The use of magnetic resonance images to investigate the influence of recruitment on the relationship between torque and cross-sectional area in human muscle

2000 ◽  
Vol 83 (6) ◽  
pp. 475-480 ◽  
Author(s):  
Hiroshi Akima ◽  
Shin-ya Kuno ◽  
Hideyuki Takahashi ◽  
Tetsuo Fukunaga ◽  
Shigeru Katsuta
Keyword(s):  
Magnetic Resonance ◽  
Magnetic Resonance Images ◽  
Human Muscle ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Cross Sectional ◽  
The Relationship

scholarly journals INDIRECT DECOMPRESSION BY LATERAL FUSION: ANALYSIS OF SAGITAL ALIGNMENT

2021 ◽  
Vol 20 (1) ◽  
pp. 50-54
Author(s):  
Thyago Guirelle Silva ◽  
Rodrigo Augusto do Amaral ◽  
Raphael Rezende Pratali ◽  
Luiz Pimenta
Keyword(s):  
Magnetic Resonance ◽  
Pelvic Incidence ◽  
Magnetic Resonance Images ◽  
Cross Sectional Area ◽  
Disc Height ◽  
Lower Limbs ◽  
Sectional Area ◽  
Cross Sectional ◽  
Indirect Decompression ◽  
The Mean

ABSTRACT Objective: To verify the effectiveness of indirect decompression after lateral access fusion in patients with high pelvic incidence. Methods: A retrospective, non-comparative, non-randomized analysis of 22 patients with high pelvic incidence who underwent lateral access fusion, 11 of whom were male and 11 female, with a mean age of 63 years (52-74), was conducted. Magnetic resonance exams were performed within one year after surgery. The cross-sectional area of the thecal sac, anterior and posterior disc heights, and bilateral foramen heights, measured pre- and postoperatively in axial and sagittal magnetic resonance images, were analyzed. The sagittal alignment parameters were measured using simple radiographs. The clinical results were evaluated using the ODI and VAS (back and lower limbs) questionnaires. Results: In all cases, the technique was performed successfully without neural complications. The mean cross-sectional area increased from 126.5 mm preoperatively to 174.3 mm postoperatively. The mean anterior disc height increased from 9.4 mm preoperatively to 12.8 mm postoperatively, while the posterior disc height increased from 6.3 mm preoperatively to 8.1 mm postoperatively. The mean height of the right foramen increased from 157.3 mm in the preoperative period to 171.2 mm in the postoperative period and that of the left foramen increased from 139.3 mm in the preoperative to 158.9 mm in the postoperative. Conclusions: This technique is capable of correcting misalignment in spinal deformity, achieving fusion and promoting the decompression of neural elements. Level of evidence III; Retrospective study.

scholarly journals Quantitative assessment of the entire thoracic aorta from magnetic resonance images

2010 ◽  
Vol 21 (2) ◽  
pp. 170-177 ◽  
Author(s):  
Ryan K. Johnson ◽  
Senthil Premraj ◽  
Sonali S. Patel ◽  
Andreas Wahle ◽  
Alan Stolpen ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Connective Tissue ◽  
Thoracic Aorta ◽  
Aortic Root ◽  
Magnetic Resonance Images ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Healthy Individuals ◽  
Cross Sectional ◽  
The Cross

AbstractObjectivesAlthough magnetic resonance imaging is a primary modality for following patients with connective tissue diseases, only a limited amount of the image data is utilised. The purpose of this study was to show the clinical applicability of an automated four-dimensional analysis method of magnetic resonance images of the aorta and develop normative data for the cross-sectional area of the entire thoracic aorta.Study designMagnetic resonance imaging was obtained serially over 3 years from 32 healthy individuals and 24 patients with aortopathy and a personal or family history of connective tissue disorder. Graph theory-based segmentation was used to determine the cross-sectional area for the thoracic aorta. Healthy individual data were used to construct a nomogram representing the maximum cross-sectional area 5th–95th percentile along the entire thoracic aorta. Aortic root diameters calculated from the cross-sectional area were compared to measured diameters from echocardiographic data. The cross-sectional area of the entire thoracic aorta in patients was compared to healthy individuals.ResultsCalculated aortic root diameters correlated with measured diameters from echo data – correlation coefficient was 0.74–0.87. The cross-sectional area in patients was significantly greater in the aortic root, ascending aorta, and descending aorta compared to healthy individuals.ConclusionThe presentation of the dimensional data for the entire thoracic aorta shows an important clinical tool for following patients with connective tissue disorders and aortopathy.

