Nonosseous, Nonurologic Uptake on Bone Scintigraphy: Atlas and Analysis

Notable Visualization of the Gallbladder on a 99mTc-MDP SPECT/CT Bone Scintigraphy in a Case of Brucellosis

Comprehension of the typical distribution pattern of 99mTc-methylenediphosphonate (MDP) is crucial for precise interpretation of bone scintigraphy. The presence of nonskeletal activity is predominantly confined to the kidneys and bladder, attributed to the standard renal excretion of 99mTc-MDP. We discuss a 70-year-old woman with a known case of brucellosis using rifampin, doxycycline, trimethoprim/sulfamethoxazole (co-trimoxazole), and ciprofloxacin for the past 8 months. Anterior and posterior aspects of the whole-body bone scan showed diffuse increased uptake in the bodies of L2 and L3 vertebrae and related intervertebral disks. However, unexpected uptake is noted in the right upper quadrant in the region of the gallbladder. Radiochemical impurities did not show during radiopharmaceutical (MDP) quality control, and the other patients showed normal distribution. This gallbladder uptake may be attributed to the altered distribution of the radiotracer and/or gallbladder injury caused by the administration of antibiotic therapy.

[Incidental Cardiac Uptake in Bone Scintigraphy Establishing a Diagnosis of Transthyretin Amyloid Cardiomyopathy: A Case Report]

This is a case of a male patient in his 70s undergoing endocrine therapy for castration-resistant prostate cancer. On follow-up, he underwent whole-body bone scintigraphy for bone metastasis surveillance, and incidental cardiac uptake was identified. The findings were reported by the radiologist to the urologist, which was followed by a cardiac consultation. Late gadolinium enhancement magnetic resonance imaging did not detect typical patterns suggestive of cardiac amyloidosis. However, pyrophosphate scintigraphy identified cardiac uptake. These findings were indicative of transthyretin amyloid cardiomyopathy, and we confirmed the diagnosis by endomyocardial biopsy. In about 0.4-2.0 percentage of elderly patients, incidental cardiac uptake in bone scintigraphy has been reported. Bone scintigraphy is the most commonly utilized techniques among all scintigraphies. Thus, it is crucial that radiologists recognize and report the findings to establish a diagnosis of transthyretin amyloid cardiomyopathy.

Prevalence and significance of extracardiac uptake on pyrophosphate imaging in the SCAN-MP study: the first 379 cases

INTRODUCTION

Technetium-labeled bone-avid radiotracers can be used to diagnose transthyretin cardiac amyloidosis (ATTR-CA). Extracardiac uptake of technetium pyrophosphate (Tc-99m PYP) in this context has not been extensively explored and its significance is not well characterized. We assessed extracardiac Tc-99m PYP uptake in individuals undergoing nuclear scintigraphy and the extent of clinically actionable findings.

METHODS

The Screening for Cardiac Amyloidosis with Nuclear Imaging in Minority Populations (SCAN-MP) study utilizes Tc-99m PYP imaging to identify ATTR-CA in self-identified Black and Caribbean Hispanic participants ≥ 60 years old with heart failure. We characterized the distribution of extracardiac uptake, including stratification of findings by timing of scan (1 hour vs 3 hours after Tc-99m PYP administration) and noted any additional testing in these subjects.

RESULTS

Of 379 participants, 195 (51%) were male, 306 (81%) Black race, and 120 (32%) Hispanic ethnicity; mean age was 73 years. Extracardiac Tc-99m PYP uptake was found in 42 subjects (11.1%): 21 with renal uptake only, 14 with bone uptake only, 4 with both renal and bone uptake, 2 with breast uptake, and 1 with thyroid uptake. Extracardiac uptake was more common in subjects with Tc-99m PYP scans at 1 hour (23.8%) than at 3 hours (6.2%). Overall, four individuals (1.1%) had clinically actionable findings.

CONCLUSION

Extracardiac Tc-99m PYP uptake manifested in about 1 in 9 SCAN-MP subjects but was clinically actionable in only 1.1% of cases.

