SU-E-I-90: Fast and Robust Algorithm Towards Vessel Lumen and Stent Strut Detection in Optical Coherence Tomography.

PURPOSE: Optical Coherence Tomography (OCT) is a catheter-based imaging method that employs near-infrared light to produce high-resolution cross-sectional intravascular images. We propose a new segmentation technique for automatic lumen area extraction and stent strut detection in intravascular OCT images for the purpose of quantitative analysis of neointimal hyperplasia (NIH). METHODS: Two clinical dataset of frequency-domainOCT scans of the human femoral artery were analyzed. First, a segmentation method based on Fuzzy C-Means (FCM) clustering and Wavelet Transform (WT) was applied towards inner luminal contour extraction. Subsequently, stent strut positions were detected by utilizing metrics derived from the local maxima of the wavelet transform into the FCM membership function. RESULTS: The inner lumen contour and the position of stent strut were extracted with very high accuracy. Compared with manual segmentation by an expert physician, the automatic segmentation had an average overlap value of 0.917 ± 0.065 for all OCT images included in the study. The strut detection procedure successfully identified 6.7 ± 0.5 struts for each OCT image. CONCLUSIONS: A new fast and robust automatic segmentation technique combining FCM and WT for lumen border extraction and strut detection in intravascular OCT images was designed and implemented. The proposed algorithm may be employed for automated quantitative morphological analysis of in-stent neointimal hyperplasia.

Deep brain stimulation for secondary dystonia: results in 8 patients.

BACKGROUND: Dystonia is a medically intractable condition characterized by involuntary twisting movements and/or abnormal postures. Deep Brain Stimulation (DBS) has been used successfully in various forms of dystonia. In the present study, we report on eight patients with secondary dystonia, treated with DBS in our clinic. METHOD: Eight patients (five males, three females) underwent DBS for secondary dystonia. The etiology of dystonia was cerebral palsy (n = 2), drug-induced (n = 1), post encephalitis (n = 2) and postanoxic dystonia (n = 3). The functional capacity was evaluated before and after surgery with the use of Burke-Fahn-Mardsen Dystonia Rating Scale (BFM scale), both movement and disability scale (MS and DS, respectively). The target for DBS was the globus pallidus internus (GPi) in 7 patients and in one patient, with postanoxic damaged pallidum, the ventralis oralis anterior (Voa) nucleus. Brain perfusion scintigraphy using Single Photon Emission Computed Tomography (SPECT) was performed in two separate studies for each patient, one in the "off-DBS" and the other in the "on-DBS" state. FINDINGS: Postoperative both MS and DS scores were found to be significantly lower compared to preoperative scores (p = 0.018 and p = 0.039, respectively). Mean improvement rate after DBS was 41.4% (0-94.3) and 29.5% (0-84.2) in MS and DS scores, respectively. The SPECT Scan, during the "on-DBS" state, showed a decrease in regional cerebral blood flow (rCBF), compared to the "off-DBS" state. CONCLUSIONS: Our results seem promising in the field of secondary dystonia treatment. More studies with greater number of patients and longer follow-up periods are necessary in order to establish the role of DBS in the management of secondary dystonia. Finally, the significance of brain SPECT imaging in the investigation of dystonia and functional effects of DBS should be further evaluated.

Errors in death certificates in a rural area of Greece.

INTRODUCTION: A death certificate is the formal document in which a physician records the time, cause and circumstances under which the death of an individual has occurred. Morbidity and mortality statistics are mainly based on the analysis of these certificates, and inaccuracies in the detail may lead to biased estimation in several epidemiological parameters. The aim of this study was to examine the quality of cause of death in death certificates in a rural area of Greece, and to identify factors that may be associated with inaccuracies in the completion of these death certificates. METHODS: All death certificates archived in the municipality of Tritaia during the period 1999-2006 were examined. Statistical analysis was performed by comparing the proportions of the unpaired case. The state of independence among the various variables was investigated by considering the class of discrete graphical models. RESULTS: In total, 516 death certificates were examined; 5.6% (29/516) were excluded because of insufficient demographic data. The remaining 487 death certificates were analyzed with the following findings: 51.5% were for males and 48.5% females (median age 82 years, range 5-103 years; and 83 years, range 0-104, respectively); and 39.4% (192/487) were correctly completed. In 168 the mechanism of death was given; in 72 multiple causal sequences were given; in 22 a single/not precise cause was given; and in 33 a single causal sequence with incorrect order was given. In all, 20.1% were completed by a physician of the regional health centre. Gender was not associated with the presence of error (p = 0.352). Errors were present in 63.8% (270/423) of the death certificates in deceased individuals > or =60 years and in 39.1% (25/64) of the death certificates in individuals < or =59 years (p<0.001). In 19.7% of the erroneously completed death certificates, the certifier was a physician working in primary health care. The presence of errors in death certificates decreased from 74.6% in 1999 to 51.8% in 2006 (p = 0.004). CONCLUSIONS: Giving the mechanism instead of the cause of death was the most frequent type of error. A statistically significant increase in the presence of errors was observed as the age of the descendent increased. During these 8 years, there has been a statistically significant decrease in errors. However, efforts should be made by trainers and physicians in order to improve the accuracy of the information in death certificates. If this is accomplished, cause-of-death statistics will be more accurate and so enable better health planning.

Doxazosin for the management of distal-ureteral stones.

PURPOSE: To evaluate the efficacy of doxazosin in inducing spontaneous passage of stones in the distal ureter and to compare its efficacy according to the size of the stone. PATIENTS AND METHODS: Seventy-three patients with a mean age of 46.38 +/- 10.17 years who presented with a distal-ureteral stone were divided into four groups according to stone size and drug treatment: <5 mm without doxazosin (group A; n=15); 5-10 mm (group B; n=16); <5 mm with doxazosin 4 mg/day for 4 weeks (group C; n=20); and 5-10 mm with doxazosin 4 mg/day for 4 weeks (group D; n=22). Groups A and B served as controls for groups C and D, respectively. RESULTS: Spontaneous stone passage was documented in 9 patients (60%) in group A v 17 (85%) in group C (P=0.047) and 7 (43.75%) in group B v 16 (72.73%) in group D (P=0.036). The average expulsion time was 8.78 +/- 1.09 days in group A v 7.59 +/- 0.80 days in group C (P=0.004) and 12.14 +/- 1.35 days in group B v 7.06 +/- 1.29 days in group D (P<0.0001). The number of pain episodes in group D patients was significantly lower than in group B (P +/- 0.0078). CONCLUSIONS: Doxazosin treatment proved to be safe and effective for distal-ureteral stones, as determined by earlier expulsion, decreased colic frequency, and absence of side effects. The efficacy of doxazosin was significantly higher for 5-to 10-mm stones than for smaller ones.