Equine skeletal scintigraphy: Comparing lesion detection ability of methylene diphosphonate and hydroxymethylene diphosphonate in the caudal cervical and proximal metacarpal/metatarsal regions.

BACKGROUND: Data regarding the lesion detection ability of different radiotracers are lacking in equine bone scintigraphy. METHODS: In this prospective study, hydroxymethylene diphosphonate (HMDP) and methylene diphosphonate (MDP) were compared in horses with increased radiopharmaceutical uptake either in the caudal cervical region (CS group) or in the proximal metacarpal/metatarsal region (PMR group). Region of interest analysis was used to determine normal bone-to-soft tissue ratios, lesion-to-normal bone ratios and lesion-to-soft tissue ratios. Qualitative scoring and total count rates were recorded for each image. RESULTS: A total of 213 scintigrams were included. Within the PMR group, there were significantly higher lesion-to-normal bone ratios for MDP compared with HMDP (p = 0.02). In the CS group, normal bone-to-soft tissue ratios were significantly higher for HMDP (p = 0.01). The interobserver agreement with regard to the qualitative assessment of the scintigrams was poor. LIMITATION: Paired studies, comparing the different radiotracers in the same patient, were not feasible. CONCLUSION: This study revealed minor differences between the two radiotracers, although these have no practical implications. Both radiopharmaceuticals are well suited for detecting lesions at the investigated sites using equine bone scintigraphy.

Flare phenomenon visualized by 99mTc-bone scintigraphy has prognostic value for patients with metastatic castration-resistant prostate cancer.

OBJECTIVE: This study aimed to determine the prognostic value of the flare phenomenon in patients with metastatic castration-resistant prostate cancer (mCRPC) using the bone scan index (BSI) derived from 99mTc-methylenediphosphonate (MDP) bone scintigraphy images. METHODS: We categorized 72 patients from the PROSTAT-BSI registry with mCRPC who were followed-up for 2 years after starting docetaxel chemotherapy to groups based on pre-chemotherapy BSI values of < 1, 1-4, and > 4. We assessed the effects of the flare phenomenon (defined as a > 10% increase in the BSI within 3 months of starting chemotherapy, followed by > 10% improvement within the next 3 months) on survival using Kaplan-Meier curves and Cox proportional hazard analyses. RESULTS: The flare phenomenon was found in 26 (36%) of the 72 patients. Prostate-specific antigen (PSA), alkaline phosphatase (ALP), and hemoglobin (Hb) levels steadily increased, then deteriorated in patients with and without flare, respectively. Elevated BSI and PSA values at 3 months after starting therapy and the absence of abiraterone or/and enzalutamide therapy led to poor 2-year overall survival (OS) in the group without flare. In contrast, no influence was noticeable in the group with flare. The results of multivariable analyses that included only factors associated with PSA and BSI showed that increased baseline BSI (hazard ratio [HR], 1.39; 95% confidence interval [CI], 1.04-1.86; P = 0.023) and PSA (HR, 7.15; 95% CI 2.13-24.04; P = 0.0015) values could be independent risk factors for patients with mCRPC without flare. However, these factors lost significance during flare. The risk for all-cause death was significantly higher among patients with BSI > 4 without, than with flare. The results of univariable analyses indicated that flare positively impacted survival (HR, 0.24; 95% CI 0.06‒0.91; P = 0.035). Multivariable analysis did not identify any factors that could predict outcomes. CONCLUSION: Favorable prognosis, with fewer disturbances from other factors such as the use of abiraterone or/and enzalutamide, PSA changes, and BSI, was attainable in cases when the mCRPC patient demonstrated flare phenomenon. Follow-up bone scintigraphy at least every 3 months could help to determine the prognosis of patients with bone metastasis of mCRPC.

Comparison of diagnostic efficacy between 99mTc-methylene diphosphate SPECT/CT and MRI for bone and joint infections: a multicenter retrospective analysis.

