The effects of natural ostium and nasoantral window on mucosal regeneration after maxillary sinus surgery in rabbits.

The aims of the study were to investigate the effects of natural ostium and the nasoantral window on the mucosal regeneration after maxillary sinus surgery and to detect the changes in the mucociliary clearance during regeneration process. Twenty-eight rabbits were studied. In the study group consisting of 21 rabbits, the mucosa of each right maxillary sinus was totally removed, natural ostium was occluded with bone-wax and a nasoantral window was created, while the left sinus mucosa was removed and the natural ostium was left open without creating a nasoantral window. Maxillary sinus mucosa taken during surgery was investigated by light and electron microscopy. The study group was divided into three subgroups. The first group was followed for 2, the second for 4, and the last group for 8 weeks. At the end of these periods, the mucociliary function was evaluated scintigraphically using 99mTc-Human serum albumin. Following this investigation mucosal biopsies were taken from the right and left sinuses and the rabbits were sacrificed. In the control group consisting of 7 rabbits a small hole was opened in the anterior wall of the maxillary sinus of each rabbit and the scintigraphic evaluation was performed for this group at the end of each follow up period as well. In the histopathologic investigation, no difference was found between the natural and the nasoantral window using light microscopy, but there was a difference between them in the electron microscopic findings (p < 0.05, Chi-square test). The scintigraphic, light and electron microscopic findings and gross appearances of the sinuses are discussed.

Evaluation of metastatic bone disease with pentavalent 99Tc(m)-dimercaptosuccinic acid: a comparison with whole-body scanning and 4/24 hour quantitation of vertebral lesions.

The aim of this study was to establish the value of 99Tcm(V)-DMSA scintigraphy in the detection of metastatic bone lesions and compare the results to 99Tcm-MDP bone scintigraphy. Thirty-four patients presenting with metastatic bone disease (Group 1) and 12 controls with degenerative skeletal lesions (Group 2) were studied. Conventional bone scanning and 99Tcm(V)-DMSA whole-body scanning were performed on all patients. All scans were interpreted visually. Furthermore, lesion-to-normal bone ratios (L/N) in vertebral metastases on the 4 and 24 h bone scans were obtained in 58 lesions of cancer patients and in 23 benign (degenerative) vertebral lesions of the control group. 99Tcm-MDP L/N ratios at 24 h (3.08 +/- 0.32) were significantly higher than those at 4 h (2.48 +/- 0.24) in the malignant foci (P < 0.001). No significant difference was observed in benign lesions (P > 0.05). In 167 (164 metastatic, 3 traumatic) of 186 99Tcm-MDP positive lesions (90%) of Group 1, 99Tcm(V)-DMSA uptake was observed. The remaining 19 lesions (10%) were 99Tcm(V)-DMSA negative. Fourteen of these 19 sites were diagnosed as benign. The remaining five foci were malignant. In four lung cancer metastases showing no 99Tcm-MDP uptake, 99Tcm(V)-DMSA uptake was observed. There was no 99Tcm(V)-DMSA accumulation in any of the 99Tcm-MDP positive degenerative lesions of Group 2. All quantitatively evaluated (n = 42) vertebral metastatic foci and two compression fractures in Group 1 showed 99Tcm(V)-DMSA accumulation and an increased 99Tcm-MDP L/N ratio at 24 h. A total of 36 degenerative lesions (Groups 1 and 2) and one compression fracture (Group 1) showed neither 99Tcm(V)-DMSA uptake nor an increased 99Tcm-MDP L/N ratio at 24 h. Our results indicate that quantitative 4/24 h analysis of vertebral lesions on 99Tcm-MDP scans has a similar diagnostic value to 99Tcm(V)-DMSA imaging in the detection of bone metastases. However, the accumulation of 99Tcm(V)-DMSA in four lung cancer metastases showing no 99Tcm-MDP uptake is encouraging and justifies further research in patients with proven bone metastases and negative bone scans.

