The term “superscan” usually refers to a characteristic pattern on skeletal scintigraphy consisting of symmetrically intense and diffuse radiotracer uptake in the skeleton with absent or diminished visualization of the genitourinary system and soft tissues. Superscans and superscan-like appearances have also been described on fluorine-18-fludeoxyglucose positron emission tomography-computed tomography (18-F-FDG PET/CT). We review reported cases of 18-F-FDG PET/CT superscans and propose criteria for differentiating pathologic superscans from physiologic causes. Knowledge of the 18-F-FDG PET/CT superscan, its reported pathologic causes, its benign imitators, and its clinical implications is important to the nuclear medicine physician or radiologist specializing in the interpretation of nuclear studies to avoid several diagnostic pitfalls.

Purpose of Study: Loss of dopamine neurons in the brain is a characteristic feature of Parkinson's disease (PD). TRODAT-1 is a tropane derivative that binds to dopamine transporter (DAT) receptors. It can be used for noninvasive in vivo imaging of DAT receptors leading to the early detection of PD. The present study aims to optimize the in-house radiolabeling of TRODAT-1 with Tc-99 m in hospital radiopharmacy set up along with performing single-photon emission computed tomography/computed tomography imaging in patients with PD. Materials and Methods: Radiolabeling was performed through transchelation method. For optimization studies, varied amount of glucoheptonate (GHA) and stannous chloride was incubated with Tc-99 m for 10 min at room temperature. TRODAT-1 was added to the reaction mixture followed by incubation at 95°C for various time intervals. Phosphate buffer saline was added to maintain the pH of the final product. After performing the quality checks, whole-body imaging was performed to check the biodistribution in 4 patients at 1 h postinjection of 20–25 mCi (740–925 MBq) of Tc-99 m-TRODAT-1. Regional brain imaging was performed at 3–4 h. Clinical evaluation was done in control (n = 5) and in patients with PD (n = 5). Results: Radiolabeling yield of 100% was achieved by incubating TRODAT-1 with Tc-99 m GHA. All the quality control indicated the suitability of radiopharmaceutical for the intravenous administration. Good uptake of Tc-99 m TRODAT-1 was observed in the striatum of normal patients. However, decreased uptake was seen in patients with PD. Conclusion: Tc-99 m TRODAT-1 is a potential radiopharmaceutical for the diagnosis and staging PD which can be radiolabeled in-house with good yield leading to its easy availability.

Objective: To detect subclinical peripheral vascular disease in obese Egyptian patients and establish relations between obesity, metabolic risk factors, and PVD. Methods: This was a prospective case-control study including 100 obese patients (BMI >30) (G1). In addition, 100 age and sex matched non-obese healthy subjects as a control group (G2). Both groups were subjected to duplex ultrasound, Radionuclide muscle scan. Angiography was done for 17 patients. Results: The image pattern of 99mTc-MIBI muscles uptake was studied and perfusion reserve (PR%) was calculated in (G1) and (G2). Comparison between the two groups showed statistically significant difference (P < 0.001) as regarding laboratory findings. Patients were categorized according to PR% into ⁺ve for ischemia (mean PR% was 28.4 ± 20.3) and ^-ve for ischemia (mean PR% was 65.0 ± 11.4). Among (G1) 64 patients positive for ischemia by both PR% and Doppler, 36 patients were negative by Doppler and 22 of them were positive for ischemia by PR%. Angiography was done for 17 of them and proved ischemia in all of them. Conclusion: The Tc-99m sestamibi muscle scan can be used as a screening and diagnostic tool of preclinical atherosclerosis in obese patients.

Objectives: The aim of this study was to develop and verify a personal computer-based software tool for calculating uniformity indices of gamma camera. Materials and Methods: The program was developed in MATLAB R2013b under Microsoft Windows operating system. Noise-less digital phantoms with known uniformity parameters were used to verify the accuracy of the program. Two hundred and forty-four Co-57 flood source images were acquired on Symbia T6 and Discovery nuclear medicine/computed tomography 670. The uniformity indices of these images were determined with their respective vendor's software and also by the tool developed. Bland–Altman plots were used for measuring the agreements between the developed program and the vendor's program for the calculation of uniformity indices. Results: The tool for calculating uniformity indices was found to be accurate. Uniformity indices measured with the tool revealed a very good correlation with vendor's software based on Bland–Altman analysis, as almost all measurements were within the ±2 standard deviation range. Conclusion: The software tool for calculation of uniformity indices is accurate, and the uniformity indices calculated by it are in agreement with uniformity indices calculated by the vendor's software.

