Prevalence of myocardial crypts in a large retrospective cohort study by cardiovascular magnetic resonance

BACKGROUND: Myocardial crypts are discrete clefts or fissures in otherwise compacted myocardium of the left ventricle (LV). Recent reports suggest a higher prevalence of crypts in patients with hypertrophic cardiomyopathy (HCM) and also within small samples of genotype positive but phenotype negative relatives. The presence of a crypt has been suggested to be a predictor of gene carrier status. However, the prevalence and clinical significance of crypts in the general population is unclear. We aimed to determine the prevalence of myocardial crypts in a large cohort of subjects using clinical cardiovascular magnetic resonance (CMR). METHODS: Consecutive subjects referred for clinical CMR during a 12-month period (n = 1020, age 52.6 ± 17, males: 61%) were included. Crypts were defined as >50% invagination into normal myocardium and their overall prevalence, location and shape was investigated and compared between different patient groups. RESULTS: The overall prevalence of crypts was 64/1020 (6.3%). In a predefined ‘normal’ control group the prevalence was lower (11/306, 3.6%, p = 0.031), but were equally prevalent in ischemic heart disease (12/236, 5.1%, p = n/s) and the combined non-ischemic cardiomyopathy (NICM) groups (24/373; 6.4%, p = n/s). Within the NICM group, crypts were significantly more common in HCM (9/76, 11.7%, p = 0.04) and hypertensive CM subjects (3/11, 27%, p = 0.03). In patients referred for CMR for family screening of inherited forms of CM, crypts were significantly more prevalent (10/41, 23%, p < 0.001), including a smaller group with a first degree relative with HCM (3/9, 33%, p = 0.01). CONCLUSION: Myocardial crypts are relatively common in the normal population, and increasingly common in HCM and hypertensive cardiomyopathy. Crypts are also more frequently seen in normal phenotype subjects referred because of a family history of an inherited cardiomyopathy and HCM specifically. It is uncertain what the significance of crypts are in this group, and because of variability in the imaging protocols used and their relative frequency within the normal population, should not be used to clinically stratify these patients. Prospective studies are required to confirm the clinical significance of myocardial crypts, as their significance remains unclear. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12968-014-0066-0) contains supplementary material, which is available to authorized users

Update on hypertrophic cardiomyopathy and a guide to the guidelines

Hypertrophic cardiomyopathy (HCM) is the most common inherited cardiovascular disorder, affecting 1 in 500 individuals worldwide. Existing epidemiological studies might have underestimated the prevalence of HCM, however, owing to limited inclusion of individuals with early, incomplete phenotypic expression. Clinical manifestations of HCM include diastolic dysfunction, left ventricular outflow tract obstruction, ischaemia, atrial fibrillation, abnormal vascular responses and, in 5% of patients, progression to a 'burnt-out' phase characterized by systolic impairment. Disease-related mortality is most often attributable to sudden cardiac death, heart failure, and embolic stroke. The majority of individuals with HCM, however, have normal or near-normal life expectancy, owing in part to contemporary management strategies including family screening, risk stratification, thromboembolic prophylaxis, and implantation of cardioverter-defibrillators. The clinical guidelines for HCM issued by the ACC Foundation/AHA and the ESC facilitate evaluation and management of the disease. In this Review, we aim to assist clinicians in navigating the guidelines by highlighting important updates, current gaps in knowledge, differences in the recommendations, and challenges in implementing them, including aids and pitfalls in clinical and pathological evaluation. We also discuss the advances in genetics, imaging, and molecular research that will underpin future developments in diagnosis and therapy for HCM

Simulation analysis of random errors of time delay estimation by cross-correlation and phase methods

W artykule przedstawiono wyniki analizy porównawczej losowych błędów estymacji czasu opóźnienia otrzymanego z funkcji korelacji wzajemnej i fazy wzajemnej gęstości widmowej mocy. Przeprowadzone symulacje wykazały, że dla małych wartości stosunku sygnał/szum (SNR) mniejsze wartości błędów uzyskuje się dla metody korelacyjnej. Metoda fazowa jest natomiast bardziej efektywna dla dużych wartości SNR, a jej zaletą jest możliwość wyznaczenia opóźnienia dla wybranych harmonicznych.The paper presents results of the comparative analysis of random errors of the time delay estimation (TDE) by means of the cross-correlation analysis and the phase of power density distribution. The simulations performed show that for the low level of signal-to-noise-ratio (SNR) the statistical errors of TDE obtained from the cross-correlation analysis are smaller than those from the phase method. However, the latter one is more efficient for higher SNR than the cross- correlation and can be applied to any selected harmonics

