Alterations in intramuscular water movement associated with mechanical changes in human skeletal muscle fibers: an evaluation using magnetic resonance diffusion-weighted imaging and B-mode ultrasonography

2011 ◽  
Vol 52 (9) ◽  
pp. 1003-1008 ◽  
Author(s):  
Osamu Yanagisawa ◽  
Toshiyuki Kurihara ◽  
Toru Fukubayashi
Keyword(s):  
Magnetic Resonance ◽  
Ankle Joint ◽  
Structural Changes ◽  
Water Movement ◽  
Morphological Changes ◽  
Muscle Fibers ◽  
Medial Gastrocnemius ◽  
Plantar Flexors ◽  
Diffusion Weighted Images ◽  
Diffusion Weighted

Background Intramuscular water movement is expected to be affected by the mechanical changes of the muscle fibers. However, the effect of changes in fiber length (FL) and pennation angle (PA) on the water movement has not been sufficiently investigated in human skeletal muscles. Purpose To determine the relationship between intramuscular water movement and the mechanical changes in human muscle fibers. Material and Methods Axial magnetic resonance diffusion-weighted images of the right leg (eight men) were taken using a 1.5-Tesla device with the ankle joint maximally dorsiflexed and maximally plantar flexed. The apparent diffusion coefficient (ADC) values of both the dorsiflexors (the superficial and deep parts of the tibialis anterior) and the plantar flexors (medial gastrocnemius and soleus) were calculated along three orthogonal axes (S-I: superior-to-inferior, A-P: anterior-to-posterior, and R-L: right-to-left). FL and PA of both muscle groups were also calculated from longitudinal B-mode ultrasound images with the ankle joint maximally dorsiflexed and plantar flexed. Results There was a significant increase in the ADC in superficial ( P < 0.05) and deeP ( P < 0.05) parts of the dorsiflexors in the S-I direction when the ankle was plantar flexed and in the A-P and R-L directions when the ankle was dorsiflexed ( P < 0.05). The plantar flexors showed significantly elevated ADC in the S-I direction when the ankle was dorsiflexed ( P < 0.05), and in the A-P and R-L directions when the ankle was plantar flexed ( P < 0.05). The dorsiflexors also showed significantly increased PA and decreased FL values when the ankle was dorsiflexed ( P < 0.05). The plantar flexors displayed similar morphological changes when the ankle was plantar flexed ( P < 0.05). Conclusion Water diffusion is affected by structural changes in the long axis of the muscle fibers, namely the changes in PA and FL.

Clinical application of three-dimensional anisotropy contrast magnetic resonance axonography

1999 ◽  
Vol 90 (4) ◽  
pp. 791-795 ◽  
Author(s):  
Tsutomu Nakada ◽  
Naoki Nakayama ◽  
Yukihiko Fujii ◽  
Ingrid L. Kwee
Keyword(s):  
Magnetic Resonance ◽  
Healthy Volunteers ◽  
Clinical Application ◽  
Color Image ◽  
Three Dimensional ◽  
Cerebral Peduncle ◽  
Imaging Method ◽  
Medial Lemniscus ◽  
Diffusion Weighted Images ◽  
Diffusion Weighted

✓ The utility of three-dimensional anisotropy contrast (3DAC) magnetic resonance (MR) axonography, a method sensitive to neuronal fibers and their directionality, was investigated in the clinical setting using a 3-tesla MR imaging system based on a General Electric Signa platform. The study focused on healthy volunteers and patients with common structural central nervous system disorders, namely chronic infarction, brainstem cavernous hemangioma, supratentorial meningioma, and astrocytoma. Three orthogonal anisotropic diffusion-weighted images were first obtained. Three primary colors were each assigned to a diffusion-weighted image, respectively, and the images were subsequently combined into a single-color image in full-color spectrum (3DAC MR axonography image). Fiber-tract definition in the cerebral peduncle of the midbrain of healthy volunteers showed intersubject variation, with two general patterns recognized: dispersed (60% of cases) and compact (40% of cases). Pathological alterations in the fiber tracts were readily identified in cases involving wallerian degeneration of the pyramidal tract, as illustrated in the cases of chronic infarction. Displacement of major tracts, such as the medial lemniscus or corticospinal tract, as well as fiber directionality, was also easily recognized in cases of mass lesions. As an imaging method uniquely capable of providing information regarding axonal connectivity, 3DAC MR axonography appears to have promising potential for routine clinical application.

