Evaluation of a 3-hour indium-111 leukocyte image as a surrogate for a technetium-99m nanocolloid marrow scan in the diagnosis of orthopedic infection

OBJECTIVES: This is a retrospective study to evaluate a 3-hour In-111-labeled leukocyte image as a surrogate for a Tc-99m nanocolloid marrow scan in the investigation of suspected orthopedic infection using In-111 leukocyte scintigraphy. METHODS: Images from 51 patients who had received contemporaneous In-111-labeled leukocyte scintigraphy and Tc-99m nanocolloid marrow scintigraphy were reviewed. Initially, the 3-hour and 22-hour In-111-labeled leukocyte images were compared. Sites of abnormal uptake on the 22-hour image were correlated with the 3-hour image and were graded according to the level of concordance or discordance. One week later, the Tc-99m nanocolloid images and 22-hour In-111-labeled leukocyte images of the same patients were compared and graded for concordance or discordance. When discrepancies in grading arose between the observers, a consensus opinion was achieved after additional review of the images a week later. RESULTS: On inspection of the 22-hour In-111 leukocyte images, 93 sites of focal, potentially abnormal leukocyte accumulation were identified. When the grading system was reduced to simply "concordant" or "discordant," there was good agreement between the observers in the majority of cases, with kappa statistics 0.77 for Tc-99m nanocolloid versus 22-hour In-111-labeled leukocyte images and 0.78 for 3-hour versus 22-hour In-111-labeled leukocyte images. Using the comparison of the Tc-99m nanocolloid marrow scan and the 22-hour In-111-labeled leukocyte images to identify concordance or discordance as the "gold standard" for scintigraphic evaluation of suspected orthopedic infection, comparison of the 3-hour In-111-labeled leukocyte images with the 3-hour In-111-labeled leukocyte images gave a sensitivity of 77%, a specificity of 77%, and an accuracy of 77%. CONCLUSIONS: A 3-hour image is helpful using In-111-labeled leukocyte scintigraphy.     

Indium-111 WBC scan in acute toxic centrilobular hepatic necrosis

In this case of prolonged fever and abnormal liver functions, dual tracer scintigraphy with In-111 WBCs and Tc-99m SC led to a biopsy-proven diagnosis of severe acute toxic hepatitis (hepatocellular necrosis). Correlation of the Tc-99m SC scan findings with those previously reported for "pseudotumors" of the liver is discussed. A "pseudonormal" scan pattern is described for the In-111 WBC scintigraphy. Discordance between In-111 WBC and Tc-99m SC scintigraphy in this clinical setting should raise the possibility of hepatic necrosis as a diagnostic alternative to hepatic abscess.     

Subacute and chronic bone infections: diagnosis using In-111, Ga-67 and Tc-99m MDP bone scintigraphy, and radiography

The usefulness of indium-111 white blood cell scintigraphy in the diagnosis of subacute or chronic bone infection was examined in 21 orthopedic patients. In-111 WBC imaging was compared with gallium-67 and technetium-99m methylene diphosphonate skeletal scintigraphy and bone radiography, all studies being performed within 1 week. In-111 WBC scintigraphy showed no definite advantage over Ga-67 scintigraphy in the identification of chronic bone infection. The two tests had the same sensitivity (80%) and similar specificity (In-111 WBC 75%, Ga-67 83%; difference not significant). Bone radiography had a sensitivity of 60% and a specificity of 67%. A negative Tc-99m MDP bone scintigram ruled out infection (sensitivity 100%), but because of low specificity (25%), final evaluation required performance of Ga-67 or In-111 WBC scintigraphy.     

Comparison of In-111 octreotide and Tc-99m (V) DMSA scintigraphy in the detection of medullary thyroid tumor foci in patients with elevated levels of tumor markers after surgery.

