Selami Serhatlioglu

Color doppler sonographic evaluation of inter-relations between diameter, reflux and flow volume of testicular veins in varicocele

OBJECTIVE Reflux is an important criterion for the diagnosis of varicoceles and in the existence of reflux more than 1 s is the lower limit for the diagnosis of varicoceles. We proposed to assess the relationship of vein diameters with the incidence, duration and flow volume of reflux using color Doppler sonography (CDS) in patients with clinically diagnosed varicocele. MATERIALS AND METHODS Forty-seven patients with varicocele (aged 16-43) were included into the study. Reflux was assessed in spectral analysis using CDS and the duration, velocity and flow volume were measured. RESULTS Mean duration of reflux on right side was 1.5 +/- 0.3 s in 14 patients, throughout the Valsalvas maneuver in eight patients and no reflux in 25 patients. Mean duration of reflux on the left side was 1.5 +/- 0.3 s in 25 patients, throughout the Valsalvas maneuver in 18 patients and no reflux in four patients. The incidence of reflux in the testicular veins with a diameter lower than 3 mm was 62.3% whereas 94.4% in veins more than 3 mm in diameter. Flow volume of reflux was less than 10 ml/min in four patients and 21.7 +/- 24.3 ml/min in 18 patients on right side. Four patients had flow volume of reflux less than 10 ml/min and 39 patients had 27.9 +/- 35.6 ml/min on the left side. Flow volume meaningfully rose with increasing in vein diameter (r=0.83 on right; r=0.65 on left, P<0.01). CONCLUSION Measurement of flow volume of reflux has been considered as a more valuable method with respect to presence of reflux and/or measurement of venous diameter since flow volume reflects a combination of the vein diameters, duration and velocity of reflux.

Classification of Transcranial Doppler Signals Using Artificial Neural Network

Transcranial Doppler signals, recorded from the temporal region of brain on 110 patients were transferred to a personal computer by using a 16-bit sound card. The fast Fourier transform (FFT) method was applied to the recorded signal from each patient. Since FFT method inherently can not offer a good spectral resolution at jet blood flows, it sometimes causes wrong interpretation of transcranial Doppler signals. To do a correct and rapid diagnosis, transcranial Doppler blood flow signals were statistically arranged so that they were classified in artificial neural network. Back propagation neural network and self-organization map algorithms of artificial neural network were used for training, whereas momentum and delta–bar-delta algorithms were used for learning. The results of these algorithms were compared in the case of classification and learning.

Classification of carotid artery stenosis of patients with diabetes by neural network and logistic regression.

The blood flow hemodynamics of carotid arteries were obtained from carotid arteries of 168 individuals with diabetes using the 7.5 MHz ultrasound Doppler M-unit. Fast Fourier Transform (FFT) methods were used for feature extraction from the Doppler signals on the time-frequency domain. The parameters, obtained from the Doppler sonograms, were applied to the mathematical models that were constituted to analyze the effect of diabetes on internal carotid artery (ICA) stenosis. In this study, two different mathematical models such as the traditional statistical method based on logistic regression and a Multi-Layer Perceptron (MLP) neural network were used to classify the Doppler parameters. The correct classification of these data was performed by an expert radiologist using angiograpy before they were executed by logistic regression and MLP neural networks. We classified the carotid artery stenosis into two categories such as non-stenosis and stenosis and we achieved similar results (correctly classified (CC) = 92.8%) in both mathematical models. But, as the degree of stenosis had been increased to 4 (0-39%, 40-59%, 60-79% and 80-99% diameter stenosis), it was found that the neural network (CC = 73.9%) became more efficient than the logistic regression analysis (CC = 67.7%). These outcomes indicate that the Doppler sonograms taken from the carotid arteries may be classified successfully by neural network.

Evaluation of the Effects of Sildenafil Citrate (Viagra) on Canine Renal Artery, Carotid and Aortic Blood Flow with the Aid of Color Doppler Sonography

Introduction: Erectile dysfunction is the inability to achieve or maintain an erection sufficient for satisfactory sexual performance. Oral use of sildenafil citrate has been proved to be effective in the treatment of erectile dysfunction. Although the effects of sildenafil citrate have been investigated in several studies, its effect on aortic, carotid and renal artery blood flow is unknown. The aim of this study was to investigate the early and late phase effects of sildenafil citrate on canine aortic, carotid and renal artery blood flow using color Doppler sonography (CDS). Materials and Methods: A total of 6 healthy adult dogs was used in this study. With the aid of CDS peak systolic flow rate, end diastolic flow rate, resistivity index (RI) and pulsatility index in aortic, renal and carotid artery were determined before the administration of sildenafil citrate, 45–75 min after drug administration and after 15 days of drug administration. Data were statistically analyzed using Friedman and Wilcoxon rank tests. p < 0.05 was considered to be statistically significant. Results and Conclusions: Significant changes were determined in only 4 out of 28 parameters studied. The significantly changed parameters were as follows: a significant increase in the early and late phase of the postdrug peak of systolic aortic blood flow compared to values before drug administration, an increase in pre- and postdrug RI values of the aorta, a significant decrease in maximum velocity of the right carotid artery, and peak systolic maximum velocity of the left renal segmental artery after drug administration compared to their respective predrug basal values. The results from this study indicate that sildenafil citrate has no significant effects on aortic, renal and carotid artery blood flow rate either in the early or in the late phase. Since this study involved only 6 dogs there is a need for further clinical studies involving larger groups of subjects to conclude that this drug is safe with respect to the hemodynamic parameters evaluated in this study.

