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.

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.

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.

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.

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.

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.

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

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.

Normal ranges of renal physiological parameters for technetium-99m mercaptoacetyltriglycine and the influence of age and sex using a camera-based method

162 normal Chinese men and women underwent a 99mTc MAG3 renal study. Seventy-two males and 90 females were evaluated in 5 age groups: group 1, 61-80 years; group 2, 51-60 years; group 3, 41-50 years; group 4, 31-40 years, and group 5, 21-30 years. Each subject was required to fit the following criteria: (1) clinically no history of renal, urinary disorders and systemic diseases, normal blood pressure, kidney morphology, urinary examination and serum creatinine, and (2) for the gamma camera study normal hydration and renal images, and no pelvic, ureteric dilatation or retention of tracer should be found. The normal range of common physiological parameters for 99mTc MAG3 renal studies was measured in normal subjects. The effective renal plasma flow (ERPF, camera-based Schlegel method), percent function in each kidney (renal index, RI), time of peak renal parenchymal activity (Tmax) and half time of parenchymal activity following the peak (T1/2) were evaluated. The Tmax and T1/2 were determined with regions of interest over the entire kidney. The results showed that (1) between the sexes, there were no significant differences for any parameter; (2) between the age groups, the only significant difference was a decrease in ERPF, normalized for body surface area, with increasing age (group 1, 511.3 +/- 91.2; group 2, 559.5 +/- 102.1; group 3, 577.1 +/- 79.2; group 4, 607.8 +/- 101.1, and group 5, 610.2 +/- 109.2), and (3) the RI, Tmax and T1/2 were symmetrical and did not vary between the sexes or age groups (left vs. right: RI = 49.6 +/- 2.2 vs. 50.4 +/- 2.2%, Tmax = 3.63 +/- 1.13 vs. 3.75 +/- 1.11 min, and T1/2 = 5.38 +/- 1.65 vs. 5.83 +/- 1.88 min). We find that (1) ERPF for 99mTc MAG3 decreases with age in normal Chinese, which is similar to the results of Western countries, and (2) the RI, Tmax and T1/2 were symmetrical and did not vary between the sexes or age groups in normal Chinese, and are also similar to the results of Western countries.

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.

Tc-99m MAG3 renal studies: renogram and effective renal plasma flow in spinal cord injury patients

To determine whether years since injury, level of injury, degree of injury, gender, or age influence renal function in 66 spinal cord injuries (SCI) patients without urological complications, individual kidney effective renal plasma flow (ERPF) and radionuclide renogram (RR) were measured using technetium-99m mercaptoacetyltriglycine (Tc-99m MAG3). The 176 individual kidneys included 84 kidneys with normal ERPF and RR, 48 kidneys with normal ERPF but abnormal RR, and 44 kidneys with abnormal ERPF and RR. The incidence of abnormal Tc-99m renal study results was higher in the kidneys of female patients (37/54, 68%) than of male patients (55/122, 45%) (p < 0.05). We found that Tc-99m MAG3 renal studies including ERPF and RR are safe and noninvasive urological screening tests for SCI patients.

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.

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.

A trial study of leukocyte labeling with stabilized Tc-99m D,L-HMPAO by methylene blue and sodium phosphate buffer

We attempted to label leukocytes with stabilized Tc-99m D,L-HMPAO by methylene blue and sodium phosphate buffer (S-HMPAO).

METHODS

The results were compared with unstabilized Tc-99m D,L-HMPAO (U-HMPAO). U-HMPAO was obtained by reconstituting a commercial vial of D,L-HMPAO. Stabilization of the kit was performed by the addition of methylene blue. The leukocytes were labeled using a modified published method. The test samples of S-HMPAO and U-HMPAO were prepared immediately, and stood for 0.5, 1, 2, 4, and 6 h, respectively, at room temperature before analysis.

