Evaluation of alveolo-capillary permeability in thyrotoxicosis using Tc-99m DTPA aerosol scintigraphy

Surfactant secreted from type II pneumocytes plays an important role in alveolo-capillary permeability. In thyrotoxicosis, high levels of T3 receptors detected at these cells might affect the alveolo-capillary permeability due to increased serum thyroid hormone levels. The results by CO-diffusion capacity measurement in thyrotoxicosis are conflicting. Changes in alveolo-capillary membrane permeability resulting from thyrotoxicosis are not well established yet. This prompted us to investigate the alveolo-capillary permeability in thyrotoxic patients in comparison with CO-diffusing capacity. For this aim twenty-two non-smoking thyrotoxic patients (before treatment) and fifteen healthy voluntary controls underwent 99mTc-DTPA aerosol scintigraphy. CO-diffusing and pulmonary function tests were performed in all subjects. After ventilation of radiotracer through a nebulizer for 15 minutes, 30 dynamic images (1 frame/minute) were taken from both lungs. ROI's were drawn over both lung areas, and the time-activity curves were generated. Then clearance half time (CT1/2) for radioaerosol was obtained. CT1/2 of thyrotoxic patients did not differ from that of the controls: 77.9 +/- 25.9 min vs. 79.4 +/- 22.3 min; p > 0.05. Similar result was found for CO-diffusion parameters. Also there was no significant correlation between CT1/2 and CO-diffusion parameters. We concluded that in patients with thyrotoxicosis, the alveolo-capillary permeability is unaffected. Further experimental research is needed to establish the possible effects of thyroid hormones on alveolo-capillary membrane.     

Water-pipe smoking effects on pulmonary permeability using technetium-99m DTPA inhalation scintigraphy

OBJECTIVE: Although extensive work has been done on cigarette smoking and its effects on pulmonary function, there are limited number of studies on water-pipe smoking. The effects of water-pipe smoking on health are not widely investigated. The aim of this study was to determine the effects of water-pipe smoking on pulmonary permeability. METHODS: Technetium-99m DTPA inhalation scintigraphy was performed on 14 water-pipe smoker volunteers (all men, mean age 53.7 +/- 9.8) and 11 passive smoker volunteers (1 woman, 10 men, mean age 43.8 +/- 12). Clearance half-time (T 1/2) was calculated by placing a monoexponential fit on the time activity curves. Penetration index (PI) of the radioaerosol was also calculated. RESULTS: PI was 0.58 +/- 0.14 and 0.50 +/- 0.12 for water-pipe smokers (WPS) and passive smokers (PS) respectively. T 1/2 of peripheral lung was 57.3 +/- 12.7 and 64.6 +/- 13.2 min, central airways was 55.8 +/- 23.5 and 80.1 +/- 35.2 min for WPS and PS, respectively (p < or = 0.05). FEV1/FVC% was 82.1 +/- 8.5 (%) and 87.7 +/- 6.5 (%) for WPS and PS, respectively (0.025 < p < or = 0.05). CONCLUSIONS: We suggest that water-pipe smoking effects pulmonary epithelial permeability more than passive smoking. Increased central mucociliary clearance in water-pipe smoking may be due to preserved humidity of the airway tracts.     

First-pass scintigraphy with (99m)Tc macroaggregated albumin: a method for evaluating pulmonary arterial flow pulsatility

OBJECTIVES: The aim of this work was to develop and describe a non-invasive scintigraphic technique to detect flow pulsatility in peripheral pulmonary arteries. METHODS: Ten normal volunteers were submitted to a first-pass scintigraphy using Tc macroaggregated albumin (Tc-MAA). A time-activity curve was generated for the right lung lateral third. Activity was shown to be restricted to the arterial compartment of the lungs, since there was no detectable progression of the radiopharmaceutical to the systemic circulation. Consequently, the rise in lung activity was attributed to the arterial inflow and the first derivative of the time-activity curve was assumed to represent pulmonary arterial flow. RESULTS: Pulmonary flow curves showed two main positive peaks in six volunteers, followed by a third small peak in three others. Flow was predominant during systole, with an important reduction in magnitude before the diastolic peak, leading to a negative count variation in eight subjects. This pattern is comparable to that described in central pulmonary vessels by different methods. CONCLUSIONS: First-pass scintigraphy with Tc-MAA was able to detect flow pulsatility in pulmonary arteries. These results need to be confirmed in a larger number of individuals, and, if shown to be reproducible, may increase our understanding of lung flow physiology, and of its modifications in the presence of cardiopulmonary diseases.     

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.     