Intratumoral 99mTc-DPD Uptake on Bone Scintigraphy in a Patient With Invasive Micropapillary Breast Carcinoma: A Pathologic Review

ABSTRACT

Invasive micropapillary carcinoma (IMPC) is a rare and aggressive subtype of breast cancer with a poorer prognosis due to high local recurrence and lymphovascular invasion. Interestingly, IMPC often does not show suspicious patterns of calcifications related to malignancy on mammography. Therefore, the lack of suspicious calcifications makes it difficult to detect breast cancer on mammography. With only nonspecific calcifications on mammography, we observed an unusual intratumoral 99mTc-DPD uptake on whole-body bone scintigraphy in an IMPC breast cancer patient during the initial staging workup, and its characteristics were compared with mammographic findings and the postoperative pathologic features.

Metastatic pulmonary calcification on bone scintigraphy of a patient with lupus nephritis and end-stage renal disease

A 65-year-old male complaining of low back pain was noted to have diffuse, homogenous bilateral lung uptake on Tc-99m methylene diphosphate (Tc99m-MDP) bone scintigraphy. The patient had no prior history of pulmonary disease with no apparent respiratory symptoms at time of imaging, but did endorse a long history of lupus nephritis and end-stage renal disease on hemodialysis. Review of prior chest CT and chest X-ray imaging over the last 5 years revealed diffuse ground-glass opacities and extensive parenchymal calcifications, consistent with metastatic pulmonary calcification. These radiological findings were further corroborated by laboratory studies, which demonstrated longstanding secondary hyperparathyroidism with a most recent work-up including an iPTH level of 1251 pg/mL. The differential diagnosis of bilateral, diffuse Tc99m-MDP uptake on bone scintigraphy includes tracer contamination, pulmonary etiologies such as pleural effusion or mesothelioma, metabolic diseases such as metastatic pulmonary calcification, and genetic diseases including pulmonary alveolar microlithiasis. In the setting of longstanding renal dysfunction and chronic hypercalcemia as in this patient, such radiological findings are a classic presentation of metastatic pulmonary calcification.

World Heart Federation Consensus on Transthyretin Amyloidosis Cardiomyopathy (ATTR-CM)

Transthyretin amyloid cardiomyopathy (ATTR-CM) is a progressive and fatal condition that requires early diagnosis, management, and specific treatment. The availability of new disease-modifying therapies has made successful treatment a reality. Transthyretin amyloid cardiomyopathy can be either age-related (wild-type form) or caused by mutations in the TTR gene (genetic, hereditary forms). It is a systemic disease, and while the genetic forms may exhibit a variety of symptoms, a predominant cardiac phenotype is often present. This document aims to provide an overview of ATTR-CM amyloidosis focusing on cardiac involvement, which is the most critical factor for prognosis. It will discuss the available tools for early diagnosis and patient management, given that specific treatments are more effective in the early stages of the disease, and will highlight the importance of a multidisciplinary approach and of specialized amyloidosis centres. To accomplish these goals, the World Heart Federation assembled a panel of 18 expert clinicians specialized in TTR amyloidosis from 13 countries, along with a representative from the Amyloidosis Alliance, a patient advocacy group. This document is based on a review of published literature, expert opinions, registries data, patients' perspectives, treatment options, and ongoing developments, as well as the progress made possible via the existence of centres of excellence. From the patients' perspective, increasing disease awareness is crucial to achieving an early and accurate diagnosis. Patients also seek to receive care at specialized amyloidosis centres and be fully informed about their treatment and prognosis.

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.

SPECT/CT in the Evaluation of Suspected Skeletal Pathology

Dedicated multi-slice single-photon emission computed tomography/computed tomography (SPECT/CT) cameras have become widely available and are becoming a mainstay of clinical practice. The integration of SPECT and CT allow for precise anatomic location of scintigraphic findings. Fusion imaging with SPECT/CT can improve both sensitivity and specificity by reducing equivocal interpretation in comparison to planar scintigraphy or SPECT alone. This review article addresses the technique, basic science principles, and applications of integrated SPECT/CT in the evaluation of musculoskeletal pathology.

Cutaneous Metastases as Initial Presentation of Lung Carcinoma

Breast cancer, in women, and lung cancer, in men, are the most common origins of cutaneous metastasis. Lung cancer can metastasize to any organ but mostly to the contralateral lung, liver, adrenal gland, bones, and brain. Over 1-12% of patients with lung cancer can develop skin metastasis. Non-small cell lung cancer includes 87% of lung cancer cases. Adenocarcinomas subtype accounts for approximately 40% of all lung cancers and is the most common histology in women. A woman’s lifetime risk of developing lung cancer is 1 in 16 women but lower than that of a man (1 in 13 men). The survival rates of women with lung cancer are usually higher than those of men. Herein, we report the case of a 66-year-old female who presented with painless multiple skin nodules over the chest back and axilla for three months. On evaluation, biopsy and immunohistochemistry were done from skin nodules suggestive of adenocarcinoma. CT thorax showed lung mass and was diagnosed as a case of metastatic adenocarcinoma, primary being from the lung. Our case demonstrated that skin metastasis could be the first sign of internal malignancy. Metastasis to the skin is often a preterminal event that heralds a poor prognosis.

