There is a sudden upsurge in the literature over the last fortnight on strategies to be followed by imaging services during this SARS-CoV-2 global pandemic. This compilation of strategies, experiences, and precautions is intended to support nuclear medicine departments, as they make decisions regarding patient care. These guidelines are a good resource to tackle the current crisis, however, situations such as these may occur again, and long-term readiness measures need to be discussed and implemented.

The growth of diagnostic nuclear medicine is substantially based on the development, availability, and regular clinical use of cyclotron-based positron emission tomography (PET) tracers. Apart from ¹⁸F (110 min) products, the radiometal ⁶⁸Ga isotope (68 min) has found an increasingly wide clinical acceptance. There is hence much merit in identifying and fostering other radiometal positron emitters, of preferably longer half-life. Titanium-45 (3.08 h) fits the bill well in this context, as it is easy to produce using natural scandium metal target and Ep of 13–14 MeV for ⁴⁵Sc(p, n) ⁴⁵Ti reaction. This Commentary cites a compelling case to foster the development of ⁴⁵Ti products for PET imaging.

Purpose of the Study: ¹⁸F-Fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT) is used in the management of recurrent differentiated thyroid cancer (DTC) patients presented with rising thyroglobulin (Tg) or anti-Tg antibody (Atg) levels and negative whole-body I-131 scan (WBS). We aimed to evaluate the utility of regional or limited PET/CT in a large population preset with variable Tg/(ATg) levels. Materials and Methods: In a retrospective study, we analyzed 137 PET/CT done on DTC patients presented with raised Tg/Atg and negative WBS. Retrospective evaluation of other available clinical information was done. Results: One hundred and thirty-seven patients aged 8–72 years (41 ± 17.7 years) were included in the study. Eighty-nine (64.9%) patients had positive findings on ¹⁸F-FDG PET-CT. It included thyroid bed recurrence, cervical, mediastinal lymphadenopathy, lung, and bone lesions. In addition, 36 patients had metabolically inactive lung nodules detected on CT. Serum Tg and female sex were the only predictors for a positive PET scan. In most (97.1%) of the patients, the disease was limited to the neck and thoracic region. Conclusions: PET/CT is an excellent imaging modality for evaluating DTC patients presented with biochemical recurrence. It not only finds the disease in more than 80% of the patients but also detects distant metastatic disease, which precludes regional therapies. Lesions were noted mostly in the neck and thoracic region with very few distant skeletal metastases (4/137 patients). In most of the patients, routine vertex to mid-thigh imaging could be avoided.

Purpose: In single-photon emission computed tomography imaging, the presence of scatter degrades image quality. The goal of this study is to optimize the main- and sub-energy windows for triple-energy window (TEW) method using Monte Carlo SImulating Medical Imaging Nuclear Detectors (SIMIND) code for samarium-153 (Sm-153) imaging. Materials and Methods: The comparison is based on the Monte Carlo simulation data with the results estimated using TEW method. Siemens Symbia gamma-camera equipped with low-energy high-resolution collimator was simulated for Sm-153 point source located in seven positions in water cylindrical phantom. Three different main-energy window widths (10%, 15%, and 20%) and three different sub-energy window widths (2, 4, and 6 keV) were evaluated. We compared the true scatter fraction determined by SIMIND and scatter fraction estimated using TEW scatter correction method at each position. In order to evaluate the image quality, we used the full width at half maximum (FWHM) computed on the PSF and image contrast using Jaszczak phantom. Results: The scatter fraction using TEW method is similar to the true scatter fraction for 20% of the main-energy window and 6 keV sub-energy windows. For these windows, the results show that the resolution and contrast were improved. Conclusion: TEW method could be a useful scatter correction method to remove the scatter event in the image for Sm-153 imaging.