Cross-Sectional Area of the Stenotic Lumbar Dural Tube Measured from the Transverse Views of Magnetic Resonance Imaging

1994 ◽  
Vol 7 (5) ◽  
pp. 388???393 ◽  
Author(s):  
Chiaki Hamanishi ◽  
Noboru Matukura ◽  
Masahiko Fujita ◽  
Mituo Tomihara ◽  
Seisuke Tanaka
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Resonance Imaging ◽  
Cross Sectional

Intra- and inter-rater reliability for the measurement of the cross-sectional area of ankle tendons assessed by magnetic resonance imaging

2021 ◽  
pp. 028418512110032
Author(s):  
Henrique Mansur ◽  
Guilherme Estanislau ◽  
Marcos de Noronha ◽  
Rita de Cassia Marqueti ◽  
Emerson Fachin-Martins ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Repeated Measures ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Resonance Imaging ◽  
Cross Sectional ◽  
Rater Reliability ◽  
The Cross ◽  
Very High

Background The cross-sectional area (CSA) records make an essential measurement for determining the mechanical properties of tendons, such as stress and strength. However, there is no consensus regarding the best method to record the CSA from different tendons. Purpose To determine intra- and inter-rater reliability for CSA measures from magnetic resonance imaging (MRI) of the following tendons: tibialis anterior; tibialis posterior; fibularis longus and brevis; and Achilles. Material and Methods We designed an observational study with repeated measures taken from a convenience sample of 20 participants diagnosed with acute or chronic ankle sprain. Two independent raters took three separate records from the CSA of ankle tendon images of each MRI slice. The intra-class correlation coefficient (ICC) and 95% limits of agreement (LoA) defined the quality (associations) and magnitude (differences), respectively, of intra- and inter-rater reliability on the measures plotted by the Bland–Altman method. Results Data showed very high intra- and inter-rater correlations for measures taken from all tendons analyzed (ICC 0.952–0.999). It also revealed an excellent agreement between raters (0.12%–2.3%), with bias no higher than 2 mm2 and LoA in the range of 4.4–7.9 mm2. The differences between repeated measures recorded from the thinnest tendons (fibularis longus and brevis) revealed the lowest bias and narrowest 95% LoA. Conclusion Reliability for the CSA of ankle tendons measured from MRI taken by independent rates was very high, with the smallest differences between raters observed when the thinnest tendon was analyzed.

Identification of the biomechanical factors associated with the perception of distension in the human esophagus

2002 ◽  
Vol 282 (4) ◽  
pp. G683-G689 ◽  
Author(s):  
J. D. Barlow ◽  
H. Gregersen ◽  
D. G. Thompson
Keyword(s):  
Cross Sectional Area ◽  
Sectional Area ◽  
Limited Information ◽  
Butyl Bromide ◽  
Cross Sectional ◽  
Impedance Planimetry ◽  
Sensory Responses ◽  
Human Esophagus ◽  
Biomechanical Factors ◽  
The Relationship

Current techniques used to investigate the mechanisms responsible for the sensory responses to distension of the human esophagus provide limited information because the degree of circumferential stretch required to determine tension can only be inferred. We used impedance planimetry to measure the cross-sectional area during esophageal distension to ascertain the degree of stretch and tension that initiated motor and sensory responses. Hyoscine- N-butyl bromide (HBB), a cholinergic muscarinic receptor blocker, was also used to alter esophageal tension during distension. Motor activity was initiated at a lower degree of stretch and tension than that which initiated sensory awareness; both increased directly with increasing distension. HBB reduced both esophageal motility and tension during distension without altering the relationship between sensation intensity and cross-sectional area. Esophageal stretch, rather than tension, thus appears to be the major factor influencing sensory responses to esophageal distension.

Changes in airway length after unilateral pneumonectomy in weanling ferrets

1990 ◽  
Vol 68 (1) ◽  
pp. 187-192 ◽  
Author(s):  
K. K. Kirchner ◽  
J. T. McBride
Keyword(s):  
Quadratic Equation ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Cross Sectional ◽  
Peripheral Airways ◽  
Peripheral Airway ◽  
The Relationship ◽  
Bronchial Casts ◽  
Central Airway ◽  
Terminal Bronchiole

We have previously shown that airway cross-sectional area increases 15-20% after pneumonectomy in weanling ferrets by measuring bronchial casts. We have now reanalyzed these same casts to quantitate changes in airway length after pneumonectomy. In each cast the distance from each of 120 airways to the terminal bronchiole along its axial pathway was measured. The relationship between the logarithm of this distance and that of the fraction of the lobe subtended by an airway could be described by a quadratic equation with a correlation coefficient greater than 0.85. Subsegmental and more distal airways of postpneumonectomy animals were 33-47% longer than those of controls. Overall the main axial pathway of airways in the left lower lobes was 12% longer in operated animals, but this increase was primarily accounted for by an increase in the length of the more peripheral airways. Central airways were little if any longer in operated animals. After pneumonectomy in weanling ferrets, subsegmental and peripheral airway lengths increase to a greater degree than lung volume and airway cross-sectional area, whereas central airway lengths increase to a lesser extent if at all. The mechanisms responsible for this difference between central and intralobar compensatory airway growth are unknown.

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