Instrumentation for bone density measurement

Measurement system evaluates the integrated bone density over a specific cross section of bone. A digital computer converts stored bone scan data to equivalent aluminum calibration wedge thickness, and bone density is then integrated along the scan by using the trapezoidal approximation integration formula

Radiation exposure from diagnostic nuclear medicine examinations in golestan province

Introduction: The aim of present study was to estimate effective dose from most common procedures performed in nuclear medicine departments of Golestan province. Methods: Data of nuclear medicine procedures performed in 2 nuclear medicine departments in Golestan province were collected during 4 years. Effective dose, collective effective dose and effective dose per examination were calculated using standard dosimetry tables. Results: Based on the data of this study, results of 10437 nuclear medicine procedures performed during 4 years have lead to 3.97 mSv as average effective dose per examination and 10.37 human-Sv as mean collective effective dose. It was also revealed that Tc-99m was the main source of effective dose (98.3%), bone scan was the most common procedure (25.9%) and cardiac scan (MIBI-rest) has the highest collective effective dose (33.5%) during 4 years. Conclusion: Beside the cardiac scan which was the most common nuclear medicine procedure and the main contributor of effective dose in patients, due to geographical condition of the northeast of Iran, bone scan was the highest performed nuclear medicine examination in the Golestan province

Practice patterns and outcomes of equivocal bone scans for patients with castration-resistant prostate cancer: Results from SEARCH.

ObjectiveTo review follow-up imaging after equivocal bone scans in men with castration resistant prostate cancer (CRPC) and examine the characteristics of equivocal bone scans that are associated with positive follow-up imaging.MethodsWe identified 639 men from five Veterans Affairs Hospitals with a technetium-99m bone scan after CRPC diagnosis, of whom 99 (15%) had equivocal scans. Men with equivocal scans were segregated into "high-risk" and "low-risk" subcategories based upon wording in the bone scan report. All follow-up imaging (bone scans, computed tomography [CT], magnetic resonance imaging [MRI], and X-rays) in the 3 months after the equivocal scan were reviewed. Variables were compared between patients with a positive vs. negative follow-up imaging after an equivocal bone scan.ResultsOf 99 men with an equivocal bone scan, 43 (43%) received at least one follow-up imaging test, including 32/82 (39%) with low-risk scans and 11/17 (65%) with high-risk scans (p = 0.052). Of follow-up tests, 67% were negative, 14% were equivocal, and 19% were positive. Among those who underwent follow-up imaging, 3/32 (9%) low-risk men had metastases vs. 5/11 (45%) high-risk men (p = 0.015).ConclusionWhile 19% of all men who received follow-up imaging had positive follow-up imaging, only 9% of those with a low-risk equivocal bone scan had metastases versus 45% of those with high-risk. These preliminary findings, if confirmed in larger studies, suggest follow-up imaging tests for low-risk equivocal scans can be delayed while high-risk equivocal scans should receive follow-up imaging

Biomechanical Computed Tomography analysis (BCT) for clinical assessment of osteoporosis.

The surgeon general of the USA defines osteoporosis as "a skeletal disorder characterized by compromised bone strength, predisposing to an increased risk of fracture." Measuring bone strength, Biomechanical Computed Tomography analysis (BCT), namely, finite element analysis of a patient's clinical-resolution computed tomography (CT) scan, is now available in the USA as a Medicare screening benefit for osteoporosis diagnostic testing. Helping to address under-diagnosis of osteoporosis, BCT can be applied "opportunistically" to most existing CT scans that include the spine or hip regions and were previously obtained for an unrelated medical indication. For the BCT test, no modifications are required to standard clinical CT imaging protocols. The analysis provides measurements of bone strength as well as a dual-energy X-ray absorptiometry (DXA)-equivalent bone mineral density (BMD) T-score at the hip and a volumetric BMD of trabecular bone at the spine. Based on both the bone strength and BMD measurements, a physician can identify osteoporosis and assess fracture risk (high, increased, not increased), without needing confirmation by DXA. To help introduce BCT to clinicians and health care professionals, we describe in this review the currently available clinical implementation of the test (VirtuOst), its application for managing patients, and the underlying supporting evidence; we also discuss its main limitations and how its results can be interpreted clinically. Together, this body of evidence supports BCT as an accurate and convenient diagnostic test for osteoporosis in both sexes, particularly when used opportunistically for patients already with CT. Biomechanical Computed Tomography analysis (BCT) uses a patient's CT scan to measure both bone strength and bone mineral density at the hip or spine. Performing at least as well as DXA for both diagnosing osteoporosis and assessing fracture risk, BCT is particularly well-suited to "opportunistic" use for the patient without a recent DXA who is undergoing or has previously undergone CT testing (including hip or spine regions) for an unrelated medical condition

