PURPOSE: The pvrpose of this study was to evaluate the accuracy of radioactivity quantitation in Tc-99m SPECT by using combined scatter and attenuation correction. MATERIALS AND METHODS: A cylindrical phantom which simulates tumors (T) and normal tissue (B) was filled with varying activity ratios of Tc-99m. We acquired emission scans of the phantom using a three-headed SPECT system (Trionix, Inc.) witb two energy windows (photopeak window: 126 154 keV and scatter window: 101 123 keV). We performed the scatter correction with dual-energy window subtraction method (k=0.4) and Chang attenuation correction. Three sets of SPECT images were reconstructed using combined scatter and attenuation correction (SC+AC', attenuation correction (AC) and without any correction (NONE). We compared T/B ratio, irnage contrast [(T-B)/(T+B)) and absolute radioactivity with true values. RESULTS: SC+AC images had the highest mean values of T/B ratios. Image contrast was 0.92 in SC+AC, which was close to the true value of 1, and higher than AC (0.77) or NONE (0.80). Errors of true activity by SPECT images ranged from 1 to 11% for SC+AC, 22-47% for AC, and 2 16% for NONE in a phantom which was located 2.4cm from the phantom surface. In a phantom located 10,0cm from the surface, SC+AC underestimated by ?4%, NON.E 40%. However, AC overestimated by 10%. CONCLUSION: We conclude that accurate SPECT activity quantitation of Tc-99m distribution can be achieved by dual window scatter correc.tion combined with attenuation correction.
Radioactivity ; Tomography, Emission-Computed, Single-Photon*

PURPOSE: To assess the quantitative accuracy and the clinical utility of 3D volumetric PET imaging with FDG in brain studies, 24 patients with various neurological disorders were studied. MATERIALS AND METHODS: Each patient was injected with 370 MBq of 2-[18F]fluoro-2-deoxy-D-glucose. After a 30 min uptake period, the patients were imaged for 30 min in 2 dimensional acquisition (2D) and subsequently for 10 min in 3 dimensional acquisition imaging (3D) using a GE AdvanceTM PET system. The scatter corrected 3D (3D SC) and non scatter-corrected 3D images were compared with 2D images by applying ROIs on gray and white matter, lesion and contralateral normal areas. Measured and calculated attenuation correction methods for emission images were compared to get the maximum advantage of high sensitivity of 3D acquisition. RESULTS: When normalized to the contrast of 2D images, the contrasts of gray to white matter were 0.75+/-0.13 (3D) and 0.95+/-0.12 (3D SC). The contrasts of normal area to lesion were 0.83+/-0.05 (3D) and 0.96+/-0.05 (3D SC). Three nuclear medicine physicians judged 3D SC images to be superior to the 2D with regards to resolution and noise. Regional counts of calculated attenuation correction was not significantly different to that of measured attenuation correction. CONCLUSION:: 3D PET images with the scatter correction in FDG brain studies provide quantitatively and qualitatively similar images to 2D and can be utilized in a routine clinical setting to reduce scanning time and patient motion artifacts.
Artifacts ; Brain* ; Humans ; Nervous System Diseases ; Noise ; Nuclear Medicine ; Positron-Emission Tomography

Purpose: We studied the clinical features and assessed the treatment outcomes of infectious endophthalmitis subsequent to Ahmed glaucoma valve (AGV) implant surgery. Methods: We performed a retrospective review of the medical records of patients who underwent AGV implant surgery between January 1, 2010 and May 31, 2022. Clinical course, microbiological lab results, and the treatment data of patients who developed infectious endophthalmitis were analyzed. Results: Of 310 eyes that underwent AGV implant surgery, 9 (2.90%) developed endophthalmitis. The average time interval between AGV implant surgery and the diagnosis of endophthalmitis was 3.59 years. As initial treatment, all affected eyes received injections of intravitreal antibiotics, while four underwent primary pars plana vitrectomy. The implanted valve was removed in seven instances. Microorganisms were found in cultures from four cases. Two patients achieved a final best-corrected visual acuity (BCVA) above 20/200, while the other five had a final BCVA of hand motion or worse. Conclusions AGV implant-related endophthalmitis is uncommon and often results in poor visual outcomes, with unpredictable onset. Consequently, it is crucial to educate patients undergoing AGV implant surgery during regular follow-ups. Immediate evaluation and treatment are necessary for patients exhibiting symptoms after surgery.

