A 12-year, prospective study of extraocular muscle imaging in complex strabismus

INTRODUCTION: Diagnostic imaging by magnetic resonance imaging (MRI) or computed x-ray tomography (CT) has become the standard of care in many medical fields. Clinical imaging of the extraocular muscles (EOMs) can now provide insight into some causes of strabismus, in some cases challenging traditional concepts of etiology and suggesting alternative treatments. METHODS: Between 1990 and 2001, 62 orthotropic volunteers and 261 strabismic patients underwent orbital imaging under a prospective protocol. Surface coil MRI was performed with fixation control with slice thickness of 1.5 to 3 mm; CT was performed with 1-mm slice thickness. Images were correlated with ophthalmological examinations. RESULTS: MRI was performed in 267 and CT in 56 subjects. Comparison with normal orbits commonly demonstrated abnormalities of EOM size or location in strabismic patients. These included absence (5 patients) or atrophy (33 patients) of the superior oblique (SO) muscle in SO palsy; abnormalities of the trochlea or SO tendon in Brown's syndrome (8 patients); heterotopy of the rectus pulleys associated with incomitant strabismus (46 patients), including instability of pulleys (9 patients); trauma to rectus EOMs (16 patients); atrophy of the lateral rectus (10 patients), inferior rectus (4 patients), medial rectus (4 patients), superior rectus (4 patients), and inferior oblique (1 patient) muscles; and EOMs disinserted by scleral buckles (3 patients). EOM abnormalities correlated closely with clinically abnormal patterns of ocular motility. CONCLUSIONS: With the appropriate technique, EOM imaging is a valuable adjunct in clinical evaluation of complex strabismus. Because imaging can provide unique information unavailable from the clinical examination alone, it should be performed when indicated to evaluate patients with strabismus more complex than concomitant esotropia and exotropia.     

Circulating serum xenoestrogens and mammographic breast density

Introduction

Humans are widely exposed to estrogenically active phthalates, parabens, and phenols, raising concerns about potential effects on breast tissue and breast cancer risk. We sought to determine the association of circulating serum levels of these chemicals (reflecting recent exposure) with mammographic breast density (a marker of breast cancer risk).

Methods

We recruited postmenopausal women aged 55 to 70 years from mammography clinics in Madison, Wisconsin (N = 264). Subjects completed a questionnaire and provided a blood sample that was analyzed for mono-ethyl phthalate, mono-butyl phthalate, mono-benzyl phthalate, butyl paraben, propyl paraben, octylphenol, nonylphenol, and bisphenol A (BPA). Percentage breast density was measured from mammograms by using a computer-assisted thresholding method.

Results

Serum BPA was positively associated with mammographic breast density after adjusting for age, body mass index, and other potentially confounding factors. Mean percentage density was 12.6% (95% confidence interval (CI), 11.4 to 14.0) among the 193 women with nondetectable BPA levels, 13.7% (95% CI, 10.7 to 17.1) among the 35 women with detectable levels below the median (<0.55 ng/ml), and 17.6% (95% CI, 14.1 to 21.5) among the 34 women with detectable levels above the median (>0.55 ng/ml; P_trend = 0.01). Percentage breast density was also elevated (18.2%; 95% CI, 13.4 to 23.7) among the 18 women with serum mono-ethyl phthalate above the median detected level (>3.77 ng/ml) compared with women with nondetectable BPA levels (13.1%; 95% CI, 11.9 to 14.3; P_trend = 0.07). No other chemicals demonstrated associations with percentage breast density.

Conclusions

Postmenopausal women with high serum levels of BPA and mono-ethyl phthalate had elevated breast density. Further investigation of the impact of BPA and mono-ethyl phthalate on breast cancer risk by using repeated serum measurements or other markers of xenoestrogen exposure are needed.     

膝关节周围骨肿瘤手术的肢体康复

0　引言　膝关节周围是骨原发恶性肿瘤的好发部位 .病变组织广泛侵袭 ,切除肿瘤造成骨与软组织缺损 ,各种重建方法都需最大限度地保留膝关节功能 .如何采取早期系统的康复治疗 ,是临床骨肿瘤保肢手术的重要内容 .1　对象和方法　 1992 - 0 5 / 1999- 0 3,膝关节周围恶性骨肿瘤患者 6 4例接受保肢手术治疗 .男 38例 ,女 2 6例 ;骨肉瘤 5 2例 ,恶性骨巨细胞瘤 5例 ,尤文瘤 3例 ,母细胞瘤 2例 ,原发神经外胚层肿瘤 2例 .手术方式 :异体半关节移植术 37例 ;异体骨段移植术 16例 ;复合异体骨段的人工全膝关节表面置换术3例 ,动力旋转铰链式人工全…     

Choledocholithiasis: diagnosis with oral-contrast-enhanced CT cholangiography

OBJECTIVE: The purpose of this study was to determine whether global statistical data from radionuclide ventilation-perfusion scans could predict the likelihood of pulmonary embolism. MATERIALS AND METHODS: Digital data were obtained from 161 patients undergoing both radionuclide ventilation-perfusion scanning and subsequent pulmonary angiography. Morphometric data characterizing whole-lung perfusion and ventilation parameters were input into artificial neural networks in an attempt to predict the likelihood of pulmonary embolism. RESULTS: The performance of artificial neural networks using only automated global region of interest-based data was superior to that of clinicians in predicting the likelihood of acute pulmonary embolism in patients with normal findings on chest radiographs with segmental or larger emboli (p < .005) and in patients with normal findings on chest radiographs and emboli of any size (p < .01). Network performance did not significantly differ from clinician performance in patients with abnormal findings on chest radiographs. CONCLUSION: The adjunctive use of artificial neural networks using only user-independent, standard image statistics can significantly improve accuracy in the diagnosis of pulmonary embolism in patients with normal findings on chest radiographs.