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[Diagnostic value of bone scintigraphy with technetium pyrophosphate. Study of 250 patients].

The authors report the results they obtained by bone scintigraphy using technetium pyrophosphate. In a study of 142 patients with cancer, the authors show, as others have done, that bone scintigraphy makes it possible to find bone metastases that are radiologically undetectable and they emphasize the importance of this discovery. In 7 patients with spondylodiscitis, of whom 1 was without radiological signs at the time the scintigraphy was carried out, the authors always observed localized vertebral hyperfixation and they noted that this examination can be valuable for distinguishing spondylodiscitis from pseudo-Pott's discarthroses and from the lesions of vertebral epiphysitis, which in their experience do not result in isotopic hyperfixation. In 7 patients with epiphyseal osteonecrosis, the authors observed isotopic hyperfixation before the appearance of radiological signs. In 12 patients with osteoporosis, the authors observed hyperfixation in bone in certain compressed vertebrae, whereas other vertebrae that had probably been compressed some considerable time earlier did not fix the isotope excessively. They never observed hyperfixation in vertebrae that were not compressed. Among 5 patients with ankylosing spondylitis with radiological signs of sacro-iliac arthritis, the authors observed sacro-iliac hyperfixation in only 3 cases. Two other patients who had signs indicating ankylosing spondylarthritis, but were without radiological signs of sacro-iliac arthritis did not show sacro-iliac hyperfixation of the isotope. Among 7 patients with Paget's disease, the authors observed hyperfixation in all the bones with radiological signs of disease; in addition, in 3 patients, there was also hyperfixation in certain bones that were radiologically clear.

Bone Diseases↗

[Scintigraphic imaging of knee synovitis in osteoarthritis after intra-articular injection of technetium-99m pertechnetate in the unilateral knee].

A case of left knee synovitis scintigraphic imaging is presented in a 66-year-old patient with bilateral knee osteoarthritis and a right knee Baker's cyst, who had undergone a 74 MBq (99m)Tc-pertechnetate intra-articular injection in the right knee. The findings in this case were compared with the intravenously injected methylene disphosphonate technetium-99m ((99m)Tc-MDP) scintigraphic findings and could be interpreted as the result of (99m)Tc-pertechenate through blood communication from the right to the left knee. This case implies that (99m)Tc-pertechnetate may be useful in imaging the synovitis in multiple arthroses even up to 60 min after its administration, instead of the 5 min imaging after the injection of (99m)Tc-MDP.

Aged↗

Diagnostic efficacy of technetium-99m pentavalent-dimercapto succinic acid versus gallium-67 citrate, imaging in patients with highly suspected acute bone and joint infections.

The purpose of this study was to evaluate and compare the diagnostic efficacy of (99m)Tc(V) dimercaptosuccinic acid ((99m)Tc(V)DMSA) with the (67)Ga-citrare ((67)Ga-C) scintigraphy in patients with suspected bone and joint infection. Thirty one patients, 19 men and 12 women, aged 18-78 y with median age 56 y, with suspected acute bone infection, were enrolled in this study. Besides (67)Ga-C and (99m)Tc(V)DMSA scintigraphy, all patients underwent X-ray radiography and technetium-99m methylene disphosphonate ((99m)Tc-MDP) bone scan for supporting the initial diagnosis. The (99m)Tc-MDP bone scan was considered positive for acute bone and joint infection when all its four scintigraphic phases were positive. Final diagnosis was based on needle aspiration and/or biopsy findings. Sensitivity, specificity, accuracy, positive and negative predictive values (PPV and NPV) were calculated. Our results have shown the following: Seventeen patients (17/31) had histologically confirmed acute bone and joint infections, while the remaining patients had no infection. (99m)Tc(V)DMSA diagnosed bone and joint infections in all positive (17/31) patients while (67)Ga-C in 16/31 patients. Discordant scintigraphic results were observed by (67)Ga-C in 2/31 cases: in one positive case of femur postoperative infection (false negative for (67)Ga-C) and in one case of clinicaly suspected infection in the femur while the patient had a preexisting fracture (false positive with (67)Ga-C). No false negative results were observed with (99m)Tc(V)DMSA. Sensitivity, specificity, PPV, NPV and accuracy were maximum for (99m)Tc(V)DMSA, while for (67)Ga-C were: 94.1%, 93%, 94.1%, 93%, and 93.5% respectively. It is concluded that considering the high sensitivity and specificity of (99m)Tc(V)DMSA in the detection of acute bone and joint infections, the lower radiation dose, the cost and the shorter time spent for the imaging procedure, as compared to (67)Ga-C, (99m)Tc(V)DMSA should be preferred to (67)Ga-C as a bone scan agent for the detection of acute bone and joint infections.