scholarly journals Ultrasound Structural Changes in Triceps Surae After a 1-Year Daily Self-stretch Program: A Prospective Randomized Controlled Trial in Chronic Hemiparesis

2019 ◽  
Vol 33 (4) ◽  
pp. 245-259 ◽  
Author(s):  
Maud Pradines ◽  
Mouna Ghedira ◽  
Raphaël Portero ◽  
Ingrid Masson ◽  
Christina Marciniak ◽  
...  
Keyword(s):  
Structural Changes ◽  
Controlled Trial ◽  
Triceps Surae ◽  
Medial Gastrocnemius ◽  
Plantar Flexors ◽  
Fascicle Length ◽  
Rehabilitation Programs ◽  
Lower Limb Muscles ◽  
Muscle Fascicle ◽  
Prospective Randomized Controlled Trial

Introduction. The effects of long-term stretching (>6 months) in hemiparesis are unknown. This prospective, randomized, single-blind controlled trial compared changes in architectural and clinical parameters in plantar flexors of individuals with chronic hemiparesis following a 1-year guided self-stretch program, compared with conventional rehabilitation alone. Methods. Adults with chronic stroke-induced hemiparesis (time since lesion >1 year) were randomized into 1 of 2, 1-year rehabilitation programs: conventional therapy (CONV) supplemented with the Guided Self-rehabilitation Contract (GSC) program, or CONV alone. In the GSC group, specific lower limb muscles, including plantar flexors, were identified for a diary-based treatment utilizing daily, high-load, home self-stretching. Blinded assessments included (1) ultrasonographic measurements of soleus and medial gastrocnemius (MG) fascicle length and thickness, with change in soleus fascicle length as primary outcome; (2) maximum passive muscle extensibility (XV1, Tardieu Scale); (3) 10-m maximal barefoot ambulation speed. Results. In all, 23 individuals (10 women; mean age [SD], 56 [±12] years; time since lesion, 9 [±8] years) were randomized into either the CONV (n = 11) or GSC (n = 12) group. After 1 year, all significant between-group differences favored the GSC group: soleus fascicle length, +18.1mm [9.3; 29.9]; MG fascicle length, +6.3mm [3.5; 9.1]; soleus thickness, +4.8mm [3.0; 7.7]; XV1 soleus, +4.1° [3.1; 7.2]; XV1 gastrocnemius, +7.0° [2.1; 11.9]; and ambulation speed, +0.07m/s [+0.02; +0.16]. Conclusions. In chronic hemiparesis, daily self-stretch of the soleus and gastrocnemius over 1 year using GSC combined with conventional rehabilitation increased muscle fascicle length, extensibility, and ambulation speed more than conventional rehabilitation alone.

scholarly journals Morphological changes in distant muscle fibers following thermal injury in Wistar rats

2010 ◽  
Vol 25 (6) ◽  
pp. 525-528 ◽  
Author(s):  
Flavia de Oliveira ◽  
Luci Rezende Bevilacqua ◽  
Carlos Alberto Anaruma ◽  
Silvia de Campos Boldrini ◽  
Edson Aparecido Liberti
Keyword(s):  
Body Surface ◽  
Wistar Rats ◽  
Thermal Injury ◽  
Morphological Changes ◽  
Muscle Fibers ◽  
The Body ◽  
Medial Gastrocnemius ◽  
Control Group ◽  
Hematoxylin And Eosin ◽  
Gastrocnemius Muscles

