Injection Of Tc-99m Pertechnetate Research Articles

Single-photon emission computed tomography/computed tomography for evaluation of salivary gland dysfunction: preliminary study on diagnostic ability of maximum standardized uptake value.

The aim of this study was to investigate of salivary gland dysfunction with single-photon emission computed tomography/computed tomography (SPECT/CT), especially the relationship between maximum standardized uptake value (SUVmax) of salivary glands and their dysfunction. Five patients (2 submandibular sialolithiasis, 2 Sjögren's syndrome, and 1 parotitis) who underwent SPECT/CT were included in this study. The salivary gland excretion function was defined as A (pre-stimulatory 20min after injection of Tc-99m pertechnetate)/B (post-stimulatory 40min after injection of Tc-99m pertechnetate) using SUVmax of parotid and submandibular glands. SUVmax before stimulation of the submandibular gland with sialoliths in a patient was lower than that in the opposite submandibular gland without sialoliths (5.81 vs 51.37). Furthermore, the A/B using SUVmax in the other patient of submandibular glands with sialoliths was lower than that in the opposite submandibular glands without sialoliths (0.70 vs 1.85). The A/B using SUVmax of right and left parotid gland in a patient with Sjögren's syndrome was 1.06 and 0.74, respectively. Furthermore, the A/B using SUVmax of right and left parotid glands in the other patient with Sjögren's syndrome was 3.20 and 4.32, respectively. The A/B using SUVmax of right and left parotid glands in a patient with left parotitis was 2.26 and 1.58, respectively. The results of the present study indicate that SUVmax using SPECT/CT seems a useful tool for evaluation of the salivary gland dysfunction.

Quantitative Single-Photon Emission Computed Tomography/Computed Tomography for Evaluation of Salivary Gland Dysfunction in Sjögren's Syndrome Patients.

The purpose of the study was to investigate the usefulness of quantitative salivary single-photon emission computed tomography/computed tomography (SPECT/CT) using Tc-99m pertechnetate in Sjögren's syndrome (SS). We retrospectively reviewed quantitative salivary SPECT/CT data from 95 xerostomic patients who were classified as either SS (n = 47, male:female = 0:47, age = 54.60 ± 13.16y [mean ± SD]) or non-SS (n = 48, male:female = 5:43, age = 54.94 ± 14.04y) by combination of anti-SSA/Ro antibody, labial salivary gland biopsy, unstimulated whole saliva flow rate, and Schirmer's test. Thyroid cancer patients (n = 43, male:female = 19:24, age = 46.37 ± 12.13y) before radioactive iodine therapy served as negative controls. Quantitative SPECT/CT was performed pre-stimulatory 20min and post-stimulatory 40min after injection of Tc-99m pertechnetate (15mCi). The %injected dose at 20min and the %excretion between 20 and 40min were calculated for parotid and submandibular glands, generating four quantitative parameters: %parotid uptake (%PU), %submandibular uptake (%SU), %parotid excretion (%PE), and %submandibular excretion (%SE). The most useful parameter for SS diagnosis was investigated. The uptake parameters (%PU and %SU) were significantly different among the SS, non-SS, and negative controls (p = 0.005 for %PU and p < 0.001 for %SU, respectively), but the excretion parameters (%PE and %SE) were not (p > 0.05 for both). The %PU and %SU were significantly lower in SS than in the negative controls and non-SS (p < 0.05 for all pair-wise comparisons). Additionally, the %SU was significantly lower in non-SS than in the negative controls (p < 0.05). Receiver-operating characteristic analysis revealed that the %SU had the greatest area-under-the curve of 0.720 (95% confidence interval = 0.618-0.807). Using the optimal cut-off value of %SU ≤ 0.07%, SS was identified with a sensitivity of 70.21% and a specificity of 70.83%. Reduced submandibular uptake of Tc-99m pertechnetate at 20min (%SU) was proved useful for the diagnosis of SS. Quantitative salivary gland SPECT/CT holds promise as an objective imaging modality for assessment of salivary dysfunction and may facilitate accurate classification of SS.

