Osteosarcoma of talus with heterotopic ossifications and lung metastases.

Osteosarcoma is the most common malignant bone tumor and is known to occur mainly in the metaphyses of long bones. However, a few cases of osteosarcoma in talus have been reported in older patients. We experienced an osteosarcoma of an 80-year-old male patient with a talus which is rarely reported and evaluated disease patterns with four different imaging modalities.

Looking beyond the indication: Bone scan for trauma providing unsuspected initial diagnosis of acute critical lower limb arterial compromise.

We report a case of rare incidental initial detection of unsuspected arterial supply compromise to the right lower extremity on a bone scan done to rule out fracture in a patient with right hip pain following a fall. Follow up CT angiogram confirmed near complete occlusion of right lower extremity arteries for which patient underwent above knee amputation.

Comparative Analysis of 99mTc-MDP Three-Phase Bone Scan with SPECT/CT and 99mTc-HMPAO-Labeled WBC SPECT/CT in the Differential Diagnosis of Clinically Suspicious Post-traumatic Osteomyelitis.

PURPOSE: To identify differences between three-phase bone scan and SPECT/CT (TBS) and WBC SPECT/CT (WS) and compare diagnostic accuracies of each modality in patients with suspicious post-traumatic osteomyelitis (OM). METHODS: Twenty-one patients with suspicious post-traumatic OM were enrolled. All patients performed TBS and WS within 1 week. Foci of MDP and WBC accumulation were divided into three categories: bone (OM), soft tissue (soft tissue inflammation; STI), negative for inflammation (NI). Confirmative diagnosis was made upon operative pathology or long-term clinical follow-up. RESULTS: Of 21 patients, four OM, eight STI, nine NI were finally diagnosed. TBS diagnosis was correct in three of four positive cases and nine of 17 negative cases. Sensitivity, specificity, accuracy, positive predictive value (PPV), negative predictive value (NPV) of TBS were 75 %, 52.9 %, 57.1 %, 27.3 %, 90 %. WS diagnosis was correct in two of four positive cases and 17 of 17 negative cases. Sensitivity, specificity, accuracy, PPV, NPV were 50 %, 100 %, 81.0 %, 100 %, 89.5 %. Twelve of 21 cases showed agreement between TBS and WS. TBS misdiagnosed nine cases (six STI and two NI as eight OM; one OM as one STI), while WS misdiagnosed four cases (two OM as two STI; two STI as two NI). Combining results from TBS and WS led to better diagnostic accuracy (91.7 %) than either TBS or WS alone. CONCLUSION: TBS and WS showed moderate agreement in assessment of clinically suspected post-traumatic OM. WS better evaluated inflammation than TBS. WS tended to underestimate inflammation whereas TBS tended to overestimate inflammation. Combining TBS and WS enhanced diagnostic accuracy.

Comparative Analysis of (99m)Tc-MDP Three-Phase Bone Scan with SPECT/CT and (99m)Tc-HMPAO-Labeled WBC SPECT/CT in the Differential Diagnosis of Clinically Suspicious Post-traumatic Osteomyelitis / 대한핵의학회잡지

PURPOSE: To identify differences between three-phase bone scan and SPECT/CT (TBS) and WBC SPECT/CT (WS) and compare diagnostic accuracies of each modality in patients with suspicious post-traumatic osteomyelitis (OM).METHODS: Twenty-one patients with suspicious post-traumatic OM were enrolled. All patients performed TBS and WS within 1 week. Foci ofMDP andWBC accumulation were divided into three categories: bone (OM), soft tissue (soft tissue inflammation; STI), negative for inflammation (NI). Confirmative diagnosis was made upon operative pathology or long-term clinical follow-up.RESULTS: Of 21 patients, four OM, eight STI, nine NI were finally diagnosed. TBS diagnosis was correct in three of four positive cases and nine of 17 negative cases. Sensitivity, specificity, accuracy, positive predictive value (PPV), negative predictive value (NPV) of TBS were 75 %, 52.9 %, 57.1 %, 27.3 %, 90 %. WS diagnosis was correct in two of four positive cases and 17 of 17 negative cases. Sensitivity, specificity, accuracy, PPV, NPV were 50 %, 100 %, 81.0 %, 100 %, 89.5 %. Twelve of 21 cases showed agreement between TBS and WS. TBS misdiagnosed nine cases (six STI and two NI as eight OM; one OM as one STI), while WS misdiagnosed four cases (two OM as two STI; two STI as two NI). Combining results from TBS and WS led to better diagnostic accuracy (91.7 %) than either TBS or WS alone.CONCLUSION: TBS and WS showed moderate agreement in assessment of clinically suspected post-traumatic OM. WS better evaluated inflammation than TBS. WS tended to underestimate inflammation whereas TBS tended to overestimate inflammation. Combining TBS and WS enhanced diagnostic accuracy.