PURPOSE: Thermal injury causes catabolic processes as the body attempts to repair the damaged area. This study evaluated the effects of a scald injury on the morphology of muscle fibers belonging to a muscle distant from the lesion. METHODS: Thirty Wistar rats were divided into control (C) and scalded (S) groups. Group S was scalded over 45% of the body surface, standardized by body weight. Rats in both groups were euthanized at four, seven and 14 days following the injury. The middle portions of the medial gastrocnemius muscles were sectioned, stained with hematoxylin and eosin and Picrosirius, and submitted to histological analysis. RESULTS: Control group sections exhibited equidistantly distributed polygonal muscle fibers with peripheral nuclei, characteristic of normal muscle. The injured group sections did not consistently show these characteristics; many fibers in these sections exhibited a rounded contour, variable stain intensities, and greater interfiber distances. A substantially increased amount of connective tissue was also observed on the injured group sections. CONCLUSION: This experimental model found a morphological change in muscle distant from the site of thermal injury covering 45% of the body surface.

DIFFUSION-WEIGHTED MAGNETIC RESONANCE IMAGING OF THE ULNAR NERVE IN CUBITAL TUNNEL SYNDROME

Hand Surgery ◽  
2010 ◽  
Vol 15 (01) ◽  
pp. 11-15 ◽  
Author(s):  
K. Iba ◽  
T. Wada ◽  
M. Tamakawa ◽  
M. Aoki ◽  
T. Yamashita
Keyword(s):  
Magnetic Resonance ◽  
Ulnar Nerve ◽  
Signal Intensity ◽  
Cubital Tunnel Syndrome ◽  
Cubital Tunnel ◽  
High Signal ◽  
Diffusion Weighted Mri ◽  
Diffusion Weighted Images ◽  
Diffusion Weighted ◽  
Tunnel Syndrome

Diffusion-weighted images based on magnetic resonance reveal the microstructure of tissues by monitoring the random movement of water molecules. In this study, we investigated whether this new technique could visualize pathologic lesions on ulnar nerve in cubital tunnel. Six elbows in six healthy males without any symptoms and eleven elbows in ten patients with cubital tunnel syndrome underwent on diffusion-weighted MRI. No signal from the ulnar nerve was detected in normal subjects. Diffusion-weighted MRI revealed positive signals from the ulnar nerve in all of the eleven elbows with cubital tunnel syndrome. In contrast, conventional T2W-MRI revealed high signal intensity in eight elbows and low signal intensity in three elbows. Three elbows with low signal MRI showed normal nerve conduction velocity of the ulnar nerve. Diffusion-weighted MRI appears to be an attractive technique for diagnosis of cubital tunnel syndrome in its early stages which show normal electrophysiological and conventional MRI studies.

Threshold Isocontouring on High b-Value Diffusion-Weighted Images in Magnetic Resonance Mammography

2019 ◽  
Vol 43 (3) ◽  
pp. 434-442
Author(s):  
Fangrong Zong ◽  
Sebastian Bickelhaupt ◽  
Tristan Anselm Kuder ◽  
Wolfgang Lederer ◽  
Heidi Daniel ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
B Value ◽  
Diffusion Weighted Images ◽  
High B Value ◽  
Diffusion Weighted ◽  
Magnetic Resonance Mammography

scholarly journals Effect of a prehop on the muscle-tendon interaction during vertical jumps

2018 ◽  
Vol 124 (5) ◽  
pp. 1203-1211 ◽  
Author(s):  
Jeroen Aeles ◽  
Glen Lichtwark ◽  
Dries Peeters ◽  
Christophe Delecluse ◽  
Ilse Jonkers ◽  
...  
Keyword(s):  
Ankle Joint ◽  
Negative Impact ◽  
Joint Moment ◽  
Medial Gastrocnemius ◽  
Plantar Flexors ◽  
Squat Jump ◽  
Generating Capacity ◽  
Length Changes ◽  
Muscle Fascicles ◽  
Ankle Joint Moment

