Usefulness of thallium-201 muscle scan to investigate perfusion reserve in the lower limbs of patients with systemic lupus erythematusus.

Patients with systemic lupus erythematosus (SLE) may develop premature atherosclerosis, notably peripheral vascular disease presenting with intermittent claudication or gangrene. This study evaluates the usefulness of thallium-201 muscle perfusion scan (Tl-201 muscle scan) for investigating perfusion reserve in the lower limbs of 25 asymptomatic, female SLE patients without peripheral ischemia findings. The patients showed no evidence of peripheral arterial disease in history, physical examination, or Doppler ultrasonography. A control group consisted of 24 healthy, age-matched women. Each subject flexed her right foot maximally both dorsally and plantarly 60 times. In the middle of this exercise, 2 mCi of Tl-201 was injected intravenously. Three minutes after the injection, a posterior image of both calves was obtained using a gamma camera. Rectangular regions of interest were symmetrically drawn over both calves. The total count in the resting calf was subtracted from the total count in the exercising calf, and the percentage of increase, termed the perfusion reserve, was determined. A significant difference was found between the perfusion reserves of the SLE patients and control groups (75.3+/-8.9% and 99.6+/-9.0%, respectively, P <0.05). In conclusion, perfusion reserve in the lower limb muscles of SLE patients may be measured by Tl-201 muscle perfusion scan.

Usefulness of 99mTc ethyl cysteinate dimer brain SPECT to detect abnormal regional cerebral blood flow in patients with acute carbon monoxide poisoning.

99mTc ethyl cysteinate dimer (99mTc-ECD) brain single photon emission computed tomography (SPECT) was used to detect abnormal regional cerebral blood flow (rCBF) in patients with acute carbon monoxide (CO) poisoning. Ten patients with acute CO poisoning and no past histories of psychoneurological disorders were enrolled in this study. After oxygen treatment, all of the 10 patients were investigated using 99mTc-ECD brain SPECT and brain computed tomography (CT) scan. Brain CT scan findings were normal in all of the 10 patients. 99mTc-ECD brain SPECT showed the hypoperfusion lesions of the basal ganglia and brain cortex in five and seven patients, respectively. Only three of the 10 patients had normal 99mTc-ECD brain SPECT findings. This study suggests that, in comparison with brain CT scan, 99mTc-ECD brain SPECT is a better tool for the early detection of hypoperfusion brain lesions in acute CO poisoning in patients with normal brain CT findings.

Comparing whole body 18F-2-deoxyglucose positron emission tomography and technetium-99m methylene diophosphate bone scan to detect bone metastases in patients with non-small cell lung cancer.

Despite advances in morphological imaging, some patients with non-small cell lung cancer (NSCLC) are found to have non-resectable disease at surgery or die of recurrence within a year of surgery. At present, metastatic bone involvement is usually assessed using conventional technetium-99m methylene diophosphate (Tc-99m MDP) whole body bone scan (bone scan), which has a high sensitivity but a poor specificity. We have attempted to evaluate the usefulness of whole body positron emission tomography with 18F-2-deoxyglucose (FDG-PET) for the detection of malignant bone metastases of NSCLC, and to compare FDG-PET results with Bone Scan findings. Forty-eight patients with biopsy-proven NSCLC and suspected to have stage IV disease underwent whole body bone scan and FDG-PET to detect bone metastases. The final diagnoses of bone metastases were established by operative, histopathological findings or clinical follow-up longer than 1 year by additional radiographs or following FDG-PET/Tc-99m MDP bone scan findings showing progressively and extensively widespread bone lesions. A total of 138 bone lesions found on either FDG-PET or Tc-99m MDP bone scan were evaluated. Among the 106 metastatic and 32 benign bone lesions, FDG-PET and Tc-99m MDP bone scan could accurately diagnose 99 and 98, as well as 30 and 2 metastatic and benign bone lesions, respectively. Diagnostic sensitivity and accuracy of FDG-PET and Tc-99m MDP bone scan were 93.4% and 92.5%, as well as 93.5% and 72.5%, respectively. In conclusion, our data suggest that FDG-PET with the same sensitivity and a better accuracy than those of Tc-99m MDP bone scan to detect metastatic bone lesions in patients with biopsy-proven NSCLC and suspected to have stage IV disease.

Objective evidence of decreased salivary function in patients with autoimmune thyroiditis (chronic thyroiditis, Hashimoto's thyroiditis).