A novel approach of 67-Gallium-citrate three-phase bone scan to diagnose bone infection: A report of three cases.

OBJECTIVES: 67-Gallium-citrate three-phase bone scan (Ga-TPBS), a new approach for the diagnosis of bone infection is evaluated. The interpretation of TPBS is based on the normal physiological vascular endothelial-related response noted in infection. MATERIALS AND METHODS: Three cases of suspected bone infection as determined by clinical, laboratory, and radiological examinations were further subjected to conventional technetium-99m-TPBS (Tc-99m-TPBS) and Ga-TPBS. Nuclear scan diagnosis of bone infection was made by the presence of generalized vasodilatation with increased capillary permeability noted on the flow and the pool phase of the TPBS and the comparative evaluation of the 4 h delayed Tc-TPBS and 24-48 h delayed Ga-TPBS. Diagnosis of bone infection was confirmed in all three cases on histopathologcal examination of the surgically excised tissues. RESULTS: The data clearly indicated that all three cases of bone infection (osteomyelitis) had generalized massive flow and pool pattern. Infection could be diagnosed only on the Ga-TPBS by noting generalized vasodilatation with increased capillary permeability on the flow and the pool phase with focal retention of the radiotracer on the delayed scan. CONCLUSIONS: By incorporating the concept of vascular endothelial-related response causing massive vasodilatation in infection, the interpretation of the Ga-TPBS can be more précised as it is based on the normal physiology. In comparison to two Tc-99m scans (white blood cell scan + bone marrow scan), a single Ga-TPBS is also cost-effective and compliance friendly. Larger, comparative, and statistically unbiased studies are needed.

Three phase bone scan interpretation based upon vascular endothelial response.

OBJECTIVES: A new method of interpretation of Three Phase Bone Scan (TPBS) scan based upon the normal physiological vascular endothelial related response. MATERIALS AND METHODS: Fifty cases of TPBS were evaluated. Thirteen were normal. In remaining 37 positive studies, 20 showed localized hyperemic response. All localized hyperemic responses except one with vascular endothelial dysfunction were without infection (95.0%). Infection could be ruled out in absence of generalized massive flow and pool response. All 17 cases with generalized massive hyperemic response had infection, consistent with infection or CRPS/RSD. Micro-bacterial or histological confirmation of infection was obtained in 11 cases. All 11 cases with confirmed infection showed generalized massive hyperemic response (100.0%). Two were CRPS/RSD and 2 cases were of cellulitis (100.0%). Among remaining 2, one refused surgery and other was lost to follow-up. Additionally, 20 published cases in the literature of osteomyelitis were also analyzed. Nineteen cases of bone and joint infection, (osteomyelitis/arthritis/cellulitis) except one with endothelial dysfunction showed generalized massive increased flow and pool response (95.0%). All published cases of osteomyelitis in the literature showed generalized massive hyperemic response (100.0%). RESULTS: The data clearly indicated that 100% of the cases of bone infection (osteomyelitis/arthritis/cellulitis) and cases of CRPS/RSD showed generalized massive flow and pool pattern. Infection could be ruled out in absence of generalized massive flow and pool response. All 100% published cases of osteomyelitis in the literature showed positive vascular endothelial response. CONCLUSION: By incorporating the concept of vascular endothelial related response causing massive vasodilatation in infection, the interpretation of the TPBS can be more précised as it is based upon the normal physiology. Larger studies are recommended.

18-F flourodeoxy glucose positron emission tomography-computed tomography imaging: A viable alternative to three phase bone scan in evaluating diabetic foot complications?

BACKGROUND: This paper is based on the initial findings from a prospective ongoing study to evaluate the efficacy of flourodeoxy glucose positron emission tomography-computed tomography (FDG-PET CT) in diabetic foot evaluation. OBJECTIVE: The aim was to compare the diagnostic accuracies of three phase bone scan (TPBS) and FDG PET-CT (FDG-PET) in diabetic foot evaluation. METHODS: Seventy-nine patients with complicated diabetic foot (osteomyelitis/cellulitis, Charcot's neuropathy) were prospectively investigated. TPBS (15 mci methylene di phosphonate [MDP] intravenous [IV]), followed by FDG-PET (5 mci IV) within 5 days were performed in all patients. Based on referral indication, patients grouped into Group I, n = 36, (?osteomyelitis/cellulitis) and Group II, n = 43 (?Charcot's neuropathy). Interpretation was based on intensity, extent, pattern of MDP and FDG uptake (standardized uptake value) along with CT correlation. Findings were compared with final diagnostic outcome based on bone/soft tissue culture in Group I and clinical, radiological or scintigraphic followup in Group II. RESULTS: Group I: For diagnosing osteomyelitis, TP: TN: FP: FN were 14:5:2:2 by FDG PET and 13:02:05:03 by TPBS respectively. Sensitivity, specificity, positive predictive value and negative predictive value (NPV) of FDG-PET were 87.5%, 71%, 87.5% and 71% and 81.25%, 28.5%, 72% and 40% for TPBS, respectively. Group II: charcot's: cellulitis: Normal were 22:14:7 by FDG PET and 32:5:6 by TPBS, respectively. CONCLUSION: Flourodeoxy glucose PET-CT has a higher specificity and NPV than TPBS in diagnosing pedal osteomyelitis. TPBS, being highly sensitive is more useful than FDG-PET in detecting Charcot's neuropathy.

