Physiological fluorodeoxyglucose uptake of spinal cord in adults.

OBJECTIVE: Physiological fluorodeoxyglucose (FDG) uptake of spinal cord needs to be correctly recognized during evaluation of whole-body PET scans, especially for oncological cases. Our aim was to analyze physiological cord FDG uptake and its relation to gender, age, body weight, environmental temperature and time to imaging. MATERIALS AND METHODS: PET scans of 254 patients in a single year, one patient for every working day were retrospectively selected. Temperature data were obtained from meteorology recordings. Maximum standard uptake value (SUVmax) of spinal cord at cervical and lower thoracic levels were noted. Spinal canal at L5 level, cerebellum and liver were used for normalization. Correlations with age, body weight, time to imaging and environmental temperature were analyzed. RESULTS: Cervical SUV was higher than thoracic SUV (2.5-2.3). Cervical and lower thoracic SUV's were strongly correlated, highest when corrected with L5 level vertebral canal and liver (corr coeff 0.84 and 0.75) and lowest with cerebellum (corr coeff 0.4). Cervical spinal cord FDG uptake was higher for females than males (2.6 to 2.4). Temperature and age did not change spinal cord uptake. There were weak positive correlations with body weight (corr coeff 0.16 and 0.28, cervical and thoracic). There was weak negative correlation of cervical uptake with time to imaging (corr coeff -0.17). CONCLUSION: Spinal cord FDG uptake at cervical and lower thoracic levels are strongly correlated. Females have slightly higher cervical SUV. Age and temperature does not change spinal cord FDG uptake in adults. Cord SUV's slightly increased with body weight.

Colonic Malignant Melanoma: 18F-FDG PET/CT Findings

Primary malignant melanoma occurs most often in the skin and much less frequently in the choroid layer of the eyes, in the leptomeninges, oral cavity, nasal mucosa, pharynx, esophagus, bronchus, under the nail and vaginal or anorectal mucosa. Primary melanoma of the gastrointestinal tract has been confirmed for lesions occurring in the esophagus, stomach, small bowel, and anorectum through several published reports, as these are the areas where melanocytes normally exist. The occurrence of primary malignant melanoma in the colon is relatively rare, because melanocytes are embryologically absent in the large bowel. Herein we report a patient whose colonic malignant melanoma was diagnosed and disseminated metastatic lesions were revealed with 18F-FDG PET/CT scan. There were multiple nodular lesions showing increased 18F-FDG uptake in both lungs. There was a soft tissue lesion with slightly increased 18F-FDG uptake, which extended to the intraluminal region of the thoracic esophagus. Increased metabolic activity was detected in the asymmetric stomach wall thickening site and in a soft tissue lesion located on the gall bladder wall that was filling the lumen. Multiple hypodense/hyper-metabolic lesions were identified in the liver. Multiple hyper-metabolic polypoid soft tissue lesions were visualized in almost the entire colonic segments. Multiple hyper-metabolic peritoneal implants were noted in all abdominal quadrants. Increased 18F-FDG uptake was detected at the right surrenal gland soft tissue lesion. There was a hyper-metabolic soft tissue lesion on the posterior wall of the rectum. Hyper-metabolic lytic lesions were seen at the thoracal and lumbar vertebrae, left scapula, left iliac bone, sacrum and left femur. There was no evidence of 18F-FDG avid skin lesions in both attenuation corrected and non-corrected images.

Can Laws Be a Potential PET Image Texture Analysis Approach for Evaluation of Tumor Heterogeneity and Histopathological Characteristics in NSCLC?

