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Giant-cell arteritis (GCA) is a type of vasculitis characterised by the presence of granulomas. It is the predominant form of systemic vasculitis in adults and primarily affects the larger arteries in individuals aged ≥ 50 years. GCA affects the major arteries, such as the aorta and its branches, particularly the outer branches of the external carotid artery. Signs and symptoms can be categorised into cranial, extracranial, and systemic manifestations. Patients with headaches, jaw claudication, and vision disturbances usually have extracranial branches of the external carotid artery. Aside from being the prevailing manifestation of GCA, our primary concern regarding this variant is the potential for irreversible vision loss if not properly identified and addressed. Conversely, the GCA can also affect other major blood vessels such as the aorta. Here, we present the case of a 70-year-old Caucasian female patient with cranial GCA who had experienced a temporal headache three years prior. The patient was successfully treated with prednisolone, which was gradually reduced to a very low level with the assistance of methotrexate. Recently, the patient presented with a dry cough that lasted for two months and elevated inflammatory markers. After thorough research, it was determined that there was no evidence of infection, including atypical infections, and that no abnormalities were found in the lungs. Ultimately, via an 18F-fluorodeoxyglucose-positron emission tomography (FDG-PET) scan, the patient was diagnosed with large vessel giant cell arteritis (LV-GCA). This impacted the aorta, carotid arteries, and subclavian arteries. The patient experienced notable improvement in her cough and a reduction in inflammatory markers after receiving a high dosage of oral prednisolone. This case exemplifies the unusual manifestation of LV-GCA and verifies that recurring symptoms may differ from the original presentation. While dry cough is not commonly listed as a symptom of LV-GCA, it can be present as a manifestation or the sole presentation in certain patients, particularly when inflammatory markers are consistently high and there is no pulmonary disease., Competing Interests: The authors have declared that no competing interests exist., (Copyright © 2024, Danial Azmy Habib et al.)

Abstract: 18 F-FDG PET/CT scan is a well-known modality to assess distant metastases and treatment response in the patients with primary colon cancer. We are presenting an interesting case of 68 Ga-PSMA-avid liver metastases in a 74-year-old man with colon cancer and recently diagnosed prostate cancer. The liver metastases were positive on initial FDG PET but lost FDG avidity on subsequent posttreatment FDG PET scans. Biopsy from the PSMA-avid liver lesions confirmed metastasis from colon origin. PSMA is expressed in various forms of tumor neovasculature other than prostate cancer with potential new applications as a theranostic agent in the future., Competing Interests: Conflicts of interest and sources of funding: none declared., (Copyright © 2023 Wolters Kluwer Health, Inc. All rights reserved.)

Background: Total-body dynamic positron emission tomography (dPET) imaging using 18 F-fluorodeoxyglucose ( 18 F-FDG) has received widespread attention in clinical oncology. However, the conventionally required scan duration of approximately 1 h seriously limits the application and promotion of this imaging technique. In this study, we investigated the possibility and feasibility of shortening the total-body dynamic scan duration to 30 min post-injection (PI) with the help of a novel Patlak data processing algorithm for accurate K i estimations of tumor lesions., Methods: Total-body dPET images acquired by uEXPLORER (United Imaging Healthcare Inc.) using 18 F-FDG of 15 patients with different tumor types were analyzed in this study. Dynamic images were reconstructed into 25 frames with a specific temporal dividing protocol for the scan data acquired 1 h PI. Patlak analysis-based K i parametric imaging was conducted based on the imaging data corresponding to the first 30 min PI, during which a Patlak data processing method based on cubic Hermite interpolation was applied. The resultant K i images acquired by 30 min dynamic PET data and the standard 1 h K i images were compared in terms of visual imaging effect, region signal-to-noise ratio, and K i estimation accuracy to evaluate the performance of the proposed K i imaging method with a shortened scan duration., Results: With the help of Patlak data processing, acceptable K i parametric images were obtained from dynamic PET data acquired with a scan duration of 30 min PI. Compared with K i images obtained from unprocessed Patlak data, the resulting images from the proposed method performed better in terms of noise reduction. Moreover, Bland-Altman plot and Pearson correlation coefficient analysis showed that that 30 min K i images obtained from the processed Patlak data had higher accuracy for tumor lesions., Conclusion: Satisfactory K i parametric images with high tumor accuracy can be acquired from dynamic imaging data corresponding to the first 30 min PI. Patlak data processing can help achieve higher K i imaging quality and higher accuracy regarding tumor lesion K i values. Clinically, it is possible to shorten the dynamic scan duration of 18 F-FDG PET to 30 min to acquire an accurate tumor K i and further effective tumor detection with uEXPLORER scanners., (© 2022 American Association of Physicists in Medicine.)