Purpose of the Study: ^99mTechnetium-methylene diphosphonate (^99mTc-MDP) bone scan images have limited number of counts per pixel, and hence, they have inferior image quality compared to X-rays. Theoretically, global histogram equalization (GHE) technique can improve the contrast of a given image though practical benefits of doing so have only limited acceptance. In this study, we have investigated the effect of GHE technique for ^99mTc-MDP-bone scan images. Materials and Methods: A set of 89 low contrast ^99mTc-MDP whole-body bone scan images were included in this study. These images were acquired with parallel hole collimation on Symbia E gamma camera. The images were then processed with histogram equalization technique. The image quality of input and processed images were reviewed by two nuclear medicine physicians on a 5-point scale where score of 1 is for very poor and 5 is for the best image quality. A statistical test was applied to find the significance of difference between the mean scores assigned to input and processed images. Results: This technique improves the contrast of the images; however, oversaturation was noticed in the processed images. Student's t-test was applied, and a statistically significant difference in the input and processed image quality was found at P < 0.001 (with α = 0.05). However, further improvement in image quality is needed as per requirements of nuclear medicine physicians. Conclusion: GHE techniques can be used on low contrast bone scan images. In some of the cases, a histogram equalization technique in combination with some other postprocessing technique is useful.

Purpose of the Study: Rutin (RUT) and quercetin (QRT) which are dietary compounds were investigated for their ability to protect against ionizing radiation (IR)-induced genotoxicity in human lymphocytes. Materials and Methods: The radiation antagonistic potential of RUT and QRT was assessed by alkaline comet and cytokinesis-block micronucleus (CBMN) assay. Results: Treatment of lymphocytes with RUT and QRT (25 μg/ml) prior exposure to 2 Gy gamma radiation resulted in a significant reduction of frequency of micronuclei as compared to the control set of cells evaluated by CBMN assay. Similarly, treatment of lymphocytes with RUT and QRT before radiation exposure showed significant decrease in the DNA damage as assessed by comet parameters, such as percent tail DNA and olive tail moment. Conclusion: The study demonstrates the protective effect of RUT and QRT against IR-induced DNA damage in human lymphocytes, which may be partly attributed to scavenging of IR-induced free radicals and also by the inhibition of IR-induced oxidative stress.

Purpose of the Study: Drug accessibility to the tumor cells is an important area of concern with an anticipation of increasing the efficacy of the drug to be delivered to a specific site. The biogenesis of gold nanoparticles using plant-mediated phytochemical extracts and their possible linkage to cancer antibodies with an aim at delivering the conjugate specifically to the tumor-associated antigen is the basic objective of the research. Materials and Methodology: Radiolabeling of antibodies with gold nanoparticles was carried out by a protocol, and the labeling extent of antibodies was compared with that of a radiogold solution to ordinary particulate size (AuNO-Ab). The amount of radiolabeling was estimated by subjecting the reaction mixtures to thin layer chromatography (ITLC-Silica-gel) in different solvent mediums, both by visual inspection of images of the Siemens Orbitor Gamma Camera ZLC-7500 and also by in vitro counting of the radioactive counts in different quarters of the chromatographic strips. Biodistribution relating to the deposition of injected dose in nontargeting sites (reticuloendothelial system [RES]-localization) was studied and efforts were made for reducing the same. Results: Much improved gold incorporation was confirmed at various molar ratios of gold to immunoglobulin (antibody) using nanogold solution (>85%). The RES uptake in the liver, spleen etc., was observed as a problem and the prior administration of unlabeled nonspecific gammaglobulin (before the actual radiolabeled product) was identified as the suitable blocking agent for this purpose. Conclusion: The study signifies the potential for PEGylated gold nanoparticles of a precise size range, suitable to use as a delivery vehicle for targeting small biomolecules (antibody etc.) to the tumor site. The stability of this labeled immunoconjugate and other toxicity effects under physiological conditions needs further evaluation. If successful, this could be a role model for attaining high tumor/nontumor ratio.

