Technetium-99m-HMPAO-labeled leukocytes and technetium-99m-labeled human polyclonal immunoglobulin G in diagnosis of focal purulent disease.

To evaluate the usefulness of 99mTc-HMPAO-labeled leukocytes and 99mTc-labeled polyclonal human immunoglobulin G (Technescan HIG) in the diagnosis of focal purulent disease, 31 comparative scintigraphies were done in 30 patients with known or strongly suspected focal infection. Focal purulent disease was the final diagnosis in 19 patients. Technetium-99m-labeled leukocytes showed 16 true-positive, no false-positive, 11 true-negative and 3 false-negative findings. The corresponding figures for 99mTc-labeled HIG were 11, 2, 9 and 8. The sensitivity and specificity of imaging with labeled leukocytes were 84% and 100%, respectively, and with labeled HIG, 58% and 82%, respectively. The overall accuracy of the leukocyte scan was significantly better than that of the HIG scan (90% versus 67%, p < 0.001). Thus, if focal infection is suspected, scintigraphy with 99mTc-labeled leukocytes is the preferable method. No cases exhibited a better imaging result with 99mTc-HIG scintigraphy than with 99mTc-labeled leukocytes.

Postoperative graft incorporation after aortic reconstruction--comparison between computerised tomography and Tc-99m-HMPAO labelled leucocyte imaging.

Aortic graft infection may result in high mortality ranging up to 88%. Therefore, early diagnosis is imperative in the treatment of this serious complication. Computerised tomography (CT) is considered as a sensitive tool in the diagnosis of aortic graft infection. Some findings used as the criteria for infection, such as periprosthetic gas and fluid are, however, normal postoperative findings. The aim of this prospective study was to compare CT-scan and Tc-99m-HMPAO labelled leucocytes in the early diagnosis of aortic graft infection. The present study includes 24 consecutive patients (all men, age 70 +/- 8 years, range 55-85 years), who were operated on for abdominal aortic aneurysm. Prosthetic and suture materials were the same in all operations. Each patient was examined with the aid of CT-scan and imaged with Tc-99m-HMPAO labelled leucocytes 2 weeks and 3, 6 and 12 months after the reconstructive aortic surgery. Two radiologists and two specialists in nuclear medicine examined the data independently without knowing the clinical picture of the results of any other examinations of the patients. Seven patients (7/24; 29%) showed significant accumulation of labelled leucocytes in the first imaging (2 weeks postoperatively) with Tc-99m-HMPAO labelled leucocytes. Three months after the surgery only four patients (4/24; 17%) were positive in this respect. One of these patients had clinically proven aortic graft infection and another positive was a patient with resected and reconstructed mycotic aneurysm. CT-examination in all scans was suggestive for aortic graft infection in two cases (2/24; 8%), but neither of these patients showed any signs of infection.(ABSTRACT TRUNCATED AT 250 WORDS)

Thrombus imaging with 99mTc-HMPAO-labeled platelets and 111In-labeled monoclonal antifibrin antibodies.

Eighteen patients with suspicion of deep venous thrombosis (DVT) in the lower extremities were imaged both with autologous 99mTc-HMPAO-labeled platelets (Tc-PLT) and 111In-labeled monoclonal antifibrin antibodies (In-MoAbs) on the same day. Presence or absence of thrombosis was verified by venography. Tc-PLT was given i.v. followed after 30 min by In-MoAbs. Anterior and posterior projections of the lower extremities were obtained with a large field-of-view gamma camera at 5 to 25 min, 2 h, 4 to 6 h, and 20 h after administration of the marker. Both Tc-PLT and In-MoAbs detected DVT well but less frequently than venography. Thrombi were visualized at 2 to 4 h after injection. The quality of images was better with Tc-PLT than with In-MoAbs. In the patients treated during the study, heparin significantly (p < 0.01) inhibited the uptake of Tc-PLT but not of In-MoAbs. We conclude that both Tc-PLT and In-MoAbs are suitable agents for the detection of DVT especially in patients without anticoagulation.

Technetium-99m hexamethyl propylene amine oxine leucocytes in the assessment of disease activity in inflammatory bowel disease.