We investigated the association between the textural features obtained from 18F-FDG images, metabolic parameters (SUVmax, SUVmean, MTV, TLG), and tumor histopathological characteristics (stage and Ki-67 proliferation index) in non-small cell lung cancer (NSCLC). The FDG-PET images of 67 patients with NSCLC were evaluated. MATLAB technical computing language was employed in the extraction of 137 features by using first order statistics (FOS), gray-level co-occurrence matrix (GLCM), gray-level run length matrix (GLRLM), and Laws' texture filters. Textural features and metabolic parameters were statistically analyzed in terms of good discrimination power between tumor stages, and selected features/parameters were used in the automatic classification by k-nearest neighbors (k-NN) and support vector machines (SVM). We showed that one textural feature (gray-level nonuniformity, GLN) obtained using GLRLM approach and nine textural features using Laws' approach were successful in discriminating all tumor stages, unlike metabolic parameters. There were significant correlations between Ki-67 index and some of the textural features computed using Laws' method (r = 0.6, p = 0.013). In terms of automatic classification of tumor stage, the accuracy was approximately 84% with k-NN classifier (k = 3) and SVM, using selected five features. Texture analysis of FDG-PET images has a potential to be an objective tool to assess tumor histopathological characteristics. The textural features obtained using Laws' approach could be useful in the discrimination of tumor stage.

Staging with PET-CT in patients with locally advanced non small cell lung cancer is superior to conventional staging methods in terms of survival.

BACKGROUND: Of patients with non small cell lung cancer (NSCLC), around one third are locally advanced at the time of diagnosis. Because only a proprotion of stage III patients can be cured by surgery, in order to improve the outcomes, sequential or concurrent chemoradiation, or concurrent chemoradiation with induction or consolidation is offered to the patients with locally advanced NSCLC. Today, PET combined with computerized tomography (PET-CT) is accepted as the most sensitive technique for detecting mediastinal lymph node and extracranial metastases from NSCLC. We aimed to compare PET-CT and conventional staging procedures for decisions regarding curative treatment of locally advanced NSCLC. MATERIALS AND METHODS: A total of 168 consecutive patients were included from Acibadem Kayseri Hospital, Acibadem Adana Hospital and Kayseri Research and Training Hospital in this study. RESULTS: While the median PFS was 13.0 ± 1.9 months in the PET-CT group, it was only 6.0 ± 0.9 in the others (p<0.001). The median OS values were 20.5 ± 15.6 and 11.5 ± 1.5 months, respectively (p<0.001). DISCUSSION: As a result, we found that staging with PET CT has better results in terms of survival staging. This superiority leads to survival advantage in patients with locally advanced NSCLC.

Sunlight may increase the FDG uptake value in primary tumors of patients with non-small cell lung cancer.

Currently, positron emission tomography with computerized tomography (PET-CT) is the most sensitive technique for detecting extracranial metastases in non-small cell lung cancer (NSCLC). It has been reported that there is a correlation between the maximal standardized uptake value (SUV(max)) of primary tumors and prognosis in patients with NSCLC. The effect of sunlight exposure on PET-CT SUV(max) value is not known. Therefore, we aimed to evaluate the effect of sunlight exposure on PET-CT SUV(max) value in patients with NSCLC. A total of 290 patients with NSCLC from two different regions of Turkey (Kayseri, n=168 and Adana, n=122) that have different climate and sunlight exposure intensity, were included in the study. Age, gender, histology of cancer, cancer stage, smoking status, comorbidity and SUV(max) of the primary tumor area at the time of staging were evaluated as prognostic factors. In the multivariate analysis, we detected that the region was the only independent factor affecting SUV(max) (P=0.019). We identified that warmer climate and more sunlight exposure significantly increases the SUV(max) value of the primary tumor area in patients with NSCLC. Further studies are warranted to clarify the issue.

Does sunlight exposure improve survival in patients with non-small cell lung cancer?

BACKGROUND: Some epidemiological studies reported that sunlight exposure and highvitamin D levels may decrease the morbidity and mortality related to cancer. We aimed to evaluate whether sunlight exposure has an impact on survival in patients with non small cell lung cancer. MATERIALS AND METHODS: A total of 546 patients with NSCLC from two different regions (Kayseri and Adana) differing according to sunlight exposure were analysed retrospectively. RESULTS: The median overall survival (OS) rates were 11. 6 (CI: 9.50-13.6) and 15.6 months (CI: 12.4-18.8) for Kayseri and Adana, respectively, in all patients (p=0.880). CONCLUSIONS: There were no differences between groups in terms of OS. While there is strong evidence regarding inverse relationship between cancer incidence and sunlight exposure, it is still controversial whether sunlight exposure is a good prognostic factor for survival in patients with lung cancer.

