Wei-Jen Yao

Long-Term Vegetarian Diet and Bone Mineral Density in Postmenopausal Taiwanese Women

This study examined bone density among postmenopausal Buddhist nuns and female religious followers of Buddhism in southern Taiwan and related the measurements to subject characteristics including age, body mass, physical activity, nutrient intake, and vegetarian practice. A total of 258 postmenopausal Taiwanese vegetarian women participated in the study. Lumbar spine and femoral neck bone mineral density (BMD) were measured using dual-photon absorptimetry. BMD measurements were analyzed first as quantitative outcomes in multiple regression analyses and next as indicators of osteopenia status in logistic regression analyses. Among the independent variables examined, age inversely and body mass index positively correlated with both the spine and femoral neck BMD measurements. They were also significant predictors of the osteopenia status. Energy intake from protein was a significant correlate of lumbar spine BMD only. Other nutrients, including calcium and energy intake from nonprotein sources, did not correlate significantly with the two bone density parameters. Long-term practitioners of vegan vegetarian were found to be at a higher risk of exceeding lumbar spine fracture threshold (adjusted odds ratio = 2.48, 95% confidence interval = 1.03–5.96) and of being classified as having osteopenia of the femoral neck (3.94, 1.21–12.82). Identification of effective nutrition supplements may be necessary to improve BMD levels and to reduce the risk of osteoporosis among long-term female vegetarians.

Dual-Phase 18F-FDG PET in the Diagnosis of Pulmonary Nodules with an Initial Standard Uptake Value Less Than 2.5

OBJECTIVEnA cutoff standard uptake value (SUV) of 2.5 has been commonly adopted for (18)F-FDG PET to evaluate pulmonary lesions, but false results can occur. Studies have shown the usefulness of delayed PET for improving accuracy. This study was designed to examine the efficiency of delayed PET of pulmonary nodules with an initial mean SUV less than 2.5.nnnMATERIALS AND METHODSnDual-phase FDG PET studies were conducted with imaging 1 and 2 hours after FDG injection, and pulmonary lesions with an initial mean SUV less than 2.5 were identified. Nodules with pathologic reports were included in the study. The differences in mean SUV, maximal SUV, and retention index between benign and malignant pulmonary lesions were analyzed. Receiver operating characteristic analysis was performed to evaluate the discriminating validity of the retention index.nnnRESULTSnA total of 31 lesions (15 benign, 16 malignant) were included in the study. Among the benign lesions, 12 were granulomatous inflammation, including 10 tuberculosis lesions and two cryptococcosis lesions, and three were focal fibrosis. A retention index greater than 0% was observed in 87% of the benign lesions; 60% of the benign lesions had a retention index greater than 10%. Among the malignant lesions, 75% had a retention index greater than 0%, and 62% had a retention index greater than 10%. We found no significant differences in mean SUV, maximal SUV, and retention index between benign and malignant lesions. The area under the receiver operating characteristic curve did not differ from 0.5.nnnCONCLUSIONnDelayed FDG PET is not useful for differentiating benign and malignant pulmonary nodules with an initial mean SUV less than 2.5 in geographic regions with epidemic granulomatous disease such as tuberculosis or in patients at high risk of granulomatous inflammation.

Differential changes in regional bone mineral density in healthy Chinese: age-related and sex-dependent.