Impaired salivary flow is found in Sjögren's syndrome, which is a common, chronic, autoimmune, inflammatory connective tissue disease, mainly affecting the exocrine glands. Histopathologically, lymphocytic infiltrations of the salivary glands are found in Sjögren's syndrome that are similar to those of the thyroid gland in autoimmune thyroiditis (chronic thyroiditis, Hashimoto's thyroiditis). To test this hypothesis by Daniels et al ., salivary function was measured by quantitative salivary scintigraphy in autoimmune thyroiditis patients, as well as in age- and sex-matched controls. Forty patients, each with a history of autoimmune thyroiditis of over 10 years, and 61 healthy controls were enrolled in the study. All of the 40 autoimmune thyroiditis patients had good blood sugar control. None presented autonomic neuropathy. They were separated into two subgroups: patient group 1, 20 patients with xerostomia; patient group 2, 20 patients without xerostomia. Two control groups of healthy subjects were included for comparison: control group 1, 36 subjects without xerostomia; control group 2, 25 subjects with xerostomia. After intravenous injection of 5 mCi (99m)Tc-pertechnetate, sequential images at 1 min per frame were acquired for 30 min. The first and 15th minute uptake ratios (URs) were calculated from the tracer uptakes in the four major salivary glands relative to the background regions of interest (ROIs). Saliva excretion was stimulated by one tablet of 200 mg ascorbic acid given orally 15 min after injection of the tracer. The maximal excretion ratios (ERs) of the four major salivary glands after sialagogue stimulation were calculated. Impaired salivary function, represented by significantly decreased UR and ER values, in autoimmune thyroiditis patients with xerostomia was demonstrated in this study. Significantly poorer salivary function was found in autoimmune thyroiditis patients with xerostomia, when compared with autoimmune thyroiditis patients without xerostomia and healthy controls with or without xerostomia, via objective and quantitative salivary scintigraphy. However, a larger series of autoimmune thyroiditis patients is necessary to confirm our findings.

Value of whole body 18F-fluoro-2-deoxyglucose positron emission tomography in the evaluation of recurrent cervical cancer.

To evaluate the clinical value of whole body positron emission tomography (PET) with 18F-fluoro-2-deoxyglucose (FDG) in recurrent cervical cancer, the records of 20 patients who underwent FDG-PET scans were reviewed to detect local recurrence, pelvic/para-aortic lymph node metastases and distal metastases. The final diagnosis was based on operative, histopathological findings or clinical follow-up for longer than one year. FDG-PET accurately detected 18 patients with recurrent diseases (12 patients with local recurrences, 16 patients with pelvic lymph node metastases, 14 patients with para-aortic lymph node metastases and 4 patients with distal metastases of other sites). However, 2 patients with local recurrences had false- negative FDG-PET results as well as 1 patient without local recurrence and 1 patient without pelvic lymph node metastases who had false-positive FDG-PET results. The overall sensitivity and specificity of FDG-PET for patients were 90% and 100%, for local recurrence were 86% and 92%, for pelvic lymph node metastases were 100% and 94%, for para-aortic lymph node metastases were 100% and 100% and for distal metastases were 100% and 100%, respectively. In conclusion, whole body FDG-PET is a useful diagnostic tool in the evaluation of recurrent cervical cancer. It appears to be promising for detecting recurrent cervical cancer, lymph node metastases and distal metastases.

Technetium-99m-sestamethoxyisobutylisonitrile scan as a predictor of chemotherapy response in malignant lymphomas compared with P-glycoprotein expression, multidrug resistance-related protein expression and other prognosis factors.

The purpose of the present study was to predict the response of malignant lymphomas (MLs) to chemotherapy using technetium-99m methoxyisobutylisonitrile (Tc-MIBI) scan and to compare it with the predictive ability of P-glycoprotein (P-gp) expression, multidrug resistance-related protein (MRP) expression and other prognosis factors. Twenty-five ML patients were enrolled in this study prior to initiation of chemotherapy. Images were obtained 10 min after intravenous injection of Tc-MIBI, interpreted visually and the tumour-to-background (T/B) ratios calculated. Immunohistochemical analyses were performed on sections of the biopsy specimens to determine P-gp and MRP expression. Chemotherapy response was evaluated in the first 1-2 years after completion of chemotherapy. The mean T/B ratio of the 15 patients with a good response (3.3 +/- 0.6) was significantly higher than that of the 10 patients with a poor response (1.2 +/- 0.1). All 15 patients with a good chemotherapy response had positive Tc-MIBI scan results and negative P-gp and MRP expression. All 10 patients with a poor response had negative Tc-MIBI scan results and either positive P-gp or MRP expression. Other prognosis factors showed no significant difference in the incidence of good and poor responses. Tc-MIBI scan results represent P-gp or MRP expression more accurately than other prognosis factors and predict the chemotherapy response in ML patients.

