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.     

Protein-losing enteropathy detected on Tc-99m HSA and Tc-99m MDP scintigraphy

The authors describe a patient with protein-losing enteropathy in whom abnormal intestinal accumulation of tracer occurred during Tc-99m human serum albumin scintigraphy. Abnormal leakage of the radiotracer was observed in the left upper abdomen and was confirmed by Tc-99m MDP scintigraphy. Both Tc-99m HSA scintigraphy and Tc-99m MDP scintigraphy are useful in the detection of protein-losing enteropathy.     

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.     

Abnormal Tc-99m MAA accumulation

Image findings are described in two patients who received radiochemically impure Tc-99m MAA radiopharmaceutical preparations. The cases are completely separate and show clinically the presence of hydrolyzed-reduced technetium (TcO2) in a radiopharmaceutical product.     

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.     

Tc-99m dextran and Tc-99m HIG findings in patients with ulcerative colitis.

PURPOSE: Various radionuclide methods have been studied for the evaluation of the disease activity and extent of ulcerative colitis and other protein-losing enteropathies. Recently, Tc-99m dextran and Tc-99m human immunoglobulin (HIG) have been used to detect inflammation and protein loss into the intestine, but only a few studies have been reported with these agents. MATERIALS AND METHODS: In this study, Tc-99m dextran and Tc-99m HIG were used to evaluate disease activity and extent in patients with ulcerative colitis. These agents were used in 12 patients with active disease and in five patients in remission, and five healthy control participants also were included. RESULTS: Large bowel activity was detected in 11 of the 12 patients with active ulcerative colitis using Tc-99m dextran and in 10 patients using Tc-99m HIG. Fifty-eight bowel segments were found to be active with endoscopy, 39 with Tc-99m dextran, and 31 with Tc-99m HIG. No intestinal activity was detected in the control participants. Grade 1 activity localization in the large bowel was detected in three patients with ulcerative colitis in remission using Tc-99m dextran and in one patient using Tc-99m HIG. CONCLUSION: Tc-99m dextran is more sensitive for detecting disease activity and extent than is Tc-99m HIG.     

Breast-milk radioactivity after a Tc-99m DTPA aerosol/Tc-99m MAA lung study

Measurements were made of the concentration of Tc-99m activity in samples of breast milk following an administration of Tc-99m DTPA aerosol for a lung ventilation image and one of Tc-99m MAA for lung perfusion. The activity was 222 nCi/ml of milk (8.2 kBq/ml) at 2 hr after the MAA injection, and it was found to be excreted exponentially with an effective half-life of 4.6 hr. There was a small incorporation of Tc-99m into breast-milk protein. We conclude that the combined use of these two Tc-99m agents did not indicate the interruption of breast feeding beyond 24 hr after administration of the MAA, and that for an aerosol ventilation study alone, breast feeding need not be interrupted for more than 4 hr after the test.     

Imaging of brain tumors and other lesions utilizing Tc-99m phosphates and Tc-99m pertechnetate

The intensity of parenchymal brain lesions was compared using Tc-99m pertechnetate and Tc-99m phosphate. The following conclusions were made: 1. If the Tc-99m phosphate intensity is greater than the intensity of the Tc-99m pertechnetate scan, and the patient is evaluated within four weeks of ictus, the lesion is a CVA (P less than .001). 2. If the Tc-99m phosphate intensity is less than or equal to the intensity of the Tc-99m pertechnetate scan, and the patient is evaluated within four weeks of ictus, the parenchymal lesion is not a CVA (P less than .001). 3. If the evaluation takes place longer than six weeks after ictus, then no evaluation about the nature of the lesion can be made based upon uptake of Tc-99m phosphate and Tc-99m pertechnetate.     

Discordant hepatic uptake between Tc-99m sulfur colloid and Tc-99m DISIDA in hypervitaminosis A

Scintigraphic findings in a patient with biopsy-proven hypervitaminosis A included markedly impaired hepatic uptake of Tc-99m sulfur colloid but essentially normal uptake of Tc-99m DISIDA . This case presents a potential cause for image discordance with these two agents.     

Infected knee prosthesis: diagnosis with In-111 leukocyte, Tc-99m sulfur colloid, and Tc-99m MDP imaging

Forty-one possible cases of infected total knee prostheses studied with indium-111-labeled leukocyte scintigraphy were retrospectively reviewed. Twenty-four of the prostheses were studied with technetium-99m methylene diphosphonate bone scintigraphy and 19 with Tc-99m sulfur colloid marrow scintigraphy. Nine prostheses were infected, and 32 were uninfected. The accuracy of combined labeled leukocyte and sulfur colloid marrow imaging (95%) was higher than that of labeled leukocyte scintigraphy alone (78%), bone scintigraphy alone (74%), or combined labeled leukocyte and bone scintigraphy (75%). The authors conclude that combined labeled leukocyte and sulfur colloid imaging is an accurate method for diagnosis of infected knee prostheses. In this series, this technique was superior to labeled leukocyte and bone imaging, alone or in combination.     

Hepatic and splenic uptake of Tc-99m HDP in multiple myeloma: additional findings on Tc-99m MIBI and Tc-99m sulfur colloid images

The authors present a case of multiple myeloma with intense hepatic and splenic uptake on Tc-99m HDP bone scan and discuss its clinical implications and possible uptake mechanisms. Tc-99m MIBI and Tc-99m sulfur colloid were used to demonstrate bone marrow involvement and focal lesions of multiple myeloma.