Comparison of Tc-99m MDP, Tc-99m HSA and Tc-99m HIG uptake in rheumatoid arthritis and its variants.

Tc-99m polyclonal immunoglobulin-G has been shown to be a successful agent in the depiction of active inflammation in rheumatoid arthritis (RA). The objective of this study was to compare the uptake behaviors of Tc-99m HIG and Tc-99m MDP in RA and variants of rheumatoid arthritis (VRA). Seventeen patients with RA and 8 patients with VRA presenting with active inflammation were included in this study. Ten subjects with well-diagnosed degenerative joint disease constituted the control group. All joints in patients were also imaged with Tc-99m HSA to evaluate the vascularization status of the joints. Tc-99m HIG and HSA scans were obtained at 2, 4 and 24 hours after the injection of 555 MBq Tc-99m HIG and 296 MBq Tc-99m HSA. Conventional bone scans were performed 4 hours after the injection of 740 MBq Tc-99m MDP. Target-to-background (T/B) ratios were obtained exclusively over the joint regions. Tc-99m HIG T/B ratios of the active joints in RA were significantly higher than those of the non-active joints and the control group (p < 0.05). Tc-99m HIG T/B ratios in active joints showed a progressive increase between 2 and 24 hour images (p < 0.05). In contrast, Tc-99m HSA T/B ratios decreased in all active joints significantly (p < 0.05) except the ankle joint region (p > 0.05). The T/B ratios in Tc-99m MDP bone scans were higher in all active joints than in non-active RA joints and joints of controls but significantly differences were only detected in wrist and elbow joints. All clinically active joints in VRA patients accumulated Tc-99m HIG and HSA, and showed increased Tc-99m MDP uptake. These joints had a very similar Tc-99m HIG retention pattern to the RA joints. The detection rate of active joint inflammation with Tc-99m HIG was much higher than that with Tc-99m MDP. The increasing Tc-99m HIG uptake ratio between 2 and 24 hours in contrast to Tc-99m HSA indicates the presence of other binding mechanisms besides increased vascularity in RA.

Bilateral pulmonary artery aneurysms in a patient with Behcet syndrome: evaluation with radionuclide angiography and V/Q lung scanning.

The case of a 14-year-old girl with Behcet syndrome is described. Besides painful and recurrent oral ulcerations, the patient had a cough and intermittent hemoptysis. The initial chest roentgenogram revealed bilateral parahilar opacities. CT and MRI scans of the thorax showed bilateral thrombosing aneurysms of the pulmonary arteries. Pulmonary blood flow imaging was performed after technegas ventilation lung scanning and Tc-99m MAA injection using a first-pass radionuclide angiography procedure. Altered blood flow in the left pulmonary artery was shown. Bilateral and well-defined ventilation/perfusion mismatched areas suggested a high probability of pulmonary embolism. Little additional information was obtained on subsequent contrast pulmonary angiography. The high incidence of pulmonary artery hypertension and associated vascular injury risk makes pulmonary angiography an unsafe procedure in patients with pulmonary Behcet syndrome. The need for pulmonary angiography could be obviated in such cases with the use of high-precision MRI and ventilation/perfusion lung scanning, including radionuclide pulmonary angiography.

Pulmonary Tc-99m tetrofosmin imaging: clinical experience with detecting malignant lesions and monitoring response to therapy.

