Extensively calcified hemangioma of the diaphragm with increased 99mTc-hydroxymethylene diphosphonate uptake.
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A 31-year-old woman visited an out-patient clinic, because of low-grade fever and general fatigue. She was referred to our hospital and admitted for examination of an abnormal shadow which had been found on the chest radiograph. She had experienced faint right lateral chest pain several times on the deep inspirations. Chest radiography showed a mass shadow with calcification in the right lower lung field on the mediastinal side. Chest radiographic computed tomography showed a 6x6 cm tumor in the right lung field. There were low-density areas with septae inside the tumor. Bone scintigraphy showed extremely high uptake of (99m)Tc-HMDP in the tumor. After surgical resection and pathological examination, we concluded that the tumor was an extensively calcified benign hemangioma of the diaphragm. (+info)
Quantitative bone single-photon emission computed tomography for prediction of pain relief in metastatic bone disease treated with rhenium-186 etidronate.
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PURPOSE: To calculate radiation doses of rhenium-186 ((186)Re) etidronate in painful bone metastases using quantitative bone single-photon emission computed tomography (SPECT) and to determine the threshold dose for predicting pain relief. We also wanted to determine whether technetium-99m ((99m)Tc) methylene diphosphonate (MDP) concentrations predict radiation doses of (186)Re etidronate in painful lesions. MATERIALS AND METHODS: Forty-eight patients with breast and prostate cancer were evaluated. Patients received therapeutic doses of (186)Re etidronate. The area under the pain over time curve (AUPC) was measured for 8 weeks after treatment. Response was calculated as the percentage of change in AUPC. Quantitative bone SPECT (QBS)-measured concentration of (186)Re etidronate was used for calculating radiation doses. Receiver operating characteristics curve analysis determined the radiation dose threshold that best separated responders from nonresponders. SPECT-measured concentration of (186)Re etidronate in the urinary bladder was correlated with its concentration in the voided urine. Concentration of (99m)Tc MDP was compared with radiation doses to painful metastases. RESULTS: The radiation dose threshold was 2.10 Gy. For a decrease of 50% in the AUPC, the positive predictive value (PPV) of this value was 75% and the negative predictive value (NPV) was 88%. For a decrease in pain of 33%, the PPV was 84% and the NPV was 81%. In prostate cancer patients only, the PPV was 81% and the NPV was 92%. The correlation between in vivo/in vitro measured urine concentration was 0.90. The correlation between (99m)Tc MDP concentration and radiation doses of (186)Re etidronate was 0.92. CONCLUSION: QBS-measured radiation doses of (186)Re etidronate in painful metastases are a good predictor of pain relief. Bone SPECT using (99m)Tc MDP predicts radiation doses delivered by (186)Re etidronate. (+info)
Different patterns of global and regional skeletal uptake of 99mTc-methylene diphosphonate with age: relevance to the pathogenesis of bone loss.
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Bone turnover changes with age have been shown by both histomorphometric and scintimetric methods; fewer studies have been performed on the regional differences of bone remodeling in the aging skeleton. To noninvasively investigate this issue, we evaluated the age-related patterns of global and regional bone uptake of 99mTc-methylene diphosphonate (MDP) in a large sample of healthy women. METHODS: In a group of 84 healthy women (33 pre- and 51 postmenopausal), the uptake of 99mTcMDP was semiquantitatively measured in 5 regions of interest. Total-body digital scans (TBDSs) were acquired at 5 min and at 4 h. Five regions of interest were drawn on the skeleton as a whole, on the lumbar spine, on the iliac wing, on the femoral neck, and on the femoral diaphysis of the 4-h TBDS. Regional skeletal uptake of the lumbar spine (LS-RSU), of the iliac wing (IL-RSU), of the femoral neck (FN-RSU), and of the femoral diaphysis (FD-RSU) was calculated as percentage injected dose retained in these skeletal segments at 4 h. RESULTS: As expected, in postmenopausal women the global skeletal uptake (GSU) values were higher than those in premenopausal women (40.7 +/- 5.9 percentage injected dose [%ID] versus 35.1 +/- 4.2 %ID; P < 0.0001). GSU correlated positively with age (r = 0.70; P < 0.001), but the addition of years since menopause to the regression model did not ameliorate the regression. On the other hand, LS-RSU (r = -0.55; P < 0.0001), IL-RSU (r = -0.45; P < 0.0001), and FN-RSU (r = -0.22; P < 0.005) decreased significantly, whereas FD-RSU increased significantly (r = 0.39; P < 0.001) with age; the same regressions were not influenced significantly by the addition of menopausal duration to the regression model. The strongest correlation among the different RSUs was that found between LS-RSU and IL-RSU (r = 0.63; P < 0.001). Moreover, the linear regression coefficients of the various RSUs with age were all significantly different from each other (P < 0.001). CONCLUSION: Our data show that the GSU of 99mTc-MDP increases with age, whereas different skeletal segments display a variable degree of turnover activation at different ages. This could ultimately induce the different rates of bone loss of different skeletal segments at various ages and, consequently, their variable propensity to fracture. (+info)
Radiographic and scintigraphic courses of union in cervical interbody fusion: hydroxyapatite grafts versus iliac bone autografts.