No apparent correlation between Behçet's disease and oxidative stress disturbance.

UNLABELLED: Behçet's disease (BD) is a chronic, progressive and inflammatory multisystemic disease, that significantly affects the cardiovascular system. Oxidative stress (OS) is a disturbance in oxidant/antioxidant balance in favor of oxidants. The OS that increases acutely and chronically due to the inflammatory process plays an important role in the pathogenesis of the cardiovascular system effects of the disease by causing endothelial dysfunction in vascular structures. The aim of our study was to investigate the relationship between OS and myocardial perfusion, which is based on microvascular dysfunction, in BD. MATERIAL AND METHOD: Twenty-seven patients with BD (16 M, 11 F, mean age: 38.7 +/- 9.4 years) and 22 healthy volunteers (12 M, 10 F, mean age: 35.8 +/- 6.5 years) participated in our study. Technetium-99m methoxyisobutylisonitrile single photon emission computed tomography (Tc-99m MIBI SPECT) stress-rest test was performed with two-day protocol. Myocardial perfusion scores (summed stress score, summed rest score, summed difference score, fix defect score) and perfusion defect prevalence (stress, rest, ischemic and fixed) were determined as the percentage of left ventricle. Coronary angiography was performed in patients with abnormal myocardial perfusion scintigraphy. For OS analysis, the blood samples were taken immediately before the first imaging procedure and were studied for malondialdehyde, glutathione, nitrite, nitrate, vitamin C, retinol, and carotene. RESULTS: In the BD group, a total of 9 patients had abnormal findings in their stress and rest electrocardiography. Perfusion defect in myocardial perfusion scintigraphy was observed in 14 patients (51.8%). Twelve patients accepted coronary angiography, and their results were normal. In the comparison of myocardial perfusion scores, perfusion defect prevalence and OS parameters, there was a significant difference between the BD and control groups. In the BD group, no correlation was observed between myocardial perfusion scores, perfusion defect prevalence and OS parameters. CONCLUSION: Defects in myocardial perfusion and increase in OS were observed in BD; however, there was no correlation between the two findings in the inactive period. In other words, the prevalence and intensity of myocardial perfusion defects can vary at different OS levels.

The effect of giving detailed information about intravenous radiopharmaceutical administration on the anxiety level of patients who request more information.

OBJECTIVES: Nuclear medicine procedures use radiopharmaceuticals, which produce radiation and potential adverse reactions, albeit at a low rate. It is the patient's ethical, legal, and medical right to be informed of the potential side effects of procedures applied to them. Our purpose was to determine the effect of providing information about intravenous radiopharmaceutical administration on the anxiety level of patients who request more information. MATERIALS AND METHODS: This study was completed in two separate Nuclear Medicine Departments. The study included 620 (247 M, 373 F) patients who had been referred for myocardial perfusion, bone, dynamic renal, and thyroid scintigraphic examinations. The patients were divided into two groups according to whether they requested more information or not. Group 1 consisted of 388 patients who wanted to receive more information about the procedure, while Group 2 consisted of 232 patients who did not request additional information. The State-Trait Anxiety Inventory (STAI-S and STAI-T) was used to determine a patient's anxiety level. After simple information was given, state and trait anxiety levels were measured in both groups. We gave detailed information to the patients in Group 1 and then measured state anxiety again. Detailed information included an explanation of the radiopharmaceutical risk and probable side effects due to the scan procedure. RESULTS: There was no statistical difference between Groups 1 and 2 in STAI-T or STAI-S scores after simple information was given (p = 0.741 and p = 0.945, respectively). The mean value of STAI-S score was increased after the provision of detailed information and there was a statistically significant difference between after simple information SATI-S and after detailed information STAI-S (p < 0.001). The STAI-S score was increased in 246 patients and decreased in 110 patients after detailed information, while there was no change in 32 patients. After detailed information, the greatest increase in STAI-S score was seen in the myocardial perfusion scan patients, when evaluating according to scan procedure (p < 0.001). However, in the dynamic renal patient group, there was no statistical difference (p = 0.271). CONCLUSIONS: Informed consent including detailed information about radiation exposure, the risk factors, and potential adverse reactions of intravenous radiopharmaceutical administration increased the patients' anxiety level in those who request more information.

