scholarly journals Evaluating Foot Kinematics Using Magnetic Resonance Imaging: From Maximum Plantar Flexion, Inversion, and Internal Rotation to Maximum Dorsiflexion, Eversion, and External Rotation

2011 ◽  
Vol 133 (10) ◽  
Author(s):  
Michael J. Fassbind ◽  
Eric S. Rohr ◽  
Yangqiu Hu ◽  
David R. Haynor ◽  
Sorin Siegler ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Internal Rotation ◽  
External Rotation ◽  
Plantar Flexion ◽  
Neutral Position ◽  
Resonance Imaging ◽  
Limit Motion ◽  
Electromagnetic Sensor ◽  
Scan Data

The foot consists of many small bones with complicated joints that guide and limit motion. A variety of invasive and noninvasive means [mechanical, X-ray stereophotogrammetry, electromagnetic sensors, retro-reflective motion analysis, computer tomography (CT), and magnetic resonance imaging (MRI)] have been used to quantify foot bone motion. In the current study we used a foot plate with an electromagnetic sensor to determine an individual subject’s foot end range of motion (ROM) from maximum plantar flexion, internal rotation, and inversion to maximum plantar flexion, inversion, and internal rotation to maximum dorsiflexion, eversion, and external rotation. We then used a custom built MRI-compatible device to hold each subject’s foot during scanning in eight unique positions determined from the end ROM data. The scan data were processed using software that allowed the bones to be segmented with the foot in the neutral position and the bones in the other seven positions to be registered to their base positions with minimal user intervention. Bone to bone motion was quantified using finite helical axes (FHA). FHA for the talocrural, talocalcaneal, and talonavicular joints compared well to published studies, which used a variety of technologies and input motions. This study describes a method for quantifying foot bone motion from maximum plantar flexion, inversion, and internal rotation to maximum dorsiflexion, eversion, and external rotation with relatively little user processing time.

scholarly journals Multi-Rigid Image Segmentation and Registration for the Analysis of Joint Motion From Three-Dimensional Magnetic Resonance Imaging

2011 ◽  
Vol 133 (10) ◽  
Author(s):  
Yangqiu Hu ◽  
William R. Ledoux ◽  
Michael Fassbind ◽  
Eric S. Rohr ◽  
Bruce J. Sangeorzan ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Image Segmentation ◽  
Magnetic Resonance ◽  
Neutral Position ◽  
Processing Unit ◽  
Joint Motion ◽  
Resonance Imaging ◽  
Registration Method ◽  
Cpu Time ◽  
Overlap Ratio

We report an image segmentation and registration method for studying joint morphology and kinematics from in vivo magnetic resonance imaging (MRI) scans and its application to the analysis of foot and ankle joint motion. Using an MRI-compatible positioning device, a foot was scanned in a single neutral and seven other positions ranging from maximum plantar flexion, inversion, and internal rotation to maximum dorsiflexion, eversion, and external rotation. A segmentation method combining graph cuts and level set was developed. In the subsequent registration step, a separate rigid body transformation for each bone was obtained by registering the neutral position dataset to each of the other ones, which produced an accurate description of the motion between them. The segmentation algorithm allowed a user to interactively delineate 14 foot bones in the neutral position volume in less than 30 min total (user and computer processing unit [CPU]) time. Registration to the seven other positions took approximately 10 additional minutes of user time and 5.25 h of CPU time. For validation, our results were compared with those obtained from 3DViewnix, a semiautomatic segmentation program. We achieved excellent agreement, with volume overlap ratios greater than 88% for all bones excluding the intermediate cuneiform and the lesser metatarsals. For the registration of the neutral scan to the seven other positions, the average overlap ratio is 94.25%, while the minimum overlap ratio is 89.49% for the tibia between the neutral position and position 1, which might be due to different fields of view (FOV). To process a single foot in eight positions, our tool requires only minimal user interaction time (less than 30 min total), a level of improvement that has the potential to make joint motion analysis from MRI practical in research and clinical applications.