Technetium-99m tetrofosmin scintigraphy for detecting malignant lymphoma.

The aim of this study was to assess the use of Tc-99m tetrofosmin (Tc-TF) scintigraphy for detecting malignant lymphomas. In the study, before any chemotherapy, 50 patients with malignant lymphoma underwent Tc-TF scintigraphy, which was performed 10 minutes after intravenous injection of 20 mCt Tc-TF. Tc-TF scintigraphy detected malignant lymphoma in 44 (88%) patients. However, there were no significant differences in the incidences of positive and negative Tc-TF scintigraphic results between female versus male patients, HD versus NHL patients, stage I-II versus stage III-IV patients, age > 40 years versus < or = 40 years patients and patients with B symptoms false-negative results occurred in 4 (8%) infradiaphragmatic malignant lymphoma. We conclude patients with that Tc-TF scintigraphy appears suitable for detecting malignant lymphoma, especially supradiaphragmatic lesions.

Evaluation of chemotherapy response using technetium-99M-sestamibi scintigraphy in untreated adult malignant lymphomas and comparison with other prognosis factors: a preliminary report.

The purpose of this study was to predict chemotherapy response using technetium-99m methoxyisobutylisonitrile (Tc-MIBI) scintigraphy in untreated adult malignant lymphomas (ML) and compare the response with other prognosis factors. Before chemotherapy, 25 adult patients with ML were enrolled in this study. Tc-MIBI scintigraphy was performed 10 min after intravenous injection of Tc-MIBI to calculate tumor-to-background (T/B) uptake ratio and interpret the results visually. Chemotherapy response was evaluated in the first 1 to 2 years after completion of treatment by clinical and radiological methods. The mean T/B uptake ratio of the 15 patients with good response (3.3 +/- 0.6) was significantly higher than that of the 10 patients with poor response (1.2 +/- 0.1). All of the 15 patients with good response had positive Tc-MIBI scintigraphic results. All of the 10 patients with poor response had negative Tc-MIBI scintigraphic results. However, there were no significant differences in the incidences of good and poor responses for other prognosis factors. In our preliminary study, when compared with other prognosis factors, Tc-MIBI scintigraphy was the best tool to predict chemotherapy response in adult patients with ML.

P-Glycoprotein and multidrug resistance-related protein expressions in relation to technetium-99m methoxyisobutylisonitrile scintimammography findings.

The purpose of this study was to retrospectively study 48 patients with infiltrating ductal breast cancer to evaluate the relationship between the degree of accumulation of technetium-99m methoxyisobutylisonitrile (Tc-MIBI) and P-glycoprotein (Pgp) or multidrug resistance-related protein (MRP) expression in breast cancer tissues. Before surgery or biopsy, all 48 patients underwent scintimammography started 10 min after the injection of Tc-MIBI. Tumor:background (T:B) ratios were calculated from the Tc-MIBI scintimammography. Immunohistochemical analysis was performed on the pathological specimens of the 48 breast tumors to determine Pgp and MRP expression. According to the results of immunohistochemical analysis, the 48 breast cancers were separated into four groups: (a) group 1, 12 cancers with both positive Pgp expression and positive MRP expression; (b) group 2, 12 cancers with positive Pgp expression and negative MRP expression; (c) group 3, 12 cancers with negative Pgp expression and positive MRP expression; and (d) group 4, 12 cancers with both negative Pgp expression and negative MRP expression. Among the four groups, the T:B ratio was lowest in group 1 (1.13+/-0.10) and highest in group 4 (2.17+/-0.14), respectively (P < 0.05). The T:B ratios of groups 2 (1.30+/-0.25) and 3 (1.32+/-0.26) were between those of groups 1 and 4. Our data confirmed that Tc-MIBI scintimammography is useful for determining Pgp and MRP expression in patients with breast cancers.

Whole body 18F-2-deoxyglucose positron emission tomography to restage non-small cell lung cancer.