Evaluation of myocardial perfusion and function by gated SPECT in patients with Behçet's disease.

BACKGROUND: Behçet's disease (BD) is a systemic multi-system vasculitis that can have a wide range of effects on the cardiovascular system. OBJECTIVE: To determine the existence of myocardial perfusion defects caused by coronary microvascular dysfunction in BD and to evaluate coronary arterial distribution and left ventricular systolic function by gated single-photon emission computed tomography (SPECT). METHODS: The study population consisted of 23 (15 men and 8 women) patients with BD and 20 healthy controls (12 men and 8 women). Technetium-99m methoxyisobutylisonitrile (Tc-99m MIBI) gated SPECT studies were performed at stress and rest in a 2-day protocol. Stress and rest left ventricular ejection fraction (LVEF) were calculated. Using non-gated SPECT images myocardial perfusion scores [summed stress score (SSS), summed rest score (SRS), summed difference score (SDS), and fix defect score (FDS)] and perfusion defect extent as percentage (stress, rest ischemic, and fix %LV) were determined. Using gated SPECT images, wall motion score indices (stress wall motion score indices and rest wall motion score indices) were calculated. Coronary angiography (CAG) was applied to patients with abnormal myocardial perfusion scintigraphy (MPS). RESULTS: The mean ages of the BD and control groups were 39.3 +/- 10.6 years and 36.2 +/- 8.3 years, respectively. No statistically significant differences were observed between the two groups regarding clinical features and cardiologic findings. Abnormal MPS was found in 13 (56.5%) of the BD patients; 3 patients had non-transmural infarcts and 10 patients reversible perfusion defects. Reversible perfusion defects were also found in two controls (10.0%). When the two groups were compared regarding the gated SPECT findings, differences were determined in the following parameters; SSS, SRS, SDS, FDS, stress and rest LVEF, stress and rest %LV, and stress and rest WMSI. In the BD group, when gated SPECT results were compared between those with and without abnormal MPS, differences were determined in SSS, SRS, SDS, FDS, stress and rest %LV, and stress and rest WMSI. Epicardial coronary arteries were normal in CAG. CONCLUSIONS: Myocardial perfusion and function are disturbed owing to influenced coronary microvascularity in BD, and CAG is frequently observed to be normal. Gated SPECT is a non-invasive reliable method that simultaneously evaluates the existence, extent and severity of myocardial ischemia or infarction and the wall movements in cardio-Behçet.

Technetium-99m diethylenetriaminepentaacetic acid radioaerosol scintigraphy in organophosphate induced pulmonary toxicity: experimental study.

BACKGROUND: The aim of this experimental study was to investigate pathological signs of lung damages caused by acute organophosphate (OP) poisoning by using Tc-99m DTPA radioaerosol scintigraphy and histopathological investigation. MATERIAL AND METHOD: Fourteen rabbits were divided into two equal groups (n = 7). Group 1 (control group) received normal saline (same volume of fenthion, 2 ml/kg) via orogastric tube. Group 2 (OP toxicity group) received 150 mg/kg of fenthion (diluted fenthion, 2 ml/kg) via orogastric tube. Six hours later, Tc-99m-DTPA aerosol inhalation lung scintigraphy was performed in both groups. Then all rabbits were anesthetized with ketamine hydrochloride (35 mg/kg, i.p.) and xysilazine (5 mg/kg, i.p.), and sacrificed by intracardiac blood discharge. The lungs were then removed. RESULTS: There was a significant difference in T1/2 values of Tc-99m DTPA clearance between control group and OP toxicity group (p = 0.04). Intraparenchymal vascular congestion and thrombosis, intraparenchymal hemorrhage, respiratory epithelial proliferation, number of macrophages in the alveolar, and bronchial lumen, alveolar destruction, emphysematous changes, and bronchoalveolar hemorrhage scores were significantly higher in the rabbits exposed to OP compared with the control group (p < 0.05). CONCLUSION: This study showed that OP toxicity caused a decrease in the alveolar clearance. Tc-99m DTPA radioaerosol inhalation lung scintigraphy was found to be a sensitive determination of acute lung damage in OP poisoning.