The inflammatory activity in 108 bowel segments of 40 patients with suspected or known inflammatory bowel disease was assessed macroscopically by endoscopy, histology and technetium-99m hexamethyl propylene amine oxine (99mTc-HMPAO) leucocytes using a numerical grading system (scores 0-3). A 4-h series of scintigrams showed a significant correlation with both histological and macroscopical assessment of disease activity (rho = 0.850, P less than 0.001 and rho = 0.773, P less than 0.001, respectively). Sensitivity, specificity and accuracy of scintigraphy in detecting active inflammatory segments were 85%, 92% and 89%, respectively. A normal scintigram did not completely exclude mild inflammatory activity, especially in the rectosigmoid area. 99mTc-HMPAO leucocytes offer an accurate and non-invasive alternative for the assessment of disease activity in ulcerative colitis and Crohn's disease.

Tc-99m HMPAO labeled leukocytes superior to bone scan in the detection of osteomyelitis in children.

Seven children (aged 7 to 16 years) with confirmed osteomyelitis underwent imaging with Tc-99m HMPAO labeled leukocytes and with Tc-99m diphosphonates. The patients were scanned at 1/2 hour and at 3 hours. The scans were evaluated visually, and the lesion-to-normal bone ratios were quantitated. All the lesions on leukocyte scans and six out of seven lesions in bone scans were readily detectable 1/2 hour after injection of the radiopharmaceutical, but 3 hours is the better imaging time. In quantitative analysis, the lesion-to-normal bone ratio increased with leukocytes significantly higher than with the bone scans (P less than 0.05). When the scintigraphic findings were compared with surgical and radiologic results, the leukocyte images detected and localized lesions better than the bone scans. According to these preliminary results, Tc-99m HMPAO labeled leukocytes seem to offer a rapid and accurate method for detecting bone infections.

Fast diagnosis of abdominal infections and inflammations with technetium-99m-HMPAO labeled leukocytes.

The diagnostic value of early 99mTc-HMPAO-leukocyte images (2 min, 0.5 hr, 2 hr and 4 hr) was studied in 87 prospectively performed investigations in 80 patients with a suspicion of abdominal inflammation or infection. Sensitivity, specificity and accuracy were 74%, 85% and 77% in the 2-min scans, 88%, 81% and 86% in the 0.5-hr scans, 95%, 85% and 92% in the 2-hr scans, and 96%, 92% and 95% in the 4-hr scans. Nonspecific bowel accumulation was seen in 7% of patients at 2 hr and in 28% at 4 hr but was easily distinguishable from pathologic activity. The uptake in early images represents an active accumulation of granulocytes at the site of inflammation rather than nonspecific blood-pool activity judged by results of 99mTc-HMPAO-RBC imaging. We found that imaging within 2 hr from injection has a high diagnostic value, and that the activity accumulates in areas of infection and inflammation faster than in the intestinal background.

Scintigraphy with 99mTc-HMPAO labeled leukocytes in acute cholecystitis.

99mTc-HMPAO labeled leukocyte scanning was performed on 38 patients with clinically suspected acute cholecystitis (AC) to evaluate its diagnostic value. The typical finding was an increasing accumulation of the tracer in the gallbladder wall in a 4 hour series of scintigrams. Leukocyte scan was positive in 16 of 17 patients with surgically and histologically confirmed AC. There were no false-positive findings. The sensitivity, specificity, and accuracy of scintigraphy were 94, 100, and 96%, respectively. In 2 patients with acute acalculous cholecystitis true-positive findings were observed. Scintigraphy with 99mTc-HMPAO labeled leukocytes is a valuable new imaging method in AC.

Chronic prosthetic vascular graft infection visualized with technetium-99m-hexamethylpropyleneamine oxime-labeled leukocytes.

Technetium-99m-HMPAO labeled leukocytes demonstrated chronic femoro-femoral prosthetic vascular graft infection several times during an 18-mo period in a 77-yr-old man. The intensity and distribution of the uptake in the graft were fluctuating in different imaging occasions possibly indicating the strength and location of the infection. Gallium-67-citrate imaging showed negative results twice. The reason for negative 67Ga results remained obscure. The infected graft was removed and the patient did well 5 mo postoperatively.

