A computed method for noninvasive MRI assessment of pulmonary arterial hypertension

2004 ◽  
Vol 96 (2) ◽  
pp. 463-468 ◽  
Author(s):  
Eric Laffon ◽  
Christophe Vallet ◽  
Virginie Bernard ◽  
Michel Montaudon ◽  
Dominique Ducassou ◽  
...  
Keyword(s):  
Arterial Pressure ◽  
Pulmonary Arterial Pressure ◽  
Cross Sectional Area ◽  
Physical Parameters ◽  
Sectional Area ◽  
Biophysical Parameters ◽  
Cross Sectional ◽  
Mean Pulmonary Arterial Pressure ◽  
Pulmonary Arterial ◽  
The Mean

The present method enables the noninvasive assessment of mean pulmonary arterial pressure from magnetic resonance phase mapping by computing both physical and biophysical parameters. The physical parameters include the mean blood flow velocity over the cross-sectional area of the main pulmonary artery (MPA) at the systolic peak and the maximal systolic MPA cross-sectional area value, whereas the biophysical parameters are related to each patient, such as height, weight, and heart rate. These parameters have been measured in a series of 31 patients undergoing right-side heart catheterization, and the computed mean pulmonary arterial pressure value (PpaComp) has been compared with the mean pressure value obtained from catheterization (PpaCat) in each patient. A significant correlation was found that did not differ from the identity line PpaComp = PpaCat ( r = 0.92). The mean and maximal absolute differences between PpaComp and PpaCat were 5.4 and 11.9 mmHg, respectively. The method was also applied to compute the MPA systolic and diastolic pressures in the same patient series. We conclude that this computed method, which combines physical (whoever the patient) and biophysical parameters (related to each patient), improves the accuracy of MRI to noninvasively estimate pulmonary arterial pressures.

scholarly journals Identification of the molecular mechanisms underlying brisket disease in Holstein heifers via microbiota and metabolome analyses

AMB Express ◽  
2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Kun Yao ◽  
Shuxiang Wang ◽  
Naren Gaowa ◽  
Shuai Huang ◽  
Shengli Li ◽  
...  
Keyword(s):  
Arterial Pressure ◽  
Molecular Mechanisms ◽  
Pulmonary Arterial Pressure ◽  
Economic Loss ◽  
Blood Oxygen Saturation ◽  
Mean Pulmonary Arterial Pressure ◽  
Pulmonary Arterial ◽  
The Mean ◽  
Low Levels

AbstractBrisket disease (BD) is common among Holstein heifers in high-altitude environments, and this disease may result in serious economic loss. At present, no effective treatment is available for brisket disease. In this study, liver and cecum samples were collected from five heifers with BD and five healthy heifers (HH) for analyses of the metabolome and microbiota. The mean pulmonary arterial pressure and systolic blood pressure were significantly higher in BD heifers, whereas the average breathing rate, blood oxygen saturation, and glucose level were significantly lower in BD group than in the HH group. Further, 16S rDNA data showed that the abundance of Firmicutes was significantly lower and that of Bacteroidetes was significantly higher in BD group than in the HH group. At the genus level, the BD group heifers harbored fewer Ruminococcaceae and Lachnospiraceae than the HH group. Several metabolites, including beta-d-fructose, d-ribose, 1,4-beta-d-glucan, sucrose, and glucose-6-phosphate were present at low levels in BD heifers. Moreover, the mean pulmonary arterial pressure was negatively correlated with beta-d-fructose (r =  − 0.74; P = 0.013), d-ribose (r =  − 0.72; P = 0.018), and acetyl-tyrosine-ethyl-ester (r =  − 0.71; P = 0.022). We also found that mean pulmonary arterial pressure was negatively correlated with most of the genera, including those in the families of Lachnospiraceae and Ruminococcaceae. In summary, the decreased levels of metabolites and microbial genera might affect BD by limiting the energy supply. This study may help us better understand the role of the microbiota in BD and provide new insights into the management of feeding to decrease the rate of BD in Holstein dairy cows in the Qinghai-Tibetan plateau.

scholarly journals Atrophy patterns in isolated subscapularis lesions

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Gernot Seppel ◽  
Andreas Voss ◽  
Daniel J. H. Henderson ◽  
Simone Waldt ◽  
Bernhard Haller ◽  
...  
Keyword(s):  
Muscle Atrophy ◽  
Area Ratio ◽  
Cross Sectional Area ◽  
Control Group ◽  
Sectional Area ◽  
Cross Sectional ◽  
Subscapularis Muscle ◽  
Mri Scans ◽  
The Mean ◽  
The Cross