Adolescent↗

[Brown tumors in the technetium-99m methyldiphosphonate bone scan mimicking metastases of parathyroid carcinoma].

This is a case of a 78 year old male with parathyroid carcinoma and multiple bone lesions in the technetium-99m methyldiphosphonate ((99m)Tc-MDP) bone scan, initially interpreted as metastatic bone disease, but finally proved to be brown tumors. The interest of this case lies on the rarity of the disease, as well as the co-existence of osteitis fibrosa cystica, which often resembles metastatic bone disease and leads to diagnostic pitfalls.

Adenoma↗

High alveolar surface tension increases clearance of technetium 99m diethylenetriamine-pentaacetic acid.

The effect of high alveolar surface tension on alveolar epithelial permeability was studied in anesthetized closed-chest mongrel dogs. Alveolar surface tension was elevated by displacement of pulmonary surfactant from the alveolar hypophase by the aerosolized detergent dioctyl sodium sulfosuccinate (OT). After measurement of baseline hemodynamics, arterial blood gases, and airway pressure, the dogs were separated into groups: Group I inhaled a 1% solution of OT (15 mg/kg) in a vehicle of equal parts saline and ethanol; group II inhaled the same volume of vehicle without OT. The pulmonary clearance of technetium 99m diethylenetriamine-pentaacetic acid (99mTc-DTPA) (half-time in minutes) was studied immediately after aerosol (OT and vehicle) delivery and compared with that of historical control values. No change was seen in arterial blood gases and airway pressure after vehicle inhalation, whereas OT caused a marked fall in arterial oxygen tension and increase in airway pressure. Vehicle inhalation effected only a slight increase in DTPA clearance, whereas OT significantly reduced half-time over control and group II. These data suggest that high alveolar surface tension increases alveolar epithelial permeability.

Aerosols↗

[Value and limitatious of scintigraphy of the sacro-iliac joints using technetium pyrophosphate].

Scintigraphic exploration of the sacroiliac (S.I.) joints by 99 m-technetium pyrophosphate is simple and free of all danger. The fixation of the isotope in the right sacroiliac (R.S.I.) and the "normal" limits of the fixation ratios R.S.I./L.R. and the lumbar rachis (L.R.), visible on the same film. A series of 28 controls having made it possible to calculate the "normal" limits of the fixation ratios R.S.I./L.R. and L.S.I./L.R., the isotopic fixation was measured in 25 patients with sacroiliac inflammation, 21 of whom were rheumatic, 3 infectious. It was shown that scintigraphy could yield useful information on the evolution of sacroiliac inflammation, making an early diagnosis possible, and also contributing to differentiation between rheumatic and infectious inflammation.

Adult↗

Unilateral pulmonary metastases from Ewing's sarcoma shown in a technetium-99m-methylene-diphosphonate bone scan.

A 32-year-old man with a history of painful swelling of the right ankle underwent bone scintigraphy, which showed increased uptake in the right ankle and also unexpected diffuse uptake throughout the right hemithorax. A single photon emission tomography scan performed after the intravenous injection of 740 MBq of technetium-99m methylene-diphosphonate ((99m)Tc-MDP) showed abnormal uptake throughout the right lung. Computed tomography (CT) revealed a large mass in the right lower lobe. CT-guided biopsy of this mass led to a diagnosis of metastatic Ewing's sarcoma. Although lung uptake on bone scans has been noted in various occasions (such as: pulmonary alveolar microlithiasis, Pneumocystis carinii pneumonia, and various tumoral lesions), increased uptake of (99m)Tc-MDP in lung metastases of Ewing's sarcoma has not been reported according to our knowledge until now. We report such a case.

Adult↗

Distinguishing soft-tissue hemangiomas from vascular malformations using technetium-labeled red blood cell scintigraphy.

Soft-tissue vascular lesions in children can be classified as either hemangiomas or vascular malformations. The distinction between the two has important prognostic and therapeutic implications. Over the past 8 years, we have evaluated 64 vascular lesions with the technetium-labeled red blood cell (Tc-RBC) scan. Twenty-eight lesions imaged as hemangiomas with intense focal uniform uptake. This diagnosis was confirmed in 27 lesions, or 96 percent. Thirty-six lesions imaged as vascular malformations with abnormal vessels or diffusely increased activity. This diagnosis was confirmed in 35 lesions, or 97 percent. Overall, the Tc-RBC scan was 97 percent accurate in distinguishing hemangiomas from vascular malformations. It is particularly useful when the clinical diagnosis of the lesion may not be evident. Not only can biopsy be avoided, but parents can be reassured at an earlier age and given accurate information regarding prognosis.

Arteriovenous Malformations↗

An instant kit method for labeling antimyosin Fab' with technetium-99m: evaluation in an experimental myocardial infarct model.