Accumulation of leucocytes labelled with technetium-99m hexamethylpropylene amine oxime in malignant abdominal tumours.

A total of 343 leucocyte scans labelled with technetium-99m hexamethylpropylene amine oxime were reviewed that had been performed in 338 patients suspected of having abdominal infection or inflammation. There was uptake by malignant abdominal tumours in 10 cases (2.9%), which represents 62.5% of known malignancies at the time of the scintigram. Accumulation was seen in 8 patients with adenocarcinoma of the colon associated with a secondary infection in the tumour or pericolic inflammation. A large tumour that had spread beyond the bowel wall was related to a positive scintigram. Accumulation was also found twice in a malignant fibrous histiocytoma in which bleeding and an inflammatory reaction to necrosis were probably responsible for the uptake. The relevant treatment was delayed for 2 weeks-2 months in 4 patients with adenocarcinoma of the colon in whom the positive uptake was regarded as confirmation of the clinically suspected acute diverticulitis.

Tc-99m labeled leukocytes in imaging of patients with suspected acute abdominal inflammation.

One hundred patients with suspected acute abdominal inflammation were imaged at 0.5, 2-3, 4-6, and 24 hours after the administration of Tc-99m HMPAO labeled autologous leukocytes. Scan findings were retrospectively compared with final diagnosis, serum C-reactive protein (CRP), and antibiotic treatment. Clinical findings were confirmed with surgery, barium enema, or sigmoidoscopy in 61 patients, and diagnosis was based only on clinical findings in 13 patients. In 26 patients, symptoms subsided before a final diagnosis was made. Tc-99m leukocyte images were positive in 45 of the 61 patients with a confirmed diagnosis, including all patients with acute cholecystitis (N = 4) and inflammatory bowel disease (N = 8). They were also positive in nineteen out of 25 patients who had acute colonic diverticulitis and in 6 out of 7 who had intra-abdominal abscesses. Abnormal activity was found in patients with colonic carcinoma, small bowel infarction, and acute appendicitis. Abnormal activity was visualized in 0.5-hour images in all but one of the positive cases. With the exception of two postoperative cases, malignant lymphoma, and a liver abscess, a CRP level of greater than 75 mg/L was associated with positive image findings. Antibiotic treatment did not affect imaging findings. Imaging with Tc-99m labeled leukocytes appears to be valuable for detecting and localizing abdominal inflammation, and three-phase imaging during the first 4-6 hours is recommended. In some cases, 24-hour images may be useful for distinguishing small bowel from large bowel inflammation.

The scintigraphy of sacroiliac joints. A comparison of 99mTc-DPD and 99mTc-MDP.

The accumulation of 99mTc-methylene diphosphonate (99mTc-MDP) and 99mTc-dicarboxypropane diphosphonate (99mTc-DPD) in sacroiliac (si) joints was evaluated as a function of imaging time in 22 control patients and 5 patients with sacroiliitis. The controls were injected with either 99mTc-DPD or 99mTc-MDP (12 and 10 patients, respectively) and the patients with sacroiliitis with both agents within 5 days. Both the anterior and posterior views of the si joints were taken. The sacroiliac joint-to-sacrum (SI/S) ratio was calculated with the region of interest method. No statistically significant differences between these bone-seeking agents were found in the SI/S ratios of the control or the diseased patients. A clear overlap of indices (mean +/- SD) was found between the control patients and the patients with sacroiliitis. When the inflamed si joint was divided into three small adjacent areas and the SI/S ratios calculated for these areas, a statistically significant (P less than 0.001) increase in the SI/S ratio was noticed when compared with the SI/S ratio of the whole joint. Comparison of control patients and patients with sacroiliitis showed the most significant differences in the anterior views as well as in the P value: P less than 0.001 in all patients injected with 99mTc-DPD and in most patients injected with 99mTc-MDP. In the posterior views, the significance was less marked. In every case, the inflamed part of the si joint was visible in the anterior views. The background subtraction had the greatest effect on the SI/S ratio of anterior images, but in the posterior views no significance was found.(ABSTRACT TRUNCATED AT 250 WORDS)

Clinical comparison of 99Tcm-HMPAO labelled leucocytes and 99Tcm-nanocolloid in the detection of inflammation.

