Oguz Dicle

Magnetic resonance imaging evaluation of incision healing after cesarean sections

Abstract. The purpose of this study was to examine the healing period of incision scar in myometrial wall and the normal pelvis after cesarean sections by means of MRI. In this study 17 voluntary women were examined after their first delivery with cesarean section in the early postpartum period (first 5 days), and following this, three more times in 3-month intervals. The MRI examinations were performed on a 1.0-T system (Magnetom, Siemens, Erlangen, Germany), and sagittal T1-weighted (550/17 TR/TE) and T2-weighted (2000/80 TR/TE) spin-echo (SE) images of the pelvis were obtained. During follow-up examinations incision scar tissues lost their signals within the first 3 months on both SE sequences, and little alteration was observed in the subsequent tests. Zonal anatomy of the uterus reappeared completely 6 months after cesarean sections. The time for the involution of the uterus was independent of the zonal anatomy recovery, and the maximum involution was inspected within the first 3 months. In conclusion, the maturation time of myometrial scar tissue in uncomplicated cesarean sections, which can be evaluated by the signal alterations in MRI, is approximately 3 months, whereas the complete involution and the recovery of the zonal anatomy need at least 6 months.

Patient oriented and robust automatic liver segmentation for pre-evaluation of liver transplantation

Identifying liver region from abdominal computed tomography-angiography (CTA) data sets is one of the essential steps in evaluation of transplantation donors prior to the hepatic surgery. However, due to gray level similarity of adjacent organs, injection of contrast media and partial volume effects; robust segmentation of the liver is a very difficult task. Moreover, high variations in liver margins, different image characteristics with different CT scanners and atypical liver shapes make the segmentation process even harder. In this paper, we propose a three stage (i.e. pre-processing, classification, post-processing); automatic liver segmentation algorithm that adapts its parameters according to each patient by learning the data set characteristics in parallel to segmentation process to address all the challenging aspects mentioned above. The efficiency in terms of the time requirement and the overall segmentation performance is achieved by introducing a novel modular classification system consisting of a K-Means based simple classification system and an MLP based complex one which are combined with a data-dependent and automated switching mechanism that decides to apply one of them. Proposed approach also makes the design of the overall classification system fully unsupervised that depends on the given CTA series only without requiring any given training set of CTA series. The segmentation results are evaluated by using area error rate and volume calculations and the success rate is calculated as 94.91% over a data set of diverse CTA series of 20 patients according to the evaluation of the expert radiologist. The results show that, the proposed algorithm gives better results especially for atypical liver shapes and low contrast studies where several algorithms fail.

Breast mass contour segmentation algorithm in digital mammograms

Many computer aided diagnosis (CAD) systems help radiologist on difficult task of mass detection in a breast mammogram and, besides, they also provide interpretation about detected mass. One of the most crucial information of a mass is its shape and contour, since it provides valuable information about spread ability of a mass. However, accuracy of shape recognition of a mass highly related with the precision of detected mass contours. In this work, we introduce a new segmentation algorithm, breast mass contour segmentation, based on classical seed region growing algorithm to enhance contour of a mass from a given region of interest with ability to adjust threshold value adaptively. The new approach is evaluated over a dataset with 260 masses whose contours are manually annotated by expert radiologists. The performance of the method is evaluated with respect to a set of different evaluation metrics, such as specificity, sensitivity, balanced accuracy, Yassnoff and Hausdorrf error distances. The results obtained from experimentations shows that our method outperforms the other compared methods. All the findings and details of approach are presented in detail.

Lipoma of the pancreas: MRI findings

Lipomas of the pancreas are very rare. Focal fatty infiltration of the pancreas is an entity that should be differentiated from a pancreatic lipoma. In this report the MRI findings of an incidentally found pancreatic lipoma are presented and the role of MRI in the differentiation of pancreatic lipoma and focal fatty infiltration of the pancreas is discussed.