RESULTS

In comparison with U-HMPAO: (1) the radiochemical purity of S-HMPAO was higher; (2) the labeling efficiencies of S-HMPAO labeled leukocytes were higher and consistent; (3) the viability of S-HMPAO labeled leukocytes was as high as the viability of U-HMPAO labeled leukocytes at any time; and (4) the percentages of disintegrated from S-HMPAO labeled leukocytes in plasma were lower.

CONCLUSION

S-HMPAO is more stable than U-HMPAO and can provide higher leukocyte labeling efficiency. S-HMPAO, therefore, has the potential to replace U-HMPAO as a leukocyte-labeling agent.

Discrepancy between regional cerebral blood flow and glucose metabolism of the brain in systemic lupus erythematosus patients with normal brain magnetic resonance imaging findings

OBJECTIVE

In this study, 2 updated brain-imaging modalities, technetium-99m hexamethylpropylene amine oxime-single-photon-emission computed tomography (HMPAO-SPECT) and fluorine-18 2-fluoro-2-deoxy-D-glucose-positron emission tomography (FDG-PET), were used to simultaneously detect regional cerebral blood flow (rCBF) and glucose metabolism of the brain in patients with systemic lupus erythematosus (SLE).

METHODS

Twenty-five female SLE patients, ages 25-40 years, were enrolled in this study and assigned to 1 of 2 groups. Group 1 consisted of 13 patients with neuropsychiatric manifestations (7 had major and 6 had minor manifestations). Group 2 consisted of 12 patients without neuropsychiatric manifestations. Serum levels of anticardiolipin antibodies (aCL) and anti-ribosomal P antibodies (anti-P) were measured. All patients had normal brain magnetic resonance imaging (MRI) findings. Ten healthy female volunteers also underwent brain MRI, HMPAO-SPECT, and FDG-PET for comparison.

RESULTS

99mTc-HMPAO-SPECT revealed hypoperfusion lesions in 11 (44%) of 25 SLE patients, including 9 (69%) of the 13 patients in group 1, 7 (100%) of the 7 patients with major manifestations, 2 (33%) of the 6 patients with minor manifestations, and 2 (17%) of the 12 patients in group 2. Parietal lobes were the areas most commonly involved. FDG-PET revealed hypometabolism in 7 (54%) of the group 1 patients, 6 (86%) of the 7 patients with major manifestations, and 1 (17%) of the 6 patients with minor manifestations. Temporal lobes were the most commonly involved areas. However, no significant hypometabolism brain lesions were found in group 2 patients. All of the 4 patients with headaches and dizziness or headaches alone had normal findings on HMPAO-SPECT and FDG-PET. Nine (36%) of the 25 patients were positive for aCL. However, the presence of aCL was not related to neuropsychiatric manifestations or to HMPAO-SPECT or FDG-PET findings. Five (20%) of the 25 patients had anti-P antibodies and psychosis/depression.

CONCLUSION

In patients with normal brain MRI findings, decreases in glucose metabolism coupled with decreases in rCBF are associated with serious neuropsychiatric SLE (NPSLE) presentations, while normal glucose metabolism with decreases in rCBF may be found in SLE patients with or without NPSLE.

Diagnostic value of bone and Ga-67 imaging in skeletal tuberculosis

Tuberculosis (TB) remains a major cause of skeletal infection in many parts of the world. Bone scintigraphy is an excellent screening test for bone lesions and Ga-67 scintigraphy is a useful tool for detecting inflammatory lesions. This study determined the value of bone and Ga-67 scans in patients with skeletal TB. Tc-99m MDP and Ga-67 whole-body scans were performed in 24 patients with proved skeletal TB. Twenty-six TB lesions were found in these 24 patients, 8 in the spine, 5 in the knee, 5 in the wrist, 4 in the ankle, 2 in the elbow, 1 in the finger, and 1 in the sacroiliac joint. Of the 26 TB lesions, Tc-99m MDP bone imaging detected 24 and Ga-67 scans revealed 23. The sensitivity rates were 92% (24 of 26) and 88.5% (23 of 26) for bone scans and Ga-67 scans, respectively. When the scans were evaluated in combination, the detection sensitivity was 96.1% (25 of 26). Two lesions that the bone scan failed to detect were in the spine. Ga-67 imaging failed to detect two spinal lesions and one lesion in the knee. The detection sensitivities of bone and gallium scans were high for skeletal TB, although neither scan was specific for TB lesions. Either the bone or Ga-67 scan can be used in the clinical setting as a convenient screening test to detect multiple sites of bone involvement in TB, and to indicate the sites for further detailed evaluation by CT, MRI, or biopsy.