Congenital coronary artery fistula as a cause of angina pectoris.

Coronary arteriovenous fistula is an uncommon anomaly, representing an incidental finding in 0.1% to 0.2% of coronary angiograms. A 46-year-old man presented with a five-month history of palpitation and atypical stabbing chest pain on exertion and/or at rest. The electrocardiogram showed normal sinus rhythm, incomplete right bundle branch block with normal axis, and borderline left atrial abnormality. Echocardiography showed normal left ventricular function, mild left ventricular hypertrophy, moderate left atrial enlargement with mild mitral insufficiency, and moderate right atrial enlargement with mild-moderate tricuspid valve regurgitation. During exercise test, frequent ventricular ectopic beats were noted and the patient complained of atypical chest pain. Scintigraphy showed an ischemic defect in the inferior wall of the left ventricle. On coronary angiography, the right coronary artery and left anterior descending artery were normal, but the circumflex coronary artery was connected to the pulmonary artery through a congenital fistula. The patient refused any further intervention for fistula closure.

Acute effect of intranasal estrogen on cerebral and cerebellar perfusion in postmenopausal women.

OBJECTIVES: Estrogen action in the brain influences many neurochemical processes. The aim of the study was to evaluate the acute effect of intranasal 17beta-estradiol on cerebral and cerebellar perfusion in postmenopausal women. METHODS: The study group included 24 healthy postmenopausal women who had been in natural menopause for at least 1 year (mean age: 47.38+/-5.9 years). We conducted an experimental, randomized, placebo-controlled, cross-over, double-blind study. Cerebral and cerebellar perfusion was measured after placebo (saline serum physiologic) or intranasal 17beta-estradiol administration by Single Photon Emission Computed Tomography (SPECT) using technetium-99m-hexamethylpropylene amine oxime (Tc99m-HMPAO). Regions of interest (ROIs) were drawn manually. Cerebral and cerebellar perfusions were calculated for each ROI using average number of counts per pixel. Semiquantitative analysis was performed in bilateral frontal, temporal, parietal and occipital lobes, thalamus, putamen, hippocampus, amygdala, caudate nuclei, cerebellar region, anterior/posterior of cingulate gyrus and pons. RESULTS: After intranasal 17beta-estradiol administration, SPECT study revealed significant increases in cerebral and cerebellar perfusion compared to placebo measurements in all studied slices (p<0.05). There was a positive correlation between serum estrogen levels after 17beta-estradiol and cerebral and cerebellar perfusion. CONCLUSIONS: Administration of single dose intranasal 17beta-estradiol increases cerebral and cerebellar perfusions in healthy postmenopausal women.

Using 99mTc-DTPA radioaerosol inhalation lung scan as compared with computed tomography to detect lung injury in blunt chest trauma.

BACKGROUND: Detection of pulmonary contusion in patients with blunt chest trauma is very important so as to commence therapy immediately to avoid irreversible damage. The purpose of our study was to evaluate the efficacy of technetium-99m diethylene triamine pentaacetic acid (99mTc-DTPA) aerosol inhalation lung scintigraphy in comparison with chest computed tomography (CT) in the diagnosis of pulmonary contusion at acute blunt chest trauma. METHODS: Twenty-nine patients with isolated blunt chest trauma were referred to the emergency department of our hospital, and nine healthy people participated in this study. Sixteen patients who had pulmonary contusion on CT scans were referred to as group 1, and 13 patients who had normal CT scans as group 2. Nine healthy people comprised a control group. 99mTc-DTPA aerosol inhalation lung scintigraphy was performed on the first day in all patients. RESULTS: The mean half time (T1/2) and penetration index values of 99mTc-DTPA clearance were significantly lower in groups 1 and 2 compared with the control group. Among the three groups, there were no significant differences in arterial blood gas analysis except for PO2. The mean T1/2 value of 99mTc-DTPA clearance did correlate with PO2 values but not with pH, PCO2, or HCO3 values. CONCLUSIONS: 99mTc-DTPA radioaerosol inhalation lung imaging may serve as a useful adjunct and supportive method to chest CT scanning for detecting mild pulmonary contusion.