F-18-fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) is routinely performed in oncology patients for various indications including staging, restaging, recurrence detection, and treatment response evaluation. Many disease- and treatment-related complications can be incidentally detected on PET/CT, which may be due to the complication of radiotherapy, chemotherapy, intervention, or primary tumor itself. Some of these complications could be life threatening and need urgent intervention. Therefore, these incidental findings should be recognized on PET/CT and immediately informed to the treating physicians if required urgent intervention.

The objective of this article is to provide an illustrative tutorial highlighting the utility of ¹⁸F-fluorodeoxyglucose-positron emission tomography/computed tomography (¹⁸F-FDG-PET/CT) imaging to detect spectrum of manifestations in patients with tuberculosis (TB). FDG-PET/CT is a powerful tool for early diagnosis, measuring the extent of disease (staging), and consequently for evaluation of response to therapy in patients with TB.

Skeletal scintigraphy with ^99mTc-methylene diphosphonate and 18-fluorine–fluoride the main stay in cancer follow-up for early detection of skeletal metastasis often reveal confusing and conflicting findings requiring proper interpretation in conjunction with clinical-radiological correlation. A series of commonly encountered findings are presented for elucidation.

Biological activity of the fracture site is very important factor in treatment planning of fracture nonunion. If no biological activity is detected, then an autologous bone graft can be supplemented or osteogenic supplementations, such as bone morphogenetic protein is given. If biological activity is present, then secure fixation is sufficient to achieve bony union. Biological activity of nonunions is usually assessed by conventional radiographs. The presence of callus formation is usually assessed as the presence of biological activity. However, high number of radiologically nonhypertrophic nonunion demonstrates intense, uniform tracer uptake on bone scan, a sign of biological activity. Poor or absent callus visualization on radiographs does not always mean a lack of biological activity and it underestimates it. Uptake in bone scintigraphy reflects blood flow and new bone formation and being functional imaging technique, it is more suitable for assessing biological activity.

Introduction: In this study, we have developed a simple image processing application in MATLAB that uses suprathreshold stochastic resonance (SSR) and helps the user to visualize abdominopelvic tumor on the exported prediuretic positron emission tomography/computed tomography (PET/CT) images. Methods: A brainstorming session was conducted for requirement analysis for the program. It was decided that program should load the screen captured PET/CT images and then produces output images in a window with a slider control that should enable the user to view the best image that visualizes the tumor, if present. The program was implemented on personal computer using Microsoft Windows and MATLAB R2013b. Results: The program has option for the user to select the input image. For the selected image, it displays output images generated using SSR in a separate window having a slider control. The slider control enables the user to view images and select one which seems to provide the best visualization of the area(s) of interest. Conclusion: The developed application enables the user to select, process, and view output images in the process of utilizing SSR to detect the presence of abdominopelvic tumor on prediuretic PET/CT image.

A rare acquired demyelinating lesion of the pons central pontine myelinolysis (CPM) typically occurs after rapid correction of hyponatremia. There is disruption of blood–brain barrier due to osmotic stress allowing access for inflammatory mediators in extravascular brain tissue, which most likely attracts glial cells of the brain, attracts macrophages, and activates astrocytes. We present a case of female with a known history of inflammatory bowel disease who presented with altered sensorium and hyponatremia. Fluorine-18-fuorodeoxyglucose (F-18-FDG) positron emission tomography/computed tomography (PET/CT) was performed which showed localized FDG uptake in the pons, consistent with the CPM findings observed on magnetic resonance imaging. Pontine uptake in F-18-FDG PET CT in hyponatremic patients who were clinically deteriotating even after correction of hyponatremic status aids for the diagnosis of CPM.