A NEW METHOD FOR THE EVALUATION OF ERECTILE DYSFUNCTION: SILDENAFIL PLUS DOPPLER ULTRASONOGRAPHY

PURPOSE Of the various methods of hemodynamic studies performed to evaluate erectile dysfunction penile color Doppler ultrasound is currently considered the best. However, intracavernous injection is invasive and has adverse effects, such as prolonged erection. We evaluated whether sildenafil may be used as a substitute for intracavernous agents when assessing impotence on color Doppler ultrasound. MATERIALS AND METHODS A total of 42 patients with erectile dysfunction underwent color Doppler ultrasound before and after intracavernous injection of 60 mg. papaverine with genital and audiovisual sexual stimulation. Peak flow and end diastolic velocity were measured in the recorded waveforms obtained 0, 1, 5, 10 and 20 minutes after injection. The patients also underwent color Doppler ultrasound after a 50 mg. oral dose of sildenafil with genital and audiovisual sexual stimulation not before 3 days after the papaverine study. The same parameters were measured at 30, 45, 60, 75 and 90 minutes, and compared with the values obtained after papaverine injection. RESULTS Mean peak flow velocity significantly increased after oral sildenafil starting at 30 minutes and achieving a maximum value at 60 minutes. There were no significant differences in the 2 methods in mean peak velocity 1, 5, 10 and 20 minutes after papaverine injection, and 30, 45, 60, 75 and 90 minutes after oral sildenafil administration. Penile color Doppler ultrasound with intracavernous papaverine injection is accepted as the gold standard but color Doppler ultrasound with sildenafil has 90% sensitivity and 100% selectivity for demonstrating arterial insufficiency. Due to prolonged erection 5 patients (11.9%) in the papaverine group required pharmacological detumescence by intracavernous injection. No adverse effects of sildenafil were observed. CONCLUSIONS Sildenafil administration achieved increased peak flow velocity comparable to that after intracavernous papaverine injection. With no prolonged erection sildenafil emerges as a safer alternative compared to more invasive intracavernous injection.

Percutaneous Treatment of Hydatid Liver Cysts in Children as a Primary Treatment: Long-term Results

PURPOSE To evaluate the effectiveness and long-term results of percutaneous treatment for hydatid liver cysts in pediatric patients. MATERIALS AND METHODS Thirty-four pediatric patients (15 male, 19 female; ages 4-17 years; mean age, 9.4 years) with 51 hydatid liver cysts underwent ultrasound (US)-guided percutaneous treatment with albendazole prophylaxis. There were 15 type II lesions with membrane detachment and 36 type I lesions resembling simple hepatic cysts with pure anechogenic content or small echogenic reflections and a regular well-delineated wall. The method of US-guided puncture, aspiration, injection of hypertonic saline solution, and reaspiration was preferred for 21 lesions. For the remaining 30 larger cysts, the intervention was performed with the same percutaneous technique but followed by catheterization, drainage, control cystography, and sclerotherapy with ethanol. During follow-up, US examinations were performed at 1, 3, 6, and 12 months for the first year and yearly thereafter. RESULTS Percutaneous treatment of hepatic hydatid disease was successful in 33 patients (97.1%). During follow-up, US findings in the lesions changed significantly; at year 1, the inner content of the lesions became heterogeneous with a semisolid appearance, and the mean reduction in volume was 81.4%. At 2-year follow-up, most hydatid cysts had become solid in nature and the reduction in volume reached 65%-99% (mean, 85.1%). There were no recurrences or additional lesions after the follow-up of 1-6 years (mean, 3.1 years). Average hospital stay for the whole group in this study was 3.5 days. CONCLUSIONS The long-term results of percutaneous liver hydatid cyst treatment in children are in accordance with the results in adults. Percutaneous treatment of uncomplicated type I and type II liver hydatid cysts in pediatric patients is an efficient and safe treatment with short hospitalization.

The Hajdu-Cheney syndrome: A case report and review of the literature

Hajdu-Cheney syndrome which is also known as type VI idiopathic osteolysis is a rare disease transmitted autosomal dominantly. In this syndrome, oestolysis involves primarily the terminal phalanges. We describe here a 18-year-old boy with typical clinical and radiological signs of Hajdu-Cheney syndrome.