The Examination of the Effects of Obesity on a Number of Arteries and Body Mass Index by Using Expert Systems

In this study, the areas affected from obesity were examined by classifying divergent arteries and body mass index (BMI) of 30 healthy persons and 52 obese persons by using expert systems, and the classifying performances of NEFCLASS and CANFIS, which are expert systems were compared. As a result of this comparison, it is observed that the classifying performance of NEFCLASS is better than that of CANFIS, and the causes of this are examined. Furthermore, it is observed that after these classifications, obesity affects the BMI rather than divergent arteries.

Neurofuzzy Classification of the Effect of Diabetes Mellitus on Carotid Artery

Here, we present a new clasification system for the effects of diabetes mellitus (DM) on carotid artery by using neurofuzzy system. Blood flow hemodynamics were obtained from 118 carotid arteries of 59 patients with DM by using 7.5 MHz transducer and Doppler-M unit. Vmax = peak systole, Vmin = end diastole, resistive index (RI), and pulsatile index (PI) were measured with the use of Doppler sonography. These values were applied to neurofuzzy system using NEFCLASS model. With the increase of epoch from 200 to 500 and pruning of fuzzy rules, our classification system was found to be successful in 85% of the cases. In 100 of 118 patients the classificitaion system was found to be correct. Our findings suggest that with the application of Doppler signal parameters from carotid arteries to neurofuzzy system may produce a new and reliable classification system for diagnosing diameter stenosis.

Preoperative sonographic diagnosis of sliding appendiceal inguinal hernia

Rarely, the appendix forms the sliding component of an inguinal hernia. We report the case of a 2‐month‐old boy who was preoperatively diagnosed with sliding appendiceal inguinal hernia by sonographic examination. To our knowledge, this is the first report in the literature of the preoperative sonographic diagnosis of a sliding appendiceal inguinal hernia.

A Neurofuzzy Classification System for the Effects of Diabetes Mellitus on Ophthalmic Artery

Here, we present a classification system for the effects of diabetes mellitus (DM) on blood flow hemodynamics of the ophthalmic arteries by using neurofuzzy system. Blood flow hemodynamics were obtained from 80 ophthalmic arteries of 20 healthy persons and 20 patients with DM by using 7.5 MHz transducer and Doppler-M unit. Peak systole, peak diastole, resistive index (RI), pulsatile index (PI), and systole/diastole rate (SDR) were measured with the use of Doppler sonography. These values were applied to neurofuzzy system using NEFCLASS model. The performance of this classification system was examined with the application of the data obtained from Doppler analyses of the right and left ophthalmic arteries to the neurofuzzy system. After learning and testing processes, 85% success rates were reached from the data of right ophthalmic arteries, and 87.5% success rates were reached from the data of left ophthalmic arteries. Our findings suggest that neurofuzzy system may provide a successful classification system for the effects of DM on either right or left ophthalmic arteries with the application of Doppler signal parameters from carotid arteries to neurofuzzy system may produce a new and reliable classification system for diagnosing diameter stenosis.

Determination of Coronary Failure with the Application of FFT and AR Methods

In this study, Doppler signals recorded from the output of carotid artery of 30 patients were transferred to a personal computer (PC) by using a 16-bit sound card. Doppler difference frequencies were recorded from each of the patients, and then analyzed using fast Fourier transform (FFT) and least squares autoregressive (AR) methods to obtain their sonograms. These sonograms are then used to compare with the applied methods in terms of medical evaluation.

Hearing in workers exposed to low-dose radiation for a long period

The aim of the present study was to evaluate changes in hearing thresholds with standard and high frequency audiometry in workers exposed to low-dose ionizing radiation for a long period. A total of 57 (49 male and 8 female) technical staff working in radiology-related jobs who were exposed to occupational radiation were included in the study. The control group consisted of 32 (27 male and 5 female) volunteer subjects with normal hearing. The symptoms like tinnitus, vertigo, weakness and lack of appetite were evaluated. A standard ascending/descending method was applied to the subjects of the study and the control groups in order to determine their hearing thresholds at eleven different frequencies between 250 and 16,000 Hz. In the study group, the working duration of subjects ranged from 4 to 23 years, and the percentage of tinnitus, weakness, vertigo and lack of appetite were 47%, 28%, 24% and 17%, respectively. It was observed that pure tone hearing thresholds were markedly increased for 4,000, 6,000, 8,000, 14,000 and 16,000 Hz frequencies in the study group compared to the control group (p<0.01). Levels of static compliance and middle ear pressures of the study group were similar to the control group. Tinnitus, vertigo and hearing loss in high frequencies were observed in the subjects exposed to the radiation for a long period. Subjects under high risk should be evaluated periodically. We suggest that the use of standard and high frequency audiometry together could be beneficial in the evaluation of these subjects.