TC-99m MIBI SPECT imaging in patients with lung carcinoma: is it a functional probe of multidrug resistance genes?

OBJECTIVE: Multidrug-resistance (MDR) phenotype concerns altered membrane transport that results in lower cell concentrations of cytotoxic drug in many cancer types, including lung cancer, and is related to the overexpression of a variety of proteins that act as adenosine triphosphate-dependent extrusion pumps. Tc-99m Sestamibi (MIBI) is a transport substrate for P-glycoprotein (Pgp) pump. In this study, we assessed the uptake and clearance of technetium-99m-2-hexakis 2-methoxyisobutylisonitrile (Tc-99m MIBI) from the tumor and its correlation with messenger RNA (mRNA) levels of Pgp, MDR-associated protein (MRP1), and lung resistance protein (LRP) in lung carcinoma. METHODS: This study was carried out on 19 patients (mean age, 60.1 +/- 2.07 years) with advanced-stage lung carcinoma. The tumor samples obtained by bronchoscopy were assessed to estimate the levels of Pgp, MRP1, and LRP expression on mRNA level by quantitative real-time reverse-transcription polymerase chain reaction. Tc-99m MIBI chest imaging was performed 15 and 180 minutes after injection of 740 MBq Tc-99m MIBI. The early (T/Be) and delayed (T/Bd) Tc-99m MIBI uptakes and washout rate (WR) of Tc-99m MIBI from the tumor were measured. RESULTS: No correlation was found between the T/Be Tc-99m MIBI uptake of tumors (T/Be) and the levels of Pgp mRNA, MRP1 mRNA, and LRP mRNA by reverse-transcription polymerase chain reaction. There was a correlation between the mean T/Bd Tc-99m MIBI uptake and Pgp expression of the tumors (P = 0.001, Spearman rho = - 0.702). There was a correlation between the WR of Tc-99m MIBI from the tumor and Pgp expression of the tumor (P = 0.000, Spearman rho = 0.875). Washout rate of Tc-99m MIBI was not related to the levels of MRP1 mRNA (P = 0.93, Spearman rho = 0.02) or LRP mRNA (P = 0.47, Spearman rho = 0.177). CONCLUSIONS: Increased WR of Tc-99m MIBI is related in Pgp over expression of the tumor. Tc-99m MIBI single photon emission computed tomography imaging may be a functional probe of overexpression of Pgp in patients with lung carcinoma. However, Tc-99m MIBI single photon emission computed tomography imaging cannot be used to identify the MDR involved in the MRP1 or LRP in these patients.

Effect of shed blood retransfusion on pulmonary perfusion after total knee arthroplasty: a prospective controlled study.

Postoperative shed blood retransfusion (autotransfusion) is a commonly used salvage method following major surgical operations, such as total knee arthroplasty (TKA). The systemic effects of shed blood are still unclear. We studied the effect of residual substances in the retransfused shed blood, on lung perfusion after TKA. Fifteen unilateral and one bilateral TKAs were performed with autotransfusion (the study group) and 15 unilateral and three bilateral TKAs were performed in a control group. Lung X-rays, arterial blood gases (ABG), D-dimer values, and lung perfusion scintigraphies were performed preoperatively and postoperatively. A mean of 300.0 +/- 335.6 ml of bank blood was needed in the autotransfusion group and a mean of 685.7 +/- 365.5 ml of bank blood was needed in the control group (p=0.001). There was a postoperative segmental perfusion defect at the lateral segment of the superior lobe of the left lung in one patient of the control group and he also had risk factors for thrombosis. Although both groups had a decrease in lung perfusion postoperatively, there were no significant differences among the groups regarding the lung perfusion scintigraphy, chest X-rays, ABG, and D-dimer values. In conclusion, although pulmonary perfusion diminishes following TKA, shed blood retransfusion does not add any risk to pulmonary perfusion.

