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A Cotten

Publications and source records attributed to A Cotten.

At least 19 recordsLinked to original sources
PubMed2006

Multimodal visualization interface for data management, self-learning and data presentation.

A multimodal visualization software, called the Data Manager (DM), has been developed to increase interdisciplinary communication around the topic of visualization and modeling of various aspects of the human anatomy. Numerous tools used in Radiology are integrated in the interface that runs on standard personal computers. The available tools, combined to hierarchical data management and custom layouts, allow analyzing of medical imaging data using advanced features outside radiological premises (for example, for patient review, conference presentation or tutorial preparation). The system is free, and based on an open-source software development architecture, and therefore updates of the system for custom applications are possible.

Anatomy↗
PubMed2006

A specific clinical pattern of camptocormia in Parkinson's disease.

BACKGROUND: Camptocormia, characterised by extreme forward flexion of the thoracolumbar spine and severe stooping in the supine position, seems to be prevalent in Parkinson's disease. OBJECTIVE: The aim of this study was to identify features of parkinsonian camptocormia and to describe the main clinical characteristics of patients with Parkinson's disease who develop the condition. METHODS: An extensive range of clinical, biochemical and imaging data were gathered for 23 patients with Parkinson's disease with camptocormia, notably including magnetic resonance imaging (MRI) of the brain and spine, electromyographic recordings of the paravertebral muscles and muscle biopsies. RESULTS: Camptocormia occurred in severe Parkinson's disease with axial predominance, motor fluctuations and dysautonomic symptoms. The condition was often associated with spondyloarthritic changes and pain. MRI showed paraspinal muscle signal abnormalities in five patients and fatty involution in seven patients. The seven patients had motor unit reductions on the spinal erector electromyogram. The MRI results for the girdle muscles were normal. Cranial MRI showed signal abnormalities for the basal ganglia in three patients. DISCUSSION: Various mechanisms may contribute to the development of parkinsonian camptocormia: dopaminergic depletion in Parkinson's disease induces functional changes in the organisation of the corticospinal and reticulospinal tracts, where dysfunction could contribute to axial rigidity. Furthermore, rigidity of the spinal flexion muscles could lead to under-use of the spinal extension muscles, which become progressively atrophic. Rigidity may also induce spinal deformations, leading to a neurogenic syndrome via compression of the spinal nerves. CONCLUSION: The screening and early management of camptocormia in Parkinson's disease is likely to be important for preventing axial disorders and spinal deformations.

Aged↗
PubMed2005

Normal anatomy of the heel entheses: anatomical and ultrasonographic study of their blood supply.

The purpose of this study was first to determine the normal blood supply of the heel entheses with cadaver injection, and second, to identify by means of ultrasound (US) this blood supply in healthy volunteers before and after the intravenous injection of a US contrast agent (SonoVue). Twenty cadaver lower limbs were cut into sagittal, coronal, or axial sections after the injection of a red-colored gelatin solution. Ten anatomical samples were selected for histology. Then 10 healthy volunteers were enrolled in a contrast-enhanced ultrasonography study (CUS). Calcaneal tendon and plantar aponeurosis entheses were studied first without any contrast-agent (B-mode, power Doppler). A single dose (2.4 ml) of the contrast agent was then administered for studying each enthesis of the right foot. The operators had to look for blood flow within the entheses and in the adjacent soft tissues. Anastomotic transverse branches were seen macroscopically at the back of the calcaneal tendon, giving some capillaries penetrating the enthesis. None of these vessels could be seen with CUS. In contrast, a high-density vascular network could be detected in Kager's triangle with CUS. No blood vessel could be seen within the plantar aponeurosis enthesis, either macroscopically or microscopically. No evidence of entheseal vascularization was found with any contrast-enhanced imaging technique. Inferior branches of the lateral plantar artery were seen on coronal and sagittal sections of the hindfoot, and could be detected with CUS. These arterioles were running toward the anterior aspect of the calcaneal tuberosity, near the plantar aponeurosis insertion. In conclusion, no vascularization was detected with CUS at the cortical bone insertion of normal heel entheses. However, some vascularization could be seen in the immediate vicinity of heel entheses. The latter feature has to be kept in mind, as it may represent a pitfall for the diagnosis of early inflammatory changes in patients, especially those with seronegative spondylarthropathies.

