Contiguous Transverse Images Research Articles

Achilles tendon adaptation in cross-country runners across a competitive season.

Ultrasound tissue characterization (UTC) is an imaging tool used to quantify tendon structural integrity. UTC has quantified Achilles tendon (AT) acute response to load in athletes; however, AT response to cumulative load over a season is unknown. The purpose of this study was to evaluate AT response across a four-month competitive season in collegiate cross-country (XC) runners. Participants (n=21; male=9, female=12; age=19.8±1.2 years; height=171.9±8.9 cm; weight=60.2±8.5 kg) were imaged using the UTC device with a 10-MHz linear-array transducer mounted in a tracking device. The device captures images at 0.2 mm intervals along the AT. UTC algorithms quantified the stability of pixel brightness over every 17 contiguous transverse images into four echo types (I-IV). A total of 168 scans (n=21, bilateral limbs) were performed monthly across the four-month season (Aug=M1, Sep=M2, Oct=M3, Nov=M4). Echo-type percentages (%) were calculated from each scan. Generalized estimating equations (GEE) linear regression models evaluated echo-type % change (β) over the season (M1=reference). Type I increased from M1 to M4 (β=9.10, P<.01; 95%CI: 7.01, 11.21) and Type II decreased from M1 to M3 (β=-2.71, P=.018; 95%CI: -4.96, -0.47) and M1 to M4 (β=-10.19, P<.01; 95%CI: -12.22, -8.17). Type III increased from M1 to M3 (β=0.42, P=.003; 95%CI: 0.19, 0.65) and M1 to M4 (β=0.49, P=.002; 95%CI: 0.18, 0.81), Type IV increased from M1 to M4 (β=0.57, P<.01; 95%CI: 0.29, 0.84). A positive adaptation in AT structural integrity was observed over the XC season, with a ~10% shift from Type II to Type I UTC echo types, suggesting AT resilience to a competitive season of repetitive loading in highly trained runners.

Structural integrity is decreased in both Achilles tendons in people with unilateral Achilles tendinopathy.

A high proportion of Achilles tendinopathy patients develop bilateral symptoms with human and animal studies showing bilateral histological changes associated with overuse/pathology in one tendon. The current study examined changes in tendon structure, assessed semi-quantitatively using ultrasound tissue characterisation, in both the symptomatic and asymptomatic tendon in unilateral Achilles tendinopathy patients in comparison to individuals with no history of tendinopathy. Cross-sectional case-control study. Participants with Achilles tendinopathy (n=21), with varying severity and length of clinical symptoms, and six participants with no history of tendinopathy were recruited. Tendons were scanned using ultrasound tissue characterisation, which captures contiguous transverse ultrasound images every 0.2mm and renders a 3-dimensional image. Ultrasound tissue characterisation quantifies tendon structure by measuring the stability of echopattern over contiguous transverse images. Four echo-types were discriminated and expressed as a percentage. Antero-posterior diameter of all tendons was measured. Significant differences were observed in the proportion of normal tendon structure between all three groups (p<0.01), with the symptomatic tendon containing the least amount of normal tendon structure (symptomatic - 79.5%, asymptomatic - 81.8%, control - 86.4%). The asymptomatic tendon contained significantly less normal tendon in comparison to the control tendon (p=0.008), suggesting the asymptomatic tendon is structurally compromised despite the absence of symptoms. Both Achilles tendons are structurally compromised in patients with unilateral Achilles tendinopathy. Future studies need to investigate whether these changes increase the risk of developing symptoms.

BILATERAL CHANGES IN UNILATERAL ACHILLES TENDINOPATHY QUANTIFIED USING ULTRASOUND TISSUE CHARACTERISATION

IntroductionAchilles tendinopathy is a prevalent musculoskeletal injury in the young athletic population as well as older individuals. A high proportion of individuals develop symptoms within both Achilles tendons as well...

ULTRASOUND TISSUE CHARACTERISATION, AN INNOVATIVE TECHNIQUE FOR INJURY-PREVENTION AND MONITORING OF TENDINOPATHY

Ultrasonography (US) is used to visualise tendon structure. However, its capacity to detect early disintegration, to reproducibly monitor progress of pathology or repair, and to objectively evaluate effect of therapies...

Ultrasonographic tissue characterisation of human Achilles tendons: quantification of tendon structure through a novel non-invasive approach

ObjectiveTo assess whether three-dimensional imaging of the Achilles tendon by ultrasonographic tissue characterisation (UTC) can differentiate between symptomatic and asymptomatic tendons.DesignCase-control study.SettingSports Medical Department of the Hague Medical Centre.PatientsTwenty-six tendons...

