Single image signal-to-noise ratio estimation for magnetic resonance images.

A novel technique to quantify the signal-to-noise ratio (SNR) of magnetic resonance images is developed. The image SNR is quantified by estimating the amplitude of the signal spectrum using the autocorrelation function of just one single magnetic resonance image. To test the performance of the quantification, SNR measurement data are fitted to theoretically expected curves. It is shown that the technique can be implemented in a highly efficient way for the magnetic resonance imaging system.

Reducing scanning electron microscope charging by using exponential contrast stretching technique on post-processing images.

An exponential contrast stretching (ECS) technique is developed to reduce the charging effects on scanning electron microscope images. Compared to some of the conventional histogram equalization methods, such as bi-histogram equalization and recursive mean-separate histogram equalization, the proposed ECS method yields better image compensation. Diode sample chips with insulating and conductive surfaces are used as test samples to evaluate the efficiency of the developed algorithm. The algorithm is implemented in software with a frame grabber card, forming the front-end video capture element.

Gaussian-Taylor signal-to-noise ratio estimation for scanning electron microscope images.

A new and robust parameter estimation technique, named Gaussian-Taylor interpolation, is proposed to predict the signal-to-noise ratio (SNR) of scanning electron microscope images. The results of SNR and variance estimation values are tested and compared with piecewise cubic Hermite interpolation, quadratic spline interpolation, autoregressive moving average and moving average. Overall, the proposed estimations for noise-free peak and SNR are most consistent and accurate to within a certain acceptable degree compared with the others.

Improvement to the scanning electron microscope image colorization by adaptive tuning.

An improvement to the previously proposed Canny optimization technique for scanning electron microscope image colorization is reported. The additional process is adaptive tuning, where colour tuning is performed adaptively, based on comparing the original luminance values with calculated luminance values. The complete adaptive Canny optimization technique gives significantly better mechanical contrast on scanning electron microscope grey-scale images than do existing methods.

Effect of gluten-free diet and co-morbidity of irritable bowel syndrome-type symptoms on health-related quality of life in adult coeliac patients.

BACKGROUND: Both coeliac disease and irritable bowel syndrome show impaired health-related quality of life, however, the impact of irritable bowel syndrome-type symptoms on health-related quality of life in coeliac disease is unclear. AIM: To evaluate the effect of gluten-free diet adherence and irritable bowel syndrome-type symptoms co-morbidity on health-related quality of life in adult coeliac disease patients. PATIENTS AND METHODS: A total of 1130 adults were enrolled in the study comprising 1001 controls from the general population and 129 diagnosed coeliac disease patients from the University Clinic in Cagliari. Irritable bowel syndrome-type symptoms and health-related quality of life were assessed using the Rome II and the SF-36 questionnaires, respectively. RESULTS: Irritable bowel syndrome-type symptoms prevalence in controls was 10.1% (102/1001) and 55% (71/129) in the coeliac disease patients. Irritable bowel syndrome-type symptom controls and coeliac disease patients both presented significantly lower health-related quality of life (p

Thyroid and celiac disease: clinical, serological, and echographic study.

OBJECTIVE: We sought to reevaluate the prevalence of thyroid dysfunction and thyroid autoimmunity in 47 patients with celiac disease; 91 healthy subjects were studied as controls. Both patients and controls were from Sardinia, Italy. METHODS: Diagnosis of celiac disease was made on the basis of clinical history, presence of positive antigliadin IgA (AGA-A) and IgG (AGA-G) antibodies, antireticulin antibodies (ARA), antiendomysium antibodies (EMA), and was confirmed by jejunal biopsy. HLA class II typing for DQB1 and DQA1 alleles was performed in 36/47 celiac patients. Thyroid was evaluated by palpation and echography; serum free thyroid hormones (FT4, FT3), thyrotropic hormone (TSH), and antithyroid peroxidase autoantibodies (anti-TPO) were assayed by radioimmunoassays. RESULTS: The prevalence of anti-TPO was higher in celiac patients (29.7%) than in healthy controls (9.6%) (p < 0.001) and thyroid echography frequently displayed (42.5%) a hypoechogenic pattern. Five anti-TPO-positive celiac patients were hypothyroid (two overt, three subclinical). A higher but not significantly different prevalence of anti-TPO (3/7 = 42.8%) was found in celiac patients displaying the DQB1*0502 genotype, when compared with the remaining patients (8/29 = 27.6%). CONCLUSIONS: An elevated prevalence of clinical and subclinical autoimmune thyroid autoimmunity was found in Sardinian celiac patients, especially in those displaying the DQB1*0502 genotype; this finding could be related to a particular genetic background of the Sardinian population.

Adult celiac disease is frequently associated with sacroiliitis.

No data are available on the presence and frequency of peripheral or central joint disease, routinely determined by bone scintigraphy with 740 MBq of [99mTc]MDP, in adult celiac disease. Bone scintigraphy was carried out to detect early acute inflammatory lesions in 22 adult celiac patients (15 females and seven males; mean age 36.72 years, range 17-63). Bone scintigraphy was positive for sacroiliitis in 14 cases (63.6%). Except in the case of one patient suffering from rheumatoid arthritis, laboratory data were normal. Our data suggest that as in other chronic intestinal diseases, celiac disease in adults, is frequently associated with central joint disease. This high incidence of sacroiliitis, the joint disease most frequently found in our patients, has not been previously reported in other series. We believe, therefore, this difference could be explained by the different methodology used for the screening of joint disease.