F-18 FDG PET/CT as a One-Stop Shop Imaging Modality for Assessment of Neurologic and Pulmonary Manifestations of COVID-19.

Neurologic manifestations are now being increasingly encountered in patients who are admitted for respiratory symptoms of COVID-19. A 67-year-old male with a recent history of Wernicke's aphasia was referred to the nuclear medicine department for risk stratification of malignancy in pulmonary nodule by 18F-FDG PET-CT scan. PET-CT revealed decreased metabolic activity in the left temporoparietal lobe of the brain consistent with recent CVA and excluded malignancy in the pulmonary nodule with low-grade metabolic activity. Incidentally noted, new bilateral pulmonary hypermetabolic ground glass opacities rising suspicious for covid-19 infection which was confirmed by PCR of nasopharyngeal mucosa sample. These findings highlight the value of 18FFDG PET-CT in the assessment of COVID-19 infection especially in non-pulmonary presentations like early neurologic manifestation.

Brain Death Confirmation by 18F-FDG PET/CT: A Case Series.

OBJECTIVES: Brain death is a state of irreversible loss of brain function in the cortex and brainstem. Diagnosis of brain death is established by clinical assessments of cranial nerves and apnea tests. Different conditions can mimic brain death. In addition, confirmatory tests may be falsely positive in some cases. In this study, we aimed to evaluate the role of positron emission tomography-computed tomography scan with 2-deoxy-2[18F]fluoro-D-glucose (18F-FDG-PET/CT) as an ancillary test in diagnosing brain death. MATERIALS AND METHODS: We analyzed 6 potential brain death donors for the confirmatory diagnosis of brain death using FDG-PET/CT. All 6 donors were brain dead by clinical criteria. All patients had electroencephalogram and brain computed tomography. Other than FDG-PET/CT, transcranial Doppler was performed in 1 patient, with other patients having no confirmatory ancillary imaging tests. Patients had nothing by mouth for 6 hours before imaging. Patients were supine in a semi-dark, noiseless, and odorless room with closed eyes. After 60 minutes of uptake,the brain PET/CT scan was performed with sequential time-of-flight-PET/CT (Discovery 690 PET/CT with 64 slices, GE Healthcare). The PET scan consisted of LYSO (Lu1.8Y0.2 SiO5) crystals with dimensions of 4.2 × 6.3 × 25 mm3. Three-dimension images were with scan duration of 10 minutes. RESULTS: The PET scan confirmed brain death in 5 of the 6 cases. However, we ruled out brain death using PET/CT in a 3-year-old child, although all clinical tests confirmed brain death. CONCLUSIONS: A PET scan illustrates a hollow skull phenomenon suggestive of brain death. It can be a powerful diagnostic tool to assess brain death.

Transient 18FDG-avid hilar lymph node on PET/CT imaging in asymptomatic COVID-19.

The most common features of coronavirus disease-2019 (COVID-19) pneumonia on chest computed tomography imaging are ground glass opacity and consolidation. Mediastinal and hilar lymph node enlargement are less frequently observed. Herein, we present an unexpected finding of fluorodeoxyglucose (FDG)-avid hilar lymph node in an asymptomatic patient with COVID-19, and show that this is a transient phenomenon, subsiding on a follow-up FDG-PET/CT within 10 days.

Isolated aplasia of submandibular salivary gland and contralateral prominence of submandibular and sublingual salivary glands incidentally found on 68Ga-prostate-specific membrane antigen positron emission tomography-computed tomography.

Prostate-specific membrane antigen (PSMA)-targeted imaging is now an effective tool for the evaluation of prostate cancer patients. Although salivary glands take up 68Ga-PSMA avidly, pathologies of these glands may be readily noticeable. Herein, we present a case of prostate cancer referred for 68Ga-PSMA positron emission tomography-computed tomography in whom an isolated aplasia of the submandibular salivary gland was incidentally found.

Diffuse Skeletal Uptake on 18F-Fluoro-2-Deoxy-d-glucose Positron Emission Tomography/Computed Tomography Scan in a Patient with Acute Lymphoblastic Leukemia: A Typical Superscan Pattern Resembling NaF Positron Emission Tomography Scan.

A 65-year-old patient with acute lymphoblastic leukemia presented for an 18fluoro-2-deoxy-d-glucose positron emission tomography computed tomography (18FDG PET) after several courses of chemotherapy for metastatic evaluation. Unexpectedly, on 18FDG PET scan, no discernible uptake was observed in the visceral organs, but instead, the skeleton/bone marrow showed homogenously intense metabolic activity. The distribution of 18FDG observed on the scan was remarkably similar to that on the NaF PET scan, indicating a superscan appearance.

Role of FDG PET/CT Scan in Head and Neck Cancer Patients.

INTRODUCTION: PET/CT scan has an emerging role in head and neck oncology with a few well-established indications, including: detection of unknown primary tumor site, tumor staging, radiotherapy planning, treatment response assessment and detection of recurrent disease. The purpose of this study is reporting PET/CT findings in head and neck cancer patients to emphasize its role in head and neck oncology. MATERIALS AND METHODS: In a retrospective study, we reviewed our PET/CT database and found 94 patients with primary head and neck cancer. This is a descriptive report of PET/CT scan findings in head and neck cancer patients referred to Masih Daneshvari hospital, Tehran, Iran between 2013 and 2016. RESULTS: The most common primary tumor sites were oral cavity (27%) and nasopharynx (22%). The most common indication for referral was tumor restaging (76%) including treatment response evaluation and differentiation between recurrence and post-treatment fibrosis. In 60% of patients with negative primary tumor site, PET/CT was able to detect evidence of regional or distant metastasis. PET/CT was able to localize the primary tumor site in 66% of patients with unknown primary tumor site. We also had 19 patients with primary head and neck cancer referred for initial staging, demonstrating evidence of metastasis in 66% of all cases. CONCLUSION: Most patients are referred for restaging and demonstrate evidence of regional or distant metastasis with significant value for further treatment planning. Providing insurance coverage and familiarizing referring physicians about correct indications of this relatively new diagnostic modality will be to the best interest of head and neck cancer patients in the long run.