Diagnostic contribution of quantitative analysis of salivary scintigraphy in patients with suspected Sjögren's syndrome

AimThe evaluation of the salivary scintigraphy is part of the classification criteria of Sjögren's syndrome (SS). The aim of the study was to determine a method of quantitative evaluation of this technique with easy application and high diagnostic accuracy. Material and methodsA review was carried out on a total of 111 patients with clinical suspicion of SS, referred to our department over the last 4 years (94 women, range 14–82 years). Thirty-minute dynamic studies were performed after injection of 99mTc-pertechnetate, with secretory stimulus at 15min. After drawing regions of interest in both parotids, submandibular glands, and in the background, quantitative parameters were determined. These included the ejection fraction, uptake ratio at 15min, and the percentage uptake (PC). Based on the definitive diagnosis, the subjects were classified into patients with SS, with sicca syndrome, and healthy subjects. ResultsSignificant differences were found between the SS group and healthy subjects in the 3 quantitative parameters for the 4 glands. Significant differences in the PC parameter were observed between the group with sicca syndrome and healthy subjects. ROC analysis showed that the best differentiation parameter for the 3 groups was the PC in both parotid and submandibular glands. ConclusionsThe quantitative analysis of salivary scintigraphy has proved to be a useful method and easy to apply in daily practice to differentiate patients with SS from healthy subjects, with the PC, both in parotid and submandibular glands, being the parameter with highest diagnostic accuracy.

Elimination of extracranial blood flow during dynamic cerebral perfusion studies using diffusible and non-diffusible radioisotope.

The extracranial blood flow seriously complicates the interpretation of dynamic cerebral studies. To eliminate this, we used a blood pressure cuff placed around the head in 50 patients with no evidence of cerebrovascular disease. The pressure in the headband was increased to 30 mmHg above the patient's systolic pressure, and the first 60 sec static scintigram was taken exactly 3 min after the injection of 99mTc-pertechnetate. A second 60 sec static scintigram was taken without pressure in the headband at 6 min after injection. After correction for diffusion of tracer into extravascular compartments we could still show 13% reduction in counting rates over the hemispheric regions and 30% over the convexity regions during application of the pressure headband. With the Xenon method, the application of the headband appears to have insignificant influence on the results of cerebral perfusion. We thus recommend that a headband should be used for dynamic 99mTc-isotope cerebral circulation studies.

Development of a test to measure gastric accommodation in humans

Postprandial symptoms of bloating, distension, early satiety, and nausea are associated with impaired postprandial gastric accommodation, which is detectable by means of an intragastric, barostatically controlled balloon in the proximal stomach and by ultrasound in the distal stomach. Our aim was to develop a noninvasive method to measure the entire gastric accommodation reflex. In 10 healthy volunteers, we used single photon emission computed tomography (SPECT) to measure fasting and postprandial gastric volumes. This method involved intravenous injection of (99m)Tc pertechnetate and gastric reconstruction of tomographic images with Analyze software. SPECT-Analyze imaging detects the postprandial gastric accommodation reflex in vivo. Mean fasting gastric volume was 182 +/- 11 (SE) ml and mean postprandial volume was 690 +/- 32 ml (P < 0.001). Both proximal and distal segments of stomach showed a two- to almost fourfold difference in volumes postprandially. Intraobserver coefficients of variation in estimated fasting and postprandial volumes were 9 and 8%; interobserver variations were 13 and 12%, respectively. SPECT-Analyze noninvasively measures postprandial gastric (total, proximal, and distal) accommodation in humans. This method appears promising to compare the accommodation response in health and disease and to perform mechanistic studies of the accommodation response.

Another "rim sign". A patent processus vaginalis demonstrated by peritoneal Tc-99m sc scintigraphy.

The rim sign Is usually associated with a missed testicular torsion. Here, a rim sign was demonstrated during peritoneoscintigraphy, in a case of an indirect Ingulnal hernia. Activity was found not only along the inguinal canal, but also around the testicle due to a large patent processus vaginalis. An intravenous injection of Tc-99m pertechnetate helped evaluate the respective size of the right and left sides of the scrotum.

Subcutaneous Radionuclide Venography

Traditional acupuncture points K-3 are physiologically tender points located halfway between the Achilles tendon and the medial malleolus. Recently, the authors developed a new method of radionuclide venography of the lower limbs, namely subcutaneous radionuclide venography (SC-RNV), by subcutaneous injection of Tc-99m pertechnetate at these points. The authors applied this method in a patient with suspected deep vein thrombosis of both lower limbs. For comparison, ascending radionuclide venography by intravenous injection (IV-RNV) of Tc-99m MAA and color Doppler ultrasound were also done. The SC-RNV showed partial obstruction of right popliteal vein and complete obstruction of the left popliteal vein with prominent collateral flows. These results were compatible with the findings of color Doppler ultrasound. However, the IV-RNV showed small narrowing with patency of the left popliteal vein, and normal flow on the right. This suggests that the results of SC-RNV may be different from that of IV-RNV. The benefits of SC-RNV in the detection of deep vein thrombosis are described.