The helpfulness of 18F-2-deoxyglucose positron emission tomography (FDG-PET) in restaging non-small cell lung cancer (NSCLC) has not been extensively evaluated. A total of 156 patients referred for restaging of NSCLC were retrospectively evaluated. According to the classification of American Joint Committee on Cancer, stages I and II were defined as conventionally resectable, stage IIIA as locally advanced but resectable, stage IIIB as locally advanced but unresectable, and stage IV as absolutely unresectable. Compared to initial staging by chest computed tomographic findings, FDG-PET down-staged 45/156 (29%) and up-staged 52/156 (33%) NSCLCs. In addition, 37/156 (23%) patients were reclassified from resectable to unresectable and 22/156 (14%) patients were reclassified from unresectable to resectable. Our results prove the helpfulness of whole body FDG-PET for restaging NSCLC.

Paclitaxel-Based chemotherapy for non-small cell lung cancer: predicting the response with 99mTc-tetrofosmin chest imaging.

UNLABELLED: The purpose of this study was to retrospectively predict the chemotherapeutic response to paclitaxel for non-small cell lung cancer (NSCLC) using 99mTc-tetrofosmin (TF) uptake and to detect the expression of 170-kDa multidrug resistance-mediated P-glycoprotein (MDR-Pgp). METHODS: Before chemotherapy with paclitaxel, 20 patients with stage IIIb or IV NSCLC were enrolled in this study to undergo early and delayed 99mTc-TF chest imaging for calculating tumor-to-normal lung ratios (T/NL) and retention indices (RI) for assessment of the MDR-Pgp in NSCLC. RESULTS: The early and delayed mean T/NLs were 1.59 +/- 0.25 and 1.50 +/- 0.25, respectively, for 10 patients with a good response and 1.09 +/- 0.09 and 1.03 +/- 0.05, respectively, for 10 patients with a poor response. The differences were shown to be significant (P < 0.001) by independent Student t tests. However, no significant differences (P = 0.801) between good-response patients (-5.70% +/- 3.67%) and poor-response patients (-5.23% +/- 4.51%) were found in RI. In addition, other prognostic factors (age, sex, tumor size, stage, and cell type) were not significantly different between good-response patients and poor-response patients. CONCLUSION: 99mTc-TF chest images are potential tools for understanding MDR-Pgp expression in NSCLC and for predicting the chemotherapeutic response to paclitaxel.

Whole body positron emission tomography with 18F-fluoro-2-deoxyglucose for the detection of recurrent ovarian cancer.

Although many cancers can be detected by whole-body positron emission tomography (PET) with 18F-fluoro-2-deoxyglucose (FDG), there has been limited clinical experience with FDG-PET for the detection of recurrent ovarian cancers. Therefore, the aim of this study was to evaluate the clinical value of FDG-PET in the detection of recurrent ovarian cancer. Whole body FDG-PET scans were performed on 24 women who had previous histories of ovarian cancer and treatment with surgery and chemotherapy. All patients also underwent physical examination, laboratory testing of serum CA-125 level and pelvic-abdominal-chest computed tomography (CT) or magnetic resonance imaging (MRI). The results of FDG-PET scans were correlated with serum CA-125 level, CT/MRI and operative pathology results. The diagnostic sensitivity was 90.9%, 90.9% and 90.9%, specificity was 92.3%, 76.9% and 46.2% and accuracy was 91.7%, 83.3% and 66.7% for FDG-PET, serum tumor marker of CA-125 level and CT/MRI in detecting recurrent ovarian cancer, respectively. FDG-PET is a useful diagnostic tool in detecting recurrent ovarian cancers with high specificity as compared with the serum tumor marker CA-125 level and the conventional CT/MRI morphological imaging methods.

Comparison of 18-fluoro-2-deoxyglucose positron emission tomography and computed tomography in detection of cervical lymph node metastases of nasopharyngeal carcinoma.

Neck lymph nodes (LNs) from 18 patients with nasopharyngeal carcinoma (NPC) were evaluated with 18-fluoro-2-deoxyglucose positron emission tomography (FDG-PET). Eighteen NPC patients underwent head and neck FDG-PET and computed tomography (CT) for detection of suspected neck LN metastases. For final diagnosis, biopsies were taken from neck LNs with discordant findings between FDG-PET and CT. Meanwhile, standard uptake values (SUVs) of the FDG-PET images were calculated to differentiate metastatic LNs from benign LNs. A total of 90 neck LNs found on either FDG-PET or CT were evaluated. In addition to 27 concordant positive results and 42 concordant negative LN results, biopsy findings revealed 11 metastatic LNs that were detected by FDG-PET but not by CT. However, the SUVs of the 11 metastatic LNs and 7 benign LNs were not significantly different. The CT scanning showed positive findings for I metastatic LN with negative FDG-PET findings. In addition, the tumor stage was upgraded in 5 patients on the basis of FDG-PET findings. In comparison with CT, FDG-PET has a higher potential for detecting neck LN metastases of NPC and assessing NPC tumor stage.