To investigate the pattern of age-related and sex-dependent bone mineral density (BMD) changes in the six skeletal regions in healthy Chinese, total-body and regional BMD were measured by dual-energy X-ray absorptiometry (DXA) in 310 women and 387 men aged 20-80 years. In women, a five-phase change was discernible in the axial bones: (1) gradual bone increase from 20-29 years old to maximal BMD at 35-39 years old; (2) maintenance of this level from 35-39 to 40-44; (3) a mild bone decrease from 40-44 to 45-49; (4) a rapid bone decrease from 45-49 to 55-59; and (5) a decelerated bone decrease after 55-59 years old. After validation of menopause status, the decrease of BMD in the late 40s became insignificant in premenopausal women. In appendicular bones, no obvious peak was observed, and significant bone decrease started at 50-54 years old. The overall bone decrease from 35-39 to 70-80 years old was 19.3% for the total body, 16.4% for the head, 29% for the spine, 23% for the pelvis, 18.2% for the ribs, 23.9% for the arms, and 20.4% for the legs. In men, the maximal bone mass was attained at 30-34 and 35-39 years old for axial and appendicular bones, respectively. The age-related bone decrease in the skeletal regions was small, except from 60-64 to 65-69 years old. The overall bone decrease in each region from maximal bone mass to 70-80 years old was 6.7% for the total body, 1.7% for the head, 7.6% for the spine, 11.3% for the pelvis, 9.5% for the ribs, 7.8% for the arms, and 10.4% for the legs. The overall magnitude of reduction in total-body BMD in women was about three times greater than that in men. The pattern of BMD changes differs in each region and is age-related as well as sex-dependent. There appeared to be no significant premenopausal bone decrease.

A False Positive 18F-FDG PET/CT Scan Caused by Breast Silicone Injection

We present here the case of a 40-year-old woman with a greater than 10 year prior history of bilateral breast silicone injection and saline bag implantation. Bilateral palpable breast nodules were observed, but the ultrasound scan was suboptimal and the magnetic resonance imaging showed no gadolinium-enhanced tumor. The 18F-FDG PET/CT scan showed a hypermetabolic nodule in the left breast with a 30% increase of 18F-FDG uptake on the delayed imaging, and this mimicked breast cancer. She underwent a left partial mastectomy and the pathology demonstrated a siliconoma.

Peritoneal tuberculosis with elevated serum CA125 mimicking peritoneal carcinomatosis on F-18 FDG-PET/CT

Abstract18F-fluorodeoxyglucose positron emission tomography (F-18 FDG-PET) plays an important role in differentiating benign from malignant tumors. However, some false-positive findings, such as tuberculosis, may occur. We report a case referred for F-18 FDG whole-body PET computed tomography (PET/CT) scan owing to an elevated serum cancer antigen 125 (CA125). An FDG-PET/CT scan showed multiple hypermetabolic foci in the mesentery and peritoneum with further increase of FDG uptake on the delayed scan, mimicking peritoneal carcinomatosis. Subsequent laparoscopic biopsy showed granulomatous inflammation, and tuberculosis polymerase chain reaction showed a positive result. Serum CA125 returned to normal following treatment with anti-tuberculosis drugs. Peritoneal tuberculosis should be considered as a differential diagnosis in a tuberculosis endemic region.

The use of dual-phase 18F-FDG PET in characterizing thyroid incidentalomas.

AIMnTo examine the usefulness of dual-phase 2-[18F]-fluoro-2-deoxy-d-glucose (FDG) positron-emission tomography (PET) for the evaluation of thyroid incidentalomas.nnnMATERIALS AND METHODSnIn this retrospective study, cases with focal thyroid lesions seen incidentally at FDG PET in which the histopathological diagnosis was available and in which dual-phase FDG PET imaging was performed at 1 and 2 h after FDG injection were reviewed. In the included cases, the 1 and 2 h maximal standard uptake value (1-hour maximal SUV and 2-hour maximal SUV, respectively) and retention index (RI) were calculated, and the differences between benign and malignant thyroid incidentalomas were analysed. Receiver operating characteristic (ROC) analysis was performed to evaluate the ability of 1-hour maximal SUV, 2-hour maximal SUV, and RI to discriminate benign from malignant lesions.nnnRESULTSnA total of 39 patients (25 females, 14 males) with 45 lesions (17 malignant, 28 benign) were included. In malignant thyroid incidentalomas, the average 1-hour maximal SUV, 2-hour maximal SUV, and RI were 5.20, 5.72, and 7.67%, respectively, and in benign thyroid incidentalomas the values were 4.67, 4.97, and 7.38%, respectively. There were no significant differences in 1-hour maximal SUV, 2-hour maximal SUV, and RI between benign and malignant lesions. The area under the ROC curve did not differ from 0.5.nnnCONCLUSIONnDual-phase FDG PET is not useful for differentiating benign from malignant thyroid incidentalomas.

