In electron therapy, lead cutout or low-melting alloy block is used for shaping the field. Material for shaping electron field affects the output factor as well as the collimation system. The authors measured the output factors of electron beams for shaped fields from Clinac-18 using ionization chamber of Farmer type on polystyrene phantom. They analyzed the incident energy, collimation system and size of shaped field. For shaped field the variation of output factor for the field (A/P) has appearance of a smooth curve for all energy and all applicator collimator combination. The output factors for open field deviate from the curves for shaped fields. An output factor for a given field can be calculated by equivalent field method such as A/P method, if a combination of applicator and collimator is fixed.
Alloys ; Polystyrenes

No abstract available.
Brain Injuries* ; Brain* ; Disability Evaluation* ; Humans ; Perfusion* ; Technetium Tc 99m Exametazime* ; Tomography, Emission-Computed, Single-Photon*

No abstract available.

PURPOSE: We investigated whether myocardial SPECT had additional usefulness to clinical, functional or surgical indices for the preoperative evaluation of cardiac risks in noncardiac surgery. MATERIALS AND METHODS: 118 patients (M: F=66:52, 62.7+/-10.5 years) were studied retrospectively. Eighteen underwent vascular surgeries and 100 nonvascular surgeries. Rest T1-201/stress Tc-99m-MIBI SPECT was performed before operation and cardiac events (hard event: cardiac death and myocardial infarction; soft event: ischemic ECG change, congestive heart failure and unstable angina) were surveyed through perioperative periods (14.6+/-5.6 days). Clinical risk indices, functional capacity, surgery procedures and SPECT findings were tested for their predictive values of perioperative cardiac events. RESULTS: Peri-operative cardiac events occurred in 25 patients (3 hard events and 22 soft events). Clinical risk indices, surgical procedure risks and SPECT findings but functional capacity were predictive of cardiac events. Reversible perfusion decrease was a better predictor than persistent decrease. Multivariate analysis sorted` out surgical procedure risk (p=0.0018) and SPECT findings (p=0.0001) as significant risk factors. SPECT could re-stratify perioperative cardiac risks in patients ranked with surgical procedures. CONCLUSION:: We conclude that myocardial SPECT provides additional predictive value to surgical type risks as well as clinical indexes or functional capacity for the prediction of preoperative cardiac events in noncardiac surgery.
Death ; Electrocardiography ; Heart Failure ; Humans ; Multivariate Analysis ; Myocardial Infarction ; Myocardial Ischemia ; Perfusion ; Perioperative Period ; Retrospective Studies ; Risk Factors ; Tomography, Emission-Computed, Single-Photon*

Cervical tuberculous lymphadenitis is a commonly encountered disease, expecially in adults, Differentiation from other lymphadenopathy and benign conditions such as cystic neck masses is important. CT findings of tuberculous lymphadenopathy in the abdomen and thorax are reported in many literatures. But there are only a few articles concerning cervical tuberculous lymphadenopathy. The authors retrospectively analyzed CT findings of 33 cases with cervical tuberculous lymphadenitis regarding distribution, contour, enhancing pattern, changes of adjacent fascial plane, and dermal and subcutaneous manifestations. We concluded that the presence of conglomerated nodal masses with central lucency, thick irregular rim of contrast enhancement and inner nodularity, varying degree of homogenous enhancement in smaller nodes, dermal and subcutaneous manifestations of inflammation such as thickening of overlying skin, engorgement of the lymphatic and thickening of adjacent muscles, and diffusely effaced fascial plane are suggestive of tuberculous lymphadenitis. However, some CT patterns of tuberculous adenitis may be seen in other disease; for example, enhancement can occur in hyperplastic nodes, vascular metastasis(thyroid, melanoma, and hypernephroma), lymphoma, granulomatous disease, and Castleman's disease.
Abdomen ; Adult ; Giant Lymph Node Hyperplasia ; Humans ; Inflammation ; Lymphadenitis ; Lymphatic Diseases ; Lymphoma ; Melanoma ; Muscles ; Neck ; Retrospective Studies ; Skin ; Thorax ; Tuberculosis, Lymph Node* ; Yemen

Serum alkaline phosphatase (AP) activity is elevated in hepatobiliary disease, bone disease, pregnancy and certain neoplasms. Recently we experienced marked elevation of serum AP activity after administration of albumin preparation in nephrotic patients who suffered from hypovolemic symptoms. So serum AP activity and the isoenzymes in the albumin preparations & patient's serum after the administration of albumin preparation were studied. Serum AP activity was significantly higher after administration of albumin preparation (318+/-101 IU/L) then before (123+/-43 IU/L). The predominant isoenzyme after administration of albumin was placental type, while liver and bone type was predominant before administration. AP activity in albumin preparation was high (2,133+/-1,410 IU/L) and the isoenzyme was mostly placental type. So we concluded that marked elevation of serum AP activity after administration of albumin was traced to the placental type AP isoenzyme in some albumin preparations which was manufactured from the plasma of placental origin. Elevated serum AP activity like these may lead to erroneous interpretation. Manufactures should notify alkaline phosphatase activity in albumin preparations of placental origin.
Administration, Intravenous* ; Alkaline Phosphatase* ; Bone Diseases ; Humans ; Hypovolemia ; Isoenzymes ; Liver ; Plasma ; Pregnancy

