ABSTRACT
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.
Subject(s)
Metacarpal Bones , Metatarsal Bones , Animals , Horses , Technetium Tc 99m Medronate , Radionuclide Imaging , Metacarpal Bones/diagnostic imaging , Prospective Studies , Diphosphonates , RadiopharmaceuticalsABSTRACT
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.
Subject(s)
Fibrous Dysplasia of Bone , Fibrous Dysplasia, Polyostotic , Female , Humans , Middle Aged , Fibrous Dysplasia, Polyostotic/diagnostic imaging , Radionuclide Imaging , Skull , Technetium Tc 99m MedronateABSTRACT
Extravasation of 99mTc-labeled radiopharmaceuticals is generally considered to require no specific intervention. In the presented case, the use of hyaluronidase could have minimized the adverse effects resulting from such an extravasation. Currently, no guidelines exist regarding the use of hyaluronidase after extravasation of [99mTc]Tc-HDP. Considering the low risk of administering hyaluronidase, it should be considered to limit the risk of injury after extravasation of [99mTc]Tc-HDP.
Subject(s)
Extravasation of Diagnostic and Therapeutic Materials , Hyaluronoglucosaminidase , Radiopharmaceuticals , Humans , Extravasation of Diagnostic and Therapeutic Materials/diagnostic imaging , Organotechnetium Compounds/administration & dosage , Radiopharmaceuticals/administration & dosage , Technetium Tc 99m Medronate/analogs & derivativesABSTRACT
ABSTRACT: A 59-year-old woman with recent history of weakness, loss of appetite, and significant weight loss was referred for malignancy workup. On the first day, the patient underwent a 99mTc-MDP scan, which revealed diffuse pulmonary uptake in both lungs. Two days later, 99mTc-FAPI scan was performed and showed diffuse pulmonary uptake in the planar and SPECT/CT images. The study present an interesting case demonstrating FAPI-ligand uptake in metastatic pulmonary calcification.
Subject(s)
Calcinosis , Technetium Tc 99m Medronate , Humans , Female , Middle Aged , Technetium Tc 99m Medronate/analogs & derivatives , Calcinosis/diagnostic imaging , Organotechnetium Compounds , Bone and Bones/diagnostic imaging , Lung Neoplasms/diagnostic imaging , Single Photon Emission Computed Tomography Computed TomographyABSTRACT
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.
Subject(s)
Arthritis, Juvenile , Technetium Tc 99m Medronate , Adolescent , Humans , Child , Artificial Intelligence , Arthritis, Juvenile/diagnostic imaging , Radionuclide Imaging , Technetium , Machine LearningABSTRACT
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.
Subject(s)
Diphosphates , Osteomyelitis , Humans , Retrospective Studies , Technetium Tc 99m Medronate , Single Photon Emission Computed Tomography Computed Tomography/methods , Tomography, Emission-Computed, Single-Photon , Magnetic Resonance Imaging , Osteomyelitis/diagnostic imagingABSTRACT
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.
Subject(s)
Bone Neoplasms , Fibroma , Fibromatosis, Aggressive , Humans , Technetium Tc 99m Medronate , Fluorodeoxyglucose F18 , Positron Emission Tomography Computed Tomography , Fibromatosis, Aggressive/diagnostic imaging , Prospective Studies , Tomography, X-Ray Computed , Bone Neoplasms/diagnostic imagingABSTRACT
CONTEXT: A major indication for referrals for bone scans (BS) to establish or exclude skeletal metastases. Few patients are referred with clinically indeterminate diagnosis or cancer of unknown primary (CUP), to search for bony metastases or primary tumor. AIMS: This study aimed to assess the usefulness or otherwise for BS in such instances. SETTINGS AND DESIGN: A retrospective cross-sectional study of BS performed for CUP and indeterminate diagnosis from 2012 to 2016 in the nuclear medicine unit of a tertiary teaching hospital. SUBJECTS AND METHODS: The study involved reviews of technetium-99m diphosphonate BS for patients with CUP. BSs were reported by nuclear physicians as normal, normal variants, suspicious for metastases or as malignant, and with solitary or multiple skeletal metastases. STATISTICAL ANALYSIS USED: Data were analyzed using SPSS version 21 for descriptive analysis. Continuous data were displayed as means along with their standard deviation; categorical data were tabulated as frequencies and percentages. RESULTS: Of 2156 BS, 42 (0.02%) were eligible. Patients were aged 27-86 years, mainly in the sixth and seventh decades of life. Bone metastases were identified in 14 (33%) of these patients, whereas 17 BS (40%) were normal, BS appeared equivocal in 10 (23.8%). CONCLUSIONS: Single-photon emission computed tomography/computed tomography availability would resolve the clinical dilemma in patients with equivocal and apparently normal BS.