PURPOSE: In this retrospective study, the authors evaluated the utility of In-111 octreotide (OctreoScan) and Tc-99m (V) DMSA scintigraphy for the localization of recurrent metastatic tumor foci in patients with medullary thyroid cancer (MTC) and compared the findings with those of conventional radiologic imaging methods. METHODS: The scintigraphic images were compared with computed tomography (CT) and magnetic resonance imaging (MRI) and ultrasonography (US) in 14 patients (8 men, 6 women; age range, 22 to 74 years) with elevated calcitonin and carcinoembryonic antigen levels after total thyroidectomy. All scintigraphic image findings were evaluated qualitatively as mild uptake (+) and moderate to marked uptake (++). RESULTS: In-111 octreotide may be superior to Tc-99m (V) DMSA for the detection of tumor foci of patients with MTC on a patient basis (78.5% versus 57.1%) and on a lesion basis (44.1% versus 30.2%). The sensitivity rate for In-111 octreotide (78.5%) was also similar to that of CT and MRI on a patient basis. Conversely, the combined use of Tc-99m (V) DMSA and In-111 octreotide revealed the best sensitivity rate (85.7%) on a patient basis, whereas the combined use of CT and MRI showed the best sensitivity rate (81.3%) on a lesion basis. CONCLUSIONS: These findings suggest that In-111 octreotide is superior to Tc-99m (V) DMSA and has a similar sensitivity rate to CT and MRI for the diagnosis of recurrent or metastatic MTC. Although the combined use of In-111 octreotide and Tc-99m (V) DMSA was most sensitive, the combined use of CT and MRI with radionuclide imaging methods may better detect more metastatic tumor foci.     

Comparison of tc-99m depreotide and in-111 octreotide in recurrent meningioma

PURPOSE: For more than a decade, In-111 octreotide has been known to accumulate in meningiomas as a result of the expression of subtype 2 somatostatin receptors. Improved imaging characteristics can be expected with the recently developed radiotracer Tc-99m depreotide, which also binds to subtype 2 somatostatin receptors. MATERIALS AND METHODS: The authors examined a patient with intraorbital and extracranial recurrent meningioma using SPECT with Tc-99m depreotide and In-111 octreotide. The tumor-to-background ratios in the lesions were compared and the findings were correlated with histopathologic findings. RESULTS: Although the tumor-to-background ratios were higher for the In-111-labeled tracer in the largest tumor lesion (5.7 versus 3.3), SPECT with the Tc-99m-labeled compound showed a proved second site of recurrence as a result of the better resolution that can be achieved with that isotope. CONCLUSIONS SPECT: with Tc-99m depreotide appears to be clinically useful for detecting recurrent meningiomas with higher resolution and may outperform In-111 octreotide imaging in patients with meningiomas.     

The role of Tc-99m MDP and Ga-67 citrate in predicting the cure of osteomyelitis

Twenty rabbits with chronic osteomyelitis of the tibia were treated for eight weeks and then scanned with Tc-99m MDP and Ga-67 citrate. All were sacrificed and bacteriologic cultures of the tibia were obtained. All rabbits had positive Tc-99m MDP scans at the end of treatment despite thirteen cures of osteomyelitis. Eight had negative gallium scans and negative cultures. Five of the twelve positive gallium scans had negative cultures, while seven had positive cultures. Tc-99m MDP alone is not sensitive enough to be useful in predicting the cure of osteomyelitis, and combining Tc-99m MDP and Ga-67 citrate scintigrams offers no additional information over the Ga-67 citrate scintigram alone in follow-up of osteomyelitis.     

Detection of acute osteomyelitis with indium-111 labeled white blood cells in a patient with sickle cell disease

A young patient with sickle cell disease (SCD) and multiple hospitalizations for crisis was admitted because of suspected osteomyelitis. Initial laboratory work, radiographs, and bone images were not contributory. An In-111 white blood cell (WBC) study demonstrated two areas of increased radionuclide uptake consistent with osteomyelitis. One of these had associated soft tissue infection. No other areas of active osteomyelitis were visualized, in spite of the presence of several additional infection sites. Imaging with In-111 WBC is probably not justified for routine diagnosis of acute osteomyelitis in areas free of previous disease, where conventional bone images are highly efficient. In-111 WBC imaging, however, may be helpful in detecting osteomyelitis in selected patients with SCD in whom Tc-99m bone images and radiographs are usually abnormal and difficult to interpret due to previous bone infarcts. Localization of the infection focus is very important in choosing the aspiration site for bacteriologic studies. A negative study, however, should be interpreted cautiously.     