Abstract Background While supraspinatus atrophy can be described according to the system of Zanetti or Thomazeau there is still a lack of characterization of isolated subscapularis muscle atrophy. The aim of this study was to describe patterns of muscle atrophy following repair of isolated subscapularis (SSC) tendon. Methods Forty-nine control shoulder MRI scans, without rotator cuff pathology, atrophy or fatty infiltration, were prospectively evaluated and subscapularis diameters as well as cross sectional areas (complete and upper half) were assessed in a standardized oblique sagittal plane. Calculation of the ratio between the upper half of the cross sectional area (CSA) and the total CSA was performed. Eleven MRI scans of patients with subscapularis atrophy following isolated subscapularis tendon tears were analysed and cross sectional area ratio (upper half /total) determined. To guarantee reliable measurement of the CSA and its ratio, bony landmarks were also defined. All parameters were statistically compared for inter-rater reliability, reproducibility and capacity to quantify subscapularis atrophy. Results The mean age in the control group was 49.7 years (± 15.0). The mean cross sectional area (CSA) was 2367.0 mm2 (± 741.4) for the complete subscapularis muscle and 1048.2 mm2 (± 313.3) for the upper half, giving a mean ratio of 0.446 (± 0.046). In the subscapularis repair group the mean age was 56.7 years (± 9.3). With a mean cross sectional area of 1554.7 mm2 (± 419.9) for the complete and of 422.9 mm2 (± 173.6) for the upper half of the subscapularis muscle, giving a mean CSA ratio of 0.269 (± 0.065) which was seen to be significantly lower than that of the control group (p < 0.05). Conclusion Analysis of typical atrophy patterns of the subscapularis muscle demonstrates that the CSA ratio represents a reliable and reproducible assessment tool in quantifying subscapularis atrophy. We propose the classification of subscapularis atrophy as Stage I (mild atrophy) in case of reduction of the cross sectional area ratio < 0.4, Stage II (moderate atrophy) in case of < 0.35 and Stage III (severe atrophy) if < 0.3.

scholarly journals The influence of muscle pennation angle and cross-sectional area on contact forces in the ankle joint

2016 ◽  
Vol 52 (1) ◽  
pp. 12-23 ◽  
Author(s):  
Ran S Sopher ◽  
Andrew A Amis ◽  
D Ceri Davies ◽  
Jonathan RT Jeffers
Keyword(s):  
Pennation Angle ◽  
Muscle Architecture ◽  
Cross Sectional Area ◽  
Contact Forces ◽  
Sectional Area ◽  
Muscle Forces ◽  
Cross Sectional ◽  
Contact Loads ◽  
The Mean ◽  
And Function

Data about a muscle’s fibre pennation angle and physiological cross-sectional area are used in musculoskeletal modelling to estimate muscle forces, which are used to calculate joint contact forces. For the leg, muscle architecture data are derived from studies that measured pennation angle at the muscle surface, but not deep within it. Musculoskeletal models developed to estimate joint contact loads have usually been based on the mean values of pennation angle and physiological cross-sectional area. Therefore, the first aim of this study was to investigate differences between superficial and deep pennation angles within each muscle acting over the ankle and predict how differences may influence muscle forces calculated in musculoskeletal modelling. The second aim was to investigate how inter-subject variability in physiological cross-sectional area and pennation angle affects calculated ankle contact forces. Eight cadaveric legs were dissected to excise the muscles acting over the ankle. The mean surface and deep pennation angles, fibre length and physiological cross-sectional area were measured. Cluster analysis was applied to group the muscles according to their architectural characteristics. A previously validated OpenSim model was used to estimate ankle muscle forces and contact loads using architecture data from all eight limbs. The mean surface pennation angle for soleus was significantly greater (54%) than the mean deep pennation angle. Cluster analysis revealed three groups of muscles with similar architecture and function: deep plantarflexors and peroneals, superficial plantarflexors and dorsiflexors. Peak ankle contact force was predicted to occur before toe-off, with magnitude greater than five times bodyweight. Inter-specimen variability in contact force was smallest at peak force. These findings will help improve the development of experimental and computational musculoskeletal models by providing data to estimate force based on both surface and deep pennation angles. Inter-subject variability in muscle architecture affected ankle muscle and contact loads only slightly. The link between muscle architecture and function contributes to the understanding of the relationship between muscle structure and function.