Résumé Contexte:Une indication majeure pour les références à des scintigraphies osseuses (BS) pour établir ou exclure des métastases squelettiques. Peu de patients sont référés avec diagnostic cliniquement indéterminé ou cancer primitif inconnu (CUP), pour rechercher des métastases osseuses ou une tumeur primitive.Objectifs:Cette étude visait à évaluer l'utilité ou non de la BS dans de tels cas.Paramètres et conception:Une étude transversale rétrospective sur le BS réalisée pour CUP et diagnostic indéterminé de 2012 à 2016 dans l'unité de médecine nucléaire d'un hôpital universitaire tertiaire.Sujets et Méthodes:L'étude comprenait des examens du diphosphonate de technétium-99m BS pour les patients atteints de CUP. Des BS ont été signalés par des médecins nucléaires comme normales, variantes normales, suspectes de métastases ou malignes, et avec métastases squelettiques solitaires ou multiples.Analyses statistiques utilisé:Les données ont été analysées à l'aide de SPSS version 21 pour une analyse descriptive. Les données continues ont été affichées comme moyennes avec leur l'ecarts t; les données catégorielles ont été présentées sous forme de fréquences et de pourcentages.Résultats:Sur 2156 BS, 42 (0,02%) étaient éligibles. Les patients étaient âgés 27 à 86 ans, principalement dans les sixième et septième décennies de la vie. Des métastases osseuses ont été identifiées chez 14 (33 %) de ces patients, alors que 17 BS (40 %) étaient normaux, la BS semblait équivoque dans 10 cas (23,8 %).Conclusions:Tomodensitométrie par émission de photons uniques/tomodensitométrie la disponibilité résoudrait le dilemme clinique chez les patients atteints de BS équivoque et apparemment normale.
Subject(s)
Bone Neoplasms , Humans , Female , Male , Bone Neoplasms/secondary , Bone Neoplasms/diagnostic imaging , Middle Aged , Cross-Sectional Studies , Retrospective Studies , Aged , Adult , Aged, 80 and over , Neoplasms, Unknown Primary/diagnostic imaging , Neoplasms, Unknown Primary/pathology , Radionuclide Imaging , Radiopharmaceuticals , Bone and Bones/diagnostic imaging , Bone and Bones/pathology , Technetium Tc 99m MedronateABSTRACT
Aim: Nano-hydroxyapatite (nHA) is a good nanocarrier to load 223Ra, but the low specific activity (sp.act.) of 223Ra@nHA limits its application in medicine. Methods: We proposed a method for preparing nHA using PEG as a template, which significantly increases the sp.act of 223Ra@nHA and a new method to loaded 99mTc for in vivo tracking. Results: The nHA synthesized using PEG as a template was associated with higher sp.act for 223Ra in comparison to nHA with identical particle size and without PEG. The nHA load 99mTc-MDP was associated with higher labeling rate and stability in comparison to 99mTc. Conclusion: All these findings suggest that using PEG as a template and 99mTc-MDP could be the most effective of synthetic 223Ra/99mTc@nHA.
[Box: see text].
Subject(s)
Bone Neoplasms , Durapatite , Particle Size , Radium , Durapatite/chemistry , Humans , Bone Neoplasms/drug therapy , Bone Neoplasms/diagnostic imaging , Radium/chemistry , Polyethylene Glycols/chemistry , Nanoparticles/chemistry , Technetium/chemistry , Cell Line, Tumor , Radiopharmaceuticals/chemistry , Animals , Technetium Tc 99m Medronate/chemistryABSTRACT
OBJECTIVE: To investigate the short-term efficacy and safety of Yunke (technetium-99 conjugated methylene diphosphonate) combined with pulsed electromagnetic field (PEMF) and Gukang capsule in the treatment of postmenopausal osteoporosis (PMOP). METHODS: A total of 112 patients with PMOP who received treatment in the Department of Nuclear Medicine of the hospital from January 2019 to June 2020 were selected and randomly divided into 4 groups of 28 patients each. Group A received Yunke and PEMFs, group B received Gukang capsules and PEMFs, group C received Yunke and Gukang capsules and PEMFs, and group D received PEMFs. All groups were given adequate amounts of calcium and active vitamin D. Intervention 2 sessions of 3 months each. Outcome measures were bone mineral density (BMD) and pain improvement. RESULTS: Compared with 1 course of treatment, the symptoms of bone pain were relieved more significantly after 2 courses of treatment in group A (50.0% vs. 64.3%), group B (46.4% vs. 64.3%), group C (78.6% vs. 92.9%) and group D (21.4% vs. 28.6%) (P < 0.05). After 2 courses of treatment, bone pain symptoms were less relieved in group A (96.4% vs. 64.3%), group B (96.4% vs. 64.3%), and group D (96.4% vs. 28.6%) compared with group C (P < 0.05). Compared with group C, BMD values of L4 vertebrae and femoral neck were significantly decreased in groups A, B, and D (P < 0.05). Compared with those before treatment, BMD of L4 vertebrae and femoral neck increased significantly in groups A, B, C, and D after 2 courses of treatment (P < 0.05). CONCLUSION: Yunke combined therapy can effectively relieve the pain symptoms, increase BMD, and reduce the risk of fracture in patients with PMOP in a short period, which is an effective method for the treatment of PMOP.