Immune status in preschool children born after mass hepatitis B vaccination program in Taiwan

A mass hepatitis B vaccination program began in Taiwan in 1984. In order to determine the immune status of hepatitis B virus (HBV) infection among preschool children, a total of 25 kindergartens in 20 townships and metropolitan precincts in central Taiwan were randomly selected through stratified sampling. Serum specimens of 2130 healthy preschool children aged 2-6 years old were screened for the HBV markers and liver function in 1996. HBV surface antigen (HBsAg), antibody against HBsAg (anti-HBs) and antibody against HBV core antigen (anti-HBc) were tested by reverse passive hemagglutination (RPHA), enzyme immunoassay (EIA) and radioimmunoassay (RIA) using commercial kits. HBV vaccination rate of the preschool children was 98%, and complete vaccination rate (three or four doses of HBV vaccine) was 94%. The HBsAg seropositive rate was 4.5% among incomplete vaccinees and 1.3% among complete vaccinees. The anti-HBs was detectable in 1637 of 2000 complete vaccinees (81.9%) and in 53 of 88 incomplete vaccinees (60.2%). The overall prevalence rate of anti-HBc was 2.4% (52 of 2130). The older the age, the lower the anti-HBs seropositive rate. The anti-HBs seropositive rats for complete vaccinees were 100% at 2 years old and 75% at 6 years old. There were no significant differences in HBsAg-seropositive rates and anti-HBs-seropositive rates among different residential areas or ethnic groups. There were three children who were seropositive on HBsAg, anti-HBs and anti-HBc, whether they were infected by the vaccine-induced escape mutant of HBV deserves scrutiny.

Detection of nasopharyngeal carcinoma with head and neck Tc-99m tetrofosmin SPECT imaging

Tc-99m tetrofosmin SPECT imaging of the head and neck was performed on 10 patients with nasopharyngeal carcinoma (NPC) and 10 controls. There was no abnormal nasopharyngeal uptake of tetrofosmin in the 10 controls. In the patients with NPC, 3/10 (30%) of the cases had no abnormal uptake and 7/10 (70%) had increased nasopharyngeal uptake. Considering our preliminary study, we find that Tc-99m tetrofosmin SPECT of the head and neck may be helpful in the detection of NPC. However, further study with a larger number of patients is needed to ascertain the value of Tc-99m tetrofosmin SPECT in such cases.

Comparison technetium of Tc-99m disofenin cholescintigraphy with ultrasonography in the differentiation of biliary atresia from other forms of neonatal jaundice

Technetium Tc-99m disofenin cholescintigraphy (CS) and ultrasonography (US) are two major clinical methods used in differentiating biliary atresia (BA) from neonatal jaundice. To compare the diagnostic utility of these two modalities, 66 patients with neonatal cholestasis (15 BA, 3 choledochal cyst (CC), 32 neonatal hepatitis, 13 prolonged jaundice, 2 total parenteral nutrition, and 1 sepsis) underwent Tc-99m disofenin CS and US. The diagnostic sensitivity, specificity, and accuracy of CS in differentiating BA from other forms of neonatal jaundice was 100%, 87.5%, and 90.5%, respectively, and for US 86.7%, 77.1%, and 79.4%, respectively. Tc-99m disofenin CS after premedication with phenobarbital and cholestyramine is a convenient and reliable method of differentiating BA from neonatal hepatitis, with a diagnostic accuracy superior to that of US. However, US is the initial imaging procedure of choice in patients presenting with jaundice to rule out anatomic anomalies such as CC.