Adult↗
PubMed2005

[Parkinson's disease, progressive lumbar kyphosis and focal paraspinal myositis].

INTRODUCTION: The camptocormia (bent spine) is characterized by a severe forward flexion of the thoracolumbar spine which disappears in the supine position. Clinical case. We describe a typical case observed in a parkinsonian patient. The MRI, electromyogram and biopsy of the paraspinal muscles revealed a typical myositis pattern. DISCUSSION: This case, the sixth published to our knowledge, confirms that focal myositis is associated with the camptocormia in Parkinson's disease. Typically it is observed in male subjects, appearing 4 to 6 years after the onset of Parkinson's disease, in fluctuating patients treated by an association of L-Dopa and agonist. It appears quickly and becomes the most important symptom. Antiparkinsonian drugs are useless. CONCLUSION: This exceptional picture raises original pathophysiological and therapeutic questions. Systematic studies should be performed in order to detail the pathophysiological link between these 3 entities: Parkinson's disease, focal myositis and camptocormia.

Disease Progression↗
PubMed2005

[Usefulness of musculoskeletal ultrasonography in a University Department of Radiology].

The excellent architectural analysis of muscles, tendons and nerves, the dynamic assessment of theses structures and the easy comparison with the controlateral side explain the usefulness of ultrasonography in the assessment of many musculoskeletal diseases. This technique also represents a pleasant way to learn the musculoskeletal anatomy and allows a better understanding of the physiology and pathophysiology of the musculoskeletal system. Finally, musculoskeletal ultrasonography is more and more used in clinical and fundamental research studies.

Humans↗
PubMed2004

Relationship between computed tomographic image analysis and histomorphometry for microarchitectural characterization of human calcaneus.

The present study aimed to characterize the relationships between several variables reflecting bone microarchitecture assessed by both computed tomographic (CT) image analysis and histomorphometry (conventional CT system) at the calcaneus. A total of 24 cadaveric specimens were studied. The mean age at death was 78 +/- 10 years (range, 53-93 years). A total of 15 sagittal sections (1 mm in width and spaced 2 mm apart) were selected for CT analysis; 6 undecalcified sections (7 microm) were analyzed for histomorphometry. The histomorphometric analysis was performed on a Leica Quantimet Q570 image analyzer. Features measured by both methods were: bone volume/tissue volume (BV/TV), trabecular thickness (Tb.Th), trabecular separation (Tb.Sp), trabecular number (Tb.N), interconnectivity index (ICI), number of nodes (N Nd), number of terminus (N Tm), node-to-node strut count (NNS), node-to-terminus strut count (NTS), terminus-to-terminus strut count (TTS), marrow space star volume (SV), Euler number (EN), and fractal dimension (FD). The coefficient of correlations' values (simple linear regression) between histomorphometry and CT image analysis varied according to the parameters selected. R values were high for BV/TV, Tb.N, and Tb.Sp (range, 0.69-0.90; P < 0.01). R values were less significant for some variables also obtained from the binary image: SV (0.5, P < 0.05) and EN (0.43, P < 0.05). Finally R values were also significant for (two) variables obtained from skeletonized images, i.e., N Nd (0.4, P < 0.05) and N Tm (0.61, P < 0.01). Other correlations were not statistically significant. Moreover, for some variables the relationships between the two methods (CT analysis and histomorphometry) seemed best-described by using nonlinear models. For example, a logarithmic model was more appropriate for SV (r = 0.71, P < 0.01), N Nd (r = 0.52, P < 0.01). Finally the relationship between apparent (App) N Tm and N Tm was most satisfying when using an exponential model (r = 0.64, P < 0.01). In conclusion, trabecular bone structure measures determined on CT images show highly significant correlations with those determined using histomorphometry. The level of correlation varies according to the type of method used for characterizing bone structure, however, and the strongest correlations were found for the most basic features (Parfitt's parameters). Finally, for some variables, nonlinear models seem more appropriate.