Prediction and validation of total and regional skeletal muscle mass by ultrasound in Japanese adults

The present study was performed to develop regression-based prediction equations for skeletal muscle (SM) mass by ultrasound and to investigate the validity of these equations in Japanese adults. Seventy-two Japanese men (n=38) and women (n=34) aged 18-61 years participated in this study and were randomly separated into two groups: the model development group (n=48) and the validation group (n=24). The total and regional SM mass were measured using magnetic resonance imaging (MRI) 1.5 T-scanners with spin-echo sequence. Contiguous transverse images (about 150 slices) with a slice thickness of 1 cm were obtained from the first cervical vertebra to the ankle joints. The volume of SM was calculated from the summation of digitized cross-sectional area. The SM volume was converted into mass units (kg) by an assumed SM density of 1.04 kg l(-1). The muscle thickness (MTH) was measured by B-mode ultrasound (5 MHz scanning head) at nine sites on the anatomical SM belly. Strong correlations were observed between the site-matched SM mass (total, arm, trunk body, thigh, and lower leg) by MRI measurement and the MTH x height (in m) in the model development group (r=0.83-0.96 in men, r=0.53-0.91 in women, P<0.05). When the SM mass prediction equations were applied to the validation group, significant correlations were also observed between the MRI-measured and predicted SM mass (P<0.05). The predicted total SM mass for the validation group was 19.6 (6.5) kg and was not significantly different from the MRI-measured SM mass of 20.2 (6.5) kg. Bland-Altman analysis did not indicate a bias in prediction of the total SM mass for the validation group (r=0.00, NS). These results suggested that ultrasound-derived prediction equations are a valid method to predict SM mass and an alternative to MRI measurement in healthy Japanese adults.

Prediction and Validation of Total and Regional Skeletal Muscle Mass by Ultrasound in Japanese Adult

0506 B-mode ultrasound has been widely employed to index skeletal muscle (SM) mass in vivo. However ultrasound-derived prediction equations for total body SM mass based on direct measurement, such as magnetic resonance imaging (MRI), have not been developed. PURPOSE: To develop regression-based prediction equations for SM mass by ultrasound, and to investigate the validity of these equations in Japanese adults. METHODS: Healthy Japanese men (n = 35) and women (n = 29) aged 18–61 yrs were randomly separated into 2 groups, a model development group (n = 48) and a validation group (n = 16). Total and regional SM mass was measured using magnetic resonance imaging (MRI) 1.5 T-scanners with spin-echo sequence. Contiguous transverse images (about 150 slices) with 1-cm slice thickness were obtained from the first cervical vertebrae to ankle joints. The volume of SM was calculated from the summation of digitized cross-sectional area. SM volume was converted into mass by an assumed SM density of 1.04 kg/l. Muscle thickness (MTH) was measured by B-mode ultrasound (5 MHz scanning head) at 9 sites on anatomical SM belly (lateral forearm, anterior and posterior upper arm, abdomen, subscapula, anterior and posterior thigh, anterior and posterior lower leg). RESULTS: Significant correlations were observed between MTH multiplied height and site-matched SM mass (total, arm, trunk body, thigh, and lower leg) by MRI measurement in the model development group (n = 48, r = 0.90–0.98, p<0.01, SEE = 0.1–1.2kg). When the SM mass prediction equations were applied to the validation group, significant correlations were also observed between the MRImeasured and predicted SM mass (n = 16, r = 0.94–0.98, p<0.01, SEE = 0.2–1.8kg). The predicted total SM mass for the validation group was 20.8 ± 6.9 kg, and was similar to the MRI-measured SM mass of 20.9 ± 7.0 kg. Bland-Altman analysis failed to disclose a bias in prediction of total SM mass for the validation group (n = 16, r = 0.03, NS). CONCLUSIONS: These results indicated that ultrasound-derived prediction equations are a valid method to predict SM mass and an alternative to MRI measurement in Japanese adults.

Sex differences in whole body skeletal muscle mass measured by magnetic resonance imaging and its distribution in young Japanese adults

Objectives: To determine sex differences in the distribution of regional and total skeletal muscle (SM) using contiguous whole body magnetic resonance imaging (MRI) data, and to examine the relations between...

RESISTANCE TRAINING-INDUCED CHANGES IN TOTAL BODY SKELETAL MUSCLE MASS AND DISTRIBUTION

Most resistance training (RT) studies have only evaluated limb muscle hypertrophy. Therefore, a complete whole-body distribution of the relative increases in RT-induced muscle hypertrophy has never been reported. PURPOSE To examine the absolute and relative changes in skeletal muscle size using whole- body magnetic resonance imaging (MRI) scans in response to RT. METHODS Three male college students volunteered for the study. Training (three sets to failure of 8–12 repetitions) was conducted 3 d/wk for 16wk of RT. Total body SM distribution and mass were measured using MRI 1.5-T scanner with spin-echo sequence. Contiguous transverse images with 1-cm slice thickness were obtained from the first cervical vertebrae to ankle joints for each subject. For each slice, the SM tissue areas (CSA) were digitized, and the SM volume was calculated. SM volume units (liters) were converted to mass units (kg) by multiplying the volumes by the assumed constant density for SM (1.04 kg/1). Bone mass was calculated from DEXA-measured bone mineral mass (bone mineral mass/bone = 0.54). Body density was measured by hydrostatic weighing with simultaneous measurement of residual lung volume by oxygen dilution. Body fat percentage was calculated from body density. Fat-free mass (FFM) was estimated as body mass minus body fat mass. RESULTS Average increase in relative upper and lower body strength following RT was 30 and 16%, respectively. Percent body fat decreased by 0.6% while average increase in FFM was 2.6kg following RT. Average increase in total SM mass following RT was 4.2kg. Relative changes in muscle hypertrophy were greater at the shoulder and chest levels and upper portion of the upper arm (+25–40%) compared to the waist, hip, forearm, thigh, and lower leg (+10–20%). CONCLUSION RT-induced change in SM was larger than the increase in FFM. Muscle hypertrophy did not occur equally throughout each individual muscle or region of the body.