Quantitative analysis of bone scans in prostate cancer patients

Prostate cancer (PCa) is one of the most common diseases in the world. PCa can primarily disseminate to the bone, causing bone metastases, which in turn can lead to death. It is important to diagnose bone metastases as soon as possible in order to treat the disease. Bone metastases are diagnosed commonly by bone scan imaging. However, interpretation of bone scan images is not always an easy task for physicians. One way of minimising the risk of misinterpretation is quantitative analysis of bone scan images in order to ascertain whether they show any metastatic lesions, and if so, to what extent. Quantification of the bone scan, i.e. the bone scan index (BSI) method, could be used for prognostication of survival, or to follow up the effect of treatment. The aim of the thesis was to develop and validate a fully automated method for the quantification of skeletal images in patients with prostate cancer based on the BSI method. This thesis is based on four papers. In paper 1, "A Novel Automated Platform for Quantifying the Extent of Skeletal Tumour Involvement in Prostate Cancer Patients Using the Bone Scan Index", we developed an automated BSI-quantification method, used it in a training group of 795 patients, compared it to a manual method and assessed the prognostic value of BSI in an evaluating group of 384 patients. The automated method showed a good correlation (r=80%) with the manual method, and BSI was strongly associated with prostate cancer death. In paper 2, "Bone Scan Index: a prognostic imaging biomarker for high-risk prostate cancer patients receiving primary hormonal therapy”, we found that BSI included prognostic information in addition to other clinical parameters such as “prostate-specific antigens”. Patients with BSI5. In paper 3, “Progression of Bone Metastases in Patients with Prostate Cancer - Automated Detection of New Lesions and Calculation of Bone Scan Index”, we further develop the automatic method to find new metastases using a training group of 266 patients. The method evaluated 31 patients who received chemotherapy. Patients with an increase in BSI during treatment had a lower two-year survival rate (18%) than those with a decrease in BSI (57%). In the final paper, “Assessment of baseline and longitudinal bone scan index measures in the context of a randomised placebo-controlled trial of tasquinimod in men with metastatic castration-resistant prostate cancer (mCRPC)”, we retrospectively calculated BSI at baseline and upon treatment in 85 patients from a clinical trial. We found that BSI and BSI change on-treatment were associated with survival. BSI correlated with known biomarkers of survival, but adds independent prognostic information. In conclusion, BSI calculated using an automated method contains prognostic information and can be used to evaluate treatment effects

Skeletal status and soft tissue composition in astronauts. Tissue and fluid changes by radionuclide absorptiometry in vivo

A device has been constructed and tested which provides immediate readout of bone mineral content and bone width from absorptiometric scans with low energy radionuclides. The basis of this analog system is a logarithmic converter-integrator coupled with a precision linear ratemeter. The system provided accurate and reliable results on standards and ashed bone sections. Clinical measurements were made on about 100 patients with the direct readout system, and these were highly correlated with the results from digital scan data on the same patients. The direct readout system has been used successfully in field studies and surveys as well as for clinical observations

Dynamics of Bone Trap-5b Level in Patients with Bone Metastases of Renal Cell Cancer at Combined Treatment

The objective of this study was to determine the sensitivity of tartrate-resistant acid phosphatase (Bone TRAP-5b) for early detection of bone metastases (BM) and to investigate the efficacy of bisphosphonates (BF) (zolendronic acid-ZA) in prevention of bone metastases in patients with Renal Cell Carcinoma (RCC). The 60 patients with RCC with proven BM were investigated to assess the sensitivity and specificity of Bone TRAP-5b. 95 patients with RCC with high level of tartrate-resistant acid phosphatase (Bone TRAP-5b) (8,5±0,2 IU/L) after radical surgical treatment were divided into two groups: 1-st group: (n=44) received zolendronic acid (ZA) (BF +), and 2-nd group (n=51) patients didn\u27t receive ZA (BF-). Patients of both subgroups were similar by age, sex, stage of disease. The levels of Bone TRAP-5b, Ca++, alkaline phosphatase, LDG were accessed every 3 months, and MRI imaging, bone scan with 99mTc every 6 month in both groups. We determined the high correlation between bone TRAP-5b and the presence of bone metastases (r=0,9; p <0,05), but its level wasn\u27t dependent with the number of BM. The results showed the high sensitivity and specificity of Bone TRAP-5b at the critical value of 5.2 IU/L (98,3 % and 90,0 %), (χ2=64,6; p<0.01). Using BF for the prevention of bone metastases in high risk group patients with RCC provides a significant difference in the incidence of bone metastases in patients

Single Photon Emission Computed Tomography-Computed Tomography (SPECT-CT) Use in Osteosarcoma with Lung Uptake

A 15-year-old patient with osteosarcoma of left distal femur underwent a bone scan with Tc-99m hydroxymethylenediphosphonate (HDP). Whole body bone scan revealed extensive bone and thoracic metastases. Single Photon Emission Computed Tomography-Computed Tomography (SPECT-CT) of the thorax localized the uptake at pleura and lung nodules. In this case study we want to share our experience using SPECT-CT

Radionuclide detection of multiple soft tissue metastases of osteosarcoma masquerading as bone metastasis

Objective: The aim of this work was to report an unusual case of multiple soft tissue metastases of osteosarcoma detected using bone scan and confirmed by CT scan. Clinical Presentation and Intervention: A 15-year-old patient with a history of osteogenic sarcoma presented with fatigue and loss of appetite in addition to a painless swelling of the distal left lower extremity. Bone scan and chest CT scan were performed for restaging purposes. The bone scan revealed multiple bone metastases and suspected tumor recurrence in the left lower extremity in addition to multiple extraosseous hot spots. The latter findings were assessed as ossified soft tissue metastases after considering the performed CT scan. Conclusion: This case showed the double role of bone scan in osteosarcoma in simultaneously assessing the bone status and tumor spread in soft tissue. The benefit of a comparison of bone scan findings with other modalities was also demonstrated. Copyright (C) 2012 S. Karger AG, Base

Combining confocal and BSE SEM imaging for bone block surfaces

The present report presents a method for the correlation of qualitative and quantitative BSE SEM imaging with confocal scanning light microscopy (CSLM) imaging modes applied to bone samples embedded in PMMA. The SEM has a proper digital scan generator: we leave the BSE image unchanged, and match the CSLM image to it, because the CSLM scan mechanism is not digital, though the signal is digitised. Our overlapping program uses a linear transformation matrix which projects one system to the other, calculated by finding three corresponding points in BSE and CSLM pictures. BSE images are empty where cells and osteoid are present. Fluorescence mode CSLM fills in these gaps. The combination images enhance our understanding of what is going on - and re-establish the need for good cellular preservation