An instant kit method for labeling antibody Fab' fragments was developed. The method utilizes a ligand exchange reaction between the intermediate complex 99mTc-D-glucarate and the free sulfhydryl groups on the antibody Fab' fragment. Radiolabeling of the Fab' using generator eluate achieves quantitative 99mTc incorporation in less than 30 min at room temperature. The radiolabel is stable in human plasma for at least 24 hr and stable to incubation with 10 mM diethylene-triaminepentaacetic acid (24 hr) and 1 mM diaminodithiol agent (up to 3 hr). Mouse biodistribution of 99mTc-antimyosin shows faster blood clearance and lower uptake in the lungs, liver, and spleen in comparison to 111In-antimyosin. Technetium-99m-antimyosin and 111In-antimyosin showed equivalent ability to detect myocardial infarct in a canine model.

Animals↗

Radionuclide assessment of penile corporal venous leak using technetium-99m-labeled red blood cells.

In an attempt to evaluate penile corporal venous outflow, a method that utilizes intracorporal injection of Tc-RBC was developed and used in 20 patients with erectile dysfunction. Seven patients showed venous leak and 13 had normal venous outflow. Technetium-labeled RBC corporal clearance in the flaccid state and after intracorporal injection of papaverine (30 mg) and regitine (1 mg) were assessed in sequence by two separate injections of 18.5 MBq of Tc-RBC each. The time for 50% corporal clearance (T50%) was determined from the time activity curves obtained in flaccid state and after intracorporal injection of the vasoactive agent. There were no statistically significant differences in T50% measured in the flaccid state between normal venous outflow (202 +/- 139 sec) and venous leak (92 +/- 35 sec, p = 0.1). However, after intracorporal injection of papaverine and regitine a significant increase in the T50% was noted in normal venous outflow (2892 +/- 1899 sec) as compared to venous leak (213 +/- 123 sec, p less than 0.001). The results suggest that measurement of corporal clearance of Tc-RBC after intracorporal injection of papaverine may be a useful method in detecting venous leak, and could be used as a screening test in patients with erectile dysfunction.

Adult↗

Localization of recurrent medullary thyroid carcinoma with technetium-99m-methoxyisobutylnitrile scintigraphy: a case report.

This case report demonstrates the successful localization of metastatic medullary thyroid carcinoma with 99mTc-labeled methoxyisobutylnitrile (MIBI). Disease recurrence was initially localized using 201Tl and by immunoscintigraphy with 111In-labeled anti-carcinoembryonic antigen (anti-CEA) antibody fragments. Scintigraphy with 99mTc-MIBI yielded higher target-to-background ratios than 201Tl or 111In-anti-CEA. Technetium-99m-MIBI may be a useful agent in the localization of recurrent medullary thyroid carcinoma.

Carcinoma↗

Technetium-99m distribution into Klebsiella pneumoniae.

Bacteria labelled with radionuclide has been the subject of much investigation and has been applied in microbiological research. Technetium-99m (99mTc) may be an alternative radionuclide for the labelling of bacteria employed in various microbiological procedures. This radionuclide is easily available, is not expensive and presents important physical and biological characteristics. 99mTc-labelled bacteria are stable and their cell viability and biological properties are not modified. Study of the distribution of radioactivity in 99mTc-labelled Klebsiella pneumoniae cultures, after homogenization and differential centrifugation of the cells fractions, showed that this radionuclide was present inside the cell, mainly in a ribosomal fraction. Treatment of these fractions with enzymes and detergent revealed a high sensitivity to pronase and Triton X-100. After phenol extraction, a large percentage of radioactivity was detected in the phenol phase. Treatment of the soluble fraction with trichloroacetic acid at different temperatures showed that the concentration of 99mTc in the precipitate was lower at 100 degrees than at 4 degrees C. These results suggest that 99mTc binds mainly to the proteins in Klebsiella pneumoniae.

Isotope Labeling↗

Evaluation of right ventricular regional perfusion with technetium-99m-sestamibi SPECT.

To evaluate technetium-99m-sestamibi as a right ventricular perfusion imaging agent, 25 normal volunteers and 25 patients with suspected coronary disease were studied with both sestamibi and thallium-201 SPECT. All patients underwent cardiac characterization. Compared to thallium-201 images, visualization of the right ventricle was superior for sestamibi in all cases. After computer masking of the left ventricle, count profiles for each 6-mm right ventricular short-axis slice were extracted and plotted in a bull's-eye type polar map with images normalized to maximal right ventricular counts. On sestamibi right ventricular polar maps, 7 of 11 patients (64%) with right coronary stenosis had fixed or reversible inferior right ventricular defects. None of the 25 volunteers or patients without right coronary stenosis had right ventricular defects (true-negative rate = 100%). We conclude that sestamibi SPECT provides an accurate means to assess right ventricular regional perfusion, with data presentation and interpretation facilitated by the polar map display.

