Unusual Artifacts Encountered during Routine Studies on Positron Emission Tomography-Computed Tomography and Gamma Camera.

Artifacts in nuclear medicine imaging are not uncommon. We are aware of some of these, for which we follow necessary protocols to avoid them. However, there are some unusual and unavoidable artifacts that we come across in daily imaging, which may be of concern and need to be detected and corrected on time.

Evaluation of treatment response by Hopkins criteria on 18 F FDG PET-CT in patients of non-small cell lung cancer and its comparison with PERCIST response criteria.

Aim: To assess treatment response on FDG PET-CT in NSCLC patients by visual Hopkins score compared to PERCIST criteria and its potential for prognostication (or its correlation with survival).

Methods: Forty-four NSCLC patients with baseline and post-treatment FDG PET-CT scans were included, and interpreted using Hopkins and PERCIST criteria classifying patients into responders and non-responders. PERCIST-based CMR and PMR, and Hopkins Scores 1,2,3 were classified responders.

F-FDG PET-CT Evaluation of Primary Adrenal Ewing Sarcoma with Venous Thrombosis: An Unusual Presentation.

Ewing sarcoma (EWS) is primarily an osseous malignancy of childhood and young adults. Extraskeletal occurrence is less frequent and primary adrenal involvement is an even rare presentation. We present such a case of a 7-year-old boy diagnosed with adrenal EWS with associated venous thrombosis and pulmonary embolism detected on F-fluorodeoxyglucose positron emission tomography-computed tomography scan.

An Unusual Case of Urothelial Carcinoma of Bladder with Metastasis to Brain and Skeletal Muscles Evaluated on 18F-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography.

Urothelial or transitional cell carcinoma is the most prevalent variant of urinary bladder carcinoma worldwide occurring in both men and women. There are a very few cases described in the literature with metastasis to skeletal muscles and even fewer cases with metastatic site in the brain. We present a case of high-grade urothelial carcinoma with metastasis to the left temporal lobe as well as multiple inter- and intra-muscular deposits in the left thigh.

Role of F-Fluorodeoxyglucose Positron Emission Tomography-Contrast-Enhanced Computed Tomography in Detection of Early Recurrence with Peritoneal Disease in a Case of Adrenocortical Carcinoma.

Adrenocortical carcinoma (ACC) is an uncommon and highly aggressive malignancy with a poor prognosis. Common sites of metastasis are lung, liver, and lymph nodes. We present a case of ACC in a 54-year-old female with an early disease recurrence of unusual hypervascular peritoneal metastatic abdominal-pelvic deposits detected on F-fluorodeoxyglucose positron emission tomography-contrast-enhanced computed tomography scan.

Mimicker of Osteoblastic Skeletal Metastasis on 18 F-FDG PET/CT Scan in a Case of Primary Mediastinal Germ Cell Tumor.

Primary mediastinal germ cell tumors are uncommon tumors, of which the nonseminomatous type is more likely to metastasize than the seminomatous type. Primary mediastinal germ cell tumors may also present with superior vena cava obstruction. Here, we present this case of primary mediastinal germ cell tumor with superior vena cava obstruction causing dilatation of collaterals in dorsal intravertebral venous plexus, which strongly mimics sclerotic skeletal lesions/metastasis on a Contrast-enhanced CT scan and also appears FDG avid on PET scan.

Role of 18F-FDG PET/CT for detection of recurrence and metastases in renal cell carcinoma-are we underusing PET/CT?

PURPOSE The aim of this study was to compare 18F-fluorodeoxyglucose positron emission tomography- computed tomography (18F-FDG PET/CT) scan with computed tomography (CT) scan for detecting recurrence and metastasis in renal cell carcinoma patients. METHODS This retrospective study included patients from October 2013 to April 2017. Contrast-enhanced CT and PET/CT scans were compared and correlated with histopathology or/and follow-up studies.

Pazopanib-Induced Asymptomatic Necrotizing Pancreatitis Diagnosed on F-FDG PET-CT Scan.

Multi-targeted tyrosine kinase inhibitor (TKI) pazopanib approved for the treatment of advanced soft tissue sarcoma (STS) has prolonged the estimated survival times and quality of life of patients. However, several adverse effects associated predominantly with the inhibition of the vascular endothelial growth factor receptor by these drugs may prove to be potentially life-threatening. One such rare adverse event with the use of pazopanib is acute pancreatitis.

Post-COVID-19 Unusual Inflammatory Syndromes Detected on 18F-FDG PET/CT Scan.

SARS-CoV-2 is primarily known to cause respiratory symptoms. However, in this global COVID-19 pandemic, we have come across many extrapulmonary manifestations during and in the immediate post-COVID phase such as gastrointestinal symptoms, kidney and liver injury, myocardial dysfunction and acute coronary syndromes, and neurological, thromboembolic, dermatological, and musculoskeletal disorders. We present 2 such unusual cases of post-COVID complications-diffuse panniculitis and inflammatory myositis, as well as their clinical and FDG PET/CT imaging features.

Incidental Detection of Mandibular Metastasis in Renal Cell Carcinoma on 99mTc-MIBI Scan.

MIBI scintigraphy is the most widely used modality to identify parathyroid adenomas preoperatively. However, MIBI is also known to accumulate in multiple benign and malignant lesions. In renal cell carcinoma, 30% of the patients present with distant metastasis, commonly lungs and bone; however, jaw bone metastases are extremely rare (<1% of oral malignancies).

An Unusual Case of Bilateral Ureteric Metastasis on PSMA PET-CT Scan in Carcinoma Prostate.

The most common locations for metastasis in adenocarcinoma of the prostate gland are lymph nodes, bone, lung, and liver. The involvement of the ureter as a site of metastasis in prostate carcinoma is quite rare in literature. Here we present a case involving bilateral ureters along with bilateral vesicoureteric junctions in a known case of prostate adenocarcinoma.

IgG4-Related disease simulating paraneoplastic syndrome: Role of FDG PET/CT imaging.

Immunoglobulin G4 (IgG4)-related systemic disease (IgG4-RSD) is a new systemic entity associated with autoimmune pancreatitis (AIP). Other organ involvements take the form of sclerosing cholangitis, sclerosing cholecystitis, sclerosing sialadenitis, retroperitoneal fibrosis, and interstitial nephritis. Recently, lung diseases related to IgG4 have been described to occur with or without other organ involvement.

Unusual Asymptomatic Fluorodeoxyglucose Avid Pheochromocytoma in a Case of Myxoid Liposarcoma of the Extremity on -F Fluorodeoxyglucose Positron Emission Tomography-computed Tomography.

Sarcomas are a heterogeneous group of rare tumors and arise either from soft tissue or from bone. Soft-tissue sarcomas (STSs) initially metastasize to the lungs. Metastases to extrapulmonary sites such as liver, brain, and soft tissue distant from primary tumor usually develop later.

Potassium Chloride Infusion as the Cause of Altered Bio Distribution of F-Fluorodeoxyglucose on Whole-Body Positron Emission Tomography-Computed Tomography Scan.

F-fluorodeoxyglucose (F-FDG) positron emission tomography-computed tomography is a standard diagnostic imaging tool in many types of cancer. Its physiological distribution includes the brain, liver, heart, kidneys, and urinary tract at 1 h after tracer injection. Skeletal muscle is known to show variable amounts of F-FDG uptake because it has a relatively high-glucose metabolism.