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41.
Chih-Hsien Chang Kuo-Hsien Fan Te-Jung Chen Wei-Chun Hsu Mei-Ling Jan Tung-Hu Tsai Pan-Fu Kao Chieh-Fu Chen Ying-Kai Fu Te-Wei Lee 《台湾医志》2004,103(11):876-881
BACKGROUND AND PURPOSE: Fluorine-18-2-deoxy-D-glucose (18F-FDG) has been used in the clinic as a diagnostic radiotracer for monitoring many kinds of tumors, but its value for monitoring fibrosarcoma is not well established. METHODS: In this study, the uptake of 18F-FDG in a fibrosarcoma-bearing mouse model was evaluated using the high resolution positron emission tomography (PET) system microPET. Tumor cells were implanted in 3 FVB/N mice, and static microPET scanning was performed on day 1, 7, 12 and 15 after implantation. A dynamic microPET image was scanned on day 12 to determine the 18F-FDG uptake in 3 other tumor-bearing mice. Time-activity curves were plotted by drawing regions of interest in the tumor, liver, kidneys and muscles. The mice were sacrificed after dynamic microPET imaging and whole-body autoradiography (WBAR) was performed. For biodistribution study, 9 tumor-bearing mice, 3 per experimental group, were studied at 3 time points and the results were compared with the static microPET images. RESULTS: MicroPET images suggested that 18F-FDG could be used to monitor the growth of tumors 7 days after implantation. Dynamic scans of 18F-FDG uptake reached a plateau in the tumor after 20 minutes on day 12 after implantation. Both microPET and WBAR revealed evidence of tumor necrosis. The results of biodistribution and WBAR agreed with those from microPET images. CONCLUSION: MicroPET was useful for monitoring the growth of fibrosarcoma and determination of the maximal uptake time point of 18F-FDG in tumors in this tumor-bearing mouse model. 相似文献
42.
Chih-Yang Lin Wen-Jeng Lee Shyh-Jye Chen Ching-Hwa Tsai Jei-Han Lee Chia-Hung Chang Yu-Tai Ching 《Journal of digital imaging》2006,19(4):351-361
Computed radiography (CR) has many advantages such as filmless operations, efficiency, and convenience. Furthermore, it is
easier to integrate with the picture archiving and communication systems. Another important advantage is that CR images generally
have a wider dynamic range than conventional screen film. Unfortunately, grid artifacts and moiré pattern artifacts may be
present in CR images. These artifacts become a more serious problem when viewing CR images on a computer monitor when a clinic
grade monitor is not available. Images produced using a grid with higher frequency or a Potter–Bucky grid (i.e., a moving
grid, Bucky for short) can reduce occurrence but cannot guarantee elimination of these artifacts [CR & PACS (2000); Detrick
F (2001), pp 7–8]. In this paper, the formation of the artifacts is studied. We show that the grid artifacts occur in a narrow
band of frequency in the frequency domain. The frequency can be determined, accurately located, and thus removed from the
frequency domain. When comparing the results obtained from the proposed method against the results obtained using previous
computer methods, we show that our method can achieve better image quality. 相似文献
43.
44.
45.
Fa-Hsuan Lin Shang-Yueh Tsai Ricardo Otazo Arvind Caprihan Lawrence L Wald John W Belliveau Stefan Posse 《Magnetic resonance in medicine》2007,57(2):249-257
Magnetic resonance spectroscopic imaging (MRSI) provides spatially resolved metabolite information that is invaluable for both neuroscience studies and clinical applications. However, lengthy data acquisition times, which are a result of time-consuming phase encoding, represent a major challenge for MRSI. Fast MRSI pulse sequences that use echo-planar readout gradients, such as proton echo-planar spectroscopic imaging (PEPSI), are capable of fast spectral-spatial encoding and thus enable acceleration of image acquisition times. Combining PEPSI with recent advances in parallel MRI utilizing RF coil arrays can further accelerate MRSI data acquisition. Here we investigate the feasibility of ultrafast spectroscopic imaging at high field (3T and 4T) by combining PEPSI with sensitivity-encoded (SENSE) MRI using eight-channel head coil arrays. We show that the acquisition of single-average SENSE-PEPSI data at a short TE (15 ms) can be accelerated to 32 s or less, depending on the field strength, to obtain metabolic images of choline (Cho), creatine (Cre), N-acetyl-aspartate (NAA), and J-coupled metabolites (e.g., glutamate (Glu) and inositol (Ino)) with acceptable spectral quality and localization. The experimentally measured reductions in signal-to-noise ratio (SNR) and Cramer-Rao lower bounds (CRLBs) of metabolite resonances were well explained by both the g-factor and reduced measurement times. Thus, this technology is a promising means of reducing the scan times of 3D acquisitions and time-resolved 2D measurements. 相似文献
46.