99Tcm-MAG3 renal studies: effective renal plasma flow in patients with spinal cord injuries

To assess whether number of years since time of injury, level or degree of injury, gender or age influence renal function in patients with spinal cord injury (SCI), single and total kidney effective renal plasma flow (ERPF) was measured in 66 patients using 99Tcm-mercaptoacetyltriglycine (99Tcm-MAG3). In approximately 50% of the SCI patients, the single kidney ERPF was less than 250 ml min-1 and total ERPF was less than 500 ml min-1. The single kidney ERPF was worse in female and older SCI patients than in male and younger patients. For total ERPF, age only was a significant factor. Total ERPF was worse in female than in male SCI patients, though this did not reach significance. We conclude that the non-invasive measurement of renal function using 99Tcm-MAG3 is safe and applied easily to SCI patients.

Bone mineral density in patients with spinal cord injuries

The bone mineral density (BMD) of 157 patients with a spinal cord injury (SCI) was measured using dual-photon absorptiometry (Lunar DP-4). The BMD of the second to fourth lumbar vertebrae (L2-L4) and the right femoral neck was measured and the mean density registered in grams per square centimetre. The likelihood of a fracture was based on the percentage of BMD in young normals and the degree of risk of fracture. The following criteria were used to separate the patients: (1) complete or incomplete immobility due to the SCI; (2) the time between the SCI and measurement of BMD was short (<or= 3 years) or long (> 3 years); (3) the level at which the SCI occurred was considered to be high (i.e. from the first cervical vertebra to the tenth thoracic vertebra) or low (i.e. from the eleventh thoracic vertebra to the first lumbar vertebra). The rate of abnormal BMD (i.e. a greater risk of fracture) in each of the groups and at each site was measured and differences evaluated using the chi-square test. Fifty-four of the 157 (34%) scans revealed an abnormal BMD at the level of L2-L4 and 126 (80%) in the right femoral neck. The difference between these two incidences was significant (P < 0.001). However, there were no significant differences in abnormal BMD with regard to severity of the SCI, time elapsing since the SCI and level at which the SCI occurred. We conclude that hip demineralization is a common complication in SCI, but that lumbar BMD is better preserved.

Serial changes in regional blood flow in the cerebrum and cerebellum of stroke patients imaged by 99Tcm-HMPAO SPET

Luxury perfusion is a well-known phenomenon that can mask ischaemic lesions in patients with cerebral infarction, thus making diagnosis difficult. In this study, we evaluated the incidence of luxury perfusion over a 3-week period following a stroke episode. The usefulness of crossed cerebellar diaschisis (CCD) as a complementary feature in the diagnosis of cerebral infarction was also evaluated using 99Tcm-hexamethylpropyleneamine oxime (99TcmHMPAO) brain single photon emission tomography (SPET). Twelve patients diagnosed as having a hemispheric ischaemic stroke of the middle cerebral arterial territory were enrolled in the study. Each patient underwent a total of four 99Tcm-HMPAO brain SPET examinations, 1 day, 1 week, 2 weeks and 3 weeks following the stroke episode. Our results show that the incidence of luxury perfusion was 67% (8/12) after 1 week, 75% (9/12) after 2 weeks and 83% (10/12) after 3 weeks. The incidence of CCD was 33% (4/12) after 1 day, 50% (6/12) after 1 week, 42% (5/12) after 2 weeks and 33% (4/12) after 3 weeks. We conclude that the detection of cerebral infarction is difficult 2 weeks or more after a stroke episode. The interval between the stroke episode and examination must be considered when reading the 99Tcm-HMPAO image. In addition, CCD may be helpful for the diagnosis of cerebral infarction within the first week after a stroke episode, especially in cases of an unidentified ischaemic region on the 99Tcm-HMPAO hemispheric image. However, the value of CCD is limited 2 weeks or more following the stroke episode.

