vendex and Burns

It is around 20 years since the first commercial 3 T MRI systems became available. The theoretical promise of twice the signal-to-noise ratio of a 1.5 T system together with a greater sensitivity to magnetic susceptibility-related contrast mechanisms, such as the blood oxygen level dependent effect that is the basis for functional MRI, drove the initial market in neuroradiology. However, the limitations of the increased field strength soon became apparent, including the increased radiofrequency power deposition, tissue-dependent changes in relaxation times, increased artifacts, and greater safety concerns. Many of these issues are dependent upon MR physics and workarounds have had to be developed to try and mitigate their effects. This article reviews the underlying principles of the good, the bad and the ugly aspects of 3 T, discusses some of the methods used to improve image quality and explains the remaining challenges and concerns.

Topics: Adipose Tissue; Artifacts; Body Water; Brain; Burns; Hot Temperature; Humans; Magnetic Fields; Magnetic Resonance Imaging; Magnetic Resonance Spectroscopy; Magnets; Radio Waves; Signal-To-Noise Ratio; Superconductivity; Time Factors; Torque

The purpose of this study was to determine the effects of early outpatient exercise on muscle mass, function, and fractional synthetic rate in severely burned children.. Forty-seven children with ≥40% total body surface area burn performed a 12-wk standard of care rehabilitation (SOC, n = 23) or rehabilitative exercise training (RET, n = 24) immediately after hospital discharge. Dual-energy x-ray absorptiometry was used to assess lean body mass (LBM) at discharge, posttreatment, and 12 months post-burn. Muscle function was evaluated with a Biodex Isokinetic Dynamometer, and peak aerobic fitness (V˙O2peak) was measured using a modified Bruce treadmill protocol posttreatment. Stable isotope infusion studies were performed in a subset of patients (SOC, n = 13; RET, n = 11) at discharge and posttreatment to determine mixed-muscle fractional synthetic rate.. Relative peak torque (RET, 138 ± 9 N·m·kg, vs SOC, 106 ± 9 N·m·kg) and V˙O2peak (RET, 32 ± 1 mL·kg·min, vs SOC, 28 ± 1 mL·kg·min) were greater at posttreatment with RET compared with those with SOC. In addition, RET increased whole-body (9% ± 2%) and leg (17% ± 3%) LBM compared with SOC. Furthermore, the percentage change in whole-body (18% ± 3%) and leg (31% ± 4%) LBM from discharge to 12 months post-burn was greater with RET compared to SOC. Muscle fractional synthetic rate decreased from discharge to posttreatment in both groups (6.9% ± 1.1% per day vs 3.4 ± 0.4% per day); however, no differences were observed between treatment groups at each time point.. Early outpatient exercise training implemented at hospital discharge represents an effective intervention to improve muscle mass and function after severe burn injury.

Topics: Absorptiometry, Photon; Adolescent; Ambulatory Care; Body Composition; Burns; Child; Exercise Test; Exercise Therapy; Female; Humans; Male; Muscle Strength; Muscle Strength Dynamometer; Muscle, Skeletal; Organ Size; Oxygen Consumption; Recovery of Function; Time Factors; Torque

Severe burns result in marked and prolonged skeletal muscle catabolism and weakness, which persist despite 'standard" rehabilitation programmes of occupational and physical therapy. Therefore, the objectives of this study were of twofold: to quantify the long-term effects of burns on leg muscle strength and to assess whether adults with thermal burn would benefit from the isokinetic training programme.. Burned adult patients, with 35-55% total body surface area (TBSA) burned, were assessed at 6 months after burn in respect to leg muscle strength at 150° s(-1), using isokinetic dynamometry. Non-burned adults were assessed similarly, and served as controls. The burned adults participated in the resistance training programme 3 times weekly. The isokinetic exercise programme was begun with 60% of the average peak torque. Intensity of isokinetic exercise was increased from one set to five sets during the first through fifth sessions and remained at six sets for the remaining 6th to 24th sessions. Finally, a dose of 10 sets was applied for the 25th to the 36th sessions. Each set consisted of five repetitions of concentric contraction in angular velocities of 150° s(-1) for knee extensors, and flexors. All exercise sessions were preceded by a 5-min warm-up period on the treadmill.. Subjects with burns more than 35% of TBSA produced significantly less torque, work, and power in the quadriceps and hamstring than control subjects (20.5%, 15.2%, p<0.05). Three months after isokinetic programme, muscle strength further increased by 17.9%±10.1% compared to the baseline measurement for burned patients but continued to be below the concurrent age-matched, non-burned adult.. We found that adults with severe burns, relative to non-burned adults, had significantly lower peak torque as well as total work performance using the extensors and flexors muscles of the thigh. Participation in isokinetic training resulted in a greater improvement in extensor and flexor muscle strength in adults with held thermal burn compared to base line values.

Topics: Adolescent; Adult; Burns; Exercise Therapy; Female; Humans; Leg Injuries; Male; Muscle Contraction; Muscle Strength; Muscle, Skeletal; Torque; Young Adult

To investigate the effects of eight weeks whole body vibration training program on leg muscle strength (force-producing capacity) in adults after healed burns.. Randomized controlled trial.. Faculty of Physical Therapy, Cairo University.. Thirty-one burned patients participated in the study and were randomized into whole body vibration group and control group. Non-burned healthy adults were assessed similarly to burned subjects and served as matched healthy controls.. The whole body vibration group performed an eight weeks vibration program three times a week on a vibration platform; the control group received home based physical therapy program without vibration training.. Assessment of knee extensors and ankle planter flexor strength by isokinetic dynamometer at 150°/s were performed at the beginning of the study and at the end of the training period for both groups.. Subjects with burns more than 36% TBSA produced significantly less torque in the quadriceps and calf muscle than non-burned healthy subjects. Patients in whole body vibration group showed a significant improvement in knee extensor and ankle planter flexor strength as compared with those in the control group. Knee extensor strength and percent improvement was 233.40±5.74 (64.93±3.03 change score) and 38.54% for the vibration group and 190.07±3.99 (21.66±4.41 change score) and 12.86% for the control group, ankle plantar flexor strength and percent improvement was 156.27±5.95 (54.53±6.16 change score) and 53.70% for the vibration group and 116.13±3.24 (14.66±2.71 change score) and 14.52% for the control group.. Participation in whole body vibration program resulted in a greater improvement in quadriceps and calf muscle strength in adults with healed thermal burn compared to base line values; a WBV program is an effective for strength gain in rehabilitation of burned patients.