Anatomic reference for computed tomography of the head of the foal.

The purpose of this study was to produce an anatomic reference for computed tomography (CT) of the head of the foal for use by radiologists, clinicians, and veterinary students. The head from each of 2 foals, euthanized for reasons unrelated to head pathology, was removed and prepared for CT scanning. Using a third-generation CT scanner, 5-mm contiguous transverse images were acquired. The heads were then frozen and sectioned using a band saw, with the cuts matched as closely as possible to the CT slices. The anatomic sections were photographed and radiographed. The radiographs and anatomic photographs were digitized and matched with the corresponding CT image. Each CT image was compared with its corresponding radiographic and anatomic section to assist in the accurate identification of specific structures. Clinically relevant structures were identified and labeled in corresponding images (CT, anatomic slice, and radiograph of slice). Only structures identified in the CT image were labeled in 1 of the other 2 images. Sagittal (reference) images of the horse's head were reconstructed from the transverse CT scans, and were used to indicate the level from which each of the transverse images was obtained. Corresponding labeled images were then formatted together with a legend for identification of specific anatomic structures.

Orbital computed tomography: technical aspects.

Computed tomographic scanning has revolutionized the diagnosis and management of orbital disease. The best use of this methodology requires knowledge of the principles and appropriate attention to scanning protocols. Computed tomographic scanning of the orbit is a demanding technique requiring thin sections through planes precisely positioned from the topographical anatomy. Ideally, orbital CT should include both transverse axial and coronal sections: The pathological condition and its plane of growth will influence the selection of the optimal plane or section. Coronal sections may be obtained either directly or indirectly by computer reconstruction from contiguous transverse images. Sagittal or oblique sections or both also are useful and may be obtained directly or indirectly. Difficulty in patient positioning may preclude direct sagittal imaging, however. The use of intravenous contrast enhancement is not necessary as a routine technique unless a mass is identified or suspected. Where surgical resection or biopsy of a space-occupying lesion is contemplated, contrast enhancement can be valuable in assessing relative vascularity and aiding diagnostic specificity. It should be continually emphasized that CT is a powerful technology which, in orbital diagnosis, produces the highest yield when clinician and radiologist collaborate in the radiodiagnostic workup. The clinical information supplied by the referring ophthalmologist is used by the radiologist both in the selection of the appropriate techniques for investigation and in striving to achieve the most specific conclusion.

SINGLE PHOTON EMISSION COMPUTED TOMOGRAPHY (SPECT)- QUANTITATIVE ASPECTS AND STUDIES IN CANINE PULMONARY PERFUSION

We have evaluated the quantitative aspects of a whole-body SPECT system which consists of 2 large-field-of-view scintillation cameras mounted in a rotatable gantry and interfaced to a minicomputer. Data are continuously collected through a 360 degree rotation and result in 32 contiguous transverse images which can be reorganized into 16 frontal and 16 sagittal images. Pulmonary perfusion studies were performed in dogs to compare the information from SPECT with routine gamma camera images. Five plastic spheres ranging from 2 to 6 cm in diameter were placed in a 22 cm diameter cylinder with technetium-99m distributed in the spheres and cylinder in varying concentration ratios. A semi-automatic region of interest program was used to evaluate the multiple slices from the SPECT data, and the volumes were calculated by computing the total number of voxels within each region of interest. The SPECT measured volumes correlated very well with the actual volumes. To evaluate the ability of SPECT to determine radionuclide concentrations in an object, elliptical and cylindrical phantoms were uniformly filled with technetium-99m in concentrations from 0.05 to 1.5 μCi/ml. Using attenuation corrected data, the SPECT concentrations correlated very well with the actual concentrations over the entire range tested. We also evaluated the concentration ratios of the spheres to the cylinder using attenuation corrected SPECT images. The concentration ratios were derived from the measured SPECT image contrast by correcting for attenuation, scattered photons and image degradation resulting from finite system spatial resolution. Using this procedure, the SPECT measured concentration ratios correlated well with the actual concentration ratios. Perfusion defects from normal anatomic structures, as well as perfusion abnormalities secondary to occlusion of a bronchus or pulmonary artery are better defined on the SPECT images than the gamma camera images. Thus, SPECT gives additional information concerning pulmonary perfusion.