Association between seropositivity of antibodies against hepatitis a virus and Helicobacter pylori.

Helicobacter pylori and hepatitis A virus (HAV) are documented to share common transmission routes including fecal-oral. This study examined the association between seropositivity of antibodies against H. pylori (anti-HP) and HAV (anti-HAV) via a community-based survey of 40 randomly selected kindergartens in 10 urban and 10 rural areas. Serum samples from 2,047 healthy preschool children and 104 teachers were screened for anti-HP by enzyme-linked immunosorbent assay, and for anti-HAV by microparticle enzyme immunoassay. In children, a low prevalence of anti-HAV (0.44%) was found, in contrast to a high prevalence in their teachers (78.8%); anti-HP seroprevalence was 6.4% for children and 30.8% for teachers. Anti-HAV and anti-HP seropositivities were significantly associated in teachers after adjustment for age, sex, and residential area through multiple logistic regression analysis (multivariate-adjusted odds ratio = 7.3; 95% confidence interval [CI] = 1.4-36.8, P < 0.001). Our findings suggest that HAV and H. pylori may have shared transmission routes in central Taiwan 15 years or more ago, but not any recently.

Seroepidemiology of Helicobacter pylori infection among preschool children in Taiwan.

Helicobacter pylori is associated with chronic antral gastritis that is related to duodenal ulcer, gastric ulcer, and probably gastric adenocarcinoma. Infection with H. pylori during childhood is considered an important risk factor for gastric carcinoma in adult life. To examine the epidemiologic characteristics of H. pylori infection among preschool children in central Taiwan, a community-based survey was carried out in 54 kindergartens in 10 urban townships, 10 metropolitan precincts, and 2 aboriginal townships randomly selected through stratified sampling. Serum specimens of 2,551 healthy preschool children (3-6 years old) randomly sampled from study kindergartens were screened for antibodies to H. pylori by latex agglutination and ELISA methods. Multivariate-adjusted odds ratios (ORs) with their 95% confidence intervals (CIs) were estimated by multiple logistic regression analysis. A total of 207 subjects were antibody-positive, giving a prevalence of 8.1%. The overall seropositive rates were 4.5% in 3-year-old group, 4.4% in 4-year-old group, 9.4% in 5-year-old group, and 11.7% in 6-year-old group. The older the age, the higher the seroprevalence (OR = 3.2, 95% CI = 1.5-6.8 for 3-year-old children versus the 6-year-old children). Seroprevalence was not different between boys and girls. The aboriginal townships had a seroprevalence greater than the urban townships and metropolitan precincts (OR = 2.6, 95% CI = 1.9-3.7). The larger the number of siblings, the higher the seroprevalence (OR = 2.4, 95% CI = 1.0-5.8 for those with no sibling versus those with > or = 3 siblings). In the multiple logistic regression analysis, the seroprevalence of H. pylori remained significantly increased with age, aboriginal township, and large sibship size after multivariate adjustment. A poor water supply system, sewage disposal, and other environmental hygiene in the aboriginal townships might have played some role in infection with H. pylori. The early childhood transmission among siblings might also be an important determinant of H. pylori seropositivity in Taiwan.

Detecting alveolar epithelial injury following volatile anesthetics by (99m)Tc DTPA radioaerosol inhalation lung scan.