继发性甲状旁腺功能亢进的99Tcm-MIBI双时相显像

目的评价９９Ｔｃｍ甲氧基异丁基异腈（ＭＩＢＩ）双时相显像法在肾性继发性甲状旁腺功能亢进（ＳＨＰ）患者中的诊断价值。方法２０例因慢性肾功能衰竭行血液透析患者,临床诊断为ＳＨＰ,均行双时相法９９ＴｃｍＭＩＢＩ甲状旁腺显像。运用甲状旁腺／甲状腺（ＰＴ／Ｔ）比值及甲状旁腺指数（ＰＴＩ）观察阳性病灶对ＭＩＢＩ的清除。３例行颈部探查术并作甲状旁腺自体移植。结果８例显像阳性,其中３例手术摘除９枚甲状旁腺,均经病理证实为增生。９９ＴｃｍＭＩＢＩ显像发现其中的８枚,其灵敏度为８８９％。在透析年限长、甲状旁腺素分泌高的患者中,有更高的阳性率。发现有３种ＭＩＢＩ清除类型。结论９９ＴｃｍＭＩＢＩ双时相显像在ＳＨＰ患者中有较高的定位诊断价值。阅片时应考虑病灶清除ＭＩＢＩ的多样性,以免漏诊     

Assessment of hepatic blood flow by PET with 15O water: correlation between per-rectal portal scintigraphy with 99Tc(m)-pertechnetate and scintigraphy with 99Tc(m)-GSA

We performed positron emission tomography with 15O water (H2(15)O) to measure hepatic arterial and portal blood flow. In addition, portal haemodynamics and hepatic functional reserve were measured by per-rectal portal scintigraphy and scintigraphy with galactosyl human serum albumin, respectively. We studied 15 patients who had cirrhosis of the liver with underlying viral infection. After the intravenous injection of H2(15)O, positron emission tomography was performed. Blood samples were obtained after beginning the emission scan. The blood samples and positron emission tomographic images were analysed to calculate the radioactivity in the blood and liver. One-compartment model analysis was used to estimate hepatic arterial and portal blood flow. Computer acquisition of gamma-camera data was started just before the injection of 99Tc(m)-galactosyl human serum albumin. A receptor index and an index of blood clearance were calculated on the basis of the radioactivity of the liver and heart. A 99Tc(m)-pertechnetate solution was instilled into the rectum; serial scintigrams were performed and radioactivity curves for the liver and heart were recorded sequentially. A per-rectal portal shunt index was calculated from the curves. Median portal blood flow was 80 ml x 100 g(-1) x min(-1), median hepatic arterial blood flow was 56 ml x 100 g(-1) x min(-1), and median total hepatic blood flow was 138 ml x 100 g(-1) x min(-1) in patients with cirrhosis. The correlations between portal blood flow and the Child-Turcotte classification score, portal shunt index and receptor index were all significant. Our results show that hepatic arterial and portal blood flow can be measured by positron emission tomography with H2(15)O non-invasively and physiologically. This technique may be useful in pathophysiological studies of liver disease.     

Use of iodine-123 metaiodobenzylguanidine scintigraphy for the detection of amiodarone induced pulmonary toxicity in a rabbit model: A comparative study with technetium-99m diethyltriaminepenta acetic acid radioaerosol scintigraphy

The purpose of the study was; (i) to determine whether 123I-MIBG scintigraphy is sensitive for detection of amiodarone induced pulmonary toxicity (AIPT) and (ii) to compare it with 99mTc-DTPA radioaerosol. Twelve white New Zealand rabbit with initial mean body weight 4.24 +/- 0.47 g were divided into two groups. AIPT group (n = 7) was administered amiodarone (20 mg/kg BW). The control group (n = 5) received the same amount of 0.9% saline. All animals underwent 123I-MIBG and 99mTc-DTPA radioaerosol scintigraphy at the end of the treatment period. 123I-MIBG static thorax images were obtained during 10 minutes at 15 minutes and 3-hours after intravenous injection of the radiopharmaceutical. Lung to heart ratios (LHR) and lung to mediastinum ratios (LMR), and retention index (LRI) of 123I-MIBG were determined. Two days after 123I-MIBG scintigraphy, 99mTc-DTPA radioaerosol scintigraphy was performed, and clearance from the lungs was measured for 10 min (1 min/frame) following termination of inhalation. 123I-MIBG lung retention index (LRI) was significantly higher in the AIPT group than the control (61 +/- 4.6 vs. 40 +/- 4.5, p = 0.01). Early LHR and LMR were significantly lower in the AIPT group than in the control group (p = 0.04, p = 0.01, respectively), whereas those of late LHR and LMR were not significantly different. T1/2 values of DTPA clearance were significantly increased in AIPT group according to the control group (55 +/- 7.2 vs. 86.6 +/- 18.5, p = 0.02). 123I-MIBG scintigraphy is a valuable tool for detecting AIPT in a rabbit model. Additionally, 99mTc-DTPA radioaerosol scintigraphy is an excellent comprehensive investigational tool for detecting AIPT with the added advantage of lower cost.     

Small pulmonary arteriovenous fistulae revealed by scintigraphy during selective injection of 99Tc(m)-macroaggregated albumin

We report a case of small pulmonary arteriovenous fistulae precisely diagnosed by a combination of selective pulmonary arteriography and scintigraphy during (99)Tc(m)-macroaggregated albumin injection via the peripheral pulmonary artery.     