Incidental cardiac uptake in bone scintigraphy: increased importance and association with cardiac amyloidosis

Extraosseous radiotracer uptake during bone scintigraphy must be carefully assessed and it offers the potential to detect previously undiagnosed disease processes. A range of neoplastic, metabolic, traumatic, ischaemic and inflammatory disorders can cause soft tissue accumulation of bone avid radiopharmaceuticals. Accordingly, cardiac uptake in bone scintigraphy has a broad differential diagnosis and is commonly attributed to ischaemia/infarction related to coronary artery disease. However, there has been renewed focus on incidental cardiac uptake in recent years in light of significant developments in the diagnosis and management of cardiac amyloidosis.

99mTc-Methylene Diphosphonate Uptake in Soft Tissue Tumors on Bone Scintigraphy Differs Between Pediatric and Adult Patients and Is Correlated with Tumor Differentiation

Objective

To analyze the difference in ^99mTc-methylene diphosphonate (MDP) uptake on bone scintigraphy in extraosseous soft tissue tumors between children and adults and the correlation between tracer uptake and tumor differentiation and histopathology.

Methods

Patients with neoplasms with MDP uptake were retrospectively identified. Based on histopathology, tumors were categorized as epithelial malignant tumors, mesenchymal tumors, blastomas and germ cell tumors. The degree of radioactivity accumulation in lesions relative to the uptake in ribs and sternum or spine was classified as “+”, “++” and “+++”. The results were compared between children and adults. The correlations between MDP uptake in soft tumors and tumor differentiation and pathology were investigated.

Results

Extraosseous soft tissue tumors that accumulated MDP were found in 33 children and 31 adults. In children, neuroblastoma was the most common extraosseous soft tissue tumor that accumulated MDP; in adults, MDP uptake was mostly found in lung cancer. MDP uptake in pediatric soft tissue tumors was higher than that in adults. MDP uptake in extraosseous soft tissue tumors with different histopathologic classifications was significantly different among 64 patients. In 41 patients with available tumor differentiation data from histopathology, MDP uptake in low or poorly differentiated soft tumors was higher than that in the moderately or well-differentiated lesions. Necrosis and/or calcifications were showed in most of pediatric and adult neoplasms.

Conclusion

Significant elevations in MDP uptake in extraosseous soft tissue tumors are associated with poorly differentiated tumors in both children and adults. The mechanism of bone tracer uptake in pediatric and adult neoplasms was mostly related to necrosis and/or necrosis and calcification. The extraosseous soft tissue tumors with MDP uptake in pediatric patients were different from those in adults. In addition, consistent with the inherent degree of tumor malignancy, MDP uptake in children was higher than that in adults.

Gastric 99mTc-Methylene Diphosphonate Accumulation in a Patient With Primary Upper Gastrointestinal Tract Melanoma

Unexpected extraosseous uptake is common on Tc-methylene diphosphonate bone scintigraphy, but accumulation by primary upper gastrointestinal tract malignant melanoma is rarely reported. The present case is a 58-year-old woman with a 10-day history of diffuse bone pain and weakness. Her bone scintigraphy showed unexpected diffuse gastric tracer uptake. Subsequent gastroscopy revealed a number of hyperpigmented lesions in the stomach and duodenal bulb. Malignant melanoma was confirmed by histopathology and immunohistochemistry. Because extensive physical examination failed to identify any other site of ocular and cutaneous melanoma, a diagnosis of primary upper gastrointestinal tract malignant melanoma was established.

Nuclear medicine image interpretation by radiographers: Findings of an accredited postgraduate module

INTRODUCTION

The study aimed to analyse the results of radiographer's image interpretation of nuclear medicine (NM) examinations following a nine-month postgraduate module.