The non-stationary two-phase flow evaluation by radioisotopes

Two-phase flows, especially those commonly applied during hydraulic exploitation of minerals, are often characterized by the presence of serious variations of density. The adequate control of such a system produces high discrepancy of the mixture velocity. These flows cannot be examined by traditional impulse injection of a tracer. A solution to these difficulties is proposed based on the application of sealed sources and measuring methods calibrated by radiotracers during steady conditions of the flow. The paper presents the results of a full-scale test in a laboratory installation where the stream of water is transporting upwards naturally dispersed nodules through a Ř150 mm vertical pipe. A specially designed equipment allows the control of mixture density as well as the measurement of water and the velocity of particular nodules. The obtained results illustrate the capabilities of radiotracers and possibilities how they can be applied in different two-phase flows, when both density and velocity of the components significantly vary during observation

Application of phase of the Cross-Power Spectral Density distribution to radioisotope measurement of two phase flows in pipelines

W artykule przedstawiono zastosowanie charakterystyki fazowej wzajemnej gęstości widmowej mocy do analizy sygnałów uzyskiwanych w radioizotopowych badaniach przepływów dwufazowych w rurociągach. Pokazano jak wykorzystanie zestawu absorpcyjnego, złożonego z dwóch źródeł promieniowania gamma 241Am i dwóch sond scyntylacyjnych NaI(Tl), oraz analizy widmowej sygnałów umożliwia pomiar prędkości transportu fazy mniejszościowej w przepływach typu ciecz-gaz w rurociągu poziomym oraz ciecz-cząstki ciała stałego w rurociągu pionowym.The paper presents an application of phase of the cross-power spectral density (CSPD) distribution to analysis of stochastic signals recorded during radiometric analysis of two-phase flows in pipelines. It shows, how a gamma absorption set, consisting of two radioactive sources 241Am and two scintillation probes NaI(Tl), may be applied to investigation of a gas transportation by liquid in a horizontal pipe and solid particles transportation by a liquid in a vertical pipe. The linear mean velocity of the minority phase transportation was calculated using phase of CSPD of digital signals recorded by the two scintillation probes. The paper is divided into four sections. The first one is a short introduction to the subject of the paper. Section 2 presents the basis of the two-phase flow velocity evaluation by the gamma absorption method (Fig. 1, Eq. 1). Following that the spectral analysis of recorded signals (Eq. 2, Eq. 4; Fig. 4 and Fig. 5) and the uncertainty evaluation of the mean linear velocity (Eq. 6) are given in Section 3. The uncertainty of the mean velocity of the flow's minority phase was reduced to 0,5% for gas and to 1% for solid particles. Finally the Section 4 summarizes the results and presents final conclusions of the paper. The authors conclude that phase spectrum analysis may be applied to meas-urement of a minority phase velocity by the gamma absorption measurements of two-phase mixtures transported through pipelines. This method is especially convenient for relatively high values of signal-to-noise ratio. Słowa kluczowe: przepływ dwufazowy, absorpcja promieniowania gamma, sygnały stochastyczne, wzajemna gęstość widmowa moc

Radioisotope evaluation of two phase liquid-solid flow in a vertical pipe Part 1. Measurement of the velocity of solid particles

W artykule omówiono wykorzystanie izotopów promieniotwórczych do opisu unoszenia przez ciecz cząstek ciała stałego w rurociągu pionowym. Pokazano jak zastosowanie zestawu absorpcyjnego złożonego z dwóch źródeł promieniowania gamma 241Am i dwóch sond scyntylacyjnych umożliwia zarówno pomiar prędkości przepływu jak i koncentracji objętościowej fazy stałej. W prezentowanej metodzie średnia prędkość przepływu ziaren była wyznaczana przy zastosowaniu metody korelacji wzajemnej sygnałów rejestrowanych przez sondy. Dla ilustracji posłużono się pomiarami wykonami na potrzeby transportu hydraulicznego konkrecji polimetalicznych z dna Pacyfiku.The paper presents an application of radioisotopes to description of transportation of solid particles by a liquid in a vertical pipe. It shows how the gamma absorption set, consisting of two radioactive isotopes 241Am and two scintillation probes, may be applied to measurements of both solid particles velocity and volumetric concentration of a flow. In this case the mean velocity of the solid phase transportation is evaluated by a cross-correlation of digital signals recorded by the probes. The paper is divided into five sections. The first is a short introduction to the subject of the paper. Section 2 presents the basis of solid particles velocity measurement by the gamma absorption method (Fig. 1, Eq. 1). Section 3 describes the laboratory installation (Fig. 2) which is an example of the transportation of ceramic models of pebbles expected during exploitation of polymetallic deposits from the Pacific. The diameter and concentration of solid particles were found to be variable and stochastically distributed in the stream. The cross-correlation analysis of the recorded signals (Eq. 2, Fig. 4) and the uncertainty evaluation of the mean velocity (Eq. 3) are given in Section 4. The uncertainty of the mean velocity of the solid particles is reduced to 1%. Section 5 summarises the results and presents final remarks. The authors conclude that the method described in this paper can be applied to many similar complex streams transported through pipelines