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This study investigated the radiographic and scintigraphic courses of union in cervical interbody fusion using hydroxyapatite (HA) grafts or iliac bone autografts. METHODS: Twelve patients underwent both serial plain radiography and bone scintigraphy during the 12 mo after surgery. Serial plain radiographs were obtained every month until the end of the study period. Bone scintigrams with 99mTc-hydroxymethylene diphosphonate (HMDP) were obtained at 2 wk and at 1, 2, 3, and 6 mo. Uptake of 99mTc-HMDP in the graft was expressed as a ratio of the counts in the graft to those in the axis. RESULTS: In the HA graft group, the plain radiographs of all patients showed a radiolucent stripe that disappeared 7.3 +/- 1.5 (mean +/- SD) months after surgery. In the autograft group, a radiolucent stripe around the graft was not seen for any patient, and union was confirmed by follow-up radiographs within 6 mo after surgery. The serial changes in the 99mTc-HMDP uptake ratio showed no difference between the 2 groups. The 99mTc-HMDP uptake ratio peaked 1 mo after surgery and decreased rapidly to a plateau within 2 mo. CONCLUSION: In the HA graft group, despite the presence of a radiolucent stripe around the graft for more than 6 mo, the scintigraphic course of union was not different from that in the autograft group. The likelihood is that the presence of a radiolucent stripe around the HA graft in the early months after surgery is not always a sign of pseudoarthrosis. (+info)
Streak artifact reduction in filtered backprojection using a level line-based interpolation method.
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Because of the limited number of projections, the mathematic reconstruction formula of the filtered backprojection (FBP) algorithm may create an artifact that streaks reconstructed images. This artifact can be imperfectly removed by replacing the ramp filter of the FBP with an ad hoc low-pass filter, the cost being the loss of contrast and definition. In this study, a solution was proposed to increase, by computational means, the number of projections to reduce the artifact at a lower cost. The cost was a postacquisition process, which was reasonably time consuming. METHODS: The process was called interpolation of projections by contouring (IPC). First, level lines were plotted on the sinogram to delimit isocount regions; then, the regions containing the interpolated points were found, and to each point was assigned the intensity of its isocount region. Using this process, the data could be resampled, allowing an increase in the number of projections or the number of pixels by projections. A phantom study of bone scintigraphy was performed to compare the slices obtained with and without the IPC process with the true image. A clinical case was also presented. RESULTS: The phantom study showed that with the IPC process, the reconstructed slice was closer to the model, inside and outside the body, when the sinogram was resampled to multiply by 2 or 3 the number of projections, with the same number of pixels per projection. In the clinical study, the streak artifact was reduced, especially outside the body, although only a ramp filter was used. CONCLUSION: The IPC process succeeded in reducing the streak artifact. This process did not require any modification in acquisition and was not operator dependent. The increase in the number of projections is likely a necessary but not a sufficient condition to reduce the streak artifact: if not corrected, the attenuation could be a limiting factor in the removal of this artifact when the number of projections increases. (+info)
Value of bone scan imaging in predicting pain relief from percutaneous vertebroplasty in osteoporotic vertebral fractures.
