Effects of aerobic exercise training on fitness and walking-related outcomes in ambulatory individuals with chronic incomplete spinal cord injury.

STUDY DESIGN: Single group, pretest-post-test study. OBJECTIVES: To determine the effects of a non-task-specific, voluntary, progressive aerobic exercise training (AET) intervention on fitness and walking-related outcomes in ambulatory adults with chronic motor-incomplete SCI. SETTING: Rehabilitation research center. METHODS: Ten ambulatory individuals (50% female; 57.94±9.33 years old; 11.11±9.66 years postinjury) completed voluntary, progressive moderate-to-vigorous intensity AET on a recumbent stepper 3 days per week for 6 weeks. The primary outcome measures were aerobic capacity (VO2peak (volume of oxygen that the body can use during physical exertion)) and self-selected overground walking speed (OGWS). Secondary outcome measures included walking economy, 6-minute walk test (6MWT), daily step counts, Walking Index for Spinal Cord Injury (WISCI-II), Dynamic Gait Index (DGI) and Berg Balance Scale (BBS). RESULTS: Nine participants completed all testing and training. Significant improvements in aerobic capacity (P=0.011), OGWS (P=0.023), the percentage of VO2peak used while walking at self-selected speed (P=0.03) and daily step counts (P=0.025) resulted following training. CONCLUSIONS: The results indicate that total-body, voluntary, progressive AET is safe, feasible, and effective for improving aerobic capacity, walking speed, and select walking-related outcomes in an exclusively ambulatory SCI sample. This study suggests the potential for non-task-specific aerobic exercise to improve walking following incomplete SCI and builds a foundation for further investigation aimed at the development of exercise based rehabilitation strategies to target functionally limiting impairments in ambulatory individuals with chronic SCI.

Intensive mobility training postcerebral hemispherectomy: early surgery shows best functional improvements.

BACKGROUND: Limited research exists on rehabilitative techniques focused on reducing disabilities after cerebral hemispherectomy despite persistent hemiparesis. OBJECTIVES: The efficacy of Intensive Mobility Training (IMT) for improving gait, balance and mobility was evaluated in patients after cerebral hemispherectomy and compared with clinical variables for signs of developmental neuroplasticity. METHODS: Participants (N.=19; 13.8±5.7 years) postcerebral hemispherectomy received IMT, three hours/day for 10 days. Outcomes measures were assessed pre- and post-intervention using the GAITRite electronic walkway® (velocity, toe in/out, step length of affected an unaffected leg), Dynamic Gait Index, Fugl-Meyer Scale, Berg Balance Scale, Timed Up and Go and Six-Minute Walk Test. Six of the nine measures that showed moderate effect sizes were incorporated into a Combined Functional Index (CFI) to assess global impact of therapy. RESULTS: After IMT, improvements were identified for toe in/out, step length of unaffected leg, Dynamic Gait Index, Berg Balance Scale and Six-Minute Walk (P<0.05; Effect Size 0.36-0.50). Using CFI for these six measures, patients improved from 77.3% to 82.7% (+5.3±3.7%) of normal following IMT. Improvements in CFI were greater in patients five years or younger at time of surgery (+7.7±3.6%) compared with older patients (+3.2±2.5%), and this accounted for 22% of variability in the change in score. CONCLUSION: The younger the participant at time of surgery correlated with the greatest improvements following IMT. These findings support the concept that the remaining hemisphere retains greater neuroplasticity if the contralateral surgery occurs earlier in cerebral development.

Phantom evaluation of angiographer performance using low frame rate acquisition fluoroscopy.

The authors have investigated the effect of 5 frames/s television fluoroscopy on the time required to selectively catheterize five test arteries in an angiographic phantom. Here, 5 frames/s acquisition was accomplished by sampling frames from a 30 frames/s video signal. Sampled frames were stored in a video memory which provided continuous display to the fluoroscopist between samples. The test phantom was a plastic model of an aorta with branching vessels immersed in an isodense suspension of barium in water. For four of the five vessels there was no significant difference in time required for catheter placement between 30 frames/s and 5 frames/s.