Objective: There is currently no non-invasive examination that can fully determine the diagnosis of osteomyelitis. SPECT/CT tomographic fusion imaging can provide both local metabolic activity and anatomical information to determine the condition and location. This study evaluates the diagnostic efficacy of 99mTc-MDP SPECT/CT in bone infections, compared to MRI. Methods: In this multicenter retrospective study, 363 patients with suspected bone and joint infections or osteomyelitis were included. Participants underwent 99mTc-MDP SPECT/CT and/or MRI examinations, supplemented by pathogenic bacterial cultures and histopathological analysis. Results: Only SPECT/CT was tested in 169 patients, and only MRI was used in 116. 78 people have implemented both inspections and have detailed information. The diagnostic sensitivity and specificity of SPECT/CT for infection were 96% and 92% respectively, with an accuracy of 96%. For MRI, these figures were 88%, 84%, and 87% respectively. Conclusion: This represents the largest global study to date evaluating osteomyelitis and bone infection diagnosis using 99mTc-MDP SPECT/CT tomographic fusion imaging. The findings indicate that 99mTc-MDP SPECT/CT fusion imaging offers superior diagnostic accuracy compared to MRI. This is particularly evident in cases involving metallic implants and chronic infections. 99mTc-MDP SPECT/CT fusion imaging emerges as a highly suitable non-invasive diagnostic modality, facilitating enhanced clinical follow-up and treatment.

Machine learning diagnosis of active Juvenile Idiopathic Arthritis on blood pool [ 99M Tc] Tc-MDP scintigraphy images.

PURPOSE: Neural network has widely been applied for medical classifications and disease diagnosis. This study employs deep learning to best discriminate Juvenile Idiopathic Arthritis (JIA), a pediatric chronic joint inflammatory disease, from healthy joints by exploring blood pool images of 2phase [ 99m Tc] Tc-MDP bone scintigraphy. METHODS: Self-deigned multi-input Convolutional Neural Network (CNN) in addition to three available pre-trained models including VGG16, ResNet50 and Xception are applied on 1304 blood pool images of 326 healthy and known JIA children and adolescents (aged 1-16). RESULTS: The self-designed model ROC analysis shows diagnostic efficiency with Area Under the Curve (AUC) 0.82 and 0.86 for knee and ankle joints, respectively. Among the three pertained models, VGG16 ROC analysis reveals AUC 0.76 and 0.81 for knee and ankle images, respectively. CONCLUSION: The self-designed model shows best performance on blood pool scintigraph diagnosis of patients with JIA. VGG16 was the most efficient model rather to other pre-trained networks. This study can pave the way of artificial intelligence (AI) application in nuclear medicine for the diagnosis of pediatric inflammatory disease.

18F-FDG PET/CT and 99mTc-MDP Bone Scintigraphy Findings of Multifocal Desmoid Fibromatosis.

ABSTRACT: Desmoid fibromatosis, also called desmoid tumors, is a group of locally aggressive fibromatous proliferative disorders. They represent less than 3% of all soft tissue sarcoma and are multifocal in approximately 10% of cases. However, there are only a few cases in the literature describing 18F-FDG PET/CT and 99mTc-MDP bone scan features of extra-abdominal desmoid fibromas, and all were solitary bone lesions. Herein, we presented a unique case of multifocal desmoid fibromatosis of bone illustrating the prospective value of 18F-FDG PET/CT and 99mTc-MDP bone scan in the evaluation of desmoid tumors.

Extraosseous distribution of 99mTc-diphosphonates during bone scintigraphy: review of the literature with case series presentation.

PURPOSE: Technetium-99m (99mTc)-diphosphonates represent the most common radiopharmaceutical used for bone scintigraphy. Even if the uptake in bone tissue has been widely explored, atypical uptake could be seen in soft tissue malignancies during bone scintigraphy. Increased vascularization and endothelium permeability represent front-row players in the biodistribution of the tracer, albeit other causes have been identified such as trauma, necrosis, the presence of calcification in metastasis, the pH of the tissue and consequently the type of ion concentration. CONCLUSION: The aim of this paper is to summarize the state of art of atypical soft tissue uptake seen in cancer tissues. The research was conducted on PubMed. The analysis of the literature suggests that calcium metabolism and ionic saturation have a pivotal role in the biodistribution of bone tracers. This phenomenon ranks in a complex scenario that includes carcinogenesis and cancer environment aspects. We also report two cases in our Institution in which atypical uptake in cancer tissues was observed.