Forty-five patients with various inflammatory diseases were imaged with 99Tcm-HMPAO labelled leucocytes and 99Tcm-nanocolloid within 7 days. The overall sensitivity of 99Tcm-leucocytes was 97% and that of 99Tcm-nanocolloid 59% and both agents had a 100% specificity. The 99Tcm-leucocyte method showed reliable results in various inflammatory and infectious conditions, and seems suitable as a primary imaging method. On the contrary, 99Tcm-nanocolloid cannot be recommended for use in inflammatory bowel diseases, soft tissue abscesses or prosthetic vascular graft infections. However, 99Tcm-nanocolloid gave reliable information in inflammatory and infectious bone and joint diseases in which it had a 90% sensitivity and 100% specificity. In those lesions the 99Tcm-nanocolloid method may be useful, because it is simple, fast and cheap. Yet, further evaluation is needed.

Technetium-99m HM-PAO-labeled leukocytes in detection of inflammatory lesions: comparison with gallium-67 citrate.

Forty-three patients with suspected benign, inflammatory, or infectious diseases were imaged with [99mTc]HM-PAO-labeled leukocytes and [67Ga]citrate. Technetium-99m leukocytes showed 22 true-positive, no false-positive, 19 true-negative, and two false-negative findings and [67Ga]citrate 23, 7, 12 and 1, respectively. The sensitivity, specificity, and accuracy values with 99mTc leukocytes were 92%, 100%, and 95%, and with [67Ga]citrate 96%, 63%, and 81%. Technetium-99m leukocyte scintigraphy has a promising future in comparison with [67Ga]citrate because of the ready availability of [99mTc]HM-PAO, the good image quality, more rapid results (within few hours), and the lower radiation exposure to the patient with 99mTc leukocytes. The usefulness of 99mTc leukocytes in chronic osteomyelitis needs further evaluation.

The visualization of femoral vessels in delayed bone scans--a sign of arteriosclerosis? A comparison of 99mTc-MDP and 99mTc-DPD.

The activity of femoral vessels in delayed bone scans was evaluated visually in 237 consecutive patients and quantified in 40 female patients. In visual analysis the patients were randomly divided into three groups and in quantitative analysis into four groups of equal size. Two different MDP preparations and one DPD preparation were used as bone-seeking agents. With aging, the activity in femoral vessels increased with all agents in visual analysis, significantly with MDPs (P less than 0.001) between patients less than or equal to 60 years and greater than 60 years. In female patients with all agents a significant increase in femoral activity was found (P less than 0.001 with MDPs, P less than 0.05 with DPD). In patients greater than 60 years, the femoral uptake was significantly higher with MDP when compared with the DPD uptake (P less than 0.01 with MDP1, P less than 0.05 with MDP2). Between the MDPs no significant differences were found. In quantitative analysis the femoral vessel to soft tissue ratio was significantly higher in patients greater than 70 years when compared with patients less than or equal to 50 years with MDP. No difference was found with DPD. Histological examination of excised arteries of ten patients with intense femoral uptake of MDP showed arteriosclerosis and calcification in all cases. The findings suggest that the femoral visualization in delayed bone scans is probably related to arteriosclerosis and is not a non specific finding. There may be age-related differences in the distribution of MDP and DPD.

Comparison of 123I monoclonal granulocyte antibody and 99Tcm-HMPAO-labelled leucocytes in the detection of inflammation.

Thirteen patients with a suspicion of bacterial infection or inflammatory disease were studied with 99Tcm-HMPAO-labelled leucocytes (99Tcm-WBC) and 123I-labelled monoclonal antibodies against granulocytes (123I-MoAb-gc) within 5 days of the first study. Images were obtained at 30-40 min, 3-5 and 20-24 h. The quality of 99Tcm-WBC images was superior to that of the 123I-MoAb-gc. Eight cases were negative with both agents. Six inflammatory or infectious sites in five patients were clearly positive with 99Tcm-WBC even at 30 min, becoming moderately or strongly positive at 3-5 h but only three of them were weakly positive with 123I-MoAb-gc. One cause of the poor result with 123I-MoAb-gc may be the quite low activity in granulocytes and high plasma activity. We cannot recommend 123I-MoAb-gc as a primary imaging agent for inflammatory or infectious diseases for which 99Tcm-WBC seems very useful.