High-resolution digital x-ray detector utilizing a discrete array of CdWO4 scintillators and a self-scanned photodiode array.

A high-resolution x-ray detector array for x-ray imaging is described. It consists of a discrete array of CdWO4 scintillators and a Reticon 1024S photodiode array with a fiber-optic faceplate. The scintillator elements measure 0.099 X 3 X 4 mm and are bonded together with aluminum foil separators to minimize light crossover. Detective quantum efficiency (DQE) of individual detector channels was 0.38. Systematic variations between channels were substantial. With only a simple correction for between channel variations, DQE for the entire array was 0.04. Evaluation of the edge response function of the array showed that resolution is similar to a detector whose line spread function is Gaussian with a standard deviation of 0.172 mm.

The effect of anode curvature on radiographic heel effect.

Previous computer modeling of radiographic heel effect has shown that a simple model can give an accurate representation of heel effect for flat anode surfaces. This paper details the extension of this model to allow curved anode surfaces. A fixed-anode x-ray tube with a demountable anode was constructed and used to test the predictions of the computational model at 25 kVp using stainless-steel anodes. The computer model was also used to estimate the magnitude of the heel effect for a tungsten anode at 60 kVp. This work allows determination of the effect of anode curvature, which is an inherent feature of certain recently proposed tube designs for scanning slit radiography.

Scatter/primary ratios for x-ray spectra modified to enhance iodine contrast in screen-film mammography.

Contrast mammography to detect the uptake of iodine-containing contrast material may be enhanced by spectral modification of the x-ray beam. Luminance scatter-to-primary ratios were measured for three candidate x-ray tube anode/filter combinations (Mo/Mo, W/Ce, and Ce/Ce). Results show that scattered radiation is significant for all tubes, is lowest for the Mo/Mo system and is essentially the same for the tungsten and cerium anode systems.

Tomography for evaluation of sacroiliitis.

The radiographs and charts of 18 patients were reviewed to determine if sacroiliac joint tomography clarified the equivocal or clinically inconsistent findings of other imaging procedures. In six of eight patients with proven sacroiliitis, tomography detected joint erosions or sclerosis that were not detected on routine pelvis radiographs. In the other 10 patients, tomography excluded sacroiliitis which had been initially suggested by plain radiographs (four patients), quantitative sacroiliac scintigraphy (three patients), or clinical findings (three patients). The estimated average skin radiation exposure was 1.27 R (0.33 mC/kg) per tomographic section. The authors conclude that tomography improves delineation of sacroiliac joint abnormalities, but its use should be restricted to problem cases because of the high radiation exposure.

Three-dimensional computer reconstructions of brain lesions from surface contours provided by computed tomography: a prospectus.

We present a prospectus on the use of computer graphics for the three-dimensional reconstruction and visualization of brain lesions from computed tomographic head examinations, including an algorithm that utilizes surface contour information to reconstruct and display three-dimensional anatomical sites. We provide examples of the use of this algorithm. We offer an algorithm for estimation of the volume and surface area of anatomical sites. The advantages and disadvantages for the clinical use of these algorithms are discussed.

A comparison of computed and measured heel effect for various target angles.

Two models for thick target emission spectra, one using constant depth of Bremsstrahlung and one using continuous slowing-down of electrons and multiple thin targets, were used to predict filtered emission spectra at various angles with respect to the central axis. Integration of these spectra and comparison against measured heel effect gave excellent agreement for tungsten targets with take-off angles of 7 degrees and 10 degrees at 60 and 100 kVp when the angular anisotropy of Bremsstrahlung was taken into account. Results for a 17.5 degrees target at 60 kVp were poor, possibly indicating a need for a better model of Bremsstrahlung angular dependence.

Computed tomographic mammography using a conventional body scanner.