METHODS

Twenty participants completed 60 summative image commentaries each at the end of the module from prospective NM worklists in England. Each submitted a mixed selection of examinations in bone, lung, renal, and thyroid scans. Prevalence of abnormalities was 51% incorporating acute and chronic pathology, normal variants and incidental findings. Every commentary was marked against reference standard radiologist definitive reports. Statistical analysis included Kappa (k), intraclass correlation coefficient (ICC) and Spearman's rank correlation coefficient (R_S).

RESULTS

Bone scan sensitivity and specificity was 93% (95% CI 91.3-95.6) and 88% (95% CI 84.3-90.9) respectively, accuracy at 91.5% (95% CI 88.6-93.7), with k = 0.82, ICC = 0.904, R_S = 0.826. Lung scans demonstrated a sensitivity of 92.6% (95% CI 85.7-96.8), specificity was 92.1% (95% CI 88.7-94.1), accuracy 92.3% (95% CI 87.7-95.0), k = 0.83, ICC = 0.910, R_S = 0.835. Renal scan sensitivity was 95% (95% CI 91.0-97.3), with 95.2% specificity (95% CI 91.8-97.3), accuracy were 95% (95% CI 91.4-97.3), k = 0.90, ICC = 0.948, R_S = 0.907. Thyroid scans sensitivity was 88% (95% CI 83.1-91.4), with 93% specificity (95% CI 85.9-96.8), accuracy were 90.2% (95% CI 84.3-93.8), k = 0.80, ICC = 0.897, R_S = 0.813.

CONCLUSION

In this small pilot study, the image interpretation ability in assessing prospective NM examinations in a clinical environment displayed encouraging results. Further work is recommended to evaluate a larger sample and case selection.

The utility of bone scintigraphy with SPECT/CT in the evaluation and management of frostbite injuries

OBJECTIVE:

Frostbite is a localized cold-thermal injury resulting from prolonged exposure of flesh to freezing and near freezing temperatures. The depth and extent of frostbite injuries are not easily assessed, from a clinical standpoint, at the time of injury making it challenging to plan appropriate management and treatment.

METHODS:

A review of the literature of management of cold-related injuries and retrospective case review of the imaging and clinical course of frostbite injury.

RESULTS:

Bone scintigraphy with single photon emission computed tomography (SPECT)/CT was performed in the acute and subacute course of frostbite injuries, subsequently leading to earlier definitive management and shorter hospital stay.

CONCLUSION:

Multiphase technetium-99m-methylenediphosphonate (⁹⁹mTc-MDP) bone scintigraphy with SPECT/CT can expedite clinical management of frostbite injuries by determining the extent of injury and can accurately predict the level of amputation if needed.

ADVANCES IN KNOWLEDGE:

 SPECT/CT is underutilized at many facilities but can have a profound and immediate impact on clinical management of patients with frostbite when used in combination with physiological bone scan imaging.

An Unexpected and Less Recognized Altered Distribution on Bone Scintigraphy; Possibility of 99mTc-Dextrose Complex as a Cause

Optimal performance of diagnostic tests and correct interpretation depend on multiple factors, one of which is proper radiopharmaceutical preparation. Unwanted impurities result in altered distribution of radiopharmaceuticals and then poor-quality or uninterpretable studies. Therefore, following the reconstitution steps according to standard and validated protocols by the technologist is mandatory. Here, we present 2 cases with unexpected and less recognized distribution of Tc-methylene diphosphonate on bone scintigraphy.

Serendipitous Detection of Extraosseous Metastases on Bone Scintigraphy: Utility of Cross-sectional and Correlative Imaging

Whole body bone scintigraphy is most commonly used imaging modality to detect and assess the extent of osteoblastic osseous metastases in malignant conditions, though visceral metastases need additional imaging. The authors describe a case of 50-year-old postoperative breast cancer female where bone scintigraphy showed soft tissue uptake in thorax and hepatic region in addition to multiple skeletal metastases, indicating the involvement of three different organs by metastatic disease. The present case highlights that extraosseous tracer uptake in addition to abnormal osseous tracer uptake may raise the suspicion of widespread and visceral metastatic disease and warrant further evaluation in the form of cross-sectional and correlative imaging.

