Synchronous Pulmonary Malignancy Detected During PSMA Ligand PET/CT for Initial Staging of Prostate Cancer: a Case Report.

We present a case of an 83-year-old man with underlying colorectal cancer who underwent a gallium-68 prostate specific membrane antigen-11 positron emission tomography/computed tomography (68 Ga-PSMA-11 PET/CT) for the initial staging of prostate cancer. PET / CT revealed two mildly PSMA-avid lung nodules without evidence of PSMA-avid nodal or bony metastasis. Subsequently, a wedge pulmonary resection was performed and the histopathology and immunohistochemistry of the nodules were consistent with synchronous primary lung cancer. Because differentiating synchronous primary lung cancer from pulmonary metastasis of prostate cancer can significantly affect treatment strategies and pulmonary metastasis rarely presents during initial staging of prostate cancer, synchronous primary lung cancer should be included in the differential diagnosis of pulmonary lesions in initial staging of 68 Ga-PSMA-11 PET/CT regardless of PSMA avidity. The lack of nodal or bony metastases also decreases the likelihood of lung metastasis, and a tissue diagnosis may be required.

Ossifying fibroma presented as an incidental [18F]FDG PET/CT uptake within the hard palate.

Incidental uptake in [18F]FDG PET/CT is not uncommon, but uptake in the oral and sinonasal regions was less frequently reported. We present a case of incidental focal [18F]FDG PET/CT uptake within the hard palate, which was later revealed to be an ossifying fibroma. We also reviewed some relevant literature and suggested that further investigation may be necessary for some patients with incidental [18F]FDG PET/CT uptake in the oral and sinonasal regions.

Positive FDG-PET/CT uptake guiding diagnosis in a patient with microscopic polyangiitis: A case report.

Microscopic polyangiits (MPA) is an autoimmune vasculitis that is challenging to diagnose because it can present with myriad of manifestations. We present a case of a woman who presented with prolonged fever. Her diagnosis of MPA was realized after fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography (F-18 FDG-PET/CT) showed abnormal diffuse renal uptake in the cortex, leading to a kidney biopsy. Our report supported the value of FDG-PET/CT as a diagnostic tool in a patient with febrile illness without localizing symptoms or signs.

Simulated daily readout for maintaining nuclear medicine education in residency training amidst declining case volume: evidence from the COVID-19 pandemic.

BACKGROUND: Simulated daily readout (SDR) is a teaching initiative in radiology and nuclear medicine developed to simulate a resident's experience during periods of case volume reduction. SDR was employed by many training centers during the coronavirus disease 2019 (COVID-19) pandemic. This study aimed to evaluate the perception of radiology residents on the effectiveness of SDR. METHOD: The SDR was conducted in the nuclear medicine rotations from 2019 to 2020 during the shutdown of the radionuclide imaging facilities using a combination of strategies including case selection, assignment, reporting and feedback. A brief 8-item questionnaire with Likert scale values was completed by radiology residents who participated in the SDR-based nuclear medicine rotations. RESULTS: Thirty-five of 54 residents returned the questionnaire. The majority of residents affirmed the negative impact of the reduction in case volume on their training experiences and perceived that SDR could alleviate the effects. The SDR strategies perceived as more effective were targeted case selection, in-advanced assignment, verbal interpretation and reporting, and verbal feedback. CONCLUSION: The radiology residents perceived the SDR as an effective tool to preserve their training experiences. The SDR has the potential to be a useful initiative when teaching centers face the threat of declining case volume.

Antral contractility following Asian-style meal in healthy volunteers: effect of genders, menstruation, smoking status and age.

Objectives: The normal range of the frequency of antral contractions, similar to other gastric motility parameters, are different depending on the population and the test meal. We, therefore, conducted the analysis to establish the normal ranges for the frequency of antral contractions derived from dynamic antral scintigraphy (DAS) following an Asian-styled solid meal in Thai healthy volunteers. Methods: We retrospectively analyzed the data from the study on normal gastric emptying values. The dynamic scintigraphic images had been obtained in a 45 degree left anterior oblique view during the first 32 minutes following the ingestion of a 267-kcal steamed rice, a technetium-99m-labeled microwaved egg and 100 mL of water. A polynomial normalization model was used to analyze and to calculate the frequency of antral contractions. The data analysis was repeated by the same operator 1 month apart to assess reproducibility. Results: Data of 18 volunteers (10 males and 8 females) were eligible for analysis. The mean±SD of the frequencies of the antral contractions were 3.06±1.08 cycles/min on the first and 3.04±1.10 cycles/min on the second analysis. Comparison of the two analyses revealed a moderate agreement (ICC=0.632, 95% CI 0.329-0.818) without significant difference (p-value=0.942). No significant effect of gender, menstruation status, smoking or age was demonstrated in this study. Conclusion: DAS is a non-invasive technique that can measure the frequency of antral contractions. The technique is reproducible and consistent. Future study may be required to assess the effect of gender, menstruation status, smoking and age.