scholarly journals Patients with Achilles Tendon Rupture Have a Degenerated Contralateral Achilles Tendon: An Elastography Study

2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Qianru Li ◽  
Qi Zhang ◽  
Yehua Cai ◽  
Yinghui Hua
Keyword(s):  
Achilles Tendon ◽  
Axial Strain ◽  
Achilles Tendon Rupture ◽  
Cross Sectional Area ◽  
Control Group ◽  
Computer Assisted ◽  
Study Group ◽  
Sectional Area ◽  
Cross Sectional ◽  
The Mean

Purpose. To evaluate differences of Achilles tendon (AT) hardness and morphology between asymptomatic tendons in patients with acute AT ruptures on the contralateral side and asymptomatic tendons in healthy people by using computer-assisted quantification on axial-strain sonoelastography (ASE). Methods. The study consisted of 33 asymptomatic tendons in 33 patients (study group) and 34 tendons in 19 healthy volunteers (control group). All the tendons were examined by both ASE and conventional ultrasound. Computer-assisted quantification on ASE was applied to extract hardness variables, including the mean (Hmean), 20th percentile (H20), median (H50) and skewness (Hsk) of the hardness within tendon, and the ratio of the mean hardness within tendon to that outside tendon (Hratio) and three morphological variables: the thickness (THK), cross-sectional area, and eccentricity (ECC) of tendons. Results. The Hmean, Hsk, H20, H50, and Hratio in the proximal third of the tendon body in study group were significantly smaller than those in control group (Hmean: 0.43±0.09 vs 0.50±0.07, p=0.001; Hsk: -0.53±0.51 vs -1.09±0.51, p<0.001; H20: 0.31±0.10 vs 0.40±0.10, p=0.001; H50: 0.45±0.10 vs 0.53±0.08, p<0.001; Hratio: 1.01±0.25 vs 1.20±0.23, p=0.003). The THK and cross-sectional area of tendons in the study group were larger than those in the control group (p<0.05). Conclusions. As a quantitative objective method, the computer-assisted ASE reveals that the asymptomatic ATs contralateral to acute rupture are softer than those of healthy control group at the proximal third and the asymptomatic tendons in people with rupture history are thicker, larger, and rounder than those of normal volunteers especially at the middle and distal thirds of AT body.

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 Mean pulmonary arterial pressure after percutaneous mitral valvuloplasty predicts long-term adverse outcomes

2012 ◽  
Vol 31 (1) ◽  
pp. 19-25 ◽  
Author(s):  
Elisabete Jorge ◽  
Rui Baptista ◽  
Henrique Faria ◽  
João Calisto ◽  
Vítor Matos ◽  
...  
Keyword(s):  
Arterial Pressure ◽  
Pulmonary Arterial Pressure ◽  
Adverse Outcomes ◽  
Mitral Valvuloplasty ◽  
Mean Pulmonary Arterial Pressure ◽  
Pulmonary Arterial

The Vertical Mean Force and Moment of Submerged Bodies Under Waves

1971 ◽  
Vol 15 (03) ◽  
pp. 231-245 ◽  
Author(s):  
C. M. Lee ◽  
J. N. Newman
Keyword(s):  
Free Surface ◽  
Added Mass ◽  
Cross Sectional Area ◽  
The Body ◽  
Slender Body ◽  
Longitudinal Distribution ◽  
Vertical Force ◽  
Sectional Area ◽  
Cross Sectional ◽  
The Mean

A neutrally buoyant slender body of arbitrary sectional form, submerged beneath a free surface, is free to respond to an incident plane progressive wave system. The fluid is assumed inviscid, incompressible, homogeneous and infinitely deep. The first-order oscillatory motion of the body and the second-order time-average vertical force and pitching moment acting on the body are obtained in terms of Kochin's function. By use of slender-body theory for a deeply submerged body, the final expressions for the mean force and the moment are shown to depend on the longitudinal distribution of sectional area and added mass and on the amplitude and the frequency of the ambient surface waves. The magnitude of the mean force for various simple geometric cylinders is compared with that of a circular cylinder of equal cross-sectional area. The mean force on a nonaxisymmetric body is often approximated by replacing the section with circular profiles of equivalent cross-sectional area. A better scheme of approximation is presented, based on a simple way of estimating the two-dimensional added mass. It is expected that the effect of the cross-sectional geometry on mean vertical force and moment will be more significant when the body is very close to the free surface.