The authors prospectively investigated the uptake and kinetics of Tc-99m tetrofosmin (Tetro) in benign and malignant lung lesions and the effect of radiotherapy, chemotherapy, or both on Tc-99m Tetro uptake in malignant lung tumors. Dynamic and planar Tetro imaging were performed in 45 patients with pulmonary lesions during a period of 28 months (34 untreated malignant tumors, 11 benign lesions). Tetro uptake was visibly increased in 26 of 34 malignant tumors, with a mean lesion to contralateral normal tissue ratio of 1.44 +/- 0.29 and a tumor washout rate of 28.4 +/- 6.6% 30 minutes after injection. In 3 of 11 benign lesions, Tetro uptake was observed. Of the 26 patients with malignant tumors and positive Tetro uptake, nine had repeated imaging 6 to 8 weeks after therapy. The patients were treated with radiotherapy, chemotherapy, or both. Reduction in radiological tumor size was used as the clinical response parameter. In five of nine patients, the course of Tetro uptake in follow-up imaging was in accordance with that of radiological tumor size. Two of four remaining patients had only slight discordance between the alteration of Tetro uptake and radiological tumor size. The sensitivity of Tetro to detect malignant lung lesions in our patients was 77%. The specificity and accuracy of the method were 73% and 76%, respectively. Tetro has limited diagnostic value in detecting lung cancer. It may be useful to monitor the response to therapy in malignant lung tumors with initial tracer uptake. Broader trials on this matter are needed for further clarification.

Gastric emptying time in patients with primary hypothyroidism.

BACKGROUND AND OBJECTIVES: Symptoms due to slowing of gastrointestinal motility constitute an important problem in most patients with primary hypothyroidism. The purpose of this study was to calculate gastric emptying time in patients with primary hypothyroidism using a radioisotopic method. PATIENTS AND METHODS: Fifteen hypothyroid patients (2 male, 13 female) participated in the study. Mean age was 43 (range 38-50) years. Only patients who had been recently diagnosed and had received no previous therapy were included in the study. Radiological and endoscopic examination of the upper gastrointestinal tract was carried out. Patients with gastric outlet obstruction were excluded. Twelve healthy and euthyroid people with no detectable gastrointestinal pathology were examined as a control group. The mean age of this group was 45 (range 35-55) years. Patients and control group received a semisolid meal containing 1 mCi technetium-99m sulphur colloid and measurements were made from the epigastrium. RESULTS: Mean gastric emptying half-time (t(half)) was 112.13+/-48.96 min in hypothyroid patients and 57.87+/-6.38 min in the control group. Gastric emptying time of the hypothyroid patients was significantly different from the control group (P< 0.001). There was no correlation between gastric emptying time and serum thyroid-stimulating hormone (TSH) levels. CONCLUSION: We concluded that radioisotopic study is a safe, rapid and reliable method for determining gastric emptying time in patients with primary hypothyroidism.

Transient reverse ventilation-perfusion mismatch in acute pulmonary nitrofurantoin reaction.

A 67-yr-old woman with a history of myocardial infarct was admitted to emergency for marked dyspnea, nonproductive cough, nausea and fever. The thorax X-ray revealed a bilateral alveolar and interstitial infiltration pattern with basal accentuation. The cardiac examinations were normal. Technegas ventilation and Tc-99m-macroaggregated albumin (MAA) perfusion scans were performed to rule out pulmonary embolism. Bilateral multiple ventilation defects with normal perfusion was observed. The patient had been taking nitrofurantoin for four days for a bladder infection. Hypersensitivity to nitrofurantoin was suspected and the drug was discontinued. An antihistaminic and anxiolytic medication was started. The majority of the clinical symptoms disappeared within 24 hours. The control chest X-rays disclosed a marked improvement. Ventilation and perfusion scans obtained 48 hours after nitrofurantoin withdrawal were normal. The drug-related pulmonary reactions should be taken into account in patients on medication. Reversible ventilation defects can be the only lung-scintigraphic finding encountered in acute pulmonary nitrofurantoin reaction.

Demonstration of frontal hypoperfusion in benign exertional headache by Technetium-99m-HMPAO SPECT.