Water exchange induced by unilateral exercise in active and inactive skeletal muscles

2002 ◽  
Vol 93 (5) ◽  
pp. 1716-1722 ◽  
Author(s):  
Anders T. Nygren ◽  
Lennart Kaijser
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Skeletal Muscles ◽  
Water Exchange ◽  
Driving Forces ◽  
Plantar Flexion ◽  
Resonance Imaging ◽  
Water Displacement ◽  
Cross Sectional ◽  
High Workload

Water exchange was evaluated in active (E-leg) and inactive skeletal muscles by using1H-magnetic resonance imaging. Six healthy subjects performed one-legged plantar flexion exercise at low and high workloads. Magnetic resonance imaging measured calf cross-sectional area (CSA), transverse relaxation time (T2), and apparent diffusion capacity (ADC) at rest and during recovery. After high workload, inactive muscle decreased CSA and T2 by 2.1% ( P < 0.05) and 3.1% ( P < 0.05), respectively, and left ADC unchanged. E-leg simultaneously increased CSA, T2, and ADC by 4.2% ( P < 0.001), 15.5% ( P < 0.05), and 12.5% ( P < 0.001), respectively. In conclusion, ADC and T2 correlated highly with muscle volume, indicative of extravascular water displacement closely related to muscle activity and perfusion, which was presumably a combined effect of increased intracellular osmoles and hydrostatic forces as driving forces. A distinguishable muscle temperature release was initially detected in the E-leg after high workload, and the ensuing recovery of ADC and T2 indicated delayed interstitial restitution than restitution of the intracellular compartment. Furthermore, absorption of extravascular water was detected in inactive muscles at contralateral high-intensity exercise.

scholarly journals Dynamic ultrasound evaluation of the syndesmosis ligamentous complex and clear space in acute ankle injury, compared to magnetic resonance imaging and surgical findings

2017 ◽  
Vol 21 (1) ◽  
Author(s):  
Chantelle Van Niekerk ◽  
Barbara Van Dyk
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Imaging Modality ◽  
Statistical Significance ◽  
Lateral Ligament ◽  
Neutral Position ◽  
Resonance Imaging ◽  
Clear Space ◽  
Ultrasound Evaluation ◽  
Dynamic Ultrasound

Background: Syndesmosis injuries are often more serious than an injury to the lateral ligament complex of the ankle, with double the recovery time, chronic discomfort and joint instability. Although magnetic resonance imaging (MRI) is considered as the best imaging modality to assess the integrity of the syndesmotic ligamentous complex and clear space, a dynamic ultrasound evaluation may provide an alternative imaging option worthy of exploring.Aim: The aim of this article is to compare the sensitivity and specificity of musculoskeletal ultrasound and MRI, in the diagnosis of syndesmosis pathology, with surgical findings as the reference point.Method: MRI was performed on 114 participants presenting with pain over the lateral aspect of the ankle after injury. This was followed by a dynamic ultrasound examination during which the anterior tibiofibular ligament (ATiFL) was assessed for continuity, contour and haematoma. The tibiofibular clear space was measured with the ankle in a neutral position, followed by internal and external rotation.Results: The Fisher’s exact test was used to determine non-random associations between variables and compute statistical significance (p < 0.05). Ultrasound achieved a sensitivity of 86.3%, specificity of 97% with a false-positive rate of 3%. The sensitivity of MRI is similar to that of ultrasound (86%) with a specificity of 100%.Conclusion: Although both imaging tests performed very well, MRI was slightly better at excluding pathology while both tests performed equally in demonstrating pathology. As a simple, inexpensive and reproducible test, dynamic ultrasound can thus be considered as an alternative to MRI in acute ankle pathology.

The Relationships between the Rotational Axes of the Distal Femur in the Arthritic Caucasian Knee: A Magnetic Resonance Imaging Analysis

2020 ◽  
Author(s):  
Mansur Halai ◽  
Sahil Kooner ◽  
Bilal Jamal ◽  
Jacquelyn McMillan ◽  
Brian Syme ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
External Rotation ◽  
Axial Rotation ◽  
Secondary Outcome ◽  
Patient Specific ◽  
Resonance Imaging ◽  
Coronal Alignment ◽  
Patient Specific Instrumentation ◽  
The Mean

AbstractFour distal femoral axes have been described to aid in the accuracy of transverse plane component alignment in total knee arthroplasty (TKA). These include the surgical epicondylar axis (SEA), the posterior condylar axis (PCA), and the anteroposterior (AP) axis. Therefore, the primary purpose of this study is to identify the axial femoral relationship with the least variation in a Caucasian population awaiting TKA for osteoarthritis. Secondarily, we further plan to determine if these femoral axis relationships differ with respect to sex or preoperative coronal alignment. These anatomic relationships were measured using preoperative magnetic resonance imaging, which was performed within 2 months of the planned operation date for patient specific instrumentation templating. In terms of our primary outcome, the mean SEA/AP angle was 92.8 degrees (standard deviation [SD]: 2.5 degrees), the mean PCA/AP angle was 95.7 degrees (SD: 2.8 degrees), and the mean PCA/SEA angle was 3.4 degrees (SD: 1.8 degrees). Overall, the PCA/SEA relationship had the smallest variance, while the PCA/AP had the most variance for all comparisons. In terms of our secondary outcome, there was no statistical difference between femoral axis relationships based on preoperative coronal plane alignment. In terms of sex differences, the PCA/SEA was significantly higher in female knees compared with males. Females had a PCA/SEA relationship of 4.7 degrees (SD: 1.3 degrees) compared with 2.6 degrees (SD: 1.2 degrees) for males (p < 0.05). By using the PCA/AP axes, the AP axis was externally rotated by 96.7 degrees (SD: 2.3 degrees) in females, compared with 93.2 degrees (SD: 2.1 degrees) in males, from the PCA. In conclusion, our results demonstrate that the PCA/SEA relationship should be used to determine axial rotation in TKA as it shows the least variation. When using the PCA, approximately 5 degrees of external rotation for Caucasian women and 3 degrees of external rotation for the Caucasian men should be dialed into the femoral cutting block to restore anatomic axial rotation. Further evaluation is needed to determine to role of preoperative coronal alignment on distal femoral axial alignment.