99Tcm-MIBI显像对乳腺癌腋窝转移淋巴结的诊断

目的 评价＾９９Ｔｃ＾ｍ－甲氧基异丁基异腈（ＭＩＢＩ）显像要诊断乳腺癌腋窝转移淋巴结中的价值,方法 １８例病理检查证实的乳腺癌病人,术前均行＾９９Ｔｃｍ－ＭＩＢＩ显像,１４例乳腺未触及肿块者作为对照组,静脉注射＾９９Ｔｃ＾ｍ－ＭＩＢＩ１１０ＭＢｑ后５,３０和６０ｍｉｎ进行早期及延迟显像,分别于左侧位,右侧位和前后位进行观察,患者均在显像扣１周内进行手术治疗,腋窝淋巴结清扫后行病理检查。结果 １８例     

^99mTc—P357血栓显像诊断急性肺栓塞的初步临床研究

为评价９９ｍＴｃＰ３５７血栓显像对急性肺栓塞的诊断价值及其安全性，对７例疑有急性肺动脉血栓栓塞的患者，经静脉注射９９ｍＴｃＰ３５７，１和２小时后行肺平面及断层显像，并与９９ｍＴｃ大颗粒聚合白蛋白肺灌注显像、肺动脉造影、超高速ＣＴ、ＤＳＡ和螺旋ＣＴ对比。结果：４例急性肺栓塞中３例９９ｍＴｃＰ３５７血栓显像阳性，１例溶栓后１个月血栓显像为阴性；另外３例显像结果为阴性，临床诊断分别为慢性肺栓塞、肺血管炎和高血压。初步临床研究表明，９９ｍＴｃＰ３５７对急性肺栓塞的诊断有较大价值。     

In vitro adsorption of 99Tc(m)-MIBI, 99Tc(m)-tetrofosmin, 99Tc(m)-furifosmin and 99Tc(m)O4- onto tubes

Adsorption of radiopharmaceuticals onto disposable syringes has been reported to amount to levels of almost 50%. Data on adsorption of radiopharmaceuticals onto materials used for in vitro studies are extremely limited. We assessed the extent of adsorption of 99Tc(m) hexakis(2-methoxyisobutylisonitrile) (99Tc(m)-MIBI), 99Tc(m)-tetrofosmin, 99Tc(m)-furifosmin and 99Tc(m)O4 onto tubes used for in vitro measurement of cellular uptake of these radiopharmaceuticals. The influence on adsorption of different incubation media, temperature and time of incubation was evaluated. Total (not corrected for adsorption) uptake was compared with corrected, net cellular uptake in SK-BR-3, MCF-7 and liposarcoma cell lines. Values of adsorption ranging from 0.94+/-0.13% to 7.07+/-0.46% were found. The extent of adsorption of all the radiopharmaceuticals varied with the type of incubation medium and the incubation temperature. With 99Tc(m)-furifosmin, adsorption was dependent on the incubation time as well on the incubation temperature and some of the incubation media investigated. Our findings indicate that systematic investigations to evaluate the adsorption of radiopharmaceuticals onto materials used during in vitro studies of cellular uptake should be considered a mandatory aspect of quality control.     

The utility of (99m)Tc-DMSA and Tc(99m)-EC scintigraphy for early diagnosis of ifosfamide induced nephrotoxicity.

A serious undesired effect of certain cytostatics is their nephrotoxicity. In this study, we investigated the toxic effects of ifosfamide and cisplatin by clinical and biochemical parameters in relation to (99m)Tc-dimercaptosuccinic acid ((99m)Tc-DMSA) and Tc(99m)N, N-ethylenedicysteine (EC) renal scintigraphy. The indicators were urinary beta2-microglobulin levels, tubular resorption of phosphate, urinary protein and glucose excretion, glomerular filtration rate, urinary pH and osmolarity. Thirteen paediatric patients (seven boys and six girls), aged 2-16 years, were investigated. Five patients received only cisplatin, six patients were treated with ifosfamide and cisplatin and two with ifosfamide and carboplatin for various malignancies. All except three patients had normal DMSA uptake (median, 19; range, 16-29%) prior to chemotherapy. The reduction in DMSA uptake was unilateral due to tumour invasion in those three patients. Following chemotherapy, DMSA uptake showed reduction in five patients with or without clinical nephrotoxicity. The observed pattern was decreased renal uptake and elevated bladder activity. Three patients with decreased DMSA uptake had normal tubular maximum phosphate reabsorption, which suggested subclinical injury. Decrease in DMSA uptake and tubular phosphate reabsorption (TPR) was detected simultaneously in two patients. No abnormalities were seen on Tc(99m)-EC scintigraphy to suggest nephrotoxicity in our investigation. However, Tc(99m)-EC clearly demonstrated a reduction in split renal function in children with tumour invasion. In summary, we found that ifosfamide induced tubular injury can be detected with (99m)Tc-DMSA scintigraphy before chemotherapy associated nephrotoxicity is observed by laboratory measurements. Our results also imply that, although a tubular agent, renal scintigraphy performed with Tc(99m)-EC is not able to detect subclinical injury or predict the outcome during treatment.