Pulmonary pressor response after prostaglandin synthesis inhibition in conscious dogs

1982 ◽  
Vol 52 (3) ◽  
pp. 705-709 ◽  
Author(s):  
B. R. Walker ◽  
N. F. Voelkel ◽  
J. T. Reeves
Keyword(s):  
Cardiac Output ◽  
Arterial Pressure ◽  
Pulmonary Arterial Pressure ◽  
Pressor Response ◽  
Conscious Dogs ◽  
Pulmonary Pressure ◽  
Time Control ◽  
Mean Pulmonary Arterial Pressure ◽  
Before And After ◽  
Pulmonary Arterial

Recent studies have shown that vasodilator prostaglandins are continually produced by the isolated rat lung. We postulated that these vasodilators may contribute to maintenance of normal low pulmonary arterial pressure. Pulmonary pressure and cardiac output were measured in conscious dogs prior to and 30 to 60 min following administration of meclofenamate (2 mg/kg iv, followed by infusion at 2 mg . kg-1 . h-1) or the structurally dissimilar inhibitor RO–20–5720 (1 mg/kg iv, followed by infusion at 1 mg . kg-1 . h-1). The animals were also made hypoxic with inhalation of 10% O2 before and after inhibition. Time-control experiments were conducted in which only the saline vehicle was administered. Meclofenamate or RO–20–5720 caused an increase in mean pulmonary arterial pressure and total pulmonary resistance. Cardiac output and systemic pressure were unaffected. The mild hypoxic pulmonary pressor response observed was not affected by meclofenamate. Animals breathing 30% O2 to offset Denver's altitude also demonstrated increased pulmonary pressure and resistance when given meclofenamate. It is concluded that endogenous vasodilator prostaglandins may contribute to normal, low vascular tone in the pulmonary circulation.

scholarly journals Pulmonary Vasodilator Therapy in Children with Single Ventricle Physiology: Effects on Saturation and Pulmonary Arterial Pressure

2020 ◽  
Vol 41 (8) ◽  
pp. 1651-1659
Author(s):  
Ida Jeremiasen ◽  
Karin Tran-Lundmark ◽  
Nikmah Idris ◽  
Phan-Kiet Tran ◽  
Shahin Moledina
Keyword(s):  
Arterial Pressure ◽  
Single Ventricle ◽  
Pulmonary Arterial Pressure ◽  
Vasodilator Therapy ◽  
Single Ventricle Physiology ◽  
Pulmonary Vasodilators ◽  
Mean Pulmonary Arterial Pressure ◽  
Pulmonary Vasodilator ◽  
Pulmonary Arterial ◽  
Stage 1

AbstractIn children with single ventricle physiology, increased pulmonary vascular resistance may impede surgical progression or result in failing single ventricle physiology. The use of pulmonary vasodilators has been suggested as a potential therapy. However, knowledge on indication, dosage, and effect is limited. A retrospective case notes review of all (n = 36) children with single ventricle physiology, treated with pulmonary vasodilators by the UK Pulmonary Hypertension Service for Children 2004–2017. Therapy was initiated in Stage 1 (n = 12), Glenn (n = 8), or TCPC (n = 16). Treatment indications were high mean pulmonary arterial pressure, cyanosis, reduced exercise tolerance, protein-losing enteropathy, ascites, or plastic bronchitis. Average dose of sildenafil was 2.0 mg/kg/day and bosentan was 3.3 mg/kg/day. 56% had combination therapy. Therapy was associated with a reduction of the mean pulmonary arterial pressure from 19 to 14 mmHg (n = 17, p < 0.01). Initial therapy with one or two vasodilators was associated with an increase in the mean saturation from 80 to 85%, (n = 16, p < 0.01). Adding a second vasodilator did not give significant additional effect. 5 of 12 patients progressed from Stage 1 to Glenn, Kawashima, or TCPC, and 2 of 8 from Glenn to TCPC during a mean follow-up time of 4.7 years (0–12.8). Bosentan was discontinued in 57% and sildenafil in 14% of treated patients and saturations remained stable. Pulmonary vasodilator therapy was well tolerated and associated with improvements in saturation and mean pulmonary arterial pressure in children with single ventricle physiology. It appears safe to discontinue when no clear benefit is observed.

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