Fibrous Dysplasia With Atypical Bilateral Upper Extremity Pattern.

ABSTRACT: Fibrous dysplasia (FD) typically presents unilaterally in the lower limbs, or in the skull, mandible, or pelvis. Bilateral presentation is rarely reported. Most cases are diagnosed in the teens with 75% of patients diagnosed before the age of 30 years. In this case, a 63-year-old woman with suspected diagnosis of malignancy was referred to 99mTc-MDP scan and found to have polyostotic FD in bilateral upper extremities. Nuclear medicine can play an important role in diagnosing FD cases with atypical presentation and help risk stratification for more aggressive transformation.

Dynamic blood flow imaging with 99mTc-hydroxymethylene diphosphonate as a therapeutic response marker in patients with Raynaud's phenomenon.

We evaluated the predictive value of dynamic blood flow scintigraphy with 99mTc-HDP (hydroxymethylene diphosphonate) for therapeutic response in patients with Raynaud's phenomenon (RP). Eighty patients who underwent dynamic blood flow scintigraphy using the one-hand chilling method were enrolled. We analyzed the quantitative variables as the ratio of chilled fingers to ambient fingers (CAfinger), that of the chilled hand to ambient hand (CAhand), and that of chilled fingers to ambient palm (FPR) (CAFPR) at 15 and 30 s after 99mTc-HDP bolus injection. Total cumulative radioactivity counts for 180 s were obtained. We evaluated the clinical utility of these quantitative parameters with other clinical variables, including RP severity, therapeutic compliance, types of RP, and scintigraphic interpretation of findings in patients with RP. Fifty-two patients showed poor therapeutic response. There were significant differences between good- and poor-therapeutic responder groups in RP intensity (p = 0.003), CAfinger15s (p = 0.008), CAfinger30s (p = 0.002), CAfinger180s (p = 0.011), CAhand15s (p = 0.008), CAhand30s (p = 0.007), CAhand180s (p = 0.017), CAFPR30s (p = 0.004), and CAFPR180s (p = 0.002). After multivariate logistic regression analysis, only CAfinger30s (p = 0.002) had an independent predictive value of the therapeutic response. 99mTc-HDP dynamic blood flow scintigraphy could be helpful in predicting the therapeutic response in patients with RP.

A Unique Case of Familial Expansile Osteolysis: Findings on 99mTc-MDP Bone Scan.

ABSTRACT: Familial expansile osteolysis is an exceedingly rare autosomal dominant bone dysplasia, which can have overlapping features with Paget disease and expansile skeletal hyperphosphatasia. We present a novel case of familial expansile osteolysis evaluated on 99mTc-MDP bone scan with correlative radiographs and CT.

Extraosseous Uptake and Multiple Metastases of Splenic Composite Hemangioendothelioma on 99m Tc-MDP Scintigraphy.

ABSTRACT: Composite hemangioendothelioma is a rare disease that exhibits biological potency ranging from benign to low-grade malignancy, and hepatic and bone metastases are even rarer. Here, we present the imaging findings of a 65-year-old man with splenic composite hemangioendothelioma and multiple metastases. A bone scan revealed abnormal uptake of 99m Tc-MDP in multiple bones and spleen, whereas enhanced CT demonstrated splenic lesions with low density and mild enhancement. Based on pathological examination, the patient was diagnosed with splenic composite hemangioendothelioma with bone metastasis.

Diagnostic Utility of 99m Tc-MDP Bone Scintigraphy for Nivolumab-Induced Inflammatory Arthritis.

ABSTRACT: Immune checkpoint inhibitors can revive exhausted helper T-cells, and inflammatory cell reactivation may cause autoimmune disease-like conditions. Drug-induced arthritis is an immune-related adverse event, but the diagnostic approach is undefined. We present the diagnostic utility of 99m Tc-MDP bone scintigraphy for nivolumab-induced inflammatory arthritis. A 67-year-old man with hypopharyngeal carcinoma presented bilateral multiple metacarpophalangeal joint pain and swelling at each nivolumab administration. Regular imaging findings were atypical for inflammatory arthritis and did not fulfill the criteria for rheumatoid arthritis. We diagnosed nivolumab-induced inflammatory arthritis based on clinical symptoms and the symmetrical moderate uptake of the affected joints on 99m Tc-MDP bone scintigraphy.