Subject(s)
Bone Density , Osteoporosis, Postmenopausal , Humans , Female , Osteoporosis, Postmenopausal/drug therapy , Osteoporosis, Postmenopausal/diagnostic imaging , Middle Aged , Bone Density/drug effects , Aged , Technetium Tc 99m Medronate , Bone Density Conservation Agents/chemistry , Radiopharmaceuticals/chemistryABSTRACT
Skeletal-related events due to bone metastases can be prevented by early diagnosis using radiological or nuclear imaging techniques. Nuclear medicine techniques such as Single Photon Emission Computed Tomography (SPECT) and Positron Emission Tomography (PET) have been used for diagnostic imaging of bone for decades. Although it is widely recognized that conventional diagnostic imaging techniques such as Computed Tomography (CT) and Magnetic Resonance Imaging (MRI) have high sensitivity, low cost and wide availability, the specificity of both techniques is rather low compared to nuclear medicine techniques. Nuclear medicine techniques, on the other hand, have improved specificity when introduced as a hybrid imaging modality, as they can combine physiological and anatomical information. Two main radiopharmaceuticals are used in nuclear medicine: [99mTc]-methyl diphosphonate ([99mTc]Tc-MDP) from the generator and [18F]sodium fluoride ([18F]NaF) from the cyclotron. The former is used in SPECT imaging, while the latter is used in PET imaging. However, recent studies show that the role of radiolabeled bisphosphonates with gallium-68 (68Ga) and fluorine-18 (18F) may have a potential role in the future. This review, therefore, presents and discusses the brief method for producing current and future potential radiopharmaceuticals for bone metastases.
Subject(s)
Bone Neoplasms , Diphosphonates , Positron-Emission Tomography , Radiopharmaceuticals , Tomography, Emission-Computed, Single-Photon , Humans , Tomography, Emission-Computed, Single-Photon/methods , Positron-Emission Tomography/methods , Bone Neoplasms/secondary , Bone Neoplasms/diagnostic imaging , Bone and Bones/diagnostic imaging , Gallium Radioisotopes , Technetium Tc 99m MedronateABSTRACT
ABSTRACT: A 53-year-old man with newly diagnosed nasopharyngeal carcinoma (NPC) underwent 99m Tc-MDP bone scintigraphy for the potential bone metastases, and paired 68 Ga-DOTATATE and 68 Ga-FAPI PET/CT for initial staging. 68 Ga-DOTATATE PET/CT identified 2 abnormal foci with increased tracer uptake in the cervical vertebra and the ilium, whereas 68 Ga-FAPI PET/CT and bone scan detected only the ilium lesion. A subsequent biopsy confirmed NPC metastasis in the ilium. Furthermore, baseline and follow-up bone scintigraphy revealed that the positive lesion in the cervical vertebra, as indicated in 68 Ga-DOTATATE PET/CT, was also a bone metastasis. This case highlighted the potential superiority of 68 Ga-DOTATATE in NPC.
Subject(s)
Bone Neoplasms , Nasopharyngeal Carcinoma , Nasopharyngeal Neoplasms , Organometallic Compounds , Positron Emission Tomography Computed Tomography , Technetium Tc 99m Medronate , Humans , Male , Middle Aged , Nasopharyngeal Carcinoma/diagnostic imaging , Nasopharyngeal Carcinoma/pathology , Nasopharyngeal Neoplasms/diagnostic imaging , Nasopharyngeal Neoplasms/pathology , Bone Neoplasms/secondary , Bone Neoplasms/diagnostic imaging , Gallium Radioisotopes , Carcinoma/diagnostic imaging , Carcinoma/secondaryABSTRACT
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 0.06â0.91; 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.