Adult↗

[Improvement in nuclear medicine diagnosis of kidney function using 99m technetium mercaptoacetyltriglycine (MAG3)].

Renal scintigraphy and clearance measurement are indispensable in nephro-urologic disorders. A continuous series of 103 sequential scintigraphies and clearance measurements were performed with the new technetium-labelled agent MAG3 (Gamma-kamera, Phillips Tomo Diagnost) and 131I-orthohippuric acid (OIH) using the Oberhausen method (Nucleopan, Siemens). The time-activity curves obtained with the two radionuclides agreed exactly. Reaching a tubular excretion rate of nearly 90%, the clearance of MAG3 differed by no more than 6% from the OIH clearance in 95% of the cases. The factor between clearances of the two radionuclides was determined by means of a commercially available software according to the Oberhausen method and amounted to 0.59 +/- 0.09. The favorable physical properties and high activity of MAG3 permit exact examination of tubular function and better assessment of renal morphology than hippuran-labelled radionuclides. The low radiation dose combined with a better spatial resolution, especially, the constant availability in a nuclear medicine department should give the preference to MAG3.

Adult↗

Estimation of technetium-99m-MAG3 renal clearance in children: two gamma camera techniques compared with multiple plasma samples.

Dynamic renal scintigraphy using technetium-99m mercaptoacetylglycylglycylglycine (MAG3) has been described in adults, and clearance values have been established using multiple plasma samples. This study of renal clearance has compared two fundamentally different gamma camera techniques (both of which require a single blood sample) with the multiple blood sampling technique in children (n = 30). Results show that a 40-min dynamic 99mTc-MAG3 renal scintigram coupled with a single plasma sample will allow analysis of the data so that clearance values, which are similar to those from multiple plasma samples, may be calculated. The curve generated from the cardiac region of interest (ROI) provided clearances values that had a high correlation coefficient (0.939-0.951) compared to the multiple-plasma sample technique immaterial of the timing of the blood sample. The renal uptake method of clearance had a lower correlation coefficient (0.89-0.92), which varied with the timing of the blood sample compared to the multiple-plasma sampling technique. This study has demonstrated that an extended gamma camera acquisition coupled with a single-plasma sample may be used for quantitative renal function studies using 99mTc-MAG3.

Adolescent↗

Technetium-99m-sestamibi myocardial perfusion imaging in detection of coronary artery disease: comparison between initial (1-hour) and delayed (3-hour) postexercise images.

Technetium-99m-sestamibi, a new myocardial perfusion imaging agent, does not show significant or rapid myocardial redistribution following its intravenous injection at stress. The purpose of this study was to evaluate the myocardial clearance of 99mTc-sestamibi and ischemic/normal wall ratios at 1 hr and at 3 hr after injection at stress in patients with significant coronary artery disease. Twenty-five patients with ischemic defects on 201Tl scans (n = 15) and/or significant disease on coronary angiogram (n = 18) were prospectively studied. Planar images were obtained at 65 and at 190 min after an injection at stress of 20-25 mCi of 99mTc-sestamibi. A rest study was performed 1-6 days later. Ischemic/normal wall ratios were 0.73 +/- 0.10 and 0.83 +/- 0.12 (p less than 0.05) at 1 and 3 hr, respectively (0.98 +/- 0.15 at rest). Myocardial washout was 26% +/- 12% for normal walls and 15% +/- 8% for ischemic walls (p less than 0.001). Segmental analysis showed 48 and 46 ischemic segments at 1 and 3 hr, respectively. In conclusion, although only a few ischemic segments were missed at 3 hr, significantly lower ischemic/normal wall ratios were found at 1 hr. Faster myocardial washout from normal walls is responsible for the partial reduction of this ratio.

Coronary Disease↗

Renal function and technetium-99m-dimercaptosuccinic acid uptake in single kidneys: the value of in vivo SPECT quantitation.

The ability to evaluate kidney function in each kidney separately by quantitative SPECT was tested in 20 patients with a single kidney and varying degrees of renal disease. Technetium-99m-dimercaptosuccinic acid (99mTc-DMSA) uptake was compared with renal function measured by creatinine clearance and serum creatinine. There was a good correlation for both serum creatinine (r = 0.89, y = 24.6 *X -1.15, error = 5.6, p less than 0.001) and creatinine clearance (r = 0.76, y = 0.6 *X 0.84, error = 8.0, p less than 0.001). The results indicate that SPECT quantitation of 99mTc-DMSA uptake can be used as an indicator of the function of each kidney individually.

Adult↗