Ming-Chi Wu

Preliminary experience of percutaneous intralesional bleomycin injection for the treatment of orbital lymphatic–venous malformation refractory to surgery

Preliminary experience of percutaneous intralesional bleomycin injection for the treatment of orbital lymphaticevenous malformation refractory to surgery C.-Y. Shen , M.-C. Wu , Y.-S. Tyan , C.-H. Ou , T.-Y. Chen , H.-F. Wong d,e,* Department of Medical Imaging, Chung Shan Medical University Hospital and School of Medicine, School of Medical Imaging and Radiological Sciences, Chung Shan Medical University, Taichung, Taiwan Department of Radiology, E-Da Hospital, I-Shou University, Kaohsiung, Taiwan Department of Radiology, Chang Bing Show Chwan Memorial Hospital, Changhua, Taiwan Department of Neuroradiology, Chang Gung Memorial Hospital, Linkou, Taiwan Chang Gung University, College of Medicine, Taoyuan, Taiwan

Ischemic stroke detection system with a computer-aided diagnostic ability using an unsupervised feature perception enhancement method

We propose an ischemic stroke detection system with a computer-aided diagnostic ability using a four-step unsupervised feature perception enhancement method. In the first step, known as preprocessing, we use a cubic curve contrast enhancement method to enhance image contrast. In the second step, we use a series of methods to extract the brain tissue image area identified during preprocessing. To detect abnormal regions in the brain images, we propose using an unsupervised region growing algorithm to segment the brain tissue area. The brain is centered on a horizontal line and the white matter of the brains inner ring is split into eight regions. In the third step, we use a coinciding regional location method to find the hybrid area of locations where a stroke may have occurred in each cerebral hemisphere. Finally, we make corrections and mark the stroke area with red color. In the experiment, we tested the system on 90 computed tomography (CT) images from 26 patients, and, with the assistance of two radiologists, we proved that our proposed system has computer-aided diagnostic capabilities. Our results show an increased stroke diagnosis sensitivity of 83% in comparison to 31% when radiologists use conventional diagnostic images.

Diagnostic Performance of Combined Contrast-Enhanced Magnetic Resonance Angiography and Phase-Contrast Magnetic Resonance Imaging in Suspected Subclavian Steal Syndrome

Purpose The study sought to evaluate the efficacy of magnetic resonance imaging (MRI) in patients with suspected subclavian steal syndrome (SSS) using both contrast-enhanced (CE) MR angiography and phase-contrast (PC) MRI. Methods Fifteen suspected SSSs from 13 patients were evaluated using CE-MR angiography and PC-MRI. Ten patients also received dynamic CE-MR angiography. Results All MRI examinations were technically successful. By combining CE-MR angiography with PC-MRI, 10 SSSs were diagnosed in 9 patients. The delay enhancement dynamic technique predicted SSS with a sensitivity, specificity, and accuracy of 57.1%, 100%, and 72.7%, respectively. Without the dynamic technique, affected delay-enhanced arteries were poorly visualized and could be mistaken for occluded vessels. Retrograde vertebral flow by PC-MRI was used to predict ipsilateral SSS with a sensitivity, specificity, and accuracy of 100%, 60%, and 86.7%, respectively. There were 2 false positives including 1 patient with a proximal total occlusion of the affected vertebral artery and another with brachiocephalic steal syndrome rather than SSS. This suggested that retrograde vertebral flow does not always indicate SSS. Conclusions CE-MR angiography combined with PC-MRI is efficacious when evaluating SSS in clinical practice.

DEGENERATIVE DISC SEGMENTATION AND DIAGNOSIS TECHNOLOGY USING IMPORTANT FEATURES FROM MRI OF SPINE IN IMAGES

In this paper, we focus on the medical imaging segmentation techniques which are used in the study of spine diseases. In the medical reports, it is shown that common people worry more about the spine diseases caused by the disc degeneration. Because of the complex composition of the spine, which includes the spine bones, cartilage, fat, water and soft tissue, it is hard to correctly and easily find out the position of each cartilage in the spine images. This above problem always causes over-segmentation or unability to extract the cartilages. Thus, we propose an accurate and automated method to detect the abnormal disc. We combine two standard models with the threshold value to accurately identify the cartilage. Among the processing, we also solve the noising problems of spine image through morphological methods, removing the noncartilage areas using our proposed method, and find out the average height of the cartilages. Therefore, we can easily determine whether the disc is degenerated or not. In the experimental result, the segmentation accuracy of the extracted region by the proposed approach is evaluated by two criterions. The first criterion is statistical evaluation indices of image segmentation. It is evaluated by professional physicians manual segmentation, and the results show that our proposed method is easily implemented and has high accuracy, with the highest rate reaching 99.88%. The second criterion is a comparison evaluation index evaluated by our proposed system and other existence system. From this result, we know that our proposed system is better than other existence system.

Surveyed data for structural shielding calculations of radiographic x-ray installations in Taiwan.

AbstractThe use of surveyed data on the x-ray tube workloads and clinical exposure parameters was suggested in NCRP Report No. 147 for the structural shielding design of medical x-ray installations. To guide the shielding design of radiographic x-ray rooms in Taiwan, a large-scale survey was conducted to collect information required for the computations of the transmissions from broad x-ray beams through shielding materials. Surveyed data were collected during one week from 10,750 projections of 6,657 examinations in 13 radiographic rooms from nine hospitals. This survey was the first time that this type of clinical data has been collected in Taiwan on a large scale. The surveyed total workload was divided into separate contributions from x-ray projections directed at the floor, the wall bucky, and all barriers (used for secondary barriers). Based on the surveyed workload distributions, the unshielded air kerma per patient at 1 m from the source was calculated by the PCXMC program using surveyed x-ray tube parameters on the generator waveform, anode material, target angle, and filtration. Subsequently, the transmissions of x-rays through different barrier materials were computed by considering the average workloads and the average workloads plus one standard deviations. The latter computations were for a sensitivity study to find the influence of workload variations in different hospitals on the shielding requirements. All surveyed data and calculated results were compared with corresponding values given in NCRP 147 to analyze the radiographic imaging differences between Taiwan and U.S.