Discordance between MRI and bone scan findings in a child with acute complicated osteomyelitis: scintigraphic features that contribute to the early diagnosis.

Early diagnosis and prompt treatment of acute osteomyelitis are of paramount importance in children because they can prevent irreversible bone damage. Magnetic resonance imaging (MRI) with its superior spatial resolution and lack of ionizing radiation is routinely preferred over bone scan for this purpose. Increased blood flow, hyperemia and focally increased tracer uptake shown by "three phase" bone scan are the typical scintigraphic findings of acute osteomyelitis. In addition, diffuse uptake along the shaft of long bones and focal "cold" lesions are two special features that may be highly suggestive of infective periostitis, soft tissue sepsis and subperiosteal abscess formation, due to the loose attachment of periosteum to bone during childhood. We present a case of complicated osteomyelitis in a child with inconclusive MRI correctly diagnosed on the basis of these special scintigraphic findings resulting in treatment change from double i.v. Vancomycin--Ceftriaxone scheme to surgical intervention.

Usefulness of asymmetry score on quantitative three-phase bone scintigraphy in the evaluation of complex regional pain syndrome.

INTRODUCTION: Complex regional pain syndrome (CRPS) is primarily a clinical diagnosis. Diagnostic imaging in CRPS can be used, especially to exclude other disorders. The sensitivity and specificity of three phase bone scintigraphy (TPBS) for the diagnosis of CRPS is variable throughout the literature. AIM: To establish a simple and effective quantitative approach to help in the diagnosis of CRPS by TPBS. MATERIALS AND METHODS: TPBS done in patients (n = 68) with suspected CRPS was analyzed retrospectively. They were classified into bone scan positive group (BSP), bone scan negative group (BSN) and non-CRPS group based on diffusely increased periarticular uptake, symmetrical uptake, and focal uptake respectively. Asymmetry score (AS) was also measured between the affected and unaffected side. RESULTS: 16 patients showed focal uptake, 37 were in BSP group with mean AS score of 1.57 ± 0.5 and 15 were in BSN group with mean AS score of 1.01 ± 0.05. The mean AS was significantly different (P < 0.0001). AS of 1.06 had sensitivity and specificity of 96.43% and 100% respectively (P = 0.0001). There was a trend of negative correlation between the AS and the duration, r = -0.21; however, it was not statistically significant (P = 0.28). CONCLUSION: TPBS should be considered in the evaluation of CRPS to rule out patients who have focal involvement, not diagnostic of CRPS (~24% in this study). Quantitative AS of 1.06 can be included to support visual interpretation in the delayed phase.

Diagnostic performance of three-phase bone scan for complex regional pain syndrome type 1 with optimally modified image criteria.

PURPOSE: Although the three-phase bone scan (TBPS) is one of the widely used imaging studies for diagnosing complex regional pain syndrome type I (CRPS-1), there is some controversy regarding the TPBS image criteria for CRPS-1. In this study, we modified the image criteria using image pattern and quantitative analysis in the patients diagnosed using the most recent consensus clinical diagnostic criteria. MATERIALS AND METHODS: The study included 140 patients with suspected CRPS-1 (CRPS-1, n = 79; non-CRPS, n = 61; mean age 39 ± 15 years) who underwent TPBS. The clinical diagnostic criteria for CRPS-1 revised by the Budapest consensus group were used for confirmative diagnosis. Patients were classified according to flow/pool and delayed uptake (DU) image patterns, and the time interval between the initiating event and TPBS (TIevent-scan). Quantitative analysis for lesion-to-contralateral ratio (LCR) was performed. Modified TPBS image criteria were created and evaluated for optimal diagnostic performance. RESULTS: Both increased and decreased periarticular DU were significant image findings for CRPS-1 (CRPS-1 positive-rate = 73% in the increased DU group, 75% in the decreased DU group). The TIevent-scan did not differ significantly between the different image pattern groups. Quantitative analysis revealed an LCR of 1.43 was the optimal cutoff value for CRPS-1 and diagnostic performance was significantly improved in the increased DU group (area under the curve = 0.732). Given the modified image criteria, the sensitivity and specificity of TPBS for diagnosing CRPS-1 were 80% and 72%, respectively. CONCLUSIONS: Optimally modified TPBS image criteria for CRPS-1 were suggested using image pattern and quantitative analysis. With the criteria, TPBS is an effective imaging study for CRPS-1 even with the most recent consensus clinical diagnostic criteria.

