Technetium-99m-hexamethylpropylene amine oxime lung scintigraphy findings in patients with Behçet's disease.

AIM: Behçet's disease (BD) is a multisystem disorder that is characterized by vasculitis, and consists of a triad of recurrent ulcers of the oral and genital mucosa with relapsing uveitis. The prevalence of pulmonary involvement varies in the range of 1-10% in various studies, and its complications are severe and life threatening. To objectively assess the degree of pulmonary vascular endothelial damage in BD, the lung uptake, and the clearance rate of technetium-99m-hexamethylpropylene amine oxime (Tc-99m-HMPAO) were determined. METHODS: Twenty-three nonsmoking patients with BD (10 female, 13 male) and 11 (six female, five male) healthy nonsmoking controls underwent Tc-99m-HMPAO lung scanning, pulmonary function tests (PFT), chest radiograph examination, contrast-enhanced spiral chest computed tomography scanning, and high-resolution computed tomography examinations. Immediately after the bolus injection of 740 MBq of Tc-99m-HMPAO posterior sequential images were obtained at 1-s intervals for 150 s and subsequent images were obtained at one frame per minute (min) over a 10-min period, using a double-headed gamma camera equipped with a low-energy all-purpose parallel hole collimator. Dynamic images were used to calculate the Tc-99m-HMPAO lung clearance rate (T1/2). Simultaneously, a static anterior image, including a large part of the liver, was obtained of 5-min duration at 10 min after the injection. Regular regions of interests were drawn over the midportion of the right lung and the highest activity area of the liver parenchyma was selected and lung/liver (L/Li) uptake ratios were calculated to represent the degree of pulmonary vascular endothelial damage. RESULTS: Chest radiograph, high-resolution computed tomography, and computed tomography findings in patients with BD were nonspecific for BD. There was also a statistically significant difference between patients with BD (30.26 ± 10.55 s) and normal controls (19.53 ± 6.24 s) on their T1/2 values (P = 0.0004). The results show that the L/Li ratios on the Tc-99m-HMPAO lung scan were significantly higher in patients with BD (0.60 ± 0.19) than those in normal controls (0.39 ± 0.07) (P = 0.0021). Using a cutoff value of 0.50, 15 of 23 (65%) patients with BD had increased L/Li ratios. No correlation was found between the mean T1/2 values of Tc-99m-HMPAO clearance and the PFT in patients with BD. The L/Li ratios were not correlated with PFT in patients with BD. CONCLUSION: The degree of pulmonary vascular endothelial damage was represented as increased L/Li ratios and decreased lung clearance rate measured on the Tc-99m-HMPAO lung scan in patients with BD. Our results indicated that determining the T1/2 values and the L/Li ratios on Tc-99m-HMPAO lung imaging should be an objective method to assess subclinical pulmonary damage even in the early stages of BD in the patients.

Assessment of alveolar epithelial permeability with Tc-99m DTPA aerosol scintigraphy in patients with Sjogren syndrome.

Sjögren's syndrome (SjS) is a systemic autoimmune disease that mainly affects the exocrine glands and usually presents as persistent dryness of the mouth and eyes. Lung disease in SjS has been reported to occur early following clinical presentation of the disease. In this study, technetium-99m diethylene triamine penta-acetic acid (Tc-99m DTPA) aerosol inhalation scintigraphy was used to assess the pulmonary membrane permeability in patients with primary SjS. A total of 18 patients with primary SjS and 13 healthy controls were investigated. Clinical evaluation, chest X-ray examination, pulmonary function tests, Tc-99m DTPA aerosol scintigraphy were performed in all the cases. The presence of respiratory symptoms (dyspnea and cough), duration of sicca symptoms were recorded. The clearance half time of Tc-99m DTPA radioaerosols in patients with SjS (20.49 +/- 2.56 min) was faster when compared to normal controls (42.32 +/- 13.28 min) (P = 0.000) which means that there is a significant increase in lung permeability in patients with SjS compared to the controls. There is also a significant difference between PI of patients with SjS (0.34 +/- 0.09) and that of controls (0.42 +/- 0.07) (P = 0.012). According to the results of our preliminary study, one can detect pulmonary involvement by Tc-99m DTPA aerosol inhalation scintigraphy in patients with primary SjS.

Effects of 99mTc-MIBI and 99mTc-MDP administration on dual-energy X-ray absorptiometry bone mineral density measurements.

