119 research outputs found

    An evaluation of overlying tissues to determine fetal exposure to ultrasound during the third trimester

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    Measurements of minimum and average total tissue thicknesses overlying the fetus during the third trimester were taken on 52 patients between 24 and 40 weeks gestation. Minimum total thickness of tissues constantly along the ultrasound path had a mean value of 1.75 cm, ranging from 0.40 to 3.70 cm. This corresponded to a mean attenuation of 0.87 dB MHz-1, ranging from 0.30 to 1.68 dB MHz-1. Average total thickness of tissues constantly along the ultrasound path had a mean value of 2.16 cm, ranging from 1.00 to 4.10 cm. This corresponded to a mean attenuation of 1.16 dB MHz-1, ranging from 0.64 to 2.03 dB MHz-1. Average attenuation was also calculated for all soft tissues along the ultrasound path, including the placenta. The resulting average attenuation was 0.47 dB cm-1 MHz-1. Maternal weight at the time of ultrasound examination had significant correlation with minimum and average ultrasound attenuation by tissues constantly along the ultrasound path. The R2 value was 46.7% for minimum attenuation (p-value p-value 2 value of the model that included all three variables was 57.2% (p-value p-value < 0.0001) for average attenuation.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/31864/1/0000814.pd

    Assessment of seminal plasma laminin in fertile and infertile men

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    Abstract Aim: To assess laminin levels in the seminal plasma of infertile and fertile men, and to analyze the correlation of laminin levels with sperm count, age, sperm motility and semen volume. Methods: One hundred and twenty-five recruited men were equally divided into five groups according to their sperm concentration and clinical examination: fertile normozoospermia, oligoasthenozoospermia, non-obstructive azoospermia (NOA), obstructive azoospermia (OA) and congenital bilateral absent vas deferens (CBAVD). The patients' medical history was investigated and patients underwent clinical examination, conventional semen analysis and estimation of seminal plasma laminin by radioimmunoassay. Results: Seminal plasma laminin levels of successive groups were: 2.82 ± 0.62, 2.49 ± 0.44, 1.77 ± 0.56, 1.72 ± 0.76, 1.35 ± 0.63 U/mL, respectively. The fertile normozoospermic group showed the highest concentration compared to all infertile groups with significant differences compared to azoospermic groups (P < 0.05). Testicular contribution was estimated to be approximately one-third of the seminal laminin. Seminal plasma laminin demonstrated significant correlation with sperm concentration (r = 0.460, P < 0.001) and nonsignificant correlation with age (r = 0.021, P = 0.940), sperm motility percentage (r = 0.142, P = 0.615) and semen volume (r = 0.035, P = 0.087). Conclusion: Seminal plasma laminin is derived mostly from prostatic and testicular portions and minimally from the seminal vesicle and vas deferens. Estimating seminal laminin alone is not conclusive in diagnosing different cases of male infertility. (Asian J Androl 2007 Jan; 9: 63-67

    A new prediction model for ventricular arrhythmias in arrhythmogenic right ventricular cardiomyopathy

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    Aims Arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVC) is characterized by ventricular arrhythmias (VAs) and sudden cardiac death (SCD). We aimed to develop a model for individualized prediction of incident VA/SCD in ARVC patients.Methods and results Five hundred and twenty-eight patients with a definite diagnosis and no history of sustained VAs/SCD at baseline, aged 38.2 +/- 15.5 years, 44.7% male, were enrolled from five registries in North America and Europe. Over 4.83 (interquartile range 2.44-9.33) years of follow-up, 146 (27.7%) experienced sustained VA, defined as SCD, aborted SCD, sustained ventricular tachycardia, or appropriate implantable cardioverter-defibrillator (ICD) therapy. A prediction model estimating annual VA risk was developed using Cox regression with internal validation. Eight potential predictors were pre-specified: age, sex, cardiac syncope in the prior 6 months, non-sustained ventricular tachycardia, number of premature ventricular complexes in 24 h, number of leads with T-wave inversion, and right and left ventricular ejection fractions (LVEFs). All except LVEF were retained in the final model. The model accurately distinguished patients with and without events, with an optimism-corrected C-index of 0.77 [95% confidence interval (CI) 0.73-0.81] and minimal over-optimism [calibration slope of 0.93 (95% CI 0.92-0.95)]. By decision curve analysis, the clinical benefit of the model was superior to a current consensus-based ICD placement algorithm with a 20.6% reduction of ICD placements with the same proportion of protected patients (P &lt;0.001).Conclusion Using the largest cohort of patients with ARVC and no prior VA, a prediction model using readily available clinical parameters was devised to estimate VA risk and guide decisions regarding primary prevention ICDs (www.arvcrisk.com).</p

    Hypo-Vascular Liver Metastases Treated with Transarterial chemoembolization: Assessment of Early Response by Volumetric Contrast-Enhanced and Diffusion-Weighted Magnetic Resonance Imaging

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    OBJECTIVE: To evaluate the value of anatomic and volumetric functional magnetic resonance imaging (MRI) in early assessment of response to trans-arterial chemoembolization (TACE) in hypovascular liver metastases. METHODS: This retrospective study included 52 metastatic lesions (42 targeted and 10 non-targeted) in 17 patients who underwent MRI before and early after TACE. Two reviewers reported response by anatomic criteria (Response Evaluation Criteria in Solid Tumor [RECIST], modified RECIST [mRECIST], and European Association for the Study of Liver Disease [EASL]) and functional criteria (volumetric apparent diffusion coefficient and contrast enhancement). Treatment endpoint was RECIST at 6 months. A 2-sample paired t test was used to compare the mean changes after intra-arterial therapy. P < .05 was considered statistically significant. RESULTS: Reduction in mRECIST and EASL at 1 month was significant in the whole cohort as well as in responders by RECIST at 6 months, and the changes fulfilled partial response criteria for both metrics in responders. Responders also had significant changes in volumetric apparent diffusion coefficient (P = .01 and P = .03) and contrast enhancement (P < .0001 and P < .0001) at 1 month for both readers, respectively. CONCLUSION: At 1 month post treatment, responders did not fulfill RECIST criteria but fulfilled mRECIST and EASL criteria. In addition, volumetric contrast-enhanced and diffusion-weighted MRI may be helpful in evaluating early treatment response after TACE in hypovascular liver metastases in patients who have failed to respond to initial chemotherapy

    Magnetic Resonance Imaging of Rectal and Anal Cancer

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    Magnetic resonance imaging plays a pivotal role in the imaging and staging of rectal and anal carcinomas. Rectal adenocarcinomas and anal squamous cell carcinomas behave differently, and are staged and treated differently. This article attempts to explain these 2 entities, which share the same regions of interest, in a comprehensive manner

    3.0-T MR Imaging of the Abdomen: Comparison with 1.5 T

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    ACR Appropriateness Criteria(R) Pancreatic Cyst

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    Incidental pancreatic cysts are increasingly detected on imaging studies performed for unrelated indications and may be incompletely characterized on these studies. Adequate morphological characterization is critical due to the small risk of malignant degeneration associated with neoplastic pancreatic cysts, as well as the risk of associated pancreatic adenocarcinoma. For all pancreatic cysts, both size and morphology determine management. Specifically, imaging detection of features, such as pancreatic ductal communication and presence or absence of worrisome features or high-risk stigmata, have important management implications. The recommendations in this publication determine the appropriate initial imaging study to further evaluate a pancreatic cyst that was incidentally detected on a nondedicated imaging study. The recommendations are designed to maximize the yield of diagnostic information in order to better risk-stratify pancreatic cysts and assist in guiding future management. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment
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