Subject(s)
Bone Neoplasms , Prostatic Neoplasms, Castration-Resistant , Radionuclide Imaging , Humans , Male , Prostatic Neoplasms, Castration-Resistant/drug therapy , Prostatic Neoplasms, Castration-Resistant/diagnostic imaging , Prostatic Neoplasms, Castration-Resistant/pathology , Aged , Prognosis , Bone Neoplasms/secondary , Bone Neoplasms/diagnostic imaging , Bone Neoplasms/drug therapy , Middle Aged , Bone and Bones/diagnostic imaging , Technetium Tc 99m Medronate , Aged, 80 and over , Prostate-Specific Antigen/bloodSubject(s)
Adenocarcinoma , Muscle Neoplasms , Ossification, Heterotopic , Rectal Neoplasms , Technetium Tc 99m Medronate , Humans , Rectal Neoplasms/pathology , Rectal Neoplasms/diagnostic imaging , Adenocarcinoma/secondary , Adenocarcinoma/diagnostic imaging , Adenocarcinoma/pathology , Ossification, Heterotopic/diagnostic imaging , Ossification, Heterotopic/etiology , Ossification, Heterotopic/pathology , Muscle Neoplasms/secondary , Muscle Neoplasms/diagnostic imaging , Male , Radionuclide Imaging , Muscle, Skeletal/diagnostic imaging , Muscle, Skeletal/pathology , Incidental Findings , Radiopharmaceuticals , Middle AgedABSTRACT
No disponible
Subject(s)
Humans , Male , Aged , Osteochondroma/diagnostic imaging , Incidental Findings , Pelvis/diagnostic imaging , Pelvis/pathology , Radionuclide Imaging , Technetium Tc 99m Medronate , Tomography, Emission-Computed, Single-PhotonABSTRACT
Se presenta el caso de un paciente con antecedente de adenocarcinoma de próstata y diagnóstico de ACV isquémico con transformación hemorrágica. La gammagrafía ósea con Tc-99m MDP complementada con SPECT e imágenes de fusión con TC cerebral simple, realizada a los 15 días, muestra hipercaptación en la región temporal izquierda, correspondiente al ACV en etapa subaguda.
We present the case of a patient with a history of prostate adenocarcinoma with a diagnosis of ischemic stroke with hemorrhagic transformation. Bone scintigraphy with Tc-99m MDP supplemented with SPECT and fusion images with simple cerebral CT, performed at 15 days, shows uptake in the left temporal region, corresponding to stroke in subacute stage
Apresentamos o caso de um paciente com história de adenocarcinoma de próstata com diagnóstico de acidente vascular cerebral isquêmico com transformação hemorrágica. A cintilografia óssea com Tc-99m MDP suplementada com SPECT e imagens de fusão com TC cerebral simple, realizadas aos 15 dias, mostra captação na região temporal esquerda, correspondente ao ACV na fase subaguda
Subject(s)
Humans , Male , Aged, 80 and over , Technetium Tc 99m Medronate , Stroke/diagnostic imaging , Radionuclide Imaging , Tomography, Emission-Computed, Single-PhotonABSTRACT
We present images of an 83-year-old female with a history of osteoporosis and bilateral total knee replacement arthroplasty, referred for bone scintigraphy and single-photon emission computed tomography (SPECT)/computed tomography (CT), owing to left knee pain. No trauma to, or intense exercise of, the kneewas reported. The bone scan and SPECT/CT revealed a focally increased Tc-99m methylene diphosphonate (MDP) uptake in the medial cortex of the left femoral diaphysis with matched linear radiolucency on CT images. This was misinterpreted as atypical femoral stress fracture; however, focal stress reaction injury to the nutrient foramen was confirmed on contrast-enhanced magnetic resonance imaging.
Subject(s)
Aged, 80 and over , Female , Humans , Arthroplasty , Arthroplasty, Replacement, Knee , Diaphyses , Fractures, Stress , Knee , Magnetic Resonance Imaging , Osteoporosis , Radionuclide Imaging , Technetium Tc 99m Medronate , Tomography, Emission-Computed , Tomography, Emission-Computed, Single-PhotonABSTRACT
Bone scan is a sensitive imaging procedure for cancer patients who are at high risk for bone metastases. Despite the high sensitivity, Tc-99m methylene diphosphonate (MDP) is not a specific tracer and its increased uptake may also be seen in extra-osseous areas. In cases where localization of extra-osseous sites of MDP uptake on planar imaging prove to be difficult, single photon emission computed tomography with computed tomography (SPECT/CT) may be useful. A known lung cancer patient was referred for whole body bone scan to detect bone metastasis. Planar images showed tracer accumulation in the left area of the head, suspicious for skull metastasis. SPECT-CT imaging of the head was done for further evaluation, which showed Tc-99m MDP uptake in the left temporoparietal lobe. Magnetic resonance imaging (MRI) of the brain was subsequently done, which showed a subacute brain infarct corresponding to the Tc-99m MDP-avid focus. Thus, SPECT-CT was helpful in proper anatomical localization of the focal Tc-99m MDP uptake in the head, which otherwise might have been easily mistaken for skull metastasis should only planar imaging was used.