OBJECTIVE: Nuclear medicine procedures are often performed in close-time proximity to bone densitometry studies. The purpose of this study was to determine the effects of Tc-hexakis-2-methoxyisobutyl isonitrile (MIBI) and Tc-methylene diphosphonate (MDP) on the accuracy of bone mineral density (BMD) measurements performed using dual-energy X-ray density. METHODS: The effect of a diagnostic dose of Tc-MIBI on BMD estimations in the lumbar spine and the left total hip was assessed in 30 patients (19 female, 11 male; mean age: 55.5+/-10.5 years) by using a Lunar DPX-NT scanner. Thirty patients, admitted to the nuclear medicine department for bone scintigraphy (15 female, 15 male; mean age: 56+/-15.92 years), were included into the study. Each patient underwent dual-energy X-ray density assessment for which a Lunar DPX-NT scanner was used before and 2 h after intravenous injection of Tc-MDP (925 MBq) and Tc-MIBI (1110 MBq). BMD measurements were calculated from lumbar spine (including L2-4) and left hip (including femoral neck, trochanter, and total hip). For statistical analysis, the Wilcoxon test was used and a P value of less than 0.05 was accepted as statistically significant. RESULTS: According to Wilcoxon's statistical test, we found extremely significant changes on the measured BMD, T-score, before and 2 h after the injection of Tc-MIBI for lumbar spine and left hip in 30 patients. We found statistically significant decrement on measured BMD from lumbar spine and trochanter before and 2 h after the injection of Tc-MDP. Although MDP BMD values in femoral neck and total hip were decreased after the injection of Tc-99m, they did not reach a statistically significant value. The comparison of pre-T-score and post-T-score values showed a statistically significant decrease after the injection for only L2-4 lumbar spine (P = 0.002), but left hip of pre-T-score and post-T-score values did not reach a statistically significant value. CONCLUSION: In this study, it was determined that measured BMD values are decreased in lumbar spine for all patients. The magnitude of the effect is dependent on the location of the activity. We assume that some radioactivity from Tc is counted by the densitometer's detector, thus resulting in a decrease in the measured BMD. Scintigraphy and bone densitometry should be performed on different days to avoid artifactual reduction in BMD measurements.

Assessment of alveolar epithelial permeability in Behçet's disease with 99mTc-DTPA aerosol scintigraphy.

OBJECTIVE: Behçet's disease (BD) is a multisystem disorder characterized by vasculitis, and consists of a triad of recurrent ulcers of the oral and genital mucosa with relapsing uveitis. The prevalance of pulmonary involvement varies in the range of 1-10% in various studies and its complications are severe and life threatening. In this study, we investigated the changes of pulmonary epithelial permeability of patients with BD using technetium-99m diethylene triamine penta-acetic acid ((99m)Tc-DTPA) aerosol scintigraphy, so as to begin the therapy regimen as soon as possible. METHODS: Twenty-one nonsmoking patients with BD (8 women, 13 men; mean age 38.67 +/- 8.86 years) and 15 healthy volunteer nonsmoking controls (8 women, 7 men; mean age 50.87 +/- 12.45 years) underwent (99m)Tc-DTPA aerosol inhalation scintigraphy and pulmonary function tests (PFTs). Subjects inhaled 1480 MBq of (99m)Tc-DTPA for 4 min in the supine position. Scintigraphic data were recorded dynamically (1 frame/min) in the posterior projection on a 64 x 64 matrix for a 30-min period using a double-headed gamma camera (Infinia, GE, Tirat Hacarmel, Israel) equipped with a low-energy all-purpose parallel hole collimator. Half time of (99m)Tc-DTPA clearance (T (1/2)) was calculated by placing a mono-exponential fit on the curves. Penetration index (PI) was also calculated by dividing the peripheral total counts by the sum of the peripheral and central total counts on the first minute image, in order to quantify the distribution of the inhaled aerosol. RESULTS: The clearance half time of (99m)Tc-DTPA radioaerosols in the BD patients (24.81 +/- 6.22 min) was faster than in the normal control group (46.53 +/- 22.41 min) (P = 0.004). There was also a significant difference between PI of the patients with BD (0.15 +/- 0.03) and that of the controls (0.21 +/- 0.06) (P = 0.002). No correlation was found between the mean T (1/2) values of (99m)Tc-DTPA clearance or the spirometric measurements in the BD patients. Penetration indices were not correlated with PFT in the BD patients. CONCLUSIONS: Lung epithelial permeability of the patients with BD was significantly higher than that of the normal subjects. The results of this study demonstrated that the assessment of lung epithelial permeability using (99m)Tc-DTPA aerosol scintigraphy could predict the presence of lung involvement in the early stages of BD.