Radionuclide Venography by Subcutaneous Injection of Tc-99m Pertechnetate at Acupuncture Point K-3: A Case Report

Recently, we developed a new method of radionuclide venography of lower limbs, namely SC-RNV, by subcutaneous injection of Tc-99m pertechnetate at acupuncture points K-3. In this study, we applied this method to evaluate the venous drainage of lower limbs in a patient with severe varicose veins and edematous swelling of the left lower extremity. For comparison, an ascending radionuclide venography by intravenous injection of Tc-99m MAA (IV-RNV) was also done. The SC-RNV showed normal venous drainage of the right side but complete obstruction of the left popliteal vein with a prominent collateral flow, compatible to the findings of IV-RNV. The findings in this case again demonstrated that SC-RNV may be useful as an alternative method of venography as previously suggested.

Differences in Acupuncture Point SP-10 and Non-acupuncture Point Following Subcutaneous Injection of Tc-99m Pertechnetate

A new method of radionuclide venography, namely SC-RNV, by subcutaneous injection of Tc-99m pertechnetate at acupuncture points was recently developed in our laboratory. The time-activity curve of SC-RNV can be divided into 3 phases as: the phase of diffusion of radioisotopes through the subcutaneous space, the phase of entrance of radioisotopes into intravascular space to reach a peak concentration and the phase of equilibrium state of radioisotopes in the intravascular space. In this study, we used the 3 phases of SC-RNV to evaluate the absorption of Tc-99m pertechnetate injected subcutaneously in the acupuncture point SP-10 (Xuehai) and in a non-acupuncture point near SP-10. The results revealed that the absorption of Tc-99m pertechnetate via SP-10 was significantly greater than that of non-acupuncture point, evidenced by shorter phase 1, higher peak activity and greater accelerating rate of phase 2. This suggests that the absorption of radioisotopes from acupuncture point is faster and greater than that of non-acupuncture point.

Subcutaneous Injection of Thallium-201 Chloride and Gallium-67 Citrate at Acupuncture Point K-3. An Animal Experiment and a Human-Being Study.

Subcutaneous (SC) injection of 99mTc pertechnetate (99mTc) at acupuncture points K-3 is a new method of lower-limb radionuclide venography. To investigate the mechanism of absorption of 99mTc from SC injected sites into vascular system, various radioisotopes such as 201Tl chloride (201T1) and 67Ga citrate (67Ga) were SC injected at K-3 points in animal and humanbeings experiments. It was found that 99mTc and 201Tl were absorbed rapidly from K-3 points through venous system and into whole body soft tissue. However, 67Ga with a larger effective ionic radius than 201Tl did not be absorbed throughout the observation of 5 minutes. Furthermore, intravenous administration of digitalis, a Na+-K+ pump blocker, did not inhibit the absorption of 99mTc and 201Tl after SC injection at K-3 points. These results suggest that absorption of radionuclides on SC injection at K-3 points is mainly through the passive pathway of diffusion rather than the active transport, and the effective ionic radius may be a major factor influencing the absorption rate of the radionuclides.

FACTORS INFLUENCING PERTECHNETATE UPTAKE BY RABBIT KNEES

The accumulation of radioactivity over rabbit knees immediately after the injection of 99mTc-pertechnetate or one of two 99mTc-labelled particulate preparations has been measured in animals with and without experimental arthritis. The results indicate that in inflamed, but not normal joints, a peak of radioactivity is detectable within 9 seconds of injection and suggest that the rate of accumulation of radioactivity over the joint may be a more sensitive indicator of inflammatory activity than measurement at a fixed time. Clearance from the circulation and tissue distribution of the three radioactive preparations were also measured.

Assessment of regional blood flow by intravenous injection of 99m-technetium-pertechnetate.

A general method for computation of regional blood flow from time-activity curves obtained after intravenous injection of 99m-TC pertechnetate is presented. The method is based on the well-known principle of Meier and Zierler, but, it also considers the dispersion of an intravenously injected activity-bolus as well as the recirculation of the nondiffusible tracer. The problems arising from the use of a nondiffusible indicator concerning the partition coefficient lambda are discussed. This method of blood flow determination is adopted for measurements of cerebral blood flow and some first results are discussed.