We present a case of benign exertional headache (BEH) in a 15-yr-old boy. The patient suffered from exclusively exercise-induced headaches with migraine-like accompanying symptoms. No pathology could be detected by routine cardiovascular or neurological examinations by CT. The postexercise 99mTc-HMPAO brain SPECT performed during the provoked headache attack showed asymmetric bifrontal hypoperfusion. A second 99mTc-HMPAO study during a symptom-free phase under resting conditions was normal. The detection of impaired regional cerebral blood flow (rCBF) by 99mTc-HMPAO brain SPECT indicates a perfusion-related pathology in this type of headache. Analysis of rCBF with 99mTc-HMPAO in larger studies could be helpful in the clarification of BEH pathogenesis.

Variable kidney position mimicking renal artery branch stenosis in a Tc-99m-DTPA captopril scintigraphy.

Tc-99m-DTPA captopril scintigraphy was performed in a patient with suspected renovascular hypertension. Markedly impaired right renal function (Glomerular filtration rate (GFR) values for the right kidney = 14 ml/min, left kidney = 79 ml/min) was detected in the initial captopril study. Only lower pole activity of the right kidney was observed during the whole study. Since prior ultrasonographic examinations have shown bilateral normal kidney parenchyma, branch stenosis of the right upper pole was suspected. Besides significant function improvement in the following baseline study (GFR values for the right kidney = 59 ml/min, left kidney = 79 ml/min), the right kidney, this time normally shaped, was visibly higher positioned. Because of the possibility of mobile kidney and/or branch stenosis, the patient underwent selective renal angiography. A long pediculed right kidney without renal artery stenosis was found. The final diagnosis was essential hypertension. Kidney position anomalies could influence the reliability of the captopril scintigraphy, particularly when a theoretical kidney depth formula is employed for the attenuation correction.

Technetium-99m-tetrofosmin uptake in malignant lung tumours.

Technetium-99m-tetrofosmin is a new myocardial imaging agent which has yielded promising results compared to thallium-201. The tumour-seeking properties of the routinely used cardiac radiopharmaceuticals 201TI and 99mTc-methoxyisobutylisonitrile are well known. Here we report the results of a pilot study demonstrating 99mTc-tetrofosmin uptake in malignant lung tumours. Five patients with bronchial carcinoma, each in different stages of chemo- or radiotherapy, were imaged. Dynamic and static acquisitions were performed to evaluate the uptake and kinetics of 99mTc-tetrofosmin in the lesions. In four of the five patients localized tumour uptake of 99mTc-tetrofosmin was observed. Time to peak tumour activity and tracer washout in the tumour, myocardium and contralateral normal lung at 30 min post injection (p.i.) were determined. Tumour/normal lung, heart/tumour and heart/contralateral normal lung ratios were calculated for 5-10, 25-30 and 85-90 min p.i. The peak concentration in all tumours was reached at the end of the first minute. The mean tumour and contralateral normal lung washout rates of 99mTc-tetrofosmin at 30 min p.i. were 18.3% +/- 9.2% and 19.5% +/- 5.85% respectively. The tumour/contralateral normal lung ratio remained higher than 1.25 until 90 min p.i. in all four patients. It is concluded that 99mTc-tetrofosmin seems to be of value in lung tumour imaging, although larger studies are necessary to ascertain its sensitivity, specificity and usefulness in clinical practice.

Thallium-201 uptake in myositis ossificans. Potential pitfall in diagnosis.

Myositis ossificans is primarily a disorder of adolescents or adults, whereby an area of muscle mass undergoes progressive ossification. Its radiographic and scintigraphic appearances have been well documented. In this paper, a case of histopathologically demonstrated myositis ossificans in the proximal thigh with unexpected TI-201 accumulation was presented.

Reflex sympathetic dystrophy syndrome secondary to organophosphate intoxication induced neuropathy.

Reflex sympathetic dystrophy or Sudeck's atrophy is a syndrome that can usually be followed by a traumatic insult. This disorder is accompanied by signs and symptoms of vasomotor instability, trophic skin changes, and rapid development of bony demineralization. This report presents a case with reflex sympathetic dystrophy syndrome secondary to organophosphate intoxication induced neuropathy. The patient was threated with calcitonin well.