Purpose: The objective is to investigate psychological status and quality of life (QoL) using Hospital Anxiety and Depression Scale (HADS) and Short-Form (36) Health Survey (SF-36) questionnaires in patients with proven differentiated thyroid cancer (DTC) who are referred for radioactive iodine (RAI) ablation before, during, and after treatment. Methods: Of patients who underwent total thyroidectomy with a pathologically proven DTC (papillary and follicular types) referred for RAI treatment to our department in 2018, 150, in whom the diagnosis was newly established, were referred for the first course of RAI treatment and were consecutively enrolled in the study. The patients received an oral dose of radioiodine (3700 or 5550 MBq). For evaluation of anxiety, depression, and QoL, all patients are given two standard questionnaires, HADS, and SF-36 and are requested to answer them at four time points. First one was at 1 month before RAI, second was at the time of RAI treatment. Third and fourth ones were 1 week and 6 months later, respectively. Results: The mean age of patients was 39.17 (±12.95) years and 121 (80.7%) were female and 29 (19.3%) were male. Values of HADS and SF-36 scores at corresponding time points were significantly correlated using Pearson correlation (HADS and SF-36 scores at 1 month before RAI: r = −0.56, P < 0.001; at time of RAI: r = −0.71, P < 0.001; 6 months after RAI: r = 0.19, P = 0.021). Using paired-sample t-test, for HADS, except for difference between time points of 1 month before RAI and time of RAI, pairwise difference between scores of other time points was statistically significant after Bonferroni correction. For SF-36, pairwise difference between scores of all three time points was statistically significant. Interaction of age, gender, RAI dose, and thyroid-stimulating hormone level at the time of RAI on HADS and SF-36 scores did not show statistical significance. Conclusion: Trend in scores over several-months' time discloses gradual improvement of QoL and merits close observation but limited psychiatric intervention.

Melioidosis is an emerging infectious disease in India. The disease has a crippling effect on the patient owing to its widespread dissemination and complications post bacteremia. The role of 18-fluorine-fluorodeoxyglucose (FDG) positron emission tomography–computed tomography (PET-CT) is becoming increasingly important in terms of documenting the extent of disease and response to treatment. Herein, we present cases of two patients who were referred for a whole-body 18F-FDG PET-CT scan with a history of long-standing fever that went undiagnosed. 18F-FDG PET-CT scan was performed to evaluate pyrexia of unknown origin. A conclusion was reached after blood culture which showed the growth of Burkholderia pseudomallei – which is considered to be the cause of this rare but debilitating disease.

Somatostatin receptor-targeted alpha radionuclide therapies have been introduced including actinium-225 labeled tetraazacyclododecanetetraacetic acid–octreotide (Ac-225 DOTATATE) for advanced metastatic neuroendocrine tumors (NET). Very limited data are available on the posttherapy imaging using Ac-225 DOTATATE therapy in metastatic NET. We present Ac-225 single-photon emission computed tomography/computed tomography images of a 72-year-old patient diagnosed as a case of advanced rectal NET treated primarily with Ac-225 DOTATATE.

Hepatic veins and inferior vena cava are opacified during the delayed venous phase on triphasic contrast-enhanced computed tomography (CECT) abdomen scan. However, their early opacification/visualization in the arterial phase is usually due to retrograde flow of intravenous contrast from the right atrium in patients with right-sided heart failure or right ventricular dysfunction. Awareness and recognition of this phenomenon is important for nuclear medicine physicians reporting F18 fluorodeoxyglucose positron emission tomography–computed tomography (FDG PET CT) scan with diagnostic CECT.

Sarcoidosis is a chronic granulomatous disorder of unknown etiology which primarily affects the respiratory system. However, 0.5%–2.5% of patients with sarcoidosis show muscle involvement, namely sarcoid myopathy. F-18 Fluorodeoxyglucose positron-emission tomography (F-18 FDG PET) has become an important component of the diagnostic algorithm of these patients, owing to its ability to assess disease extent and identify occult sites of disease involvement and guiding sites of biopsy. Awareness of pattern of FDG uptake in sarcoid myopathy not only helps in identifying muscular involvement in already known cases but also helps in the initial diagnosis of sarcoidosis as in the present case.