Purpose: To investigate the bacterial culture, clinical characteristics, and prognosis associated with infectious endophthalmitis in western Gyeongsangnam-do. Methods: This study was a retrospective review of the medical records of 98 eyes that presented with infectious endophthalmitis from 2010 to 2019. All patients were analyzed for the type of causative bacteria, treatment method, and the visual prognosis. Results: The bacterial cultures (n = 98 eyes) revealed bacterial growth in 67 eyes (68.4%). The most commonly isolated causative microorganism was Gram-positive Staphylococcus epidermidis (14.3%). As a result of analyzing the best corrected visual acuity (VA) based on 1.0 (logMAR), baseline VA was worse than counting fingers, and whether pars plana vitrectomy was undertaken showed a difference in the final visual acuity (p < 0.001, p = 0.021). Conclusions Exogenous endophthalmitis occurs frequently after cataract surgery, and S. epidermidis is the most common causative agent, but a good visual prognosis resulted. Liver abscess was a common extraocular source of endogenous endophthalmitis and Klebsiella pneumonia was the most common causative agent for a poor visual prognosis.

Purpose: To investigate the bacterial culture, clinical characteristics, and prognosis associated with infectious endophthalmitis in western Gyeongsangnam-do. Methods: This study was a retrospective review of the medical records of 98 eyes that presented with infectious endophthalmitis from 2010 to 2019. All patients were analyzed for the type of causative bacteria, treatment method, and the visual prognosis. Results: The bacterial cultures (n = 98 eyes) revealed bacterial growth in 67 eyes (68.4%). The most commonly isolated causative microorganism was Gram-positive Staphylococcus epidermidis (14.3%). As a result of analyzing the best corrected visual acuity (VA) based on 1.0 (logMAR), baseline VA was worse than counting fingers, and whether pars plana vitrectomy was undertaken showed a difference in the final visual acuity (p < 0.001, p = 0.021). Conclusions Exogenous endophthalmitis occurs frequently after cataract surgery, and S. epidermidis is the most common causative agent, but a good visual prognosis resulted. Liver abscess was a common extraocular source of endogenous endophthalmitis and Klebsiella pneumonia was the most common causative agent for a poor visual prognosis.

OBJECTIVE: To compare clinicopathologic characteristics and surgical outcomes of laparoscopic surgery in women with endometrial cancer according to body mass index (BMI). METHODS: From June 2009 to October 2010, prospective observational study without randomization of 159 patients treated by laparoscopic surgery from 10 hospitals nationwide. RESULTS: Patients were divided according to the WHO guidelines for Asia-Pacific populations and the distributions of BMI were as follows: 3 patients (1.9%) in underweight (BMI < 18.5 kg/m2), 50 patients (31.4%) in normal weight (BMI, 18.5-22.9 kg/m2), 45 patients (28.3%) in overweight (BMI, 23.0-24.9 kg/m2), 49 patients (30.8%) in obese (BMI, 25.0-29.9 kg/m2), and 12 patients (7.5%) in morbid obese (BMI > or = 30.0 kg/m2). Age, history of previous surgery, surgery extend, and history of previous surgery were not different between non-obese patients (BMI < 25.0 kg/m2) and obese patients (BMI > or = 25.0 kg/m2). Co-morbidities were more common in obese patients but marginally significant (23.5% vs. 37.7%, p=0.072). Four patients (2.5%) were converted to abdominal surgery because of severe adhesion. Regarding to surgical outcomes, operation time was significantly longer in obese patients (199 min vs. 235 min, p=0.013) but blood loss, lymph node yield, hospital stay, Foley removal, transfusion rate and peri-operative complication were not statistically significant. Regarding to pathologic results, there were no difference in terms of lymphovasucular space invasion, tumor grade, histologic type, lymph node metastasis and FIGO stage. CONCLUSION: Clinicopathologic characteristics and surgical outcomes does not seem to be significantly influenced by BMI except operation time. So the laparoscopic approach can be the alternative method for obese patients.
Body Mass Index ; Endometrial Neoplasms ; Female ; Humans ; Laparoscopy ; Length of Stay ; Lymph Nodes ; Neoplasm Metastasis ; Obesity ; Overweight ; Prospective Studies ; Random Allocation ; Thinness