Fully automated liver segmentation from SPIR image series

Accurate liver segmentation is an important component of surgery planning for liver transplantation, which enables patients with liver disease a chance to survive. Spectral pre-saturation inversion recovery (SPIR) image sequences are useful for liver vessel segmentation because vascular structures in the liver are clearly visible in these sequences. Although level-set based segmentation techniques are frequently used in liver segmentation due to their flexibility to adapt to different problems by incorporating prior knowledge, the need to initialize the contours on each slice is a common drawback of such techniques. In this paper, we present a fully automated variational level set approach for liver segmentation from SPIR image sequences. Our approach is designed to be efficient while achieving high accuracy. The efficiency is achieved by (1) automatically defining an initial contour for each slice, and (2) automatically computing weight values of each term in the applied energy functional at each iteration during evolution. Automated detection and exclusion of spurious structures (e.g. cysts and other bright white regions on the skin) in the pre-processing stage increases the accuracy and robustness. We also present a novel approach to reduce computational cost by employing binary regularization of level set function. A signed pressure force function controls the evolution of the active contour. The method was applied to ten data sets. In each image, the performance of the algorithm was measured using the receiver operating characteristics method in terms of accuracy, sensitivity and specificity. The accuracy of the proposed method was 96%. Quantitative analyses of results indicate that the proposed method can accurately, efficiently and consistently segment liver images.

Faculty Development Program in Dokuz Eyl?l School of Medicine: In the process of curriculum change from traditional to PBL

Abstract Introduction: In Dokuz Eylül School of Medicine (DESM) a faculty development program is being carried out by the “Trainers’ Training Committee?. DESM made a fundamental change in its curriculum from traditional to Problem-based Learning (PBL) in 1997. This was the first implementation of a PBL curriculum in Turkey. Faculty development activities were initiated in the same year. This paper describes the faculty development activities with a special emphasis on PBL courses. Program description: Between 1997-2000 27 four-day long PBL courses were held for 343 participants. The curriculum consisted of PBL philosophy, PBL steps, role of the tutor and students in PBL process, effective case design, assessment principles and group dynamics. PBL simulations enabled the participants to play the roles of both tutors and students. Process evaluation: At the end of the program most of the participants stated that length of the program, content, training methods and the course organization was appropriate. The majority of the participants (89.5%) found the program very useful. PBL steps, PBL practices and PBL philosophy were found as the most useful sessions. Discussion: These courses gave medical staff the opportunity to develop their understanding of PBL methodology and theory. PBL courses and continuous educational activities such as weekly tutor meetings are being held and new courses on advanced tutoring skills are being planned for the near future in DESM.

THE PREDICTION OF PAPAVERINE INDUCED PRIAPISM BY COLOR DOPPLER SONOGRAPHY

PURPOSE We identified color Doppler sonography findings that are useful for predicting priapism in patients after the intracavernous injection of diagnostic papaverine. MATERIALS AND METHODS We evaluated 72 men with erectile dysfunction by color Doppler sonography after the diagnostic injection of papaverine. Cavernous artery waveforms were recorded, and peak systolic and diastolic velocity of the recorded waveforms was measured. In cases of priapism color Doppler sonography findings were retrospectively evaluated to identify any finding that would predict priapism. RESULTS Priapism was observed in 8 of the 72 patients (11.1%). In 6 of 8 priapism cases there was no blood flow in the cavernous artery during or after adequate erection, including after minutes 5, 10 and 20 in 3, 1 and 2, respectively. This absence of encoding was not relieved even after all stimuli were removed. In 2 patients who later presented with complaints of priapism the Doppler study was completed normally and all parameters were acquired without any cessation of blood flow in the cavernous artery. The persistent disappearance of color and pulse encoding in the cavernous artery predicted priapism with 75% sensitivity, 100% specificity, a positive and negative predictive value of 100% and 96.9%, respectively, and 97% accuracy. CONCLUSIONS The persistence of absent blood flow in the cavernous artery even after the elimination of all stimuli during penile color Doppler ultrasound is a reliable predictor of priapism. The finding is accurate enough to initiate treatment for priapism to avoid further delay.