- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Relationship between body habitus and image quality and radiation dose in chest X-ray examinations: A phantom study
摘要： Purpose: To evaluate the influence of being overweight on image quality (IQ), radiation dose and acquisition parameters when undertaking adult chest X-ray (CXR) examinations using routine acquisition protocols. Methods: The Lungman chest phantom, with and without chest plates, was used to simulate the chest region for larger size and average adult patients, respectively. Radiographic acquisitions were conducted using 17 X-ray machines located in eight hospitals using their routine clinical protocols. IQ was assessed using relative visual grading analysis (VGA) and 2 alternative forced choice (2AFC) by six observers. Incident air kerma (IAK) was measured using a solid-state dosimeter. Results: IQ mean (range) scores between the hospitals were 16.2 (12.0–21.3) with a 56.0% difference and 20.9 (14.1–23.6) with a 50.2% difference for the standard and larger size phantoms, respectively. IAK mean (range) scores 63 μGy (19–136 μGy) with a 150% difference and 159 μGy (27–384 μGy) with a 173% difference for the standard and larger size phantoms, respectively. The chest plates had a significant negative impact on IQ (P = 0.001) and lead to an increased in IAK by approximately 50%. Conclusion: Visual measures of IQ and IAK showed large differences between hospitals for standard and larger phantom sizes; differences within the hospitals was lower. Overall, Lungman with chest plates was found to degrade IQ and increase radiation dose by a factor of two. Further optimisation is required especially for the larger sized patient’s imaging protocols for all eight hospitals.
关键词： Overweight,Image quality,Obesity,Adult chest radiography,Dose optimisation,Radiation dose
更新于2025-09-23 15:23:52
-
18F-FDG uptake in the normal appendix in adults: PET/CT evaluation
摘要： Objective This study aimed to determine the level of 18F fluorodeoxyglucose (18F-FDG) activity in the normal adult appendix using positron emission tomography/computed tomography (PET/CT). Materials and methods We performed a retrospective review of PET/CT images using 18F-FDG in 563 consecutive asymptomatic adult patients without appendiceal pathology. We excluded 257 patients for an undetected or obscured appendix and three patients for appendicitis found on CT imaging. FDG uptake in the appendix was qualitatively and quantitatively assessed. The maximum standardized uptake value (SUVmax) was calculated for quantitative analysis with SUVmax of the normal liver for comparison. A total of 303 patients (200 males, 103 females, mean age of 66 years) were included in this study. Medical charts and histories were evaluated for patients who showed positive FDG accumulation. Pearson’s correlations between appendiceal SUVmax and age, body mass index, and blood glucose levels were analyzed. Results The mean appendiceal SUVmax was 1.14 (range 0.52–5.12) with an appendix-to-liver SUVmax ratio of 0.34 (range 0.06–1.28). Three patients qualitatively showed a positive FDG accumulation with appendiceal SUVmax greater than 3.00. There were no correlations between appendiceal SUVmax and age, body mass index, or blood glucose levels. Conclusions FDG in the normal adult appendix shows a low activity level and is lower compared with normal liver. However, the normal appendix can rarely show high FDG accumulation. In such cases, differentiation from appendiceal pathology solely by PET/CT images would be difficult.
关键词： Normal variants,Adult,PET/CT,Appendix
更新于2025-09-23 15:22:29
-
Application of Fluorine-18-Deoxyglucose Positron Emission Tomography and Gallium Scan for Assessment in a Patient With Adult-Onset Still's Disease
摘要： A 53-year-old female patient suffered from pain in almost her entire body, particularly the joints. Chest computed tomography revealed multiple lymphadenopathies over cervical, mediastinal, and axillary areas. A fluorine-18-deoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) revealed increased FDG uptake in many lymph nodes and the spleen. Lymphoma was suspected. However, the result of a biopsy showed no malignancy, and the gallium-67 citrate scan showed no gallium-avid tumor throughout the whole body. Adult-onset Still's disease was diagnosed and the patient responded well to steroid therapy. The follow-up PET/CT six months later showed complete remission of the FDG-avid lesions seen in the previous PET/CT. Our study suggests that FDG PET/CT combined with gallium-67 scan may be helpful in diagnosing patients with adult-onset Still's disease. In addition, the use of FDG PET/CT alone may be useful for the evaluation of disease distribution, disease activity, and therapeutic response.