Evaluation of alveolar clearance by Tc-99m DTPA radioaerosol inhalation scintigraphy in welders.

OBJECTIVES: The welding process produces metal fumes and gases which may affect respiratory health. Technetium-99m diethylenetriaminepentaacetic acid (Tc-99m DTPA) dynamic lung scanning is an easy, noninvasive method to assess disorders of alveolar-capillary barrier permeability secondary to epithelial damage. We aimed to investigate the alveolar clearance by Tc-99m DTPA radioaerosol inhalation scintigraphy in welders, to assess additive effects of exposure to welding fumes and cigarette smoking on clearance rate of alveolar epithelium and to determine the correlation between Tc-99m DTPA aerosol lung scintigraphy and spirometric measurements. METHODS: Nine nonsmoking welders, 9 smoking welders, and a control group of 6 nonsmokers and 6 smokers were accepted to the study. Tc-99m DTPA radioaerosol inhalation scintigraphy was performed in all subjects. Clearance half time (Tl/2) was calculated by placing a monoexponential fit on the curves. Penetration index (PI) was also calculated on the first minute image. Pulmonary function tests of welders and control group were compared. RESULTS: The mean T1/2 values of Tc-99m DTPA of the nonsmoking welders were significantly higher than those of the nonsmoking control group (82.1+/-24.3 min and 48.1+/-9.7 min, respectively; p = 0.003). The mean T1/2 values of Tc-99m DTPA of the smoking welders were higher than those of the smoking control group (53.3+/-24.5 min and 44.5+/-9.7 min, respectively; p = 0.510). PI of the nonsmoking welders was significantly higher than that of the nonsmoking control group (0.46+/-0.38 and 0.39+/-0.46 respectively; p = 0.004). PI of the smoking welders was significantly higher than that of smoking control group (0.43+/-0.38 and 0.37+/-0.45, respectively; p = 0.019). There was a negative correlation between T1/2 value and FEV1% (r = -0.468, p = 0.016), FVC% (r = -0.442, p = 0.024) and FEF25-75% (r = -0.391, p = 0.048) in the welders and control group. No statistically significant differences were found in the values of the standard pulmonary function tests of any of the subjects. CONCLUSIONS: Welding seems to decrease alveolar clearance which causes an increase in the penetration index. This was considered to be due to fibrotic changes and increased number of alveolar macrophages induced by welding fumes.

Detection of hibernate myocardium by 99mTc sestamibi gated SPECT during low-dose dobutamine infusion plus nitrate in patients with first acute myocardial infarction.

AIM: To investigate the role of Tc-MIBI gated SPECT imaging following the administration of low-dose dobutamine plus nitrate (LDD+nitrate) in the assessment of left ventricular function and the perfusion of hibernate myocardial tissue. METHODS: The study group comprised 29 patients diagnosed as having acute myocardial infarction. In the first month post-infarction, Tc-MIBI gated SPECT imaging was performed in all patients at rest-dobutamine stress and LDD+nitrate. Ejection fraction, end diastolic volume (EDV), end systolic volume (ESV), stroke volume, volume, extent score, and reversibility score values were calculated. RESULTS: The findings of Tc-MIBI gated SPECT imaging following the administration of LDD+nitrate and the rest Tc-MIBI gated SPECT findings revealed that while the levels of ejection fraction (P=0.004) and reversibility score (P=0.000) increased significantly, there was a significant decrease in EDV (P=0.001), ESV (P=0.001), volume (P=0.017), stroke volume (P=0.257) and extent score (P=0.039) values. CONCLUSION: The use of Tc-MIBI gated SPECT concomitantly with the administration of LDD+nitrate is useful in the determination of myocardial hibernation in patients with left ventricular failure following acute myocardial infarction.