Characterization of the normal cardiac myofiber field in goat measured with MR-diffusion tensor imaging

2002 ◽  
Vol 283 (1) ◽  
pp. H139-H145 ◽  
Author(s):  
L. Geerts ◽  
P. Bovendeerd ◽  
K. Nicolay ◽  
T. Arts
Keyword(s):  
Diffusion Tensor Imaging ◽  
Diffusion Tensor ◽  
Wall Stress ◽  
Helix Angle ◽  
Myocardial Wall ◽  
Angle Data ◽  
Mr Diffusion ◽  
Myocardial Wall Stress ◽  
Left And Right

Cardiac myofiber orientation is a crucial determinant of the distribution of myocardial wall stress. Myofiber orientation is commonly quantified by helix and transverse angles. Accuracy of reported helix angles is limited. Reported transverse angle data are incomplete. We measured cardiac myofiber orientation postmortem in five healthy goat hearts using magnetic resonance-diffusion tensor imaging. A novel local wall-bound coordinate system was derived from the characteristics of the fiber field. The transmural course of the helix angle corresponded to data reported in literature. The mean midwall transverse angle ranged from −12 ± 4° near the apex to +9.0 ± 4° near the base of the left ventricle, which is in agreement with the course predicted by Rijcken et al. (18) using a uniform load hypothesis. The divergence of the myofiber field was computed, which is a measure for the extent to which wall stress is transmitted through the myofiber alone. It appeared to be <0.07 mm−1 throughout the myocardial walls except for the fusion sites between the left and right ventricles and the insertion sites of the papillary muscles.

Transmural heterogeneity of diffusion anisotropy in the sheep myocardium characterized by MR diffusion tensor imaging

2007 ◽  
Vol 293 (4) ◽  
pp. H2377-H2384 ◽  
Author(s):  
Yi Jiang ◽  
Julius M. Guccione ◽  
Mark B. Ratcliffe ◽  
Edward W. Hsu
Keyword(s):  
Diffusion Tensor Imaging ◽  
Volume Fraction ◽  
Diffusion Tensor ◽  
Extracellular Volume ◽  
Extracellular Volume Fraction ◽  
Left Ventricular ◽  
Fiber Direction ◽  
Significant Difference ◽  
Mr Diffusion ◽  
Mr Diffusion Tensor Imaging

The orientation of MRI-measured diffusion tensor in the myocardium has been directly correlated to the tissue fiber direction and widely characterized. However, the scalar anisotropy indexes have mostly been assumed to be uniform throughout the myocardial wall. The present study examines the fractional anisotropy (FA) as a function of transmural depth and circumferential and longitudinal locations in the normal sheep cardiac left ventricle. Results indicate that FA remains relatively constant from the epicardium to the midwall and then decreases (25.7%) steadily toward the endocardium. The decrease of FA corresponds to 7.9% and 12.9% increases in the secondary and tertiary diffusion tensor diffusivities, respectively. The transmural location of the FA transition coincides with the location where myocardial fibers run exactly circumferentially. There is also a significant difference in the midwall-endocardium FA slope between the septum and the posterior or lateral left ventricular free wall. These findings are consistent with the cellular microstructure from histological studies of the myocardium and suggest a role for MR diffusion tensor imaging in characterization of not only fiber orientation but, also, other tissue parameters, such as the extracellular volume fraction.

Left Heart Decompression in Acute Complicated Myocardial Infarction During Extracorporeal Membrane Oxygenation

2017 ◽  
Vol 32 (6) ◽  
pp. 405-408 ◽  
Author(s):  
Seok In Lee ◽  
So Young Lee ◽  
Chang Hyu Choi ◽  
Kook Yang Park ◽  
Chul-Hyun Park
Keyword(s):  
Myocardial Infarction ◽  
Extracorporeal Membrane Oxygenation ◽  
Cardiogenic Shock ◽  
Wall Stress ◽  
Left Ventricular ◽  
Papillary Muscle Rupture ◽  
Membrane Oxygenation ◽  
Mechanical Complications ◽  
Myocardial Wall ◽  
Myocardial Wall Stress

Acute myocardial infarction (AMI) can progress to cardiogenic shock and mechanical complications. When extracorporeal membrane oxygenation (ECMO) is applied to a patient with AMI with cardiogenic shock and mechanical complications, left ventricular (LV) decompression is an important recovery factor because LV dilation increases myocardial wall stress and oxygen consumption. The authors present the case of a 72-year-old man with AMI and LV dilation who developed cardiogenic shock and papillary muscle rupture and who was treated successfully by ECMO with a left atrial venting.

scholarly journals MR diffusion tensor imaging of the spinal cord: can it help in early detection of cervical spondylotic myelopathy and assessment of its severity?