Abdominal aortic aneurysm (AAA) is an uncommon entity with high mortality. Etiologically, they are classified as inflammatory and infective (mycotic), the latter being less common. Clinical presentation, laboratory investigations, and treatment for these may considerably overlap. However, choice of management and the need for surgical intervention depends on factors such as size and progression of aneurysm, persistent symptoms, and presence or absence of distant pathology. Although computed tomography (CT) is the gold standard for AAA, in selected cases, especially in infected AAA, fluorodeoxyglucose positron emission tomography-CT can provide valuable information.

Primary pleuropulmonary synovial sarcoma, a mesenchymal tumor of lung and pleura, is very rare and highly aggressive condition among the primary lung malignancies. As role of fluorodeoxyglucose positron emission tomography-computed tomography (FDG PET-CT) has been established in lung malignancies in terms of staging, restaging, biopsy guidance, and treatment response evaluation, there is also role of FDG PET-contrast-enhanced CT (CECT) to raise suspicion or increase confidence in reporting of sarcomatous lung malignancy by studying characteristics of CECT scan features. We present a case of a 57-year-old female patient having large lung mass, who underwent FDG PET-CT scan and findings raised strong suspicious of noncarcinomatous pattern of lung mass and may have sarcomatous primary lung malignancy which was later proven on histopathological and immunohistochemistry report.

Silicone injected for cosmetic purposes can provoke an inflammatory granulomatous response. In turn, silicone granulomas can lead to hypercalcemia, which is a rare, though potentially life-threatening condition. Hypercalcemia is a nonspecific laboratory finding with many potential etiologies. It may be difficult for clinicians to diagnose silicone-induced hypercalcemia, since the history of cosmetic silicone injections may not be elicited from the patient. Positron emission tomography using F-18-fluorodeoxyglucose (FDG-PET) can be used to evaluate patients with unexplained hypercalcemia as a means of searching for an occult malignancy or granulomatous process. FDG-PET findings may be the initial and perhaps only indication of silicone granulomas as the cause of hypercalcemia. Nuclear medicine physicians should have a low threshold for suggesting this diagnosis, particularly in the setting of unexplained hypercalcemia. This case report highlights the value of FDG-PET in diagnosing silicone granuloma-induced hypercalcemia.

Numerous studies over past four decades have implicated a strong association of Streptoccus bovis infection with colorectal carcinomas. Strong is this association that a screening colonoscopy for identifying malignancy is considered mandatory in patients whose blood/fecal cultures show growth of this particular pathogen. Here, we report an interesting case of a 61-year-old female patient who presented with pyrexia of unknown origin for 3 weeks. Positron emission tomography/computed tomography, in addition to helping diagnose mitral valve endocarditis, also identified a clinically occult T2N0 rectal carcinoma.

A 54-year-old male patient was referred for computed tomography angiography to rule out cardiovascular disease. The examination revealed a single coronary artery originating from the right sinus of Valsalva, extending to the normal left circumflex artery and left anterior descending artery domains. The computed tomography showed only mild coronary sclerosis. The myocardial stress flow on the subsequently performed ¹³NH₃myocardial perfusion positron emission tomography demonstrated a relative stress flow reduction in the distal segments along the monocoronary. In the presented patient without significant coronary disease and a benign course of the monocoronary, the relative inability to increase blood flow during stress in the distal segments of the artery is a remarkable finding.

Transitional cell carcinoma (TCC) urinary bladder is known to metastasize to regional lymph nodes (LNs), liver, lung, bone, adrenal glands, and intestine. However, an asymptomatic TCC bladder manifesting as metastatic axillary LN mass and extensive retroperitoneal lymphadenopathy is rarely heard of. A 46-year-old male, smoker, presented with 8 cm × 6 cm right axillary swelling of 1-month duration. Aspiration cytology revealed metastatic deposits of poorly differentiated carcinoma favoring TCC. Metastatic evaluation with ¹⁸F-fluorodeoxyglucose positron emission tomography (¹⁸FDG-PET) scan showed mass lesion urinary bladder, conglomerate right axillary mass and extensive retroperitoneal LNs with significant metabolic activity, biopsy from which revealed deposits of TCC. Transurethral-resection of bladder confirmed TCC and was exhibited palliative chemotherapy on which he progressed. Received palliative radiotherapy to axilla to which he showed significant symptomatic clinical response. He developed obstructive uropathy and was kept on supportive care. Review of literature reveals that our case may be the second case of TCC bladder with generalized lymphadenopathy and the first case of asymptomatic bladder carcinoma manifesting with upfront disseminated abdominopelvic lymphadenopathy detected by ¹⁸FDG-PET scan ever reported in world literature.