Radiopharmaceutical extravasation in bone scintigraphy: a cross-sectional study.

OBJETIVES: Tc-99m Hydroxymethylene diphosphonate (HMDP) bone scintigraphy is commonly used to diagnose bone disorders. We aimed to quantify and characterize the occurrence of radiopharmaceutical extravasation in bone scintigraphy, using Tc-99m HMDP, as well as to compare the visual classification of the events with an independent analysis using image processing software. METHODS: We conducted a cross-sectional study, using data from a total of 400 (9.1%) exams, randomly selected from all the procedures performed in 2018 in the Portuguese Institute of Oncology of Porto, Portugal. Prevalence estimate and the corresponding 95% confidence interval (CI) was computed for the presence of extravasation. Odds ratios and 95% CI were computed to quantify the association between demographic and clinical characteristics, and the occurrence of extravasation. RESULTS: The prevalence of Tc-99m HMDP extravasation was 26.5% (95% CI: 22.4-31.0). Those from an inpatient setting had almost seven-fold higher odds of extravasation than those from an outpatient setting. When the wrist was used for administration, there was three times more odds of extravasation when compared to the use of hand. There were statistically significant differences in the median scores of extravasations severity obtained from image processing software according to the different grades attributed by visual appreciation ( P  < 0.001). CONCLUSION: Tc-99m HMDP extravasation occurred in one out of four patients, being more frequent among those from an inpatient setting and when the wrist was used for administration. Visual appreciation of the extravasation seems to be acceptable to classify its severity.

Spectrum of technetium-99m methylene diphosphonate (99mTc MDP) uptake in Osteosarcoma.

Osteosarcoma is a frequently occurring primary skeletal malignancy in the adolescent population. It arises from primitive mesenchymal bone forming cells and frequently involves long bones near the metaphyseal growth plate. Multiple imaging modalities are used for complete staging workup at the time of presentation; including magnetic resonance imaging (MRI) for local disease extent, computed tomography (CT) scan to rule out pulmonary metastasis, and bone scan to look for distant osseous metastases. We present the case of a young boy with osteosarcoma of left tibia, showing additional findings on MDP bone scan acquired for initial staging work up.

Vertical Appearance of Urinary Bladder on Bone Scintigraphy Might Not Always Suggest Adjacent Pathology.

ABSTRACT: Previous publications suggested that vertical appearance of the urinary bladder on 99m Tc-MDP whole-body bone scintigraphy was likely due to an adjacent abnormality. Here we report bone scan findings of a vertical appearance of the urinary bladder in a 66-year-old man with lung cancer without corresponding pathology nearby.

Deep learning enhanced ultra-fast SPECT/CT bone scan in patients with suspected malignancy: quantitative assessment and clinical performance.

Objectives. To evaluate the clinical performance of deep learning-enhanced ultrafast single photon emission computed tomography/computed tomography (SPECT/CT) bone scans in patients with suspected malignancy.Approach. In this prospective study, 102 patients with potential malignancy were enrolled and underwent a 20 min SPECT/CT and a 3 min SPECT scan. A deep learning model was applied to generate algorithm-enhanced images (3 min DL SPECT). The reference modality was the 20 min SPECT/CT scan. Two reviewers independently evaluated general image quality, Tc-99m MDP distribution, artifacts, and diagnostic confidence of 20 min SPECT/CT, 3 min SPECT/CT, and 3 min DL SPECT/CT images. The sensitivity, specificity, accuracy, and interobserver agreement were calculated. The lesion maximum standard uptake value (SUVmax) of the 3 min DL and 20 min SPECT/CT images was analyzed. The peak signal-to-noise ratio (PSNR) and structure similarity index measure (SSIM) were evaluated.Main results. The 3 min DL SPECT/CT images showed significantly superior general image quality, Tc-99m MDP distribution, artifacts, and diagnostic confidence than the 20 min SPECT/CT images (P< 0.0001). The diagnostic performance of the 20 min and 3 min DL SPECT/CT images was similar for reviewer 1 (pairedX2= 0.333,P= 0.564) and reviewer 2 (pairedX2= 0.05,P= 0.823). The diagnosis results for the 20 min (kappa = 0.822) and 3 min DL (kappa = 0.732) SPECT/CT images showed high interobserver agreement. The 3 min DL SPECT/CT images had significantly higher PSNR and SSIM than the 3 min SPECT/CT images (51.44 versus 38.44,P< 0.0001; 0.863 versus 0.752,P< 0.0001). The SUVmaxof the 3 min DL and 20 min SPECT/CT images showed a strong linear relationship (r= 0.991;P< 0.0001).Significance.Ultrafast SPECT/CT with a 1/7 acquisition time can be enhanced by a deep learning method to achieve comparable image quality and diagnostic value to those of standard acquisition.