Absorptiometry, Photon↗
PubMed2003

The fibrocartilaginous sesamoid: a cause of size and signal variation in the normal distal posterior tibial tendon.

The aim of this study was to investigate the presence of fibrocartilage within the distal posterior tibial tendon (PTT) before its division correlating with size and signal variation on MR images through a radio-anatomic and pathologic study. Eight fresh cadaveric feet underwent MR imaging were cut into 4-mm slices in the axial plane. The PTT specimens were harvested at the tendon distal portion before its division and sent to pathology. Thirty-three asymptomatic subjects underwent axial double-echo turbo-spin-echo MR imaging. Proximal and distal PTT signal and diameter were evaluated. In cadavers, every PTT flared distally. Intratendinous fibrocartilage and ossified sesamoid were found in, respectively, 87.5 and 12.5% of the cases. Distal PTT flaring was demonstrated in 100% of the asymptomatic subjects (mean diameter 8 mm). An intratendinous high signal intensity on proton-density-weighted images and sesamoid bone were evidenced in, respectively, 36 and 33% of the cases. Proximally, PTT presented a 4-mm mean diameter and was hypointense in 100% of the cases. Only one accessory navicular bone was detected. Laterally off-centered increased intratendinous signal intensity as well as PTT distal widening with otherwise normal MR imaging features are related to an intratendinous fibrocartilage.

Adult↗
PubMed2003

Does quantitative ultrasound of bone reflect more bone mineral density than bone microarchitecture?

Relationships among quantitative ultrasound of bone (QUS), bone mineral density (BMD) and bone microarchitecture have been poorly investigated in human calcaneus.Twenty-four specimens, from 12 men and 12 women (mean age 78 +/- 10 years; range 53-93), removed from cadavers were studied. The feet were axially sectioned above the ankle. Two variables were measured for QUS (Achilles, Lunar): broadband ultrasound attenuation (BUA) and speed of sound (SOS). A third variable, the stiffness index (SI), which is a combination of both BUA and SOS, was also calculated. BMD (a lateral view) was measured on a QDR 2000 densitometer (Hologic). Bone microarchitecture was assessed by computed tomography (CT) using a conventional CT-system. Fifteen sagittal sections (1 mm in width and 2 mm apart) were selected for CT. Methods used for characterizing bone microarchitecture consisted in structural (trabecular network characterization) and a fractal analyses. The relationships between QUS and bone microarchitecture were assessed by simple linear regression analysis with and without adjustment for BMD (partial correlation) and by backward stepwise regression analysis. Strong relationships were found between BMD and QUS. Adjusted r(2) values were 0.545 for SOS and 0.717 for SI. Two microarchitectural variables were also significantly correlated with both SOS and SI: apparent trabecular separation (App Tr Sp) and trabecular bone pattern factor (App TBPF). After adjustment for BMD few correlations between QUS and microarchitectural variables were always significant. Adjusted squared semipartial coefficients of correlation (rsp2) values between SOS and bone microarchitecture were 6%, 6.8%, 13.2% and 4.6% for App BV/TV, App Tr Sp, App TBPF and fractal dimension (FD), respectively. For SI, corresponding figures were 3.7%, 4.1%, 5.2% and 3.2%. Backward stepwise regression analysis using BMD and microarchitecture showed a slight increase of r(2) values that varied from 8.4% for SI to 17.8% for SOS, compared with BMD alone. The current study suggests that although BMD is a major determinant of acoustic properties of human calcaneus, significant density independent relationships with bone microarchitecture should also be taken into account.

Aged↗
PubMed2003

Anatomic and biometric study of the acromioclavicular joint by ultrasound.

The aim of this study was to describe the normal ultrasound anatomy of acromioclavicular joint (ACJ) and to establish ultrasound biometric criteria of this joint. Thirty healthy volunteers (16 men, 14 women) underwent a bilateral ultrasound examination of the ACJ in both planes (superior, anterosuperior) by two different observers. Six measurements were evaluated on the ACJ. The morphological appearance was also studied. Five morphological types of the ACJ were identified. No significant biometric difference was found between the observers, the planes, the dominant and the non-dominant side, and between men and women (except for the deep joint space distance). However, the variability of the ACJ made this biometric study difficult. The maximum distance between the joint capsule and the deep joint space through the superior plane, seemed to be a reproducible measurement with the best confidence interval.