Comparison of Tc-99m methylene diphosphonate, Tc-99m human immune globulin, and Tc-99m-labeled white blood cell scintigraphy in the diabetic foot.

PURPOSE: The aims of this prospective study were to evaluate the contribution of Tc-99m methylene diphosphonate (MDP), Tc-99m human immune globulin (HIG), and Tc-99m white blood cell (WBC) to the diagnosis of osteomyelitis in the diabetic foot and to evaluate the surgical or medical therapy with Tc-99m HIG and Tc-99m WBC scans. METHODS: Twenty patients (15 men, 5 women) with suspected pedal osteomyelitis were included in the study. All patients had type II diabetics. Three- and four-phase bone scintigraphy (3P-MDP, 4P-MDP), early (e) and late (l) HIG, and WBC scans were completed within 1 week in all patients. The lesion-to-background ratios were calculated for early and late images of the feet for all scans and named as the indices. Eight weeks after the end of medical or surgical therapy, Tc-99m HIG and Tc-99m WBC scans were repeated in 10 patients. The difference in indices between 3P-MDP and 4P-MDP for osteomyelitis and indices for osteomyelitis, cellulitis, and inflammation in Tc-99m HIG and Tc-99m WBC in early and late scans were tested for significance. RESULTS: In 20 patients, 53 lesions were investigated. Among these 53 lesions were 25 sites of proved osteomyelitis, 6 sites of cellulitis, and 22 sites of inflammation confirmed by radiography, microbiologic culture, and clinical evaluation. 4P-MDP was more specific than 3P-MDP for detecting osteomyelitis (50% and 67%, respectively). There was also a significant difference between the mean indices of 3P-MDP and 4P-MDP (P < 0.000). The index values were increased in 4P-MDP scans. There was no significant difference between the indices of early and late Tc-99m HIG scans for inflammation, cellulitis, and osteomyelitis. Early and late Tc-99m WBC scans did not show a significant difference in differentiating osteomyelitis. However, Tc-99m WBC scans could differentiate aseptic inflammation from infection (P < 0.031) in early and late scans. There was a significant difference of index values between pre- and post-treatment Tc-99m HIG and Tc-99m WBC scans. The best combination of scans for detecting osteomyelitis was 4P-MDP with WBC scans, with an accuracy rate of 92%. CONCLUSIONS: These results show that four-phase bone scintigraphy with early Tc-99m WBC scanning is preferred for detecting osteomyelitis of the diabetic foot. To evaluate the response to therapy, Tc-99m WBC scans are the preferred method, but if this is not available, Tc-99m HIG scanning can be used.     

Tc-99m(V) DMSA imaging. A new approach to studying metastases from breast carcinoma.

Combined Tc-99m MDP skeletal imaging and Tc-99m(V) DMSA whole body scans to detect metastases were performed during the follow-up of 30 patients who underwent surgery for breast carcinoma. Eight patients had normal Tc-99m MDP and Tc-99m(V) DMSA scans and were declared free of metastatic disease, further confirmed by no change in symptomatology over a 1-year follow-up period. Twenty-two patients had positive Tc-99m MDP scans with varied skeletal involvement. Tc-99m(V) DMSA scans showed matched areas of increased radiotracer concentration in bony metastases in 20 of these patients. Tc-99m(V) DMSA concentration was not seen in traumatic vertebral collapse or in coexistent osteoarthritic disease in vertebral metastatic involvement. Interestingly, Tc-99m(V) DMSA showed increased concentration in brain and liver metastases. Pentavalent Tc-99m(V) DMSA appears useful for detecting skeletal and soft-tissue metastases in breast carcinoma, and can improve the specificity of Tc-99m MDP bone scans in screening for bone metastases.     