Artifacts in positron emission tomography (PET)/computed tomography imaging can result from a number of factors. Presence of imaging artifacts affects interpretation and can sometimes render the image uninterpretable. Correction of artifacts can be attempted by reprocessing of data. In the present study, one PET maximum intensity projection image artifact was corrected by employing the method of retro-reconstruction.

Tc-99m-methylene diphosphonate (MDP) bone scintigraphy is mainly directed toward identifying sites of altered skeletal metabolism and abnormal foci of calcium phosphate deposition due to various etiologies. One of the requirements of an ideal bone scintigraphy is little or no extraosseous uptake. Nonosseous uptake of MDP in the bone scintigraphy is an unusual finding. We report a case of carcinoma prostate referred for bone scan, where diffuse hepatic and splenic uptake has been seen on the bone scan. However, on a further repeat bone scan, there was no nonosseous uptake.

Gastric neuroendocrine tumors (G-NETs) express somatostatin receptors (SSTR), which can be imaged using radiolabeled somatostatin analogs, including ⁶⁸Ga-DOTA octreotide analogs. SSTR expression is also seen in activated lymphocytes and macrophages, which might result in false-positive results on SSTR imaging, in patients with coexistent granulomatous pathologies including tuberculosis, sarcoidosis, and Wegener's granulomatosis. We present a case where ⁶⁸Ga-DOTANOC positron emission tomography/computed tomography (PET/CT) showed primary G-NET, with SSTR expressing nonregional lymph nodes which on histopathology showed necrotizing granulomas with Langhans histiocytes. Antitubercular therapy was started, and a decrease in size and SSTR expression in involved lymph nodes was noted on follow-up ⁶⁸Ga-DOTANOC PET/CT.

New onset refractory status epilepticus (NORSE), is a rare, neurological condition characterised by prolonged periods of refractory epileptic seizure with no readily identifiable cause in otherwise healthy individuals. Anatomical imaging like MRI and serology is usually unremarkable. In patients who have underlying etiology as auto-immune encephalitis without any evidence of auto-antibodies FDG PET may help in early diagnosis and treatment response as it tends to accumulate in the neuronal tissue whenever there is increased blood flow, metabolic demand or increased electrical activity which reverts back with clinical recovery.

We report an extremely rare case of acute inflammatory myopathy during combination chemotherapy with docetaxel and transtuzumab for metastatic breast carcinoma in a 44-year-old female patient. Despite the significant response in the follow-up fluorodeoxyglucose (FDG) positron emission tomography/computed tomography, of the underlying malignancy to the chemotherapeutic regimen, there was diffusely increased FDG uptake in the upper and lower limb muscles with associated painful, proximal muscle weakness. These symptoms regressed after the discontinuation of docetaxel and the administration of corticosteroids, suggesting it to be the drug-induced myositis.

Bladder cancer is one of the most common malignancies of the urinary tract. Cutaneous metastasis of bladder carcinoma is extremely rare with a limited number of cases, resulting mainly from iatrogenic seeding. Here, we present scan findings of cutaneous metastasis in a known case of carcinoma urinary bladder. The 18F FDG PET/CT scan revealed FDG avid nodular thickening of the skin and sub-cutaneous tissue with ulcerations involving anterior pelvic wall, walls of the scrotum and the base of the penis. Histopathology confirmed the diagnosis of cutaneous and subcutaneous metastasis.

Parathyroid hormone (PTH) is a key in maintaining calcium homeostasis. Decreased PTH will result in decreased bone remodeling and increased bone density. The major cause is iatrogenic injury to parathyroid gland. X-ray and dual-energy X-ray absorptiometry are used to identify the skeletal changes. Typical skeletal changes are metaphyseal sclerosis in long bones and sclerosis of vertebrae and pelvic bones. ^99mTc methylene diphosphonate scintigraphy is used to identify metabolic bone diseases. There are no typical scan findings in case of hypoparathyroidism. We like to report an interesting image of skeletal scintigraphy in case of hypoparathyroidism.