99Tcm-MDP and 99Tcm-DPD in pathologic bone lesions. A visual and quantitative comparison.

The efficiency of 99Tcm-methylene diphosphonate (MDP) and 99Tcm-dicarboxypropane diphosphonate (DPD) to detect pathologically increased bone uptake was evaluated both by computed quantitative intra-individual and visual inter-individual comparison. Twelve patients with altogether 44 metastases in ribs and lumbar vertebrae were evaluated quantitatively. The lesion to normal bone ratio (mean +/- SD) was, with MDP, 2.9 +/- 1.6 and with DPD 2.4 +/- 1.2 (p less than 0.001), and the normal bone to soft tissue ratios with MDP 8.5 +/- 5.0 and with DPD 9.4 +/- 6.1 (NS). Visual analysis of 162 patients with 334 focal lesions showed no significant difference between two MDP preparations and one DPD preparation. Visual and quantitative comparison in the three most common malignancies studied (breast, prostatic, and lung carcinoma) gave the same result. Because the lesion to normal bone ratios were high with both agents, and there was no significant difference on visual analysis, both radiopharmaceuticals are considered to be relevant bone seeking agents and the difference between MDP and DPD is only academic and not of practical value.

Comparison of gallium-67 citrate and technetium-99m glucoheptonate in the evaluation of pulmonary malignancies.

Sixty-five patients with suspected or proven pulmonary malignancy were examined with [67Ga]citrate and [99mTc]glucoheptonate ([99mTc]GH) scintigraphy. In the final diagnosis 39 had primary lung carcinoma, four metastases in lung, mediastinum, and pleura from carcinomas elsewhere, and 22 benign pulmonary diseases. The sensitivity in the detection of pulmonary malignancies was 91% with 67Ga and 95% with [99mTc]GH. The intensity of uptake was somewhat greater with 67Ga than with [99mTc]GH in almost all malignant lung tumor groups. The specificity to detect malignant tumors was 82% with both radiopharmaceuticals. Irradiation and chemotherapy seemed to decrease 67Ga uptake but not [99mTc]GH uptake. Only four of 22 benign diseases showed accumulation of both 67Ga and [99mTc]GH. The intensity of uptake in benign processes was almost equal with that in malignant diseases, but most malignant processes were better delineated than the benign lesions. There were many differences between 67Ga and [99mTc]GH uptake, which suggest different mechanisms of accumulation of these agents. It is concluded that some 67Ga studies could be replaced by cheaper and more practical [99mTc]GH.

Detection of inflammation with 99mTC-HMPAO labelled leucocytes.

20 patients were studied with 99mTcHMPAO labelled leucocytes for detection of inflammation. 14 patients had positive uptake. 6 patients were examined also with 67Ga-citrate and 5 with 99mTc-nanocolloid. The 99mTc-HMPAO images were superior to other methods. Abscesses, osteitis, inflammatory bowel disease and graft infection were positive. Abscesses were positive at 30 min images and became more positive at 4 h. The 99mTc-HMPAO labelled leucocyte scan can be used also to follow up healing of inflammation.

Clinical significance of lung uptake in liver scanning.

99mTc tin colloid accumulated in the lungs in 102 patients during liver imaging both in malignant and benign diseases. The percentage of neoplastic diseases increased when the lung uptake became greater and only patients with malignant final diagnosis had marked lung uptake. Abnormal liver image was seen only in 23%, which disagrees highly with some earlier findings on a rather small number of patients. The cause of increased lung uptake was suggested to be the activation of the reticuloendothelial system (RES) by disease. The activation of the RES was stronger in malignant than in benign diseases. Some type of regional stimulation of the RES was suggested as being due to the location of the disease and both malignant and benign diseases of the chest region stimulated the pulmonary part of the RES more than other parts of the RES.