18F-fluorodeoxyglucose positron emission tomography/CT in the diagnosis of right-sided endocarditis in children and adults with infective endocarditis.

OBJECTIVE: Infectious endocarditis poses a diagnostic challenge due to its highly variable clinical presentation. To establish a definitive diagnosis, different imaging modalities are essential. In recent years, positron emission tomography/CT has gained increasing significance in diagnosing infective endocarditis; however, its application in the pediatric age group remains limited. This study encompasses patients definitively or potentially diagnosed with infectious endocarditis at our institution from 2018 to 2023. METHODS: A total of 29 patients underwent 18F-fluorodeoxyglucose positron emission tomography/CT examinations, with 19 of them presenting with right-sided infective endocarditis. RESULTS: Evidence consistent with infective endocarditis was observed in 18 (94.7%) of the patients. Pulmonary septic embolism was identified in 15 (78.9%) cases, and splenic involvement was noted in 12 (57.8%) cases. Transthoracic/transesophageal echocardiography failed to reveal vegetation or provided uncertain results in six patients, whereas fluorodeoxyglucose-positron emission tomography-CT exhibited involvement. Subsequently, the diagnosis of infective endocarditis was confirmed post-surgery based on the fluorodeoxyglucose-positron emission tomography-CT findings. CONCLUSION: Our results, along with our clinical experience, demonstrate that fluorodeoxyglucose-positron emission tomography-CT is a safe and viable method for diagnosing right-sided endocarditis, which is often challenging to visualize using echocardiography.

Diagnostic utility of 68Ga-citrate and 18FDG PET/CT in sarcoidosis patients.

Sarcoidosis is a chronic granulomatous disease of unknown etiology. The disease  most commonly involves the lungs and the mediastinal lymph nodes while extrapulmonary organs such as the skin, eye, liver or spleen may also be comprised. Many imaging modalities have been used for the clinical evaluation of sarcoidosis patients but all have been found to have certain drawbacks for a reliable identification assessment due to the equivocal diagnostic results.  This case series was designed to determine the clinical trenchancy of simultaneous 68Ga citrate PET/CT [Positron emission tomography with 68Ga citrate (68Ga citrate PET/CT)] and 18F-FDG PET/CT [Positron emission tomography with 2-deoxy-2-[fluorine-18] fluoro-D-glucose integrated with computed tomography (18F-FDG PET/CT)] imaging in sarcoidosis patients. The main goal of the study was to evaluate sarcoidosis with respect to disease activity and organ involvement. A total of eight sarcoidosis patients with a comorbid disease suspicion were included in the study. Conventional clinical parameters used for  the diagnosis and the activity of sarcoidosis including CT [Computed tomography (CT)] were compared with the 68Ga-citrate PET/CT findings. Concurrent 18F-FDG PET/CT was performed to verify the granulomatous inflammation of sarcoidosis and to determine coexisting malignant or other inflammatory diseases. Our study results revealed that 68Ga citrate PET/CT imaging appears to be highly useful for the diagnosis, activity assessment and extrapulmonary organ involvement in sarcoidosis. Another crucial finding was the detection of extrapulmonary organ disease that are exceptionally involved, almost inaccessible by biopsy and that could not be otherwise displayed by other conventional imaging modalities. The third hallmark was the identification of a clinically asymptomatic and occult malignancy accompanying sarcoidosis that would not be revealed in any way if synchronous 18FDG PET/CT had not been performed. Simultaneous application of 68Ga citrate and 18FDG PET/CT may provide extremely useful data for the clinical evaluation of sarcoidosis patients in terms of the primary disease diagnosis, activity state, extrapulmonary organ involvement unachievable for biopsy and the clinically occult malignant disorders.

Impacts of 18F-FDG PET/CT Parameters on Differential Diagnosis and Outcome of Patients with Primary Invasive Mucinous and Lepidic Predominant Adenocarcinoma of the Lung.

