Biomedical subjects

Bernd Jung

Publications and source records attributed to Bernd Jung.

6 recordsLinked to original sources

PubMed2006

MRI myocardial motion and fiber tracking: a confirmation of knowledge from different imaging modalities.

OBJECTIVE: A helical configuration underlies the anatomy of cardiac structure, and a structure/function relationship is needed to determine if the ventricular myocardial band model defines this spatial relationship. This report explores how studies of velocity-encoded phase contrast magnetic resonance imaging (MRI) for myocardial motion and fiber tracking algorithms that imply fiber orientations can (a) quantify regional myocardial wall motion of the entire heart, (b) determine if these motion of implied fiber orientation link with the helical heart model, and (c) reveal if this new knowledge correlates with imaging information from other different imaging modalities. METHODS: Accumulated left ventricular motion patterns that accurately differentiate radial (i.e. contraction and expansion), rotational (i.e. twisting and untwisting), and longitudinal (i.e. lengthening and shortening) motion components are correlated with structure/function data achieved by sonomicrometer crystals, echocardiography, corrosion casts, and MUGA recordings. RESULTS: Acceleration fiber tracking to determine fiber orientation and cardiac motion during the ejection and rapid filling phases of the cardiac cycle corresponded to maximal force displayed by ultrasonic crystals placed into the angulation of the presumed functional units of the descending and ascending segments of the apical loop of the helical ventricular myocardial band, and motion by echocardiographic recordings. These integrated findings imply a favourable interaction of MRI with the myocyte orientation of the helical ventricular myocardial band. CONCLUSIONS: These composite findings indicate that phase contrast MRI techniques for high temporal resolution velocity mapping during cardiac motion and myocardial fiber tracking confirm other technologies, and centralize the capacity of MRI to link other imaging methods together relative to a single helical structural model. The close agreement amongst a spectrum of imaging studies provide a very powerful integration that transcends a single look; the same thing is observed by each component of global technology, thereby implying that the helical ventricular band is the structural basis for these functional changes.

Echocardiography↗

PubMed2006

Investigating myocardial motion by MRI using tissue phase mapping.

OBJECTIVE: Velocity-encoded phase contrast magnetic resonance imaging (MRI) provides a tool to quantify regional myocardial wall motion of the entire heart. It allows the acquisition of three-directional velocity vector fields with high spatial resolution that reflect the temporal evolution of myocardial velocities over the cardiac cycle. In contrast to other imaging modalities such as echocardiography left ventricular performance can be assessed without limited anatomical or functional coverage. METHODS: Compared to other techniques that quantify local myocardial contractility (e.g. implanted ultrasonic crystals) by means of regional displacement, phase contrast MRI provides information about local and global left ventricular velocities (i.e. motion) by utilizing the intrinsic motion sensitivity of MRI. The resultant motion components of contraction, expansion, rotation, lengthening, and shortening of the left ventricle are described in high spatial and temporal detail. Phase contrast measurements were performed in 12 healthy volunteers with a respiratory-gated technique in order to achieve a high temporal resolution of 13.8ms to demonstrate the detailed assessment of global and regional myocardial motion. RESULTS: Data revealed details in left ventricular motion patterns that were previously not seen in phase contrast measurements and are only known from echocardiography. For all volunteers, characteristic myocardial motion patterns and locally different radial (i.e. contraction and expansion), rotational (i.e. twisting and untwisting) and longitudinal (i.e. lengthening and shortening) motion components could be detected with high accuracy. CONCLUSIONS: The phase contrast MRI technique for high temporal resolution velocity mapping is therefore very promising for the investigation and better understanding of the myocardial motion in normal subjects and patients with disturbed left ventricular performance and may validate further testing of different models of cardiac structure.

Heart↗

PubMed2006

Detailed analysis of myocardial motion in volunteers and patients using high-temporal-resolution MR tissue phase mapping.