The dual-isotope ProstaScint imaging procedure: clinical experience and staging results in 145 patients

PURPOSE: Whole-body, regional planar, and SPECT imaging using the In-111-labeled monoclonal antibody capromab pendetide (In-111 MAb; ProstaScint) has been shown to increase the detection of early disease spread in patients with prostate cancer. However, recognition of metastatic tumor sites can be difficult, especially if the involved nodes are near blood vessels. We have developed an alternate approach to the identification of metastatic sites that is based on a single simultaneous In-111 MAb and Tc-99m RBC SPECT acquisition of the pelvis and abdomen on day 5 after injection. We have also developed software that dynamically subtracts the Tc-99m RBC data set (vascular component) from the In-111 MAb data set (prostate and lymph node component), which allows for easier identification of metastatic sites. METHODS: We evaluated the effectiveness of ProstaScint for staging 145 patients with prostate cancer, 19 newly diagnosed and 126 with recurrence, using these two modifications. RESULTS: With clinical follow-up in 13 of 19 (68%) patients with primary disease, 10 of 13 (78%) had organ-confined disease. With follow-up in 64 of 126 (51%) patients with possible recurrent disease, 49 of 64 (77%) were found to have prostatic fossa activity only. Disease stage was deemed more advanced in 3 of 13 (22%) patients with primary cancer and in 13 of 64 (20%) of those with recurrent disease based on ProstaScint findings when all other imaging tests were inconclusive. Six patients with recurrent disease had negative results of their scans. In the 16 patients with more advanced disease, 3 of 59 lesions (5%) were documented as false positive, and there were no reported cases of false-negative findings. CONCLUSIONS: Using both the dual-isotope procedure and the subtraction analysis software with the ProstaScint examination provides additional information for staging primary and possibly recurrent prostate cancer compared with standard imaging techniques.     

Comparison of Tc-99m pyrophosphate and Tc-99m methylene diphosphonate in acute myocardial infarction: concise communication.

This study compared Tc-99m pyrophosphate (PPi) and Tc-99m methylene diphosphonate (MDP) for myocardial infarct imaging in 24 patients with diagnosed acute myocardial infarction. The radiopharmaceuticals were administered randomly and interpreted without knowledge of the sequence used. Twenty-three patients (96%) had positive Tc-99m PPi scintigrams, but only 17 (71%) had a positive Tc-99m MDP study (P less than 0.05). In addition, a comparison of the relative intensity with each agent revealed greater intensity with Tc-99m in 21 cases, equal intensity in two cases, and less intensity in only one case (p less than 0.001). These findings support the superiority of Tc-99m PPi as the agent of choice for myocardial scintigraphy in acute infarction.     

Tc-99m white cell scintigraphy in suspected acute infection

The usefulness of In-111 labeled white cells in acute infection is well documented but the role of Tc-99m labeled white cell scintigraphy (WCS) has not been as clearly established. Using stannous fluoride colloid and a simple labelling procedure with 20 ml of autologous whole blood, three cases are presented in which Tc-99m WCS established unexpected diagnoses in patients who had remained undiagnosed despite extensive investigation.     

