Effect of Obesity on Left Ventricular Mass: Results from 320 Multi-Slices Computed Tomography.

Objective: To determine effects of obesity and gender on left ventricular mass in normotensive and hypertensive Thai patients using 320-slice cardiac computed tomography (CT). Material and Method: Left ventricular mass (LVM) obtained from 320-slice coronary CT angiogram was compared in 597 normotensive subjects (175 men [65 obese] and 422 women [133 obese], aged 55±7 years) and 483 hypertensive patients (180 men [104 obese] and 303 women [170 obese], aged 60±7 years). Obesity in Asian population was defined by body mass index (BMI) ≥ 25 kg/m2 in both genders. LV mass was normalized for body surface area (BSA)and height2.7. Results: The upper normal limit of LVM/ height2.7 developed from 244 (197 women, 47 men) low risk subjects (non-smoking normal-weight adults free from hypertension, diabetes, coronary artery disease & dyslipidemia) was lower than the established criteria for left ventricular hypertrophy (LVH) (31 versus 44 g/m2.7 in women; 36 versus 48 g/m2.7 in men). There is statistical difference between men and women in all groups of analysis. Among both hypertensive and normotensive subjects, the prevalence of LVH and LVM/height2.7 are higher in the obese group than normal-weight group in both genders (LVM/height2.7p<0.001; prevalence of LVH ­ obese versus normal-weight hypertension: 58% versus 34% in women, 43% versus 14% in men; obese versus normal-weight normotension: 35% versus 16% in women, 40% versus 15% in men). The same differences between obese and normal-weight groups were also present when normalizing LVM for height but not with LVM/BSA. Logistic regression analysis revealed that systolic blood pressure and BMI were the main predictors of LVH in the entire population (p<0.001 in both genders). Equations for predicting LVH in men and women were: Risk of LVH = 1/(l+e-w) where w is as follows: w (men) = 0.02* systolic pressure + 0.25*BMI ­ 9.86, w (women) = 0.03* systolic pressure + 0.17*BMI ­ 8.82. Conclusion: Obesity is an independent stimulus to increase LVM in normo-tensive subjects, and its effect is additive in hypertensive patients. Gender and obesity affect LVM and prevalence of LVH.

The Diagnosis of Acute Cholecystitis: Sensitivity of Sonography, Cholescintigraphy and Computed Tomography.

OBJECTIVE: To compare the sensitivity of sonographic, cholescintigraphic, and computed tomographic examination of acute cholecystitis to the pathology result, which is considered the Gold Standard. MATERIAL AND METHOD: A retrospective analytic study was conducted among 412 patients, aged between 15 and 98 years, who underwent cholecystectomy surgeries, and whose pathology results indicated acute cholecystitis between July 2004 and May 2013. The sensitivity and the differences between sensitivity of the three methods were calculated in all patients. Complicated acute cholecystitis cases were analyzed separately. RESULTS: The three methods demonstrated statistically significant differences in sensitivity (p-value = 0.017), with the cholescintigraphy as the most sensitive method (84.2%), followed by computed tomography (67.3%), and sonography (59.8%). Concerning the samples with the pathology result indicating complicated acute cholecystitis, computed tomography was statistically significantly more sensitive than sonography in detecting acute cholecystitis, whether or not the complications were identified (100% and 63.6%, respectively, with p-value = 0.0055). None of the patients with the pathology result of complicated acute cholecystitis case was examined by cholescintigraphy, thus, no calculation was possible. Regarding the ability to detect the complications of acute cholecystitis, computed tomography had a sensitivity of 35.71% (5 in 14 patients), while sonographic examinations could not detect any of the complications. CONCLUSION: Cholescintigraphy is a more sensitive method than computed tomography and sonography, but the three methods have its own advantages, disadvantages, and limitations, which must be consideredfor each individual patient.

The average collective equivalent dose and fatal cancer risk for radiation workers in Radiology Department at Phramongkutklao Hospital, 2004-2008.

OBJECTIVE: To evaluate the five years average equivalent dose, the average collective equivalent dose and fatal cancer risk for the radiation workers in Radiology Department at Phramongkutklao Hospital. MATERIAL AND METHOD: In the Radiology Department at Phramongkutklao Hospital, occupationally exposed workers are measured by the Division of Radiation Protection Services, Department of Medical Sciences which measures radiation exposures and evaluated doses from external exposures. Individual's doses of external exposure were monitored using film badges. The present study design describes a retrospective survey of occupational exposure in the Radiology Department at Phramongkutklao Hospital 2004-2008. RESULTS: The distribution of radiation workers monitored according to the groups in the years 2004-2008, physicist, technologist and assistant of technologist were the most numerous occupational group (51.13%). Nurse, assistant of nurse and nurse aids constituted 22.73%. About 59.73% of radiation workers in the Radiology Department at Phramongkutklao Hospital received an annual average equivalent dose below 0.02 mSv which defined as recording level and no radiation workers received doses above the International Commission on Radiological Protection (ICRP) Publication 60 recommended dose limit (20 mSv per year). The five years average equivalent dose per radiation worker was 1.098 mSv. Of all occupational groups measurably exposed, the nuclear medicine group received the highest of the five years average equivalent dose, collective equivalent dose and fatal cancer risk. The five years average equivalent dose, collective equivalent dose and fatal cancer risk for the physicist, technologist and assistant of technologist were the highest. CONCLUSION: Total risk per the whole monitored radiation workers were 3.86 x lW due to receive the five years average collective equivalent dose 0.096 man Sv. These values were estimated from a very small of number of radiation workers.

Economic evaluation of computed radiography comparing to film method in quality control of general X-ray machine at Phramongkutklao Hospital.

OBJECTIVE: To evaluate the efficiency of quality control performance for a general x-ray machine between computed radiography (CR) and film method. MATERIAL AND METHOD: CR performance as a quality control method for a general x-ray machine was compared to the film method. Two raters independently analyzed the result of quality control from both methods. Economic evaluation was performed by cost-minimization analysis. All data (result for quality control and cost) were collected from Phramongkutklao Hospital from August 2007 to January 2008. RESULT: Quality control performances of a general x-ray machine by using CR and film method were equivalent. Interobserver agreement for analysis of quality control measurements was almost perfect. Unit cost, test performance time, radiation dose for quality control by CR were less than the film method (p < 0.001). CONCLUSION: The performances of quality control of a general x-ray machine done by the CR method are more efficient than the film method. Using the CR method for quality control performance of the general x-ray machines will save cost enormously.