BACKGROUND: Many volatile anesthetics have long been thought to affect alveolar epithelial permeability. OBJECTIVE: The purpose of this study was to examine the acute effects of volatile anesthetics on the permeability of the alveolocapillary barrier to (99m)Tc DTPA. METHODS: Twenty-seven patients (24 females, 3 males, age 29-73 years) undergoing operation were enrolled in this study and grouped according to the type of anesthesia received. Group 1 patients were administered 1% halothane. Group 2 patients were given 1.5% isoflurane. Intravenous anesthesia without volatile anesthetics were used for group 3 patients. Before and after anesthesia, (99m)Tc DTPA radioaerosol inhalation lung scans were performed to detect alveolar epithelial injury due to volatile anesthetics. The negative slope of the regression line was designated as the (99m)Tc DTPA pulmonary clearance rate and was expressed in terms of percentage decrease in radioactivity per minute. RESULTS: In group 1, the (99m)Tc DTPA clearance rates were 1.26 +/- 0.34 and 1.29 +/- 0.38 before and after anesthesia, respectively. The difference was not significant (p > 0.05). In group 2, the rates were 0.76 +/- 0.20 and 1.10 +/- 0. 37, before and after anesthesia, respectively. The difference was significant (p < 0.05). In group 3, the clearance rates were 1.07 +/- 0.38 and 1.21 +/- 0.48, before and after anesthesia, respectively. The difference was not significant. CONCLUSIONS: Following isoflurane administration, the more rapid pulmonary clearance of (99m)Tc DTPA indicates that isoflurane increases the permeability of the alveolo-capillary barrier.

Gastric emptying in spinal cord injury patients.

Prolonged gastric emptying half-time (GET1/2) has been observed in several neurological disorders. However, findings of altered gastric emptying (GE) in previous studies on subjects with spinal cord injuries (SCI) have been questioned. Thus, GET1/2 of solid meals in SCI patients was studied by radionuclide imaging. This prospective study was conducted to assess GET1/2 in 50 SCI patients using radionuclide labeled solid meals. GET1/2 was abnormal in 58% of the 50 SCI patients. Age (abnormal GET1/2 in 57% of young vs 59% of old patients) and injury duration (abnormal GET1/2 in 61% of long vs 56% of short duration patients) were not statistically significant factors influencing GET1/2 (P > 0.05). However, the incidences of abnormal GET1/2 in female SCI patients (57%) and patients with high level injury (quadriplegic) (83%) were higher than in male SCI patients (47%) and patients with low level injury (paraplegic) (35%) (P < 0.05). SCI can cause significant prolonged GE of a solid meal, especially in female patients and patients with high level injury.

Evaluation of regional cerebral blood flow with 99mTc-HMPAO in primary antiphospholipid antibody syndrome.

UNLABELLED: In this study, 99mTc-hexamethyl propyleneamine oxime (HMPAO) SPECT was used to evaluate the regional cerebral blood flow (rCBF) of the brain in patients with primary antiphospholipid antibody syndrome (PAPS). METHODS: Twenty-two women who were PAPS patients, aged 28-60 y, with mild neuropsychiatric manifestations and normal brain MRI findings were enrolled in this study. Brain HMPAO SPECT was performed to detect brain abnormalities. Meanwhile, serum anticardiolipin antibodies (ACA) and lupus anticoagulant (LA) were measured. RESULTS: HMPAO SPECT revealed hypoperfusion lesions in 16 of 22 (73%) PAPS patients. Cerebral cortex and cerebellum were the most and the least commonly involved areas, respectively. Eighteen of 22 (82%) and 14 of 22 (64%) patients had positive ACA and positive LA, respectively. ACA and LA results were related to HMPAO SPECT findings. CONCLUSION: HMPAO SPECT is a sensitive tool for detecting brain abnormalities in PAPS patients with only mild neuropsychiatric manifestations and normal brain MRI findings.

Evidence for decreased salivary function in patients with reflux esophagitis.

It has been speculated that impaired salivary flow contributes to abnormal acid clearance of the esophagus in gastroesophageal reflux and results in reflux esophagitis (RE). To test this hypothesis, salivary functions were measured by quantitative salivary scintigraphies in patients with RE and in age- and sex-matched controls for comparison. Nineteen patients with RE and 36 healthy volunteers were enrolled in the study. After an intravenous injection of 5 mCi Tc-99m pertechnetate, sequential images of 1 min/frame were acquired for 30 min. The 1- and 15-min uptake ratios (UR) of the tracer in the four major salivary glands over the backgrounds were calculated. Saliva excretion was stimulated by 1 tablet of 200 mg ascorbic acid given orally 15 min after injection of the tracer, then the maximal excretion ratios (ER) of the four major salivary glands were calculated for the sialagogue stimulation. RE patients had lower values of 1st and 15th min UR and maximal ER than controls in the 4 major salivary glands. Poor salivary functions which represented a decrease in both UR and ER for patients with RE have been confirmed by quantitative salivary scintigraphy in this study.