The comparison of dual phase Tc-99m MIBI and Tc-99m MDP scintimammography in the evaluation of breast masses: Preliminary report

The aim of this prospective study was to determine the diagnostic value of Tc-99m MDP scintimammography (SMG) for the detection of breast cancer in patients with breast masses and to compare the results with Tc-99m MIBI scintimammography. Twenty patients, categorized as suspicious, positive or benign for breast cancer according to the mammographic findings were included in the study. Dual phase Tc-99m MIBI and Tc-99m MDP SMG were performed in the prone lateral position within 5 days of each other. Although early and late Tc-99m MIBI SMG showed equal (90.4%) sensitivity, the specificity of late Tc-99m MIBI (87.5%) was found superior to early (62.5%) imaging. The overall sensitivity and specificity of early Tc-99m MDP SMG were 71.4% and 62.5%, respectively. Although late Tc-99m MDP imaging showed 100% specificity, its sensitivity was only 23.8%. In the patients with palpable masses, both early Tc-99m MDP and Tc-99m MIBI showed equal sensitivity (100%), but the sensitivity of early Tc-99m MIBI (37.5%) was found slightly higher than Tc-99m MDP (25.0%) for nonpalpable breast lesions. The sensitivity of Tc-99m MIBI and Tc-99m MDP SMG in detecting metastatic axillary involvement was 66.6% and 50%, respectively. High sensitivity and specificity together with its low cost, easy availability and the possibility of detecting bone metastases seems to make Tc-99m MDP a contributive agent in the evaluation of breast lesions as an alternative to Tc-99m MIBI.     

Comparison of technetium-99m pyrophosphate and technetium-99m methylene diphosphonate with variable amounts of stannous chloride in the detection of acute myocardial infarction

The authors prospectively compared the ability of Tc-99m pyrophosphate (PYP) and Tc-99m methylene diphosphonate (MDP) to detect acute myocardial infarctions. The agents used were PYP (12 mg) with 3.4 mg of stannous chloride, MDP (10 mg) with 1.0 mg of stannous chloride, and MDP (10 mg) with 3.4 mg of stannous chloride. Imaging was performed on three consecutive days on 34 patients with proven myocardial infarctions, using the same agent on the first and third days of the study and an alternate agent on the second day. Agents were assigned randomly to each of six groups of patients. First images were obtained an average of 3.7 days (range, one to six days) following myocardial infarction. Seventeen of 23 patients (75%) had images positive for acute myocardial infarction with Tc-99m PYP, whereas only two of 21 patients (9.5%) had positive studies with Tc-99m MDP with 3.4 mg of stannous chloride and one of 24 patients (4.2%) had positive studies with Tc-99m MDP and 1.0 mg of stannous chloride. All three myocardial infarctions detected by Tc-99m MDP were extensive and transmural. When MDP and PYP were both positive in the same patient, the apparent size of the myocardial infarction was much smaller with the MDP. It is concluded that MDP can detect only large myocardial infarctions, has poor localization in the infarcted tissue, and varying the stannous chloride content of the preparation does not improve the ability of MDP to detect acute myocardial infarctions.     

Tc-99m methylene diphosphonate versus Tc-99m pyrophosphate: biologic and clinical comparison.

The biologic and imaging characteristics of Tc-99m MDP and Tc-99m PPi were compared in animals and patients using freeze-dried bone-imaging kits. Biodistribution data in rabbits showed Tc-99m MDP had slightly higher bone uptake, significantly lower blood levels, and faster urinary excretion compared with Tc-99m PPi. Duplicate studies performed on ten patients showed the following: (a) blood clearance of Tc-99m MDP was more prompt and complete, resulting in significantly lower blood levels at 4 hr; (b) urinary excretion was greater with Tc-99m MDP than with Tc-99m PPi; and (c) Tc-99m PPi showed significant red-cell labeling, whereas Tc-99m MDP did not. Image quality was generally better with Tc-99m MDP than with Tc-99 m PPi, although there was no obvious difference in diagnostic sensitivity between the two agents.     

Indium-111 chloride for detecting suspected hepatomas in patients with focal defects on technetium-99m sulfur colloid liver imaging

Twenty-three patients with hepatic cirrhosis and focal defects on Tc-99m sulfur colloid (SC) scintigrams were restudied with In-111 chloride to determine if indium localization in the focal defect is indicative of a hepatoma. Seven of eight patients with proven hepatomas had positive studies; however, six of 15 patients without hepatomas also had studies interpreted as positive. Thus, In-111 chloride is highly sensitive for the detection of hepatomas, and a negative indium study would militate against this diagnosis. The high false-positive rate found may be due to technical factors rather than a lack of specificity of localization; the experience of others seems to support this impression. At present, In-111 chloride scintigraphy for focal hepatic defects appears to be useful in ruling out hepatoma.     