The clinical value of three phase bone scans in differentiating benign from malignant bone foci / 肿瘤研究与临床

Objective To compare the results of three phase bone scans between benign and malignant lesions, and explore its clinical value. Methods Patients with pain symptom underwent three phase bone scan. Their corresponding clinical data was collected and input into SPSS software package for further evaluation. Results Forty-nine patients had 73 positive foci in the acquiring field of vascular and blood pool phase bone scans. Excluding 10 foci that suspected of bone metastasis, 37 of 63 were malignant,26 were benign lesion. On vascular, blood pool and delayed images, benign and malignant foci did not exist any significant difference (χ2 =3.341, 1.685 and 2.923, P ＞0.05). In these lesions, 33.3 % (5/15) foci had positive vascular and blood pool results in thoracic, 72.2 % (13/18) in extremity and 75.0 % (18/24) in pelvic.There were no significant difference among subgroup of chest, abdomen, limb and pelvic diseases. In addition,4 foci outside bone system were occasionally found in three phase bone scans. Conclusion Acquiring position could significantly affect the results of three phase bone scan, for example more sensitive rate can be found for limb and pelvis lesions. This method could not significantly differentiate malignant from benign lesions, but could detect soft tissue foci or the change of blood flow, and provide more information for differential diagnosis.

Juvenile Dermatomyositis Diagnosed by (99m)Tc-HDP Three-phase Bone Scintigraphy / 핵의학분자영상

Juvenile dermatomyositis is a common inflammatory muscle disease of childhood, characterized by weakness in proximal muscles and specific skin rash. In case of juvenile dermatomyositis without characteristic clinical features, non-invasive imaging tools such as (99m)Tc-HDP three-phase bone scan are very helpful in diagnostic workup of myopathies. We report a case of 13-year old female with juvenile dermatomyositis, in which (99m)Tc-HDP three-phase bone scan was useful in diagnosis and assessing therapy response.

The Effectiveness of a Three Phase Bone Scan for Making the Diagnosis of Complex Regional Pain Syndrome

BACKGROUND: Complex regional pain syndrome (CRPS) is still difficult to diagnose in the field of chronic pain management. CRPS is diagnosed by purely clinical criteria based on the characteristic signs and symptoms, which have to be differentiated from similar pain conditions like posttraumatic neuropathic pain. Until now, there has been a lack of objective diagnostic tools to confirm the diagnosis of CRPS. The aim of this study was to evaluate the usefulness of a three phase bone scan (TBS) for making the diagnosis of CRPS. METHODS: A total of 121 patients who had been diagnosed with CRPS were evaluated. All the patients were examined by performing a TBS as a part of the diagnostic work-up. A diffuse increased tracer uptake on the delayed image (phase III) was defined as a positive finding for CRPS. RESULTS: Forty-one patients (33.9%) out of 121 showed the positive results on the TBS. The patients with a duration of pain of less than 24 months had a significantly higher positive result (43.4%) on the TBS than did the patients with duration of pain longer than 24 months (12.1%). CONCLUSIONS: A TBS could give a better objective result for diagnosing CRPS for patients with a shorter duration of pain and a TBS gives little information for the diagnosis of CRPS in patients with a duration of pain longer than 24 months.

The Value of Three Phase Bone Scan in Diagnosing Reflex Sympathetic Dystrophy in Hemiplegia

The purpose of this study is to determine the usefulness of the three-phase bone scan(TBS) in the diagnosis of reflex sympathetic dystrophy(RSD) and to evaluate the differences of TBS findings with the clinical stages of RSD. Twenty-four hemiplegic patients were assessed prospectively for radionuclide and clinical features of RSD. 5 cases of stage II RSD patients also had TBS. The results of TBS showed a high diagnostic sensitivity for the stage I RSD within three months of stroke onset. If the "positive TBS" was defined as increased radioisotope uptake in all three phase images, it showed 83.3% of sensitivity and 91.7% of specificity. If the "positive TBS" was defined as increased radioisotope only in delayed image, it showed 100% sensitivity and 66.7% specificity, There was no significant difference in TBS findings with the clinical stages of RSD. Considering difficulties in the clinical diagnosis as various features of the symptoms of RSD are often present for other reasons and increased radioisotope uptake of the delayed image can be present also in other conditions such as disuse and immobilization, TBS may be a useful diagnostic tool for RSD during early rehabilitation if "positive TBS" is defined as increased radioisotope uptake in all three images. Increased radioisotope uptake of the delayed image in patients who have no clinical RSD does not seem to be a predictor of the subsequent development of RSD.