关键词： fluorine-18-deoxyglucose,Adult-onset Still's disease,positron emission tomography/computed tomography,gallium-67
更新于2025-09-23 15:22:29
-
Autofluorescence and spectral-domain optical coherence tomography of optic disk melanocytoma
摘要： The authors report fundus autofluorescence (FAF) and spectral-domain optical coherence tomography (OCT ) findings of two consecutive patients who presented with optic disk melanocytoma (ODM). A retrospective study was performed by reviewing medical records and ophthalmic imaging examinations. Optical coherence tomography findings were sloped and brightly reflective anterior tumor surface, adjacent retinal desorganization and abrupt posterior optical shadowing. Vitreous seeds were found in one patient. Fundus autofluorescence revealed outstanding hypoautofluorescence at the tumor area and isoautofluorescence at the remaining retina. Optical coherence tomography findings of the reported cases are consistent with those reported in the reviewed literature. Fundus autofluorescence has been used in the assessment of choroidal melanocytic tumors, but not yet in melanocytomas. We assume that this is the first report of these findings and believe that when its pattern has become clearly defined, fundus autofluorescence will be a useful tool to avoid misdiagnosis in suspicious cases and for follow-up.
关键词： Melanoma/diagnosis,Female,Adult,Male,Case reports,Optic nerve neoplasms/diagnosis,Fluorescein angiography,Humans,Tomography, optical coherence
更新于2025-09-23 15:22:29
-
Enhanced Depth Imaging Optical Coherence Tomography in Adult-Onset Foveomacular Vitelliform Dystrophy
摘要： Purpose: To compare mean choroidal thickness in patients with adult-onset foveomacular vitelliform dystrophy (AOFVD) and healthy subjects, to analyze patients with AOFVD in order to evaluate choroidal thickness disease-related changes, also in relation to the different stages of AOFVD disease and to the retinal pigment epithelium (RPE) features, and to correlate mean choroidal thickness with age in both groups. Methods: In this prospective observational cross-sectional study, a total of 63 eyes of 51 consecutive subjects were examined, consisting of a control group (n = 28 eyes) and the AOFVD group (n = 35 eyes). A complete ophthalmologic examination, fundus autofluorescence, and spectral-domain optical coherence tomography were performed in all patients. Results: Mean subfoveal choroidal thickness was 214.78 ± 62.35 μm in healthy subjects and 222.31 ± 73.29 μm in the AOFVD group (p = 0.33). In the vitelliruptive group, the mean choroidal thickness was significantly thicker than in the control group at each choroidal location. Mean choroidal thickness was significantly increased in the pseudohypopyon stage when compared to the vitelliform one (+66.34 μm, p = 0.02). Eyes with subretinal fluid (SRF) showed significantly thicker choroid when compared with those without SRF. No significant correlations were found between age and choroidal thickness in the study group. Conclusions: The study of the choroid in patients with AOFVD suggested a possible role in the pathologic changes during the different stages of disease, and could help us to evaluate progression of the disease. Greater choroidal thickness associated with SRF and RPE bumps are signs of RPE alterations and could be related to evolution of the AOFVD lesion to a different stage.