Tc-99m HMPAO-labeled leukocytes for hematopoietic marrow imaging. Comparison with In-111 chloride.

The current study was initiated to define whether Tc-99m leukocyte imaging, compared to In-111 chloride imaging, could provide additional information on the hematopoietic activity of the bone marrow in diffuse hematologic disorders. A total of 11 patients with hematologic disorders were studied both with Tc-99m leukocytes and In-111 chloride. One patient with myelofibrosis showed disparate tracer distribution in the bone marrow between the two; Tc-99m leukocyte uptake in the central marrow was highly decreased, whereas In-111 chloride showed expanded marrow. The disparate results of granuloid hypoplasia and erythroid hyperplasia obtained by bone marrow biopsy and aspiration in this patient were thought to give an explanation for the radionuclide findings. The remaining 10 patients showed similar tracer distribution in the marrow, and the observation of hematopoietic cellularity confirmed by bone marrow biopsy and aspiration correlated well with the radionuclide findings. These results demonstrate that Tc-99m leukocytes may be a potential imaging agent for evaluating hematopoietic activity in the bone marrow, in particular granulopoietic activity.     

Tc-99m ciprofloxacin scans for detection of tubercular bone infection

Tc-99m MDP and Tc-99m ciprofloxacin scans were performed in 14 patients with suspected tubercular bone disease and in 2 cases of nontubercular bone infection. In 5 patients the findings were true negative. There were no false positives and 1 was false negative. The sensitivity, specificity, and positive predictive value were found to be 93, 71, and 87.5%, respectively, for detection of bone tubercular lesions. However, the test does not distinguish TB osteomyelitis from other types of osteomyelitis. Delayed 24 hour scans were found useful to differentiate between inflammatory and infective lesions. The aim of this study was to evaluate the usefulness of the Tc-99m ciprofloxacin scan as a means to detect tubercular bone disease.     

Cerebral perfusion imaging with albumin microspheres tagged with Tc-99m and In-111 in cases with internal carotid occlusion

Cerebral perfusion imaging with dual-tracer (Tc-99m and In-111) human albumin microspheres (HAM scintigraphy) was performed in 15 cases with unilateral occlusion of the internal carotid artery, for the diagnosis and evaluation of collateral circulation patterns. After injection of Tc-99m microspheres into one common carotid artery and In-111 HAMs into the other, two perfusion images, one for each carotid artery, were clearly differentiated by appropriate pulse-height discrimination. With this method, diagnosis of internal carotid artery occlusion was definitely made in eight patients, suspected in six, and missed in one. The collateral perfusion areas from the contralateral ICA and ipsilateral external carotid artery were well demonstrated by this method, and the scintigraphic results agreed well with the angiographic findings in all cases. Dual-tracer HAM scintigraphy is capable of adding information about collaterals at the capillary level to the anatomic information obtained by angiography.     

Increased liver and spleen accumulation of Tc-99m methylene diphosphonate associated with intravenous injection of MRI contrast gadolinium-diethylenetriaminepentaacetic acid

Several conditions that can cause diffuse hepatic or splenic uptake of Tc-99m methylene diphosphonate (Tc-99m MDP) have been previously reported. Nevertheless, diffuse abnormal liver and spleen uptake of Tc-99m MDP associated with intravenous injection of magnetic resonance imaging contrast gadolinium-diethylenetriaminepentaacetic acid is not previously known. In our series, we reported diffuse increased Tc-99m MDP activity in the liver and spleen in bone scans in patients who received Tc-99m MDP injection shortly after contrast-enhanced magnetic resonance imaging.