BACKGROUND AND OBJECTIVES: Dual isotope myocardial SPECT, rest thallium-201/dipyridamole stress Tc-99m sestamibi is used to diagnose coronary artery disease. We examined predictive value of myocardial SPECT for the prognosis of patients having or suspected coronary artery disease. MATERIALS AND METHOD: We examined 692 patients referred for dipyridamole stress myocardial perfusion SPECT. Cardiac events (hard and soft events) were followed up with medical record review and telephone interview. Survival analysis and multivariate Cox proportional hazard model were used to find significant predictors and the incremental predictive value of myocardial SPECT. Patients with coronary angiography (n=246) were analyzed in separate group. RESULTS: There were 4 hard events and 3 soft events in 341 normal SPECT group (1.20%/yr). There were 5 hard events and 21 soft events in 351 abnormal SPECT group (4.69%/yr). Survival curve was separated between normal SPECT group and abnormal SPECT group (p<0.01). In univariate analysis, smoking, history of myocardial infarction, typical chest pain and SPECT findings were important variables. In multivariate analysis, SPECT result was the single most independent predictor. Large reversible perfusion abnormality predicted worse prognosis. In patients with coronary angiography, SPECT did not add statistically significant predictive value to the coronary angiography. CONCLUSION: Dipyridamole stress Tl-201/ MIBI dual isotope myocardial perfusion SPECT provided excellent prognostic information. Extent of reversible perfusion decrease was the independent predictor of future cardiac events.
Chest Pain ; Coronary Angiography ; Coronary Artery Disease ; Dipyridamole ; Humans ; Interviews as Topic ; Medical Records ; Multivariate Analysis ; Myocardial Infarction ; Perfusion ; Prognosis ; Proportional Hazards Models ; Smoke ; Smoking ; Tomography, Emission-Computed, Single-Photon*

No abstract available.
Aviation* ; Humans*

National vaccine injury compensation serves as a crucial and significant safety net for individuals affected by government-recommended vaccines during a pandemic, contributing to the community’s overall safety. In the Republic of Korea, compensation for adverse events resulting from coronavirus disease 2019 (COVID-19) vaccinations has been provided through the National Vaccine Injury Compensation Program introduced in 1995. However, there have been limitations with these measures during the COVID-19 pandemic owing to strict criteria for substantiating causality between the vaccine and injury, its nontransparent process of determining whether to compensate, and the compensation amount that is not practically calculated. This article reviewed the Vaccine Injury Compensation Programs in 10 major countries to present implications for improving the Korean system. Expanding the scope of national accountability is essential to compensate for the consequences of adhering to national policies during public health crises. Therefore, valuable insight can be obtained from examining the systems in Germany, Japan, and Taiwan, which have implemented more relaxed criteria for determining causality in compensation cases; Thailand’s system, which provides the mandatory payment of preliminary compensation for damage caused by vaccination; systems in Germany, France, and Japan, which offer compensation for vaccine injuries from a practical perspective; and systems in France and the United Kingdom, which have a process allowing the assessment records to be shared with the claimants.Furthermore, a dedicated agency for vaccine injury compensation, as seen in France, the United Kingdom, and Australia, is necessary to enhance the efficiency of the Korean system.

Trait impulsivity is a known risk factor for suicidality, and the prefrontal cortex plays a key role in impulsivity and its regulation. However, the relationship between trait impulsivity, neural basis, and suicidality has been inconsistent. Therefore, this study aimed to explore the relationship between impulsivity and its structural correlates (prefrontal gray matter volume), suicidal ideation, and actual suicide attempts. A total of 87 individuals with major depressive disorder participated in study, and the gray matter volume of the prefrontal regions was extracted from T1 images based on region of interest masks. The variables for the mediation models were selected based on correlation analysis and tested for their ability to predict suicide attempts, with impulsivity and suicidal ideation as the mediation variables and gray matter volume as the independent variable. A significant correlation was observed between suicidal ideation and the left dorsolateral prefrontal cortex and right dorsomedial prefrontal cortex. The dual-mediation model revealed a significant indirect relationship between gray matter volume in both regions and suicide attempts mediated by motor impulsivity and suicidal ideation. The counterintuitive positive relationship between gray matter volume and suicidality was also discussed.