Multiple symmetric lipomatosis in two chinese patients, one typical and one unusual.

Multiple symmetric lipomatosis (MSL; Madelung disease) is an uncommon disorder with diffuse multiple symmetrical unencapsulated accumulations of fat located in the neck and the upper trunk. MSL usually occurs in middle aged Caucasian men of Mediterranean ancestry with a history of alcoholism. In the past decade, an increasing number of cases in the Chinese population have been reported which appear to be limited to the head and neck regions. We describe two Chinese patients with MSL who have a history of alcoholism. The MR and CT findings disclosed that one patient had the typical accumulation of unencapsulated fat in the neck and upper back, while the other patient had more than the typical neck involvement and an unusual distribution of fat in the scrotum.

Impact of Sjogren's syndrome on Parkinson’s disease: A nationwide case-control study

Objective To investigate whether Sjogren’s syndrome would have an influence on the development of Parkinson’s disease. Methods A population-based case-control study was conducted. Participants consisted of 7716 subjects with newly diagnosed Parkinson’s disease and a population of 75129 matched control subjects between 2000 and 2010. We measured the risk of Parkinson’s disease in association with Sjogren’s syndrome by using adjusted odds ratios. Results A total of 143 Parkinson’s disease subjects (1.9%) and 893 control subjects (1.2%) suffered from Sjogren’s syndrome (p < 0.001). The crude odds ratio for Parkinson’s disease among subjects with Sjogren’s syndrome was 1.56 (95% CI 1.30–1.86; p < 0.01). After adjustment for potential confounders which have been proposed that would increase the risk of development of Parkinson’s disease, Sjogren’s syndrome was found to be significantly associated with the risk of Parkinson’s disease with an odds ratio of 1.37 (95% CI 1.15–1.65; p < 0.01). Conclusion This study preliminarily proposed that Sjogren’s syndrome was significant associated with an increased risk of Parkinson’s disease.

The benign and Malignant Recognition System of Nasopharynx in MRI image with Neural-Fuzzy based Adaboost classifier

The current state of diagnosis of nasopharyngeal approach to image interpretation is artificial, but this way will be sentenced to cross-cultural experience for each practice discrimination and may lead to refractory time delay. We used the image taken from radiologists and applied the Unsharp Mask to enhance the image edge. In order to reduce the computation time and increase the efficiency, the doctor may specify an ellipse region of interest (ROIs) of nasopharynx in the image. After that, we use histogram equalization to denoise and use Otsu methods to obtain the threshold value to binaries it in this region. After performing the above two methods, we can successfully segment the tumor region of the nasopharynx. Then, we use texture and geometric feature extraction method to extract the tumor region feature, and trained the data by Neural-Fuzzy based AdaBoost classifier to recognize benign or malignant tumors of the nasopharynx. This paper hope that it can improve nasopharyngeal malignant cancer identification accuracy, and assist doctors make more accurate diagnosis through using tumor texture, hypertrophy and symmetrical distribution features in Neural-Fuzzy based Adaboost classifier.

Image quality improvement in three-dimensional time-of-flight magnetic resonance angiography using the subtraction method for brain and temporal bone diseases.

Background: Time‐of‐flight (TOF) magnetic resonance (MR) angiography is based on flow‐related enhancement using the T1‐weighted spoiled gradient echo, or the fast low‐angle shot gradient echo sequence. However, materials with short T1 relaxation times may show hyperintensity signals and contaminate the TOF images. The objective of our study was to determine whether subtraction three‐dimensional (3D) TOF MR angiography improves image quality in brain and temporal bone diseases with unwanted contaminations with short T1 relaxation times. Methods: During the 12‐month study period, patients who had masses with short T1 relaxation times noted on precontrast T1‐weighted brain MR images and 24 healthy volunteers were scanned using conventional and subtraction 3D TOF MR angiography. The qualitative evaluation of each MR angiogram was based on signal‐to‐noise ratio (SNR), contrast‐to‐noise ratio (CNR) and scores in three categories, namely, (1) presence of misregistration artifacts, (2) ability to display arterial anatomy selectively (without contamination by materials with short T1 relaxation times), and (3) arterial flow‐related enhancement. Results: We included 12 patients with intracranial hematomas, brain tumors, or middle‐ear cholesterol granulomas. Subtraction 3D TOF MR angiography yielded higher CNRs between the area of the basilar artery (BA) and normal‐appearing parenchyma of the brain and lower SNRs in the area of the BA compared with the conventional technique (147.7 ± 77.6 vs. 130.6 ± 54.2, p < 0.003 and 162.5 ± 79.9 vs. 194.3 ± 62.3, p < 0.001, respectively) in all 36 cases. The 3D subtraction angiography did not deteriorate image quality with misregistration artifacts and showed a better selective display of arteries (p < 0.0001) and arterial flow‐related enhancement (p < 0.044) than the conventional method. Conclusion: Subtraction 3D TOF MR angiography is more appropriate than the conventional method in improving the image quality in brain and temporal bone diseases with unwanted contaminations with short T1 relaxation times.