57%, 49%, 32%, and 15%, respectively, for relative progression (P<0.05). On the coronary segmental level, changes were largely restricted to typical predilection sites of coronary atherosclerosis. The presence of angiographically defined coronary narrowing influenced absolute, but not relative, progression. Of the risk factors, only low density lipoprotein cholesterol levels showed a trend, although not significant, for predicting progression. These data indicate that baseline plaque burden determines the rate of progression of calcification. This appears to be a coronary systemic process, reflecting the natural history of coronary atherosclerosis.

Rare but serious complications of acupuncture: traumatic lesions.

Acupuncture has a reputation among the public of being safe. Although recently performed prospective studies on the frequency of adverse effects of acupuncture found no severe complication, since 1965 many case reports of serious or even life-threatening incidents caused by acupuncture have appeared in the scientific literature. The most frequently reported complications are pneumothorax and lesions of the spinal cord. Severe injuries of peripheral nerves and blood vessels due to acupuncture seem to be very rare. Although case reports do not produce reliable data on the frequency of adverse events. information on sources of application errors can be extracted to increase the quality of acupuncture in education and therapy. All traumatic injuries described in this article could be avoided if practitioners had better anatomical knowledge, applied existing anatomical knowledge better, or both.