Frostbite: Spectrum of Imaging Findings and Guidelines for Management

Frostbite is a localized cold thermal injury that results from tissue freezing. Frostbite injuries can have a substantial effect on long-term limb function and mobility if not promptly evaluated and treated. Imaging plays a critical role in initial evaluation of frostbite injuries and in monitoring response to treatment. A multimodality approach involving radiography, digital subtraction angiography (DSA), and/or multiphase bone scintigraphy with hybrid single photon emission computed tomography (SPECT)/computed tomography (CT) is often necessary for optimal guidance of frostbite care. Radiographs serve as an initial survey of the affected limb and may demonstrate characteristic findings, depending on the time course and severity of injury. DSA is used to evaluate perfusion of affected soft tissues and identify potential targets for therapeutic intervention. Angiography-directed thrombolysis plays an essential role in tissue preservation and salvage in deep frostbite injuries. Multiphase bone scintigraphy with technetium 99m-labeled diphosphonate provides valuable information regarding the status of tissue viability after initial treatment. The addition of SPECT/CT to multiphase bone scintigraphy enables precise anatomic localization of the level and depth of tissue necrosis before its appearance at physical examination and can help uncover subtle findings that may remain occult at scintigraphy alone. Multiphase bone scintigraphy with SPECT/CT is the modality of choice for prognostication and planning of definitive surgical care of affected limbs. Appropriate use of imaging to direct frostbite care can help limit the effects that these injuries have on limb function and mobility. ©RSNA, 2016.

High (18)F-FDG uptake in urinary calculi on PET/CT: An unrecognized non-malignant accumulation

AIM

To assess the high (18)F-fluorodeoxyglucose ((18)F-FDG) uptake in urinary calculi on positron-emission tomography/computed tomography (PET/CT).

METHODS

In this study, (18)F-FDG PET/CT examinations were retrospectively reviewed from November 2013 to February 2016 in a single center, and patients with high (18)F-FDG uptake in urinary calculi were identified. The following data were collected from each patient, including age, sex, primary disease, method to verify the urinary calculus, and imaging characteristics of the calculus.

RESULTS

A total of 2758 PET/CT studies (2567 patients) were reviewed, and 52 patients with urinary calculi were identified, in which 6 (11.5%, 6/52) patients (5 males, 1 female, age 34-73 years, median age 60.5 years) demonstrated high (18)F-FDG uptake in the urinary calculi. Among the 6 patients, 3 patients had bladder calculi, 2 patients had renal calculi, and 1 patient had both bladder and renal calculi. The size of the urinary calculi varied from sandy to 19mm on CT. The maximal Hounsfield units of the calculi ranged from 153 to 1078. The SUVmax of the calculi on the routine PET/CT scan ranged from 11.7 to 143.0. Delayed PET/CT scans were performed on 4 patients, which showed the calculi SUVmax increasing in 2 patients, while decreasing in the other 2 patients. One patient with bladder calculus underwent a follow-up PET/CT, which showed enlargement of the calculus as well as the increased SUVmax.

CONCLUSION

This study shows an uncommon high (18)F-FDG uptake in urinary calculi. Recognition of this non-malignant accumulation in urinary calculi is essential for correct interpretation of PET/CT findings.

Calcified peritoneal metastasis identified on 18F-fluoride positron emission tomography/computed tomography: Importance of extraosseous uptake of F-18 fluoride

F-18 NaF positron emission tomography/computed tomography (PET/CT) is used for the evaluation of malignant and nonmalignant osseous disease. Extraosseous uptake of 18 fluoride-NaF has been observed in the arterial vasculature, gastrointestinal tract, and genitourinary tract. We describe a case of a woman with carcinoma of unknown primary in whom F-18 NaF PET/CT showed tracer uptake in the calcified peritoneal metastasis. Extraosseous findings on F-18 NaF PET/CT, though rare, may be visualized and may result in important management changes.

Skin Uptake of 99mTc-HDP in a Case of Annular Elastolytic Giant Cell Granuloma

Sometimes unexpected extraosseous uptakes appear in a bone scintigraphy as a consequence of a wide spectrum of nonosseous disorders. Recognition of these findings is important to enhance the diagnostic value of bone scintigraphy. We report a case of intense bone scintigraphy cutaneous uptake due to elastolytic actinic giant cell granuloma (EAGCG). We present the case of a patient with intense extraosseous uptakes of Tc-HDP that appeared in a bone scintigraphy that was performed for lumbar pain.