Acromioclavicular Joint↗
PubMed2003

SAPHO: syndrome or concept? Imaging findings.

The SAPHO syndrome was a term coined to include a variety of musculoskeletal disorders associated with skin conditions, mainly palmoplantar pustulosis and acne conglobata. It is more correctly a spectrum which includes the following: skin lesions, osteoarticular manifestations of synovitis hyperostosis and osteitis affecting particular target sites, and.a clinical course marked by relapses and remissions. The major sites of involvement are the anterior chest wall, the spine, long bones, flat bones, and large and small joints. The distribution and severity of involvement varies from the adult to the pediatric form of chronic recurrent multifocal osteomyelitis (CRMO). The diagnosis of SAPHO syndrome is not difficult when the typical osteoarticular lesions are located in characteristic target sites. The diagnosis is more difficult if atypical sites are involved and there is no skin disease.

Acquired Hyperostosis Syndrome↗
PubMed2003

Multi-fasciculated anterior talo-fibular ligament: reassessment of normal findings.

The aims of this study were to (a) provide an accurate description of the anterior talo-fibular ligament (ATFL) multifasciculated feature by means of cadaver study, and (b) to further delineate contour and signal variations on MR images related to this feature in a group of asymptomatic subjects. After MR imaging, three cadaveric feet were frozen and cut in the coronal plane. The ATFL were harvested and sent to pathology. Another cadaveric foot was dissected. The MR imaging was performed in 3 healthy volunteers and 19 patients without pathology of the ATFL. For both cadaveric feet and subjects, MR imaging protocol consisted of axial and coronal proton-density (PD) and T2-weighted turbo-spin-echo (TSE) sequences (TR/TE: 3500 ms/17-119 ms). On MR images, ATFL signal and fascicle numbers were assessed, respectively, in the axial and coronal planes. Gross anatomy and pathology confirmed the ATFL bifasciculated aspect. On cadaveric coronal MR images, 3 of 4 ATFLs were bifasciculated and one of four was striated. On patients' coronal MR images, 2 of 22 of the ATFL were monofasciculated, 12 of 22 bifasciculated, and 8 of 22 striated. On axial MR images, 16 of 22 of the ATFL demonstrated a low signal intensity and 8 of 22 an intraligamentous subtle increased signal intensity. Two of 22 of the ATFL had contour irregularities. Isolated anterior talo-fibular intraligamentous signal abnormalities or contour irregularities on axial PD and T2-weighted MR images with an otherwise normal ATFL aspect on coronal MR images and no other MRI criteria for ankle sprain may reflect normal anatomy.

Ankle Injuries↗
PubMed2003

[Value of US imaging of metacarpophalangeal joints in patients with early rheumatoid arthritis].

Technological advances in the field of ultrasound imaging may have, especially in metacarpophalangeal joints, an impact on decision making in patients with early rheumatoid arthritis. First, the normal anatomy of the metacarpophalangeal joints is briefly reviewed. Then, the authors describe the main ultrasound imaging findings of early RA. The role of ultrasound imaging in the assessment of therapeutic response as well as the benefit of microbubble ultrasound contrast agents are considered.

Arthritis, Rheumatoid↗
PubMed2002

Computed tomography image analysis of the calcaneus in male osteoporosis.