Ming-Shian Tsai Wen-Hsi Lin Wen-Ming Hsu Hong-Shiee Lai Po-Huang Lee Wei-Jao Chen 《Journal of gastrointestinal surgery》2008,12(12):2191-2195
Background/aims Surgical resection of choledochal cysts (CC) has become standard treatment. However, surgery is not universally recommended
in early infancy and/or asymptomatic patients. In order to investigate the optimal timing of CC excision, we analyzed clinicopathological
data and surgical results from different age groups.
Material and methods This retrospective review included 107 patients (77 females, 30 males) who underwent CC resection at the National Taiwan University
Hospital between January 1988 and December 2005. Patient demographic, clinical, and surgical data were collected and analyzed.
Results The patients were divided into three groups according to age at the time of surgery: <1 year old (group I, n = 26), 1−16 years old (group II, n = 48), and >16 years old (group III, n = 33). About two thirds of the patients in group I had jaundice, while abdominal pain related to inflammation was the commonest
symptom in groups II and III. Group I suffered significantly fewer surgical complications and less severe liver fibrosis than
groups II or III.
Conclusion CC surgery in infancy and in asymptomatic patients is safe and may prevent the complications of this condition. The results
support a recommendation for early excision. 相似文献
47.
Decompressive hemicraniectomy as an appropriate treatment for malignant middle cerebral artery (MCA) infarction is still a controversial issue. This study aimed to determine the survival rate and functional outcome, and factors associated with these, in patients with malignant MCA infarction. From January 2000 to December 2003, 60 patients with malignant MCA infarction were treated in our hospital. All patients in the study underwent a large ipsilateral craniectomy and duroplasty for decompression. The infarction territory was evaluated by either diffusion weighted magnetic resonance imaging or computed tomography. Clinical neurological presentation was evaluated using the Glasgow Coma Scale. Functional outcome was evaluated using the Barthel index (BI) and the Glasgow Outcome Scale (GOS) at follow-up 12 months later. Thirty-day mortality was 20% (12 patients) and 12-month mortality was 26.6%. The factors associated with higher mortality were age>or=60 years, involvement of more than one vascular territory, presence of signs indicating clinical herniation before surgery, and treatment more than 24 hours after ictus. The mean GOS score was 3.3+/-1.7. The mean Barthel index was 65.1+/-40.1. Twenty-nine (65.9%) patients had a favourable outcome (BI>or=60). The factors associated with favourable outcome were age<60 years and treatment within 24 hours of ictus, before clinical signs of herniation were noted. Decompressive hemicraniectomy should be performed in patients younger than 60 years within 24 hours of ictus before clinical signs of herniation develop. Age, timing of surgery and clinical signs of herniation are prognostic factors for mortality and functional outcome. 相似文献
48.