Topics: Adult; Burns; Female; Humans; Leg; Male; Muscle Strength; Muscle Weakness; Muscle, Skeletal; Quadriceps Muscle; Torque; Vibration

This study tested the hypothesis that participation in a rehabilitation exercise program following hospital discharge would increase the level of physical activity in burned children than that seen in free-living nonburned children. Thirty-one severely burned children (12 ± 3 years, 144 ± 18 cm, 42 ± 17 kg, 48 ± 12% TBSA burns) were matched to 31 nonburned children (12 ± 3 y, 147 ± 17 cm, 45 ± 15 kg) based on age and sex. Pedometers were used to track minutes and steps in burned children during their exercise rehabilitation and nonburned children under free-living conditions (healthy control). We found that the average minutes of activity per day was lower in burned children (56 ± 25minutes) than in nonburned children (74 ± 28 minutes, P < .05). However, no difference was detected for average steps per day or week or maximal minutes in 1 day or week. At discharge, burn children had peak torque and mean power values that were 61% of nonburned values, and exercise training improved these by 27 and 28%, respectively (88 and 89% of nonburned values; each P ≤ .0001). Likewise, cardiorespiratory fitness at discharge was 72% of nonburned values, and exercise training improved fitness by 10% (82% of nonburned values, P < .05). Percentage TBSA burned was inversely associated with steps (r = -0.54, P = .001) and minutes of activity (r = -0.53, P = .002), accounting for 28-29% of the variability in burned children. These results show that, at discharge, burned children are capable of matching steps of physical activity levels seen in nonburned healthy children. Physical activity monitoring may be a viable option for continued improvement of physical exercise capacity when burned children are under free-living conditions.

Topics: Burns; Cardiorespiratory Fitness; Case-Control Studies; Child; Exercise Therapy; Female; Humans; Male; Monitoring, Ambulatory; Muscle Strength; Torque

Currently, there are no clear guidelines for the implementation of rehabilitative exercise training (RET) in burned individuals. Therefore, we quantified the training logs for exercise intensity, frequency, and duration of 6 weeks of this program to develop a basic framework for outpatient RET in patients recovering from severe burns. Thirty-three children (11 female, [mean ± SD] 12 ± 3 years, 145 ± 18 cm, 40 ± 11 kg, 49 ± 31 BMI percentile) with severe burns (49 ± 15% total body surface area burned, with 35 ± 22% third-degree burns) completed our 6-week resistance and aerobic exercise training program. Cardiorespiratory fitness (peak VO2), strength, power, and lean body mass (LBM) were measured before and after RET. Outcome measures were analyzed as a relative percentage of values in age- and sex-matched nonburned children (11 female, 12 ± 3 years, 154 ± 20 cm, 49 ± 22 kg, 56 ± 25 BMI percentile). At discharge, burned children had lower LBM (77% of age-sex-matched nonburn values), peak torque (53%), power (62%), and cardiorespiratory fitness (56%). After 6 weeks of training, LBM increased by 5% (82% of nonburn values), peak torque by 18% (71%), power by 20% (81%), and cardiorespiratory fitness by 18% (74%; P < .0001 for all). Quantification of data in exercise training logs suggested that physical capacity can be improved by aerobic exercise training performed at five metabolic equivalents (>70% of peak VO2) at least 3 days/week and 150 minutes/week and by resistance training performed at volume loads (reps × sets × weight) of 131 kg for the upper body and 275 kg for the lower body for 2 days/week. We present for the first time the quantification of our RET and provide clear exercise prescription guidelines specific to children with severe burn injury.

Topics: Body Mass Index; Burns; Cardiorespiratory Fitness; Child; Exercise Therapy; Female; Humans; Male; Muscle Strength; Resistance Training; Torque

The posttraumatic response to a severe burn leads to marked and prolonged skeletal muscle catabolism and weakness, which persist despite standard rehabilitation programs of occupational and physical therapy. We investigated the degree to which the prolonged skeletal muscle catabolism affects the muscle function of children 6 months after severe burn.. Burned children, with >40% total body surface area burned, were assessed at 6 months after burn in respect to lean body mass and leg muscle strength at 150 degrees /s. Lean body mass was assessed using dual-energy X-ray absorptiometry. Leg muscle strength was assessed using isokinetic dynamometry. Nonburned children were assessed similarly, and served as controls.. We found that severely burned children (n=33), relative to nonburned children (n=46) had significantly lower lean body mass. Additionally they had significantly lower peak torque as well total work performance using the extensors of the thigh.. Our results serve as an objective and a practical clinical approach for assessing muscle function and also aid in establishing potential rehabilitation goals, and monitoring progress towards these goals in burned children.

Topics: Absorptiometry, Photon; Adolescent; Analysis of Variance; Body Mass Index; Body Weight; Burns; Case-Control Studies; Child; Energy Metabolism; Female; Humans; Male; Muscle Proteins; Muscle Strength; Muscle, Skeletal; Torque