The dissemination and autotransplantation of viable splenic tissue in different anatomic compartments of the body can present a diagnostic dilemma, especially when metastatic disease is suspected. We report a case of a 30-year-old male with well-differentiated gastric neuroendocrine tumor (Grade II) treated with surgery. Follow-up ⁶⁸Ga-DOTA-NOC demonstrated a suspicious peritoneal soft-tissue nodule in the right paracolic gutter with increased tracer uptake. In view of splenectomy 10 years ago, the patient underwent ^99mTc heat-denatured erythrocyte study which showed a very unusual pattern of multiple tracer-avid foci of splenic tissue in both intraperitoneal and extraperitoneal distributions. The integration of the patient's history and complementary nuclear imaging results led to the correct diagnosis of splenosis.

Cutaneous squamous cell carcinoma (SCC) metastasizes most commonly to the regional lymph nodes and lungs. Metastasis to heart, although described in literature, is a very rare phenomenon. We present the ¹⁸F-fluorodeoxyglucose positron emission tomography–computed tomography findings in a 50-year-old woman who was a biopsy-proven case of SCC left foot, showing cardiac metastasis in addition to lymph nodes, lungs, and skeletal metastases.

Leucine-rich glioma-inactivated 1 (LGI1) antibody encephalitis is an emerging autoimmune disorder with antibodies to the voltage-gated potassium channel complex. Here, we report clinico-imaging findings of a 77-year-old female presenting with acute-onset seizures, normal magnetic resonance imaging and with abnormal fluordeoxygluose positron-emission tomography-computed tomography and positive anti-LGI1 antibodies on immunofluroscence assay.

Spontaneous cavitation in primary lung malignancies although common, but is rare in secondary metastatic lung tumors. We present a case of 20-year-old male who presented with cavitary left lung lesion 1-year postexcision of the left tibia osteosarcoma on ¹⁸F-fluorodeoxyglucose positron emission tomography-computed tomography which on histopathology confirmed as metastatic lesion secondary to the sarcomatous primary.

Meningiomas arise from meningothelial cells of the arachnoid membranes. They are classified into three grades according to the WHO criteria, Grade I (Benign), Grade II (atypical), and Grade III (anaplastic). Radiological and structural imaging computed tomography (CT) and magnetic resonance imaging are done routinely for defining the location, extent, and follow-up. However, these imaging techniques have their limitations. Since meningiomas have overexpression of somatostatin receptor 2, DOTANOC positron-emission tomography (PET)/CT scan is suggested for their delineation and distinguish postradiotherapy necrosis from recurrence. Here, we present a case where DOTANOC PET/CT scan helped in confirming recurrence postsurgery and radiotherapy.

In the treatment of hepatocellular carcinoma, achieving complete pathological response (CPR) in explanted liver specimens following any locoregional treatments is associated with reduced recurrence rates and better posttransplant survival compared to the incomplete response. Here, we present the imaging findings of a patient who achieved CPR in the explanted liver following Y-90 SIR-Spheres® therapy.

A 65-year-old woman presented with a neuroendocrine pancreatic head tumor and known liver and bone metastasis. We performed Tc-99m-tektrotyd scintigraphy on this patient, which showed more developed diffuse bone metastases, in addition to the known lesions.

Prostate-specific membrane antigen (PSMA) is a type II transmembrane glycoprotein which is overexpressed in prostate cancer. However, the widespread use of PSMA positron-emission tomography (PET) scan revealed various nonprostatic PSMA-avid diseases. Here we present a report of a known case of carcinoma prostate, post orchidectomy, radiotherapy, on hormonal therapy with complain of back pain, referred for Ga68 PSMA PET/CT scan. The scan revealed PSMA-avid lesion of contiguous D6 and D7 vertebrae with associated soft-tissue component. The biopsy of the lesion was suggestive of tuberculosis.