Shuu-Jiun Wang Kwong-Kum Liao Hung-Hsiang Liou Shei-Shee Lee Ching-Piao Tsai Kon-Ping Lin Ko-Pei Kao Zin-An Wu 《Muscle & nerve》1994,17(4):411-418
Sympathetic skin response (SSR) and R–R interval variation (RRIV) were studied in 36 chronic, nondiabetic uremics to compare with their nerve conduction studies (NCS) and clinical dysautonomia. Abnormal SSR was noted in 5 (13.9%) patients, abnormal RRIV in 14 (38.9%), and abnormal NCS in 26 (72.2%). The patients were classified into three groups: group (GP) 1: “normal,” n = 21 (58.3%), normal RRIV and SSR; GP 2: “isolated parasympathetic dysfunction,” n = 10 (27.8%), abnormal RRIV and normal SSR; and GP 3: “sympathetic sudomotor dysfunction,” n = 5 (13.9%), abnormal SSR. A significant difference in age was found among the three groups (GP 3 > GP 2 > GP 1; P < 0.0001, ANOVA). After controlling the age factor, we still noted a tendency toward increasing NCS disturbances (distal latency and nerve conduction velocity of peroneal nerve; P < 0.05, multiple regression analysis) and frequencies of clinical autonomic symptoms (postural dizziness and impotence; P < 0.05, Mantel–Hanszel test) from GP 1 to GP 3. Patients with abnormal SSR (GP 3) displayed significantly higher frequencies of postural dizziness and impotence, indicating the relationship between an absence of SSR and clinical dysautonomia. © 1994 John Wiley & Sons, Inc. 相似文献
49.
Absence of mutations in the regulatory domain of the gap junction protein connexin 43 in patients with visceroatrial heterotaxy. 总被引:2,自引:0,他引:2 下载免费PDF全文
M. Penman Splitt M. Y. Tsai J. Burn J. A. Goodship 《Heart (British Cardiac Society)》1997,77(4):369-370
OBJECTIVE: To determine the frequency of mutations in the regulatory domain of the gap junction protein connexin 43 in patients with visceroatrial heterotaxy. DESIGN: Mutation screening of the terminal 200 base pairs of connexin43 gene coding sequence in a series of patients from tertiary care centres. PATIENTS: 48 patients with visceroatrial heterotaxy attending UK Regional Paediatric Cardiology Centres. RESULTS: No changes from the published connexin43 consensus sequence were found in any of the 48 patients studied. CONCLUSIONS: Germline mutations of the phosphorylation sites in teh regulatory domain of the connexin43 gene are rare in patients with visceroatrial heterotaxy. 相似文献
50.
Feng-Chun Tsai Daniel Marelli Jessica Bresson David Gjertson Reza Kermani Abbas Ardehali Fardad Esmailian Michele Hamilton Gregg C Fonarow Jaime Moriguchi Mark Plunkett Antoine Hage Julie Tran Jon A Kobashigawa Hillel Laks 《American journal of transplantation》2002,2(6):539-545
Older age, prior transplantation, pulmonary hypertension, and mechanical support are commonly seen in current potential cardiac transplant recipients. Transplants in 436 consecutive adult patients from 1994 to 1999 were reviewed. There were 251 using standard donors in 243 patients (age range 18-69 years). To emphasize recipient risk, 185 patients who received a nonstandard donor were excluded from analysis. The indications for transplant were ischemic heart disease (n = 123, 47%), dilated cardiomyopathy (n = 82, 32%), and others (n=56, 21%). One hundred and forty-nine (57%) recipients were listed as status I; 5 and 6% were supported with an intra-aortic balloon and an assist device, respectively. The 30-d survival and survival to discharge were 94.7 and 92.7%, respectively; 1-year survival was 89.1%. Causes of early death were graft failure (n = 6), infection (n = 4), stroke (n = 4), multiorgan failure (n = 3) and rejection (n = 2). Predictors were balloon pump use alone (OR= 11.4, p =0.002), pulmonary vascular resistance > 4 Wood units (OR = 5.7, p = 0.007), pretransplant creatinine > 2.0 mg/dL (OR = 6.9, p = 0.004) and female donor (OR = 8.3, p = 0.002). Recipient age and previous surgery did not affect short-term survival. Heart transplantation in the current era consistently offers excellent early and 1-year survival for well-selected recipients receiving standard donors. Early mortality tends to reflect graft failure while hospital mortality may be more indicative of recipient selection. 相似文献