Comparison of the Diagnostic Performance of Myocardial Perfusion Scintigraphy with and Without Attenuation Correction.

Objectives: Myocardial perfusion scintigraphy (MPS) is an important diagnostic test for detecting of coronary artery stenosis (CAS); however, tissue attenuation can lead to a difference in accuracy. We evaluated the diagnostic accuracy of attenuation-corrected (AC) and non-attenuation-corrected (NC) MPS for the detection of CAS. Methods: We retrospectively recruited patients who underwent invasive coronary angiography within 10 months after Tc-99m sestamibi MPS. The AC and NC perfusion images were analyzed separately, and each myocardial segment was scored based on relative uptake from 0 to 4. The summed stress score (SSS), summed rest score (SRS), and summed difference score (SDS) were calculated. The diagnostic performances were analyzed using the area under the curve (AUC) of the receiver operating characteristic curve. Results: From 117 patients, significant coronary stenosis was present in 66 patients (56%). The SSS and SRS obtained from NC-images were higher than those from AC, supporting the presence of attenuation artifacts in NC images. The AUC of SSS and SDS were significantly higher than those of SRS in both AC- and NC-images, but no significant difference was found between the AUC of SSS, and those of SDS. The optimal cut-offs were >12 for AC-SSS, >15 for NC-SSS, >4 for AC-SDS and >3 for NC-SDS. There was no statistically significant difference in the sensitivity, specificity, positive predictive value, negative predictive value, and accuracy among AC-SSS, NC-SSS, AC-SDS, and NC-SDS. Conclusion: NC-based Tc-99m-sestamibi MPS promised comparable accuracy to AC images by using different cut-off values for diagnosis.

The Evaluation of Tau Deposition with [18F]PI-2620 by Using a Semiquantitative Method in Cognitively Normal Subjects and Patients with Mild Cognitive Impairment and Alzheimer's Disease.

Background: Some studies have reported the effectiveness of [18F]PI-2620 as an effective tau-binding radiotracer; however, few reports have applied semiquantitative analysis to the tracer. Therefore, this study's aim was to perform a semiquantitative analysis of [18F]PI-2620 in individuals with normal cognition and patients with mild cognitive impairment (MCI) and Alzheimer's disease (AD). Methods: Twenty-six cognitively normal (CN) subjects, 7 patients with AD, and 36 patients with MCI were enrolled. A dynamic positron emission tomography (PET) scan was performed 30-75 min postinjection. PET and T1-weighted magnetic resonance imaging scans were coregistered. The standardized uptake value ratio (SUVr) was used for semiquantitative analysis. The P-Mod software was applied to create volumes of interest. The ANOVA and post hoc Tukey HSD were used for statistical analysis. Results: In the AD group, the occipital lobe had a significantly higher mean SUVr (1.46 ± 0.57) than in the CN and MCI groups. Compared with the CN group, the AD group showed significantly higher mean SUVr in the fusiform gyrus (1.06 ± 0.09 vs. 1.49 ± 0.86), inferior temporal (1.07 ± 0.07 vs. 1.46 ± 0.08), parietal lobe, lingual gyrus, and precuneus regions. Similarly, the AD group demonstrated a higher mean SUVr than the MCI group in the precuneus, lingual, inferior temporal, fusiform, supramarginal, orbitofrontal, and superior temporal regions. The remaining observed regions, including the striatum, basal ganglia, thalamus, and white matter, showed a low SUVr across all groups with no statistically significant differences. Conclusion: A significantly higher mean SUVr of [18F]PI-2620 was observed in the AD group; a significant area of the brain in the AD group demonstrated tau protein deposit in concordance with Braak Stages III-V, providing useful information to differentiate AD from CN and MCI. Moreover, the low SUVr in the deep striatum and thalamus could be useful for excluding primary tauopathies.