Many movements use stretch-shortening cycles of a muscle-tendon unit (MTU) for storing and releasing elastic energy. The required stretching of medial gastrocnemius (MG) tendinous tissue during jumps, however, requires large length changes of the muscle fascicles because of the lack of MTU length changes. This has a negative impact on the force-generating capacity of the muscle fascicles. The purpose of this study was to induce a MG MTU stretch before shortening by adding a prehop to the squat jump. Eleven well-trained athletes specialized in jumping performed a prehop squat jump (PHSJ) and a standard squat jump (SSJ). Kinematic data were collected using a 3D motion capture system and were used in a musculoskeletal model to calculate MTU lengths. B-mode ultrasonography of the MG was used to measure fascicle length and pennation angle during the jumps. By combining the muscle-tendon unit lengths, fascicle lengths, and pennation angles, the stretch and recoil of the series elastic element of MG were calculated using a simple geometric muscle-tendon model. Our results show less length changes of the muscle fascicles during the upward motion and lower maximal shortening velocities, increasing the moment-generating capacity of the plantar flexors, reflected in the higher ankle joint moment in the PHSJ compared with the SSJ. Although muscle-tendon interaction during the PHSJ was more optimal, athletes were not able to increase their jump height compared with the SSJ. NEW & NOTEWORTHY This is the first study that aimed to improve the muscle-tendon interaction in squat jumping. We effectively introduced a stretch to the medial gastrocnemius muscle-tendon unit resulting in lower maximal shortening velocities and thus an increase in the plantar flexor force-generating capacity, reflected in the higher ankle joint moment in the prehop squat jump compared with the standard squat jump. Here, we demonstrate an effective method for mechanical optimization of the muscle-tendon interaction in the medial gastrocnemius during squat jumping.

Correlation of Placental Magnetic Resonance Imaging With Histopathologic Diagnosis: Detection of Aberrations in Structure and Water Diffusivity

2019 ◽  
Vol 23 (4) ◽  
pp. 260-266
Author(s):  
Crystal Bockoven ◽  
Roland D Gastfield ◽  
Thomas Victor ◽  
Palamadai N Venkatasubramanian ◽  
Alice M Wyrwicz ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Relaxation Time ◽  
Magnetic Resonance ◽  
Unknown Etiology ◽  
Placental Pathology ◽  
Resonance Imaging ◽  
Fixed Tissue ◽  
Diffusion Weighted Images ◽  
Diffusion Weighted ◽  
And Diffusion

Objective Noninvasive methods to identify placental pathologic conditions are being sought in order to recognize these conditions at an earlier stage leading to improved clinical interventions and perinatal outcomes. The objective of this study was to examine fixed tissue slices of placenta by T2- and diffusion-weighted magnetic resonance imaging (MRI) and correlate the images with placental pathologic findings defined by routine gross and histologic examination. Methods Four formalin-fixed placentas with significant placental pathology (maternal vascular malperfusion, chronic villitis of unknown etiology, and massive perivillous fibrin deposition) and 2 histologically normal placentas were evaluated by high-resolution MRI. Representative placental slices were selected (2 cm long and 10 mm wide) and rehydrated. Imaging was performed on a Bruker Avance 14.1 T microimager. Diffusion-weighted images were acquired from 16 slices using slice thickness 0.5 mm and in-plane resolution approximately 100 µm × 100 µm. T2 maps were obtained from the same slices. T2 relaxation time and apparent diffusion coefficient (ADC) were acquired from representative regions of interest and compared between normal and diseased placentas. Results In T2- and diffusion-weighted images, the placental microstructure differed subjectively between diseased and normal placentas. Furthermore, diseased placentas showed statistically significantly longer mean T2 relaxation times and generally higher mean ADC. Conclusion Diffusion- and T2-weighted MRI can potentially be used to detect significant placental pathology by using T2 relaxation time and ADC as markers of altered placental microstructure.

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