Objectives: The purpose of this study was to investigate whether 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) parameters have a role in differentiating invasive mucinous lung adenocarcinoma (IMA) from lepidic predominant lung adenocarcinoma (LPA). Additionally, we compared the 18F-FDG-PET/CT features between survivors and non-survivors. Methods: Tumors were divided into 2 groups according to CT appearance: Group 1: nodular-type tumor; group 2: mass- or pneumonic-type tumor. Unilateral and bilateral multifocal diseases were detected. Clinicopathological characteristics and PET/CT findings were compared between IMAs and LPAs, as well as between survivors and non-survivors. Results: We included 43 patients with IMA and 14 with LPA. Tumor size (p=0.003), incidence of mass/pneumonic type (p=0.011), and bilateral lung involvement (p=0.049) were higher in IMAs than in LPAs. IMAs had more advanced T, M, and Tumor, Node, and Metastasis stages than in LPAs (p=0.048, p=0.049, and p=0.022, respectively). There was no statistically significant difference in maximum standardized uptake value (SUVmax) between the IMA and LPA (p=0.078). The SUV was significantly lower in the nodular group than in the mass/pneumonic-type group (p=0.0001). A total of 11 patients died, of whom SUVmax values were significantly higher in these patients (p=0.031). Male gender (p=0.0001), rate of stage III-IV (p=0.0001), T3-T4 (p=0.021), M1 stages (p=0.0001), multifocality (p=0.0001), and bilateral lung involvement (p=0.0001) were higher in non-survivor. Conclusions: Although CT images were useful for the differential diagnosis of LPAs and IMAs, SUVmax was not helpful for differentiation of these 2 groups. However, both 18F-FDG uptake and CT findings may play an important role in predicting prognosis in these patients.

A case of hepatic focal nodular hyperplasia mimicking hepatocellular carcinoma identified on gallium-68-prostate-specific membrane antigen positron emission tomography/computed tomography.

Prostate-specific membrane antigen (PSMA) is a glycosylated type-II transmembrane protein highly expressed in individual tumor cells. Lesions with PSMA expression in the liver are commonly reported as prostate cancer metastasis or hepatocellular cancer previously. This is the first case reported as hepatic focal nodular hyperplasia, mimicking hepatocellular carcinoma with imaging features. This patient, having a lesion that has been enlarged from 2.0 cm to 2.5 cm in 3 months, was referred to our department for restaging by gallium-68 PSMA (68Ga-PSMA) positron emission tomography/computed tomography (PET/CT). The CT scan showed a focal segment VI hypodensity, which was significantly PSMA-avid. Consequently, its biopsy resulted as focal nodular hyperplasia in liver. His follow-up 68Ga-PSMA PET/CT ultimately revealed a mass lesion of 8 cm of axial diameter.

Active Giant Cell Vasculitis Diagnosis with 68Ga PSMA PET/CT Imaging.

Vasculitis is a multisystem disease characterized by inflammation with infiltration of leukocytes into the blood vessels. Giant cell arteritis (GCA) is the most common form of vasculitis that mostly affects medium- and large-sized arteries. 18Fluorine-fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) is increasingly used to diagnose inflammation of large arteries in GCA. Galium-68 prostate-specific membrane antigen (PSMA) PET/CT has a vital role in the assessment of patients with prostate cancer for recurrence and metastasis of the disease. Various benign and non-prostate malignant conditions may give rise to increased PSMA uptake. Herein, we demonstrate that PSMA uptake can be seen in GCA.

Candida esophagitis incidentally detected by 18F-FDG PET/CT in a patient with CNS lymphoma.

Corticosteroids are commonly used in lymphoma patients, and findings in favor of esophageal involvement in 18F-FDG PET-CT should be considered suspicious and definitely be confirmed by biopsy. We describe a 58-year-old lady with diffuse large B-cell lymphoma and central nervous system involvement having an increased metabolism in the distal esophagus with 18F-FDG PET/CT, which was consistent with esophageal candidiasis, most probably due to prolonged use of dexamethasone. Esophageal candidiasis can be misdiagnosed as malignancy with a high SUVmax and may lead to difficulties while managing these patients.