The technique for computed tomographic (CT) examination of the breasts using a conventional body scanner is described, and experience with 67 patients is reported. In the diagnosis of both malignant and benign breast lesions, the results with a body scanner were equal to those of a dedicated CT/M mammographic unit. Although the CT study of the breast cannot replace conventional mammography in screening or in routine diagnostic workup, the unique capability of demonstrating both anatomic changes and increased iodide concentration in a cancer provides many advantages over conventional mammography. CT mammography appears to have the capability to detect breast cancers that are occult to other methods. Indications for a CT study of the breasts are: (1) clinically suspected breast cancer, especially with a mammographically occult lesion; (2) questionable mammographic findings, including microcalcifications, tumor shape, architectural distortion, and uncertain lesion location; and (3) evaluation of postbiopsy or postlumpectomy breast cancers when a primary irradiation therapy is contemplated. Breast CT also appears to be a valuable diagnostic tool in searching for a second primary breast cancer, follow-up study of postirradiation of breast cancer, followup study for postmastectomy patients, and screening procedure for genetically high-risk patients, especially those with dense breasts.

Direct radiographic magnification: evaluation of three microfocus x-ray tubes.

Three microfocus x-ray tubes (RSI, Siemens, and Eimac) were evaluated for their focal and imaging characteristics. The RSI and Siemens focal spots had similar homogeneous radiation intensity distributions. The Eimac tube had an asymmetric intensity distribution. Because of their focal spot characteristics, the RSI and Siemens tubes provided superior magnification radiographs for small objects. The Siemens and Eimac tubes were preferable for magnification of thick objects because their larger object-film air gap reduced scattered radiation reaching the film.

Radiographic projections for the diagnosis of arthritis of the hands and wrists.

One hundred consecutive sets of radiographs with the hands halfway supinated (Nørgaard's view) were reviewed retrospectively without knowledge of the clinical diagnosis to determine the value of this view for diagnosis of rheumatoid arthritis. Indistinct cortex at specific sites, reported to be a sensitive indicator of rheumatoid arthritis, was seen in 81% of rheumatoid patients: however, it was not specific for rheumatoid arthritis, being present in both inflammatory and noninflammatory arthritides. These changes are apparently due to variations in cortical morphology and are not true erosions. Definite erosions, which were more specific for inflammatory arthritis, were seen at the same sites; however, erosions could be identified on postero-anterior radiographs in 14 of the 16 cases in which they were seen on the Nørgaard views.

ROC analysis of diagnostic performance in liver scintigraphy.

Studies on the accuracy of liver scintigraphy for the detection of metastases were assembled from 38 sources in the medical literature. An ROC curve was fitted to the observed values of sensitivity and specificity using an algorithm developed by Ogilvie and Creelman. This ROC curve fitted the data better than average sensitivity and specificity values in each of four subsets of the data. For the subset dealing with Tc-99m sulfur colloid scintigraphy, performed for detection of suspected metastases and containing data on 2800 scans from 17 independent series, it was not possible to reject the hypothesis that interobserver variation was entirely due to the use of different decision thresholds by the reporting clinicians. Thus the ROC curve obtained is a reasonable baseline estimate of the performance potentially achievable in today's clinical setting. Comparison of new reports with these data is possible, but is limited by the small sample sizes in most reported series.

A method for minimizing the radiation exposure from scoliosis radiographs.

The radiation exposure resulting from standard scoliosis radiographs was determined for eighteen adolescent girls. The risk of inducing breast cancer was estimated from the skin-exposure doses. The average skin exposure to the breasts was 59.6 millirads (0.59 mGy) for the anteroposterior radiograph. Assuming a total of twenty-two anteroposterior radiographs during a course of treatment, the cumulative exposure would result in a 1.35% relative increase in the risk of development of breast cancer. By utilizing collimation of the x-ray beam and proper selection of grids, films, and screens, the radiation risk of scoliosis radiographs is minimized.