Intense and diffuse lung uptake of 99mTc-MDP in a patient with pneumonia associated with secondary hemophagocytic lymphohistiocytosis

99mTc-methylene diphosphonate (MDP) bone scan was performed in a 49-year-old female patient who had non-Hodgkin lymphoma. 99mTc-MDP uptake was significant in both lungs. Bilateral bacterial pneumonia associated with secondary hemophagocytic lymphohistiocytosis was diagnosed after extensive examination.

Extraosseous Findings on Bone Scintigraphy Using Fusion SPECT/CT and Correlative Imaging

OBJECTIVE

Extraosseous radioactivity outside of the expected biodistribution is often encountered on (99m)Tc-methylene diphosphate (MDP) bone scintigraphy, and proper interpretation requires an understanding of the mechanisms underlying this uptake and knowledge of the possible causes, depending on the site or structure involved.

CONCLUSION

We present examples of extraosseous radiotracer uptake seen on (99m)Tc-MDP bone scans in which either SPECT with integrated CT or correlative imaging improved the study's interpretation.

Hepatic metastasis arising from diverse primary pathologies diagnosed on 99mTc-Methylene diphosphonate bone scan

We are presenting two cases that illustrate nonosseous localization of 99mTc-Methylene diphosphonate (MDP) in hepatic metastases arising from varied primary pathology and review of the literature. This series emphasizes the evidence of MDP localization in hepatic metastases arising from adenocarcinoma of rectum and infiltrating duct cell carcinoma of the breast.

Technetium-99m-methylene Diphosphonate Uptake in Hepatic Necrosis Secondary to Respiratory Failure

Tc-99m methylene diphosphonate (MDP) bone scintigraphy has long been used for the evaluation of benign as well as malignant skeletal conditions. However, non-osseous tracer uptake on a bone scan is an unusual finding. On one hand, there is a need for awareness of the pathophysiologic basis underlying such uptake, as it may be of critical clinical relevance in the evaluation of the patient. On the other hand, some alterations in biodistribution may be of little clinical significance, but have deleterious consequences on the quality of the bone study. Recognition of these abnormalities will reduce errors and provide important clinical information. We described a case of 57-year-old male patient with history of carcinoma base of tongue, where a 99mTc-MDP bone Scintigraphy was performed for metastasis survey. It revealed avascular necrosis of head of right femur. In addition incidentally demonstrated diffuse increased pathologic uptake of Tc-99m-MDP in the liver and multiple foci in bilateral lungs. This article reviews several possible reasons for such diffuse hepatic uptake. In the present case diffuse hepatic necrosis secondary to respiratory failure due to bilateral miliary pulmonary metastasis is considered to be the cause of the diffuse liver uptake of 99mTc-MDP.

Metastatic ovarian carcinoma showing surprisingly widespread subcutaneous 99mTc-MDP soft-tissue uptake

Cutaneous involvement is generally unusual for metastases in a variety of primary malignancies including patients diagnosed with ovarian cancer. We report the rare observance of subcutaneous lesions from an aggressive ovarian primary carcinoma with unusual uptake of 99mTc-MDP on a tomographic whole-body bone scan without osseous metastatic lesions or uptake. The findings were correlated with cross-sectional imaging in addition to histological analysis.

Osseous and Nonosseous Bone Scan Findings in Liver Transplant Candidates with end-stage Chronic Liver Disease

Objective: End-stage chronic liver disease (CLD) adversely affects the function of multiple organ systems including the skeletal system. The aim of this study was to assess osseous and nonosseous bone scintigraphy (BS) findings in liver transplant (LT) candidates with end-stage CLD.

Methods: We retrospectively evaluated BS findings in 50 consecutive patients with end-stage CLD who were undergoing preoperative assessment for LT from January 2006 to December 2011. All the patients were analyzed with respect to clinical and laboratory parameters, and BS findings. Scintigrams were visually assessed for the presence of osseous and nonosseous abnormalities. Osseous abnormalities were classified as those indicating bone metabolism changes or metastatic bone disease. Typical scintigraphic findings denoting to changes in bone metabolism were the presence of decreased osseous uptake, increased periarticular uptake, asymmetrical or unusual uptake patterns. Nonosseous findings were classified according to the degree of soft-tissue uptake as mild and severe.