Interpretation of FDG PET images in oncology patients is in general a visual exercise of search for focal increased uptake (hypermetabolism). However, in some cases, hypometabolism (focal decreased uptake) can matter as much as hypermetabolism. We report three cases of FDG PET studies for oncological indications. All of them showed focal hypometabolic lesions suspicious of metastases. The diagnoses were then supported either by histological proof and/or follow-up imaging studies. The importance of being alert to both focal hypermetabolism and focal hypometabolism when interpreting FDG PET images is underscored., Competing Interests: Conflict of interest: The authors declare that there is no conflict of interest., (© 2023 The Authors. Published by the British Institute of Radiology.)

Although severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)/coronavirus disease 2019 (COVID-19) infection predominantly affects the respiratory system, it has also been found to be responsible for several gastrointestinal effects due to its capability to attack angiotensin-converting enzyme (ACE) type 2 cells in various parts of the body. Several cases of radiologically confirmed thyroiditis, axillary lymphangitis, and acute pancreatitis related to COVID-19 infection have been reported, which seem to arise from a direct cytotoxic effect of the virus itself. This case report presents an incidental 18-fluoro-2-deoxyglucose (FDG) positron emission tomography (PET) computed tomography (CT) finding of mild pancreatic inflammation/pancreatitis in an otherwise asymptomatic patient undergoing routine imaging as part of the staging process following stem cell transplant, who had recently recovered from a severe form of COVID infection. This case highlights the fact that COVID can trigger insidious inflammatory processes in a variety of organs often remaining clinically undetectable until resultant end-organ damage causes incipient clinical symptoms., Competing Interests: The authors have declared that no competing interests exist., (Copyright © 2022, Qurban et al.)

In this report we describe a case of pulmonary epithelioid hemangioendothelioma (PEH) in a young woman. The neoplasm manifested with dry cough, chest pain, finger clubbing, and multiple bilateral pulmonary nodules on chest x-ray and computed tomographic (CT) scan. She underwent thoracoscopy, and the histological features of the lung biopsies were initially interpreted as consistent with a not-well-defined interstitial lung disease. Our patient was clinically and radiologically stable over a period of four years, after which the disease progressed to involve not only the lung but also mediastinal lymph nodes, liver and bone. Fiberoptic bronchoscopy showed subtotal occlusion of the right middle and lower lobe bronchi. The histologic examination of bronchial biopsies revealed a poorly differentiated neoplasm immunohistochemically positive for vimentin and vascular markers CD31, CD34 and Factor VIII. A diagnosis of malignant hemangioendothelioma was made. Positron emission tomography (PET) is more sensitive than CT scan and bone scintigraphy in detecting PEH metastases. Furthermore, 18-fluorodeoxyglucose (FDG) uptake seems to be related to the grade of malignancy of PEH lesions. Therefore, we suggest that FDG-PET should be included in the staging system and follow-up of PEH.

In the present review the reader will be led across the most relevant observations that prompted oncologists and haematologist to consider FDG-PET/CT as a new paradigm for FL management in clinical practice. The contribute of functional imaging for lymphoma staging, restaging, prognostication, and tumour burden definition before radio-chemo-immunotherapy will be reviewed in detail. Moreover, a special focus will be addressed to technical and practical aspects of PET scan reporting, which have been set during the last decade in order to ensure the reproducibility of the therapeutic results. Finally, the predictive role of PET/CT on long-term treatment outcome will be compared with other well-known prognosticator as minimal residual disease (MRD) detection by gene rearrangement assessment by molecular biology.

Competing Interests: All authors have nothing to disclose.