Unexpected Solitary Subcutaneous Metastasis From Esophageal Carcinoma Revealed by MDP Bone Scintigraphy.

ABSTRACT: A 60-year-old man with back pain underwent 99m Tc-MDP to evaluate bone metastases from newly esophageal carcinoma. No bone metastasis was found on the whole-body bone scan. Unexpectedly, subcutaneous metastasis revealed increased 99m Tc-MDP activity.

Alternative Isotope Options for Amyloidosis Imaging: A Technologist's Perspective.

The recent pyrophosphate shortages can limit the availability of 99mTc-pyrophosphate scans for cardiac amyloidosis. However, another radiotracer is available: 99mTc-hydroxymethylene diphosphonate (HMDP). 99mTc-HMDP, widely available in the United States for bone scanning, has effectively been used in Europe to diagnose transthyretin amyloidosis. 99mTc-HMDP and 99mTc-pyrophosphate have comparable blood clearance and sensitivity. The imaging protocols for 99mTc-HMDP and 99mTc-pyrophosphate are similar, except 99mTc-HMDP is imaged 2-3 h after injection and whole-body imaging is optional. The interpretation is also essentially the same; however, caution is needed because of the high soft-tissue uptake with 99mTc-HMDP, which can affect heart-to-contralateral-lung ratios.

Generalized Muscular Uptake of 99m Tc-MDP on Bone Scan in a Patient With Scleromyxedema-Associated Myopathy.

ABSTRACT: A 62-year-old man presented with a 5-year history of progressive myasthenia, myalgia, and skin changes. Upon laboratory testing, elevated serum creatine kinase and lactate dehydrogenase, as well as monoclonal immunoglobulin Gκ, were observed. A bone scan revealed generalized muscular uptake of 99m Tc-MDP, whereas 18 F-FDG PET/CT demonstrated only mild hypermetabolism of the muscles. A muscle biopsy showed myofibrillary vacuolar degeneration, and a skin biopsy indicated scleromyxedema. Based on these findings, the patient was diagnosed with scleromyxedema-associated myopathy.

Renal tumoural calcinosis: Extensive and multifocal form.

Renal tumoural calcinosis is rare, but the incidence is rising with increasing life expectancy due to dialysis. Whole body skeletal scintigraphy with 99mTc- MDP is a sensitive method to detect sites of osseous involvement. We share an interesting image of the bone scan, in a patient with extensive renal tumoural calcinosis.

99mTc-MDP Bone Scan and 18F-FDG PET/CT Imaging of Primary Hepatic Osteosarcoma.

A 65-year-old man presented with abdominal bloating, pain, and nausea for 5 days. Abdominal CT revealed a heterogeneous mass with a large area of calcification, and rupture of the mass was seen around the capsulafibrosa. According to pathological examination after percutaneous puncture biopsy, the histopahological and immunohistochemical findings were suggestive of metastatic or primary hepatic osteosarcoma. Whole body bone scintigraphy demonstrated elevated 99mTc-MDP activity in hepatic mass, but no skeletal lesions. The diagnosis of primary hepatic osteosarcoma was finally confirmed. PET/CT showed hepatic mass with heterogeneous high-uptake, and multiple metastases in portacaval lymph nodes, lungs and the third thoracic vertebra were considered.