EVALUATION AND VALIDATION OF URETERIC JET INDEX BY GLOMERULAR FILTRATION RATE

RATIONALE AND OBJECTIVESnUreteric jet index (UJI), a newly developed technique derived from color Doppler ultrasonography, may hold promise in evaluating renal function because of its ability to evaluate individual renal function and the use of nonionizing radiation. To assess the usefulness of UJI, the authors in this study analyzed the relation between UJI and the glomerular filtration rate (GFR).nnnMETHODSnFifteen adult patients with a wide range of renal function were included in this study. Subjects were well hydrated before color Doppler ultrasonography examinations. The UJI formula was: Vmean (average jet velocity) x D (jet duration) x F (jet frequency). GFR was calculated by the radionuclide method. Correlations between UJI, serum creatinine, and GFR were analyzed.nnnRESULTSnUreteric jet index had only a fair correlation with GFR. The coefficient of correlation value was 0.61, and the standard error of estimate of GFR was 17.9 mL/min.nnnCONCLUSIONSnWith the measurement of UJI, color Doppler ultrasound can provide both structural images and individual renal function information. It could substitute for a renal scan in determining individual renal function when a radionuclide examination is unavailable. Even if a renal scan were available, UJI can play a valuable role in the ultrasound examination of patients with suspected impaired renal function, providing further assessment of individual renal function.

Tc-99m sestamibi scanning in the preoperative localization of mediastinal parathyroid adenomas

We report on two patients with mediastinal parathyroid adenomas who underwent preoperative Tc-99m sestamibi scintigraphy. Excellent physical characteristics of technetium and slow washout of Tc-99m sestamibi made possible clear delineation of mediastinal parathyroid adenomas by Tc-99m sestamibi imaging.

Peritoneal Scintigraphy for Diagnosing Periumbilical Leakage in a Patient on Continuous Ambulatory Peritoneal Dialysis

Continuous ambulatory peritoneal dialysis (CAPD) offers several advantages over hemodialysis for patients with end-stage renal disease; however, this technique also includes many documented complications. A case with clinical suspicion of dialysate leakage on CAPD was investigated by peritoneal scintigraphy using technetium-99m macroaggregated human albumin (99mTc-MAA). Peritoneal scintigraphy showed radiotracer accumulation over the periumbilical area at 2 hours 30 minutes after intraperitoneal infusion of 99mTc-MAA. Six hours of imaging revealed more apparent radioactivity at the same site. This study is to illustrate the simple diagnostic helpfulness of peritoneal scintigraphy in a patient with a CAPD-related structural defect.

The impact of smoking on incident type 2 diabetes in a cohort with hepatitis B but not hepatitis C infection

Smoking may be a risk factor for diabetes, and it has been suggested that viral hepatitis may predispose to diabetes. We studied diabetes and smoking histories in people with viral hepatitis. From 1997 to 2004, we studied the risk of incident diabetes in a community cohort with hyperendemic HBV and HCV infection in southern Taiwan. The cohort involved 3539 people (40–70 years old) without diabetes. Four hundred and twenty‐three individuals developed diabetes. Those who were ≥65 years old, frequently consumed alcohol, had a BMI ≥25, had <9 years of education, were anti‐HCV+ or smoked ≥1 pack per day were more likely to develop diabetes (P < 0.05). A cumulative hazard function test showed that the higher the smoking levels, the greater the cumulative incidence rate of diabetes in HBsAg+ participants only (P = 0.03 by log‐rank test). A multiple Cox proportional hazards model analysis in different hepatitis statuses showed smoking levels were strong predictors of diabetes with a dose–response relationship for type 2 diabetes in those with HBsAg+: hazard ratio (HR) = 3.8, (95% CI: 1.2, 12.3) for light smokers (<1 pack per day) and HR = 4.4 (95% CI: 1.5, 13.3) for heavy smokers (≥1 pack per day). Increasing BMI was a common predictor in all people. Smoking is a strong predictor for diabetes with a dose–response relationship in HBsAg+ individuals and a mild predictor for seronegative individuals but not significant in anti‐HCV+ individuals.