PURPOSE: To detect and investigate details in left ventricular (LV) motion patterns with a temporal resolution comparable to that of echocardiography. MATERIAL AND METHODS: To assess global and regional myocardial motion in high temporal detail, respiratory-gated MR phase-contrast measurements with three-directional velocity encoding (venc) were performed in 12 healthy volunteers and two patients with LV hypertrophy in basal, midventricular, and apical locations of the LV with a temporal resolution of 13.8 msec. RESULTS: The volunteer data revealed details in LV motion patterns that were known only from echocardiography. For all volunteers, characteristic myocardial motion patterns, such as triphasic global diastolic expansion, could be detected with high accuracy. One volunteer underwent an additional echocardiographic measurement in order to corroborate the complex motion features as measured by MRI. Patient examinations revealed substantial changes in diastolic function compared to motion patterns in healthy volunteers. CONCLUSION: The proposed high-temporal-resolution velocity-mapping technique provides previously undetectable information on LV performance, and is highly promising for the detection of local and global motion abnormalities in patients with disturbed LV performance, such as diastolic dysfunction.

Adult↗

PubMed2006

Navigator gated high temporal resolution tissue phase mapping of myocardial motion.

Data acquisition for phase contrast velocity mapping of myocardial motion is typically based on multiple breath-held 2D measurements with limited acquisition duration and consequently relatively poor temporal resolution. In order to overcome the limitations of breath-hold acquisitions, an improved navigator-guided technique was implemented based on 2 navigator signals within each cardiac cycle in combination with paired acceptance and rejection criteria of successive navigator signals. Respiratory gated phase contrast measurements with 3-directional velocity encoding were performed in 12 healthy volunteers in basal, midventricular, and apical locations of the left ventricle during free breathing with a temporal resolution of 13.8 ms. Results were compared to standard breath-hold measurements with a temporal resolution of 69 ms. Data from the high temporal resolution study revealed details in left ventricular motion patterns that were previously not seen in phase contrast measurements and are only known from echocardiography. The proposed navigator gated technique for high temporal resolution velocity mapping is, therefore, highly promising for the detection of local and global motion abnormalities in patients with disturbed left ventricular performance, such as diastolic dysfunction.

Adult↗

PubMed2004

Complete molecular remission of chronic eosinophilic leukemia complicated by CNS disease after targeted therapy with imatinib.

Many cases of hypereosinophilia, formerly classified as hypereosinophilic syndrome, can now be characterized as chronic eosinophilic leukemia (CEL) based on the demonstration of characteristic genetic markers indicating clonality of hematopoiesis. Here we report on a 33-year-old male patient with central nervous system manifestations of CEL and an excellent response to low-dose imatinib (Glivec). Molecular analysis demonstrated a constitutive activation of the platelet-derived growth factor receptor-alpha (PDGFR-A) as the mechanism of responsiveness to imatinib.

Adult↗

PubMed2004

Measurement of left ventricular velocities: phase contrast MRI velocity mapping versus tissue-doppler-ultrasound in healthy volunteers.

The aim of this study was the comparison of phase contrast magnetic resonance imaging (PCMRI) measurements of left ventricular velocities in a physiological in vivo setting with tissue-Doppler-ultrasound (tissue Doppler imaging: TDI) data in healthy volunteers. Images were acquired in short axis view using a flow compensated black blood k-space segmented gradient echo sequence. Velocity encoding was performed by adding a bipolar gradient after each rf-pulse to the otherwise identical pulse sequences. Full in-plane velocity information of the moving heart was obtained in 16 heartbeats within one breath-hold measurement. Twenty-nine healthy volunteers (mean age=25 years) were examined with both imaging modalities. Both PCMRI and TDI demonstrate a biphasic profile of radial velocities over the cardiac cycle. Intraindividual comparison of left ventricular velocity data acquired using PCMRI and TDI show a very good correspondence with r-values of 0.97. The in vivo study in 29 healthy volunteers demonstrates a high validity of time-resolved phase contrast measurements for the analysis of left ventricular myocardial velocities.

Adult↗