The change in the distribution of Tc-99m human serum albumin radioaerosols in asthma after a 1-week course of corticosteroid inhalation treatment

This study evaluated the effects of corticosteroid inhalation on the deposition pattern of Tc-99m HSA radioaerosols in 24 patients with asthma. The homogeneous degree of depositing radioaerosol was quantitatively evaluated using a modified standard score system over both lungs. The baseline scores were calculated before inhalation therapy of 0.05 mg beclomethasone dipropionate four times daily for 1 week. The studies were then repeated after treatment to evaluate the effects of inhalation therapy. After treatment, the scores decreased in 16 of 24 cases (67%), which means that the degree of the bronchial obstruction decreased. The statistical results revealed significant differences in the total homogeneity score (P < 0.001) before and after therapy. Thus, a 1-week course of beclomethasone dipropionate inhalation therapy improves the bronchial obstruction in asthma patients as shown by the quantitative homogeneity score system of the Tc-99m HSA radioaerosol inhalation lung scintigraphy.

Tc-99m DTPA aerosol lung clearance test in systemic lupus erythematosus

Systemic lupus erythematosus (SLE) can affect every organ. Involvement of the lung in systemic lupus erythematosus may be a significant cause of morbidity and mortality. To evaluate alveolar epithelial damage in SLE, we studied lung epithelial permeability by measuring the clearance of inhaled Tc-99m DTPA aerosol. Twenty-three SLE patients without clinical pulmonary manifestations were studied. Of the 23 patients, 16 had normal clearance rates of Tc-99m DTPA (T1/2 > 60mins) and normal chest X-ray findings. A mild increase in the clearance rate was found in 5 cases (T1/2 between 40-60 min) and a significant increase in clearance rate in the remaining 2 (T1/2 < 40mins). Totally, 30% (7/23) of SLE patients have abnormal lung permeability. Of the 7 patients with abnormal clearance of Tc-99m DTPA, 3 had abnormal findings in chest X-rays and four had normal chest X-rays. Our study suggests that the clearance of Tc-99m DTPA aerosol may be a useful complementary study to assess pulmonary involvement in SLE.

Application of radioisotope renography with technetium-99m mercaptoacetyltriglycine on patients with spinal cord injuries

The effectiveness of radioisotope renography with Technetium-99m (Tc-99m) mercaptoacetyltriglycine (MAG3) to provide possible routine urological follow-up was evaluated for the spinal cord injury (SCI) population. Sixty-six SCI patients were examined with radioisotope renography and renal ultrasonography. Excretory urography was done on 46 patients and voiding cystourethrography was done on 46 patients and voiding cystourethrography was done on 59 patients. The time-activity curve patterns of renography were classified into six groups. Curves A were normal. Curves B and C showed various excretion delay but normal effective renal plasma flow (ERPF). Curves D, E, and F showed definite decreased ERPF and excretion delay of different severity. The respective incidence of upper urinary tract complications were 12.0% (10/83) for A, 68.2% (15/22) for B, 100% (4/4) for C, 100% (8/8) for D, 100% (11/11) for E, and 100% (4/4) for F curves. The sensitivity of radioisotope renography was 83.9%, and the specificity was 92.0% in detecting the upper urinary tract complications. There was no adverse effect after 80 renography examinations on 66 SCI patients. As excretion delay occurred in the earlier stage of renal dysfunction, followed by decrease of ERPF, the abnormal time-activity curves can be sensitive indicators to subject SCI patients with early renal deterioration for further urodynamic and morphological studies. For patients with normal renograms, conventional uroradiological studies are not recommended because they are more invasive, cumbersome, and have more side effects as well as higher radiation exposure. We found that radioisotope renography with Tc-99m MAG3 is a safe, noninvasive, sensitive, and valuable urological screening test for SCI patients.