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BACKGROUND AND PURPOSE: Patient selection for percutaneous vertebroplasty is often complicated by the presence of multiple fractures or non-localizing pain. Our purpose was to determine whether increased activity revealed by bone scan imaging is predictive of a positive clinical response to percutaneous vertebroplasty. METHODS: A retrospective chart review conducted at our institution yielded 28 vertebroplasty treatment sessions that had been performed after obtaining bone scan imaging for painful, osteoporotic compression fractures in 27 patients. Thirty-five compression fractures were treated during these 28 treatment sessions. In all cases, increased activity was revealed by bone scan imaging before treatment with vertebroplasty. Positive outcome was defined as subjective decrease in pain severity and/or increased level of patient mobility. RESULTS: Subjective pain relief was noted in 26 (93%) of 28 treatment sessions. In 14 (100%) of 14 cases with quantifiable pain levels, pain improved at least 3 points on a 10-point scale (range of improvement, 3-10 points; mean improvement, 7.4 points). Among the remaining 14 treatment sessions in which patients were unable or unwilling to quantify pain severity, the pain relief was described as complete or excellent pain relief in 11 (78%) of 14 cases. In 14 (100%) of 14 cases for which semiquantitative assessment of mobility was available, mobility improved at least one level (5-point graded scale; range of improvement, 1-4 points; mean improvement, 1.7 points). CONCLUSIONS: Increased activity revealed by bone scan imaging is highly predictive of positive clinical response to percutaneous vertebroplasty. (+info)
Bone scintigraphy for osteonecrosis of the knee in patients with non-traumatic osteonecrosis of the femoral head: comparison with magnetic resonance imaging.
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OBJECTIVE: To determine whether technetium bone scintigraphy (BS) is useful for screening of non-traumatic osteonecrosis of the knee (ONK), which was a major affected site, secondary to the femoral head, among multiple osteonecrosis, in patients with non-traumatic osteonecrosis of the femoral head (ONFH). METHODS: A total of 214 knee joints in 107 patients with ONFH were evaluated by BS and a comparison made with magnetic resonance imaging (MRI). ONK was classified into five sites, including the femoral condyles (ONFC), distal femoral metaphysis (ONFM), tibial plateau (ONTP), proximal tibial metaphysis (ONTM), and patella (ONP). RESULTS: Based on the diagnosis by MRI, ONK was detected in 103 knees of 62 patients (48%). ONFC was most common (86 knees, 40%), ONFM (15%), followed by ONTM (10%), ONP (3%), and ONTP (0.9%). Sensitivity, specificity, and accuracy of BS for ONFC detection were 63%, 71%, and 68%, respectively. When the ONFC lesions on the coronal views of MRI were large or medium sized and occupied two thirds, or the entire anteroposterior joint surface on the sagittal views, the sensitivity of BS for ONFC detection increased to 89% (34/38 knees). The sensitivity of BS for ONFM, ONTM, and ONP detection was 3%, 0%, and 0%, respectively, but these lesions showed a low likelihood of collapse. CONCLUSION: BS is useful for screening large ONK in patients with ONFH given that 89% of patients with ONFC who had a high risk of collapse of the knee were identified. (+info)
Primary mineralization at the surfaces of implants.
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Osteogenesis around implants is affected by the physical and chemical characteristics of the biomaterials used. The osteoprogenitor cells must migrate to the implant site and synthesize and secrete a mineralizable extracellular matrix. Because this is neo-bone formation, the mechanism by which the cells calcify their matrix involves extracellular organelles called matrix vesicles in a process termed "primary mineralization". Two different methods for assessing the effects of implant materials on primary mineralization are presented in this report. In the first approach, different implant materials used in dentistry and orthopedic surgery were placed in rat tibial bones after marrow ablation. Two groups of implants were used, bone-bonding and non-bonding materials. We examined the effects of the materials on calcification morphometrically by quantitating changes in matrix vesicle morphology and distribution in endosteal tissue around implants as compared with normal endosteal bone healing. In addition, matrix vesicles were isolated from the endosteal tissue around the implant as well as from the contralateral limb and were examined biochemically. The results demonstrated that bone-bonding materials induced a greater increase in matrix vesicle enzyme activity than did non-bonding materials. However, all materials caused changes in matrix vesicles that were different from those seen in normal endosteal bone formation following injury. The effects of implant materials on biochemical markers of mineralization, including specific activities of matrix vesicle alkaline phosphatase and phospholipase A2 and phosphatidylserine content, demonstrated a high correlation with the morphometric observations with regard to enhancement and/or delay of primary mineralization. In the other approach, we used a radioisotopic method to evaluate the effects of implant materials on primary mineralization. This analysis revealed that implants alter bone healing, as shown by the differential uptake of 99mTc and 32P in different bone compartments. Decreased 32P uptake by the organic phase in the presence of bone-bonding implants suggests that cleavage of 99mTcMD32P into its technetium and methylene diphosphonate moieties was inhibited by the presence of the implants. In summary, these approaches to evaluating the effects of materials on primary mineralization demonstrate that the marrow ablation model can easily distinguish between bone-bonding and non-bonding materials. The use of this model can be valuable in the development of new materials. (+info)