The present study aimed to characterize bone microarchitecture assessed by computed tomography (CT) at the calcaneus in male subjects suffering from osteoporosis. Seventy-nine subjects were assessed (45 with osteoporosis and 34 control subjects matched for age). Osteoporosis was defined according to the World Health Organization classification either at the lumbar spine or at the femoral neck. Thirty-three subjects (73%) had a past history of low-energy fracture mainly represented by vertebral fractures (24/33). Nine axial sections (1 mm in width and 2 mm apart) were selected for each subject. Bone microarchitecture analysis was performed using structural (binary and skeletonized images but also skeletonization from gray levels) and fractal analyses. Bone densitometry by dual-energy X-ray absorptiometry (DXA) at the calcaneus was also performed in 73 cases. Bone mineral density (BMD) was decreased in osteoporotic patients compared with controls both at the lumbar spine and hip and also at the calcaneus (p<0.01). Also 14 microarchitectural features among 25 measured were significantly different between the two groups (p<0.01). The odds ratio for fracture per 1 control group standard deviation decrease were also significant for 13 structural features but also for BMD at the calcaneus. The odds ratios after adjustment for BMD at the calcaneus were significant for the following features (p<0.05): number of valleys, 2.8 (1.2-6.9); trabecular partition, 3.3 (1.3-7.9); apparent trabecular spacing, 1.8 (1.0-3.1); trabecular bone pattern factor, 2.2 (1.1-4.3); Euler number, 3.0 (1.1-8.7); node-to-terminus strut count, 3.3 (1.4-7.8); terminus-to-terminus strut count, 2.9 (1.2-6.9); and fractal dimension, 3.7 (1.5-9.7). Few and weak correlations were found between BMD at the calcaneus measured with DXA and features obtained from CT, suggesting that these two methods give different information about bone status. In conclusion, male osteoporosis is a disease characterized by decreased bone mass but also by microarchitectural deterioration of bone tissue which is partly independent of BMD.

Absorptiometry, Photon↗
PubMed2002

[Imaging of lipoma and liposarcoma].

The aim of this paper is to describe the two most frequent lipomatous soft tissue tumors, lipoma and liposarcoma, and to highlight the radiologic features allowing their differentiation.

Diagnosis, Differential↗
PubMed2002

[Imaging of the lumbar spine].

The role of conventional radiographs in the evaluation of the lumbar spine remains unchanged. The respective place of CT and MRI in the evaluation of lumbar spine disorders has not significantly changed in spite of technical advances. However, their diagnostic capabilities have improved.

Adult↗
PubMed2001

Image-guided endoscopic spine surgery: Part I. A feasibility study.

STUDY DESIGN: A feasibility study was performed to determine the efficacy of computer assistance in endoscopic spine surgery. OBJECTIVES: To assess a new method for computer assistance based on image guidance during thoracoscopic or any endoscopic spine procedure. To evaluate the reproducibility, the sensitivity and the reliability of the technique first in vitro and second in clinical use. SUMMARY OF BACKGROUND DATA: The computer-based, image-guided surgery is now a routine tool used in open spine surgery. Exposure of the anatomy of the vertebra is needed for registration. This methodology is inapplicable in endoscopic approach. Fluoroscopic-based navigation combines the technology of image-guided surgery and C-arm fluoroscopy. The navigation is based on the fluoroscopic images acquired before surgery. This technology is applicable to endoscopic surgery but the navigation is based on fluoroscopic image. The computed tomography images are not exploited. There are no published data on a technique that allows image-guided surgery based on computed tomography and magnetic resonance imaging. METHOD: A laboratory study was performed on a thoracic human spine. One vertebra was marked on the right lateral side of the body with five titanium marks. A percutaneous reference frame was specifically designed to be placed in the pedicle of the same marked vertebrae. The reference frame acted as a 3D localizer and a registration tool. The spine model was scanned including the reference frame. A standard Stealth station treatment guidance platform (Medtronic, Sofamor Danek, Memphis, TN) was used for simulation. The registration was obtained using the reference frame. Twenty navigation procedure trials were done and the error was recorded based on the distance between the anatomical point and the corresponding virtual one. RESULTS: Registration was always possible using the stealth station and a standard spine navigational software (spine 3, Medtronic Sofamor Danek, Memphis, TN). The mean error after registration given by the computer was 0.96 mm. The mean error recorded during the navigation simulation was 1.6 mm. CONCLUSIONS: This technique allows the possibility of computed tomography and magnetic resonance imaging-based, image-guided endoscopic surgery. It is probable that in the near future, as image fusion technology improves, the fluoronavigation based on fluoroscopic images would enable to navigate on multimodal images. Otherwise the technique described in this article is the only reproducible one that allows computed-tomography-based computer assistance during endoscopic procedures.

Endoscopy↗