Radioisotope evaluation of two phase liquid-solid flow in a vertical pipe Part 2. Determination of the volumetric flow rate of solid particles

W artykule omówiono wykorzystanie metody radioizotopowej w badaniach przepływu mieszaniny ciecz - cząstki ciała stałego w rurociągu pionowym. W tej części pracy przedstawiono sposób pomiaru objętościowego natężenia przepływu fazy stałej przy pomocy absorpcji promieniowania gamma. Podstawą metody jest kalibracja zestawu wykorzystywanego do wyznaczenia zależności liczby zliczeń od koncentracji objętościowej fazy stałej w rurociągu. Opisano specjalnie wykonane stanowisko kalibracyjne i sposób prowadzenia pomiarów. Przedstawiono przykładowe wyniki i określono niepewność rozszerzoną wyznaczonego natężenia przepływu cząstek stałych, która w rozważanym przypadku wyniosła 10%.The paper presents an application of radioisotopes to determination of the solid phase volumetric flow rate in a hydromixture by calibration of the measuring set. It shows how the gamma absorption equipment consisting of two radioactive isotopes 241Am and two scintillation probes can be applied to measurement of both solid particles velocity and volumetric concentration of a flow. In this case the mean volumetric flow rate of the solid phase is evaluated by the gamma radiation intensity recorded during the experiment. The paper is divided into five sections. The first is a short introduction to the subject of the paper. Section 2 presents the basis of the solid phase volumetric flow rate determination in a hydromixture method (Fig. 1, Eqs. 1 ÷ 4). Section 3 describes calibration of the measuring equipment. This section is divided into three parts, the first one presents the measurement geometry (Fig. 2), assumptions and basic equations. The second one describes the especially constructed calibration stand (ig. 3). The last one gives the obtained relation between the related intensity of radiation and the mean volumetric concentration of the solid phase (Fig. 4). The example of the measuring result is given in Section 4. The mean volumetric concentration of solid phase obtained from the experiment was WRQ029 CVP = 0,23 š 0,02. In consequence, the mean flow rate of the solid phase in that experiment QS = (10,0 š 1,0)•10-3 m3/s was evaluated with the accuracy of 10%. Its extended uncertainty U0,95 (QS) = 1,0•10-3 m3/s was obtained due to the assumption of normal error distribution and the confidence level equal to 0,95. In Section 5 the authors summa-rise the results and conclude that the method described in this paper may be applied to many similar complex hydromixtures transported through pipelines

A laboratory stand for testing the methods used for measurement of the fluid flow in a pipe

W artykule omówiono stanowisko laboratoryjne do badań metod pomiaru cieczy jedno- i dwufazowych z wykorzystaniem technik jądrowych. Jako przykład wykorzystania stanowiska przedstawiono wyniki pomiarów prędkości przepływu wody metodami: radioznacznikową i ultradźwiękową oraz pokazano możliwości rozszerzenia badań po wprowadzeniu fazy gazowej.The paper presents a laboratory stand constructed for testing the methods used for measurement of single- and two-phase flow. Especially the paper focuses on application of nuclear methods to measurement of stream velocity in a horizontal pipe with the future possibility of a gas phase inclusion. As an example the comparison of water velocity measurements by radiotracers and an ultrasonic meter is given

Statistical signal analysis in the radioisotope two-phase flow measurements

W artykule omówiono wybrane metody analizy sygnałów stosowane w radioizotopowych absorpcyjnych pomiarach parametrów przepływów dwufazowych: metodę korelacji wzajemnej i metodę fazy wzajemnej gęstości widmowej mocy. Na wybranych przykładach pokazano wykorzystanie obydwu metod do pomiaru prędkości przepływu fazy gazowej w mieszaninie woda-powietrze transportowanej rurociągiem poziomym. Wyznaczono i porównano niepewności wyników pomiarów prędkości uzyskane przy zastosowaniu prezentowanych metod.The paper presents gamma absorption methods applied to two-phase flow evaluation by advanced statistical analysis of the recorded stochastic signals. Two selected methods based on the cross-correlation function and the phase of the cross-spectral density distributions are considered. The examples illustrate application of the specified functions to measurement of velocity of the gas phase transported by water in a horizontal pipe. Moreover, the uncertainties of the velocity measurement results obtained by using both statistical methods presented are calculated and compared