Results: The group consisted of 46 adult and 4 adolescent patients. All adolescent patients had normal skeletal accumulation with growth plate uptake and one had mildly increased renal cortical activity. A total of 46 adult patients had one or more of the following osseous findings: generalized decrease in osseous uptake (n=4, 8.7%); bilateral decrease in lower extremity uptake (n=26, 56.5%); symmetrically increased periarticular uptake (n=26, 56.5%); bilateral cortical/periosteal increased uptake in the lower extremity indicating hepatic hypertrophic osteoarthropathy (HOA) (n=8, 17.4%); bilateral increased sacroiliac activity (n=16, 34.8%); sacral activity (n=10, 21.7%), coccygeal activity (n=2, 4.3%), focally increased uptake suggestive of metastases (n=5, 10.9%). Three rib metastases appeared to be linear. Nonosseous findings observed in adult patients were mild diffuse liver uptake (n=4, 8.7%) and bilateral diffuse mild or severe degree of renal cortical uptake (n=20, 43.5%). There was a statistically significant difference in serum creatinine values between mild and severe renal uptake groups (p<0.05). There was also statistically significant difference in serum BUN and creatinine values between patients with severe degree of renal uptake and without renal uptake (p<0.05).

Conclusion: The results of the current study has shown that adolescent LT candidates with end-stage CLD had no osseous abnormality on BS. However, all of adult patients exhibited one or one more osseous abnormalities. Typical scintigraphic findings denoting to abnormalities in bone metabolism were generalized decreased osseous uptake, decreased lower extremity osseous uptake, increased periarticular uptake, increased cortical/periosteal uptake indicating hepatic HOA, and other unusual uptake patterns. Hepatocellular carcinoma metastases may present itself as rib metastases linear in pattern. Soft-tissue uptake in the form of diffuse bilateral mild or severe degree of renal uptake and less commonly mild diffuse liver uptake can be observed. Increased renal uptake may be an early marker of renal dysfuntion or a predictor of hepatorenal syndrome.

Conflict of interest:None declared.

Accidental finding of bladder cancer in 99mTc methylene diphosphonate whole-body bone scan

A 53-year-old woman with a history of nasopharyngeal carcinoma underwent (99m)Tc methylene diphosphonate (MDP) whole-body scintigraphy for tumor staging. An MDP-avid lesion located in the urinary bladder was found. Computed tomography showed a protruding mass with calcific surface in the left inferolateral wall of the urinary bladder. A biopsy was conducted and the pathological report confirmed the diagnosis of transitional cell carcinoma. The patient received transurethral resection and Bacillus Calmette-Guérin intravesical therapy. Four months later, she underwent an (18)F-FDG PET/CT scan. Unfortunately, tumor recurrence in the bladder cancer was diagnosed by the (18)F-FDG PET/CT scan.

An Unusual Case of Extraosseous Accumulation of Bone Scan Tracer in a Renal Calculus - Demonstration by SPECT-CT

Extraosseous localization of radioisotope, used in bone scan, in a variety of physiological and pathological conditions is a well-known phenomenon. The causes of extraosseous accumulation of bone-seeking radiotracers should be kept in mind when bone-imaging studies are reviewed to avoid incorrect interpretations. We report an extremely rare occurrence of extraosseous accumulation of bone scintigraphy tracer in a renal calculus, in a patient with adenocarcinoma of prostate, that was demonstrated by Single Photon Emission Computed Tomography and Computed Tomography (SPECT-CT) fusion imaging.

Extraosseous accumulation of bone scan tracer (99m)Tc-methylene diphosphonate in a phlebolith

Uptake in non-osseous, non-urologic tissues is occasionally found in the performance of bone scintigraphy. These uptakes reflect an atypical interaction between the radiopharmaceutical and the patient. Knowledge of the rare extraskeletal uptakes and their clinical relevance helps in better interpretation of bone scans. We report an unusual occurrence of extraosseous accumulation of ^99mTc-methylene diphosphonate in a phlebolith in bone scan, confirmed with the aid of photon emission computed tomography and computed tomography.

MDP uptake in peritoneal carcinomatosis and Krukenberg tumors from mucinous adenocarcinoma

Altered biodistribution of Tc-99m methylene diphosphonate is a common occurrence on bone scintigraphy and mucin-producing neoplasms of the gastrointestinal tract are associated with dystrophic uptake. In addition to the uptake in the primary tumor, activity has been reported in metastasis within lymph nodes and liver. We present a case of Tc-99m methylene diphosphonate uptake in peritoneal carcinomatosis and metastatic Krukenberg tumors from a primary mucinous adenocarcinoma of the descending colon. Each of these findings is uncommon and their combination in this case is particularly unique.