scholarly journals DYNAMIC MAGNETIC RESONANCE IMAGING: PRELIMINARY PRESENTATION OF A TECHNIQUE

2016 ◽  
Vol 15 (3) ◽  
pp. 209-212
Author(s):  
BRUNO DA COSTA ANCHESCHI ◽  
ANIELLO SAVARESE ◽  
RAPHAEL DE REZENDE PRATALI ◽  
DANIEL AUGUSTO CARVALHO MARANHO ◽  
MARCELLO TEIXEIRA CASTILHA ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Spinal Cord ◽  
Cervical Spine ◽  
Magnetic Resonance ◽  
Cervical Spondylotic Myelopathy ◽  
Dynamic Magnetic Resonance Imaging ◽  
Neutral Position ◽  
Resonance Imaging ◽  
Significant Difference ◽  
Flexion And Extension

ABSTRACT Objective: To evaluate morphometric variations of the cervical spine in patients with cervical spondylotic myelopathy (CSM) using dynamic magnetic resonance imaging (MRI) in neutral, flexion and extension positions. Methods: This is a prospective study of patients with CSM secondary to degenerative disease of the cervical spine. The morphometric parameters were evaluated using T2-weighted MRI sequences in the sagittal plane in neutral, flexion and extension position of the neck. The parameters studied were the anterior length of the spinal cord (ALSC), the posterior length of the spinal cord (PLSC), the diameter of the vertebral canal (DVC) and the diameter of the spinal cord (DSC). Results: The ALSC and PLSC were longer in flexion than in extension and neutral position, with statistically significant difference between the flexion and extension position. The DVC and the DSC were greater in flexion than in extension and neutral position, however, there was no statistically significant difference when they were compared in the neutral, flexion and extension positions. Conclusion: Dynamic MRI allows to evaluate morphometric variations in the cervical spinal canal in patients with cervical spondylotic myelopathy.

Clinical Association of Acute Lateral Ankle Sprain with Syndesmotic Involvement

2002 ◽  
Vol 30 (6) ◽  
pp. 816-822 ◽  
Author(s):  
Hendrik D. Uys ◽  
Arie M. Rijke
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Plantar Flexion ◽  
Ligament Injury ◽  
Lateral Ligament ◽  
Ankle Sprains ◽  
Resonance Imaging ◽  
Severe Injuries ◽  
Lateral Ankle ◽  
Lateral Ligament Injury

Background Information concerning the clinical association between syndesmosis injury and grade of lateral ankle ligament damage would aid in the diagnosis and treatment of ankle sprains. Hypothesis Evaluation of lateral ligament injury in terms of percentage tear of both the anterior talofibular and calcaneofibular ligaments can provide information on the extent of syndesmotic involvement. Study Design Prospective cohort study. Methods Twenty-five patients volunteered to have magnetic resonance imaging examinations performed and 21 volunteered to undergo graded stress radiographs. Talar tilt angles were measured from radiographs taken with 0, 6, 9, 12, and 15 daN of force applied medially just above the ankle joint, and the percentage of ligament tear and grade of injury were determined. Scans were obtained with the foot in neutral and plantar flexion to image the anterior talofibular and calcaneofibular ligaments. Results Grades of lateral ligament injury determined by magnetic resonance imaging and graded stress radiography were the same. The extent of syndesmotic injury could be assessed for all patients. Conclusions Intact tibiofibular ligaments were found equally frequently among patients with normal or any grade of lateral ligament damage, but the more severe injuries to the syndesmotic ligaments were associated with normal or minimally traumatized lateral ligaments. The inverse correlation can be explained on the basis of the difference between the mechanisms that precipitate these injuries.

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