2019 ◽  
Vol 50 (1) ◽  
Author(s):  
Talaat Ahmed Abd El Hameed Hassan ◽  
Ramy Edward Assad ◽  
Shaimaa Atef Belal
Keyword(s):  
Spinal Cord ◽  
Diffusion Tensor Imaging ◽  
Early Detection ◽  
Cervical Spondylotic Myelopathy ◽  
Diffusion Tensor ◽  
Cervical Spinal Cord ◽  
Cervical Cord ◽  
Mr Diffusion ◽  
Compressive Myelopathy ◽  
Mr Diffusion Tensor Imaging

Abstract Background The aim of this study is to evaluate the potential application of MR diffusion tensor imaging (with calculation of fractional anisotropy (FA) values) in assessment of the spondylotic cervical spinal canal compromise and comparison with the information issued from conventional MR sequences for early detection of cervical spondylotic myelopathy (CSM). Thirty patients (11 males and 19 females) were included in this study; age ranged from 22 to 70 years (mean age = 44). All patients had conventional and diffusion tensor imaging (DTI) examinations of the cervical spine for detection and assessment of degree of cervical cord myelopathy. FA values of the whole cord circumference and at 3, 6, 9, 12 o’clock positions of the normal cord (opposite to C2), opposite to the most affected disc, and below the level of the most affected disc were measured. Results High statistically significant P values were obtained when comparing the FA values of the normal cord with the cord opposite to the most affected disc, the normal cord with the cord below the affected disc and the cord at the level of the most affected disc with the cord below the level of the most affected disc. Conclusions DTI of the cervical spinal cord with FA measurement in patients with cervical spondylosis helps in early detection of cervical cord compressive myelopathy prior to appearance of changes in conventional MRI, which can improve the clinical outcome and help in treatment plans.

scholarly journals Paradoxical Higher Myocardial Wall Stress and Increased Cardiac Remodeling Despite Lower Mass in Females

2020 ◽  
Vol 9 (4) ◽  
Author(s):  
Andrew I. H. Phua ◽  
Thu‐Thao Le ◽  
Su W. Tara ◽  
Antonio De Marvao ◽  
Jinming Duan ◽  
...  
Keyword(s):  
Cardiac Remodeling ◽  
Wall Stress ◽  
Lower Mass ◽  
Myocardial Wall ◽  
Myocardial Wall Stress

Preoperative Diffusion Tensor Imaging: A Landmark Modality for Predicting the Outcome and Characterization of Supratentorial Intra-Axial Brain Tumors

2019 ◽  
Vol 124 ◽  
pp. e540-e551
Author(s):  
Khursheed Alam Khan ◽  
Shashi Kant Jain ◽  
Virendra Deo Sinha ◽  
Jyotsna Sinha
Keyword(s):  
Diffusion Tensor Imaging ◽  
Brain Tumors ◽  
Diffusion Tensor

Migraine affects white-matter tract integrity: A diffusion-tensor imaging study

Cephalalgia ◽  
2015 ◽  
Vol 35 (13) ◽  
pp. 1162-1171 ◽  
Author(s):  
Catherine D Chong ◽  
Todd J Schwedt
Keyword(s):  
Diffusion Tensor Imaging ◽  
White Matter ◽  
Corticospinal Tract ◽  
Diffusion Tensor ◽  
Mean Diffusivity ◽  
Imaging Study ◽  
White Matter Tract ◽  
Inferior Longitudinal Fasciculus ◽  
Left And Right ◽  
The Right

Background Specific white-matter tract alterations in migraine remain to be elucidated. Using diffusion tensor imaging (DTI), this study investigated whether the integrity of white-matter tracts that underlie regions of the “pain matrix” is altered in migraine and interrogated whether the number of years lived with migraine modifies fibertract structure. Methods Global probabilistic tractography was used to assess the anterior thalamic radiations, the corticospinal tracts and the inferior longitudinal fasciculi in 23 adults with migraine and 18 healthy controls. Results Migraine patients show greater mean diffusivity (MD) in the left and right anterior thalamic radiations, the left corticospinal tract, and the right inferior longitudinal fasciculus tract. Migraine patients also show greater radial diffusivity (RD) in the left anterior thalamic radiations, the left corticospinal tract as well as the left and right inferior longitudinal fasciculus tracts. No group fractional anisotropy (FA) differences were identified for any tracts. Migraineurs showed a positive correlation between years lived with migraine and MD in the right anterior thalamic radiations ( r = 0.517; p = 0.012) and the left corticospinal tract ( r = 0.468; p = 0.024). Conclusion Results indicate that white-matter integrity is altered in migraine and that longer migraine history is positively correlated with greater alterations in tract integrity.

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