关键词： Choroidal thickness,Enhanced depth imaging optical coherence tomography,Adult-onset foveomacular vitelliform dystrophy
更新于2025-09-10 09:29:36
-
Fluorescence in?situ hybridization comparison of the prognostic factors in adult and pediatric acute lymphoblastic leukemia: A retrospective analysis of 282?cases
摘要： Acute lymphoblastic leukemia (ALL) affects both children and adults. However, the prognosis of the two cohorts is quite different. The present aim was to review and evaluate one potential cause of why survival is poorer in adult ALL than pediatric ALL via fluorescence in situ hybridization (FISH). Clinical significant features were analyzed in 282 ALL cases. FISH was performed to study mixed lineage leukemia (MLL) translocation and the Philadelphia (Ph) chromosome in newly diagnosed patients, and was used to detect trisomy 4 or 10 and the translocation ETS leukemia-acute myeloid leukemia 1 (TEL-AML1) fusion gene. The overall survival/event-free survival (OS/EFS) outcome of adult ALL and pediatric ALL was analyzed using Kaplan-Meier analysis. Adult ALL had a higher median leukocyte count and lower hemoglobin level than pediatric ALL. FISH revealed that Ph positivity (Ph+) was associated with the high-risk feature of older age. In pediatric ALL, trisomy 4 or 10 was present in 71/207 cases (34.3%), while the TEL-AML1 fusion gene was present in 16/207 cases (7.7%). By contrast, there were very few such positive cases in adult ALL. Survival analysis revealed that, in adult ALL, the 3-year OS and EFS rates were higher in the Ph-negative group than in the Ph+ group. Adult or pediatric lymphoblastic leukemia, ALL is an independent prognostic factor of OS. The present analysis of the clinical and biological features between adult and pediatric ALL indicates that adult ALL has a poorer prognosis than pediatric ALL based on Ph+ status and presence of trisomy 4 or 10. Ph+ ALL is an independent prognosis factor of ALL. FISH may serve an important role in the comparison of prognostic factors in adult and pediatric ALL.
关键词： fluorescence in situ hybridization,poor survival,pediatric acute lymphoblastic leukemia,adult acute lymphoblastic leukemia,Philadelphia+ acute lymphoblastic leukemia
更新于2025-09-09 09:28:46
-
Intrastromal crosslinking in post-LASIK ectasia
摘要： We describe a case of early post-LASIK ectasia detected in the first 6 months after surgery. The patient was treated by means of intrastromal corneal crosslinking under the flap, without de-epithelialization, which resulted in a positive outcome. At the time of writing, 2 years after the procedure, the patient remained free of progression.
关键词： Keratomileusis, laser in situ,Adult,Case reports,Corneal wavefront aberrations,Corneal stroma,Astigmatism,Postoperative complications,Cross-linking reagent,Refractive surgical procedures,Humans,Female
更新于2025-09-09 09:28:46
-
100 kVp Low-Tube Voltage Abdominal CT in Adults: Radiation Dose Reduction and Image Quality Comparison of 120 kVp Abdominal CT
摘要： Purpose: To compare image quality and the effect of radiation dose reduction after decreasing tube voltage from 120 kVp to 100 kVp for abdominal CT in adults. Materials and Methods: A total of 200 patients who underwent abdominal CT at 120 kVp (n = 100) or 100 kVp (n = 100) were enrolled. Automatic tube current modulation was applied with other scan parameters being constant. Radiation dose was calculated based on CT dosimetry index. The image quality of abdominal organs and image noise were assessed quantitatively and qualitatively. Results: A radiation dose reduction of 13.3% was found in the 100 kVp group. On quantitative analysis, image noise was increased up to 47% in the 100 kVp group. CT numbers of liver, pancreas, renal cortex, aorta, portal vein, and psoas muscle in the 100 kVp group were significantly (p < 0.05) higher than those in the 120 kVp group. Signal-to-noise ratio was significantly higher (p < 0.05) in the 120 kVp group. Contrast-to-noise ratio (CNR) of the liver was higher in the 120 kVp group. However, no significant (p > 0.05) difference was observed in the CNR of other organs between the two groups. On qualitative analysis, noise texture of abdominal organs, artifact, and diagnostic acceptability were not significantly (p > 0.05) different. Conclusion: 100 kVp abdominal CT reduced radiation dose by 13.3% without sacrificing image quality compared to 120 kVp abdominal CT.
关键词： Tomography, X-ray Computed,Adult,Diagnostic Imaging,Technology, Radiologic,Abdomen
更新于2025-09-09 09:28:46