Transit time of a radionuclide bolus through inferior vena cava.

The effect of an intrinsic block or extrinsic pressure on blood flow through the inferior vena cava (IVC) was studied after rapid injection of 99mTc-pertechnetate or 99mTc-phytate into the femoral vein. Peak-to-peak transit time (PTT) between the curves generated at IVC origin and over the cardiac blood pool was measured in twelve normal patients (PTT = 2.0 +/- 0.7 s) and six patients clinically suspected of circulatory impediment through the IVC (PTT = 3.0 to 30.0 s). PTT measurements augmented the information obtained from sequential scintiphotos of IVC circulation. It is felt that this may be a more objective parameter for follow-up of patients having a progressive, primary disease of this vessel.

The retained gastric antrum. A case report.

A case of retained gastric antrum, confirmed by radiographic and isotopic techniques, is presented. Any patient with chronic, recurrent peptic ulceration following subtotal gastric resection and gastrojejunostomy should have an adequate upper gastrointestinal series with filling of the afferent loop. In addition, intravenous injection of 99mTc pertechnetate is a noninvasive technique which aids in the identification of a retained gastric antrum.

Sequential brain scanning as an adjunctive scanning procedure.

Sequential brain scans were performed at various time intervals of up to four hours after injection of 99mTc pertechnetate in 108 patients who had previously undergone "routine" one-hour brain scans which were considered normal or equivocal. Forty-six patients were proved to have a discrete morphologic brain lesion. Pathologic processes were demonstrated by the sequential scanning technique in all but 6 cases. In nearly a third of these 46 patients (28%), careful observation of the progressive and subtle changes in radioactivity in the whole sequential scan series was necessary for detection of the lesions: they could not be appreciated on any single static scan when viewed independently.

Radionuclide Angiography in Juvenile Angiofibroma of the Nasopharynx

Radionuclide angiography was performed by intravenous injection of 99mTc-pertechnetate and recorded by serial gamma camera scintiphotographs. Its usefulness as a prebiopsy or preoperative procedure is demonstrated by two case reports of angiofibroma of the nasopharynx and it was also found to be useful for radiation therapy follow-up assessment. Radionuclide angiography offers a convenient and safe method to assess the vascularity of a mass and by this technique the surgeon may be alerted to the possibility of severe postbiopsy hemorrhage and also the occasional dramatic complications of radiological carotid angiography can be avoided.

Left ventricular performance after myocardial infarction assessed by radioisotope angiocardiography.

Radioisotope angiocardiography was performed by peripheral venous or pulmonary arterial injection of 99m Tc pertechnetate in 64 patients with acute myocardial infarction. End-diastolic volume determined with this technic averaged 101 ± 7 (± sem ) ml/m 2 and was elevated (&gt; 90 ml/m 2 ) in 47 patients. Initial ejection fraction (EF) averaged 0.38 ± 0.03 and was reduced (&lt;0.52) in 58 patients. The extent of diameter shortening at the minor left ventricular equator determined from the isotope angiocardiograms was depressed in 51 patients, a reduction which was not consistently related to the site of infarction determined electrocardiographically. In 53 survivors EF averaged 0.40 ± 0.02, compared to 0.26 ± 0.07 ( P &lt; 0.05) in 11 patients who died within 1 month. EF correlated inversely with infarct size estimated by analysis of serial changes in serum CPK activity (r = 0.71, n = 42). Of the 64 patients with acute infarction, 47 exhibited abnormal wall motion detectable by the radionuclide technic and confirmed by radarkymography. Serial radioisotope angiocardiograms (6 hours-1 month) showed improvement of cardiac function in 30 of 55 patients, with no change in 12, and deterioration in 13 patients. Results obtained indicate that radioisotope angiocardiography performed by peripheral intravenous injection of 99m Tc pertechnetate can be performed safely, rapidly, and serially without hemodynamic perturbation to assess left ventricular performance in patients critically ill with acute myocardial infarction.

Sensitivity of brain scanning in the detection of arteriovenous malformations.

99mTc pertechnetate brain scans and cerebral angiograms were correlated in 10 cases of arteriovenous malformation. Lesions 2.7 em or more in mean diameter were detected by rectilinear scanning technique after the injection of 99mTc pertechnetate intravenously. Limitations of detection appear to be more dependent on size than on location.