Lymphoma with skeletal muscle involvement is a rare clinical presentation. They may occur as primary skeletal muscle lymphoma, contiguous spread from bones or by metastatic spread. We present a rare case of non-Hodgkin's lymphoma with pelvic skeletal muscle involvement presenting as low back ache. Lymphoma as the first differential diagnosis in this case was clinched after an ¹⁸F-fluorodeoxyglucose positron emission tomography (FDG-PET) and confirmed as diffuse large B-cell lymphoma on histopathology. We seek to present an uncommon manifestation of lymphoma and highlight the role of ¹⁸F-FDG PET CT in the diagnosis, staging, and management of lymphoma.

Fluorodeoxyglucose (FDG) positron emission tomography-computed tomography (PET-CT) is a useful proven imaging modality in the management of many types of cancers. It is being used at various stages of treatment of cancer. Knowledge regarding the physiological biodistribution and false-positive findings should be kept in mind for correct interpretation. Pulmonary FDG uptake can be due to different causes such as infection, inflammation, and metastases which are invariably associated with structural abnormality on CT. In rare circumstances, there can be a focus of FDG uptake in the lung with no corresponding structural abnormality which might be due to an inflammatory vascular microthrombus or due to iatrogenic microembolism caused during the injection of radiotracer. It is important to be aware of this as it can cause difficulty in interpreting the scan and can lead to false-positive findings. It also highlights the importance of hybrid imaging in the form of PET-CT as there is a definite possibility of misinterpreting this as a site of metastasis in a known carcinoma patient if there was no corresponding CT image.

A 7-year-old girl with an episode of hematochezia and melena, suspicious for bleeding Meckel's diverticulum, was referred for a Tc-99m pertechnetate Meckel's scan. On dynamic planar scan, apart from prompt gastric visualization an oval-shaped, area of inhomogeneous tracer uptake was observed in the left lower quadrant of the abdomen. Subsequent single-photon emission computed tomography/computed tomography localized this to intestinal lumen, thus establishing the diagnosis of intestinal duplication (ID) with functional gastric mucosa. Surgical exploration confirmed the presence of a tubular ID in a distance of 1.5 m from the ileocecal valve and pathologic examination showed gastric mucosa lining the lumen of the duplication.

Primitive neuroectodermal tumor is a malignant small round cell tumor of presumed neural crest origin, usually affecting the bony structures of the nasal cavity and its clinical and radiological features may be confused with those of infection and malignancy. I report a case with primitive neuroectodermal tumor of the nasal cavity showing increased tracer uptake on ¹⁸F-fluorodeoxyglucose positron emission tomography-computed tomography mimicking an another primary malignancy in a 17-year-old boy.

Multiple colorectal adenomas (MCRAs) syndrome is a genetic syndrome characterized by multiple colorectal polyps. Patients usually present late in late fourth or fifth decade of life. They have a high risk for developing malignancy. We here present such case of a 61-year-old man with MCRAs who developed malignant degeneration of multiple colorectal polyps, which was demonstrated on ¹⁸F-fluorodeoxyglucose positron emission tomography–computed tomography.

A 39-year-old male presented to the emergency department (ED) with frostbite to the fingers of both hands. In the ED, he received warm baths, acetylsalicylic acid, clopidogrel, and heparin. A three-phase bone scintigraphy with technetium-99m-methylene diphosphonate revealed absent radiotracer uptake in distal phalanges of both hands. The patient received acetylsalicylic acid, clopidogrel and wound care for the next 5 days and made an excellent recovery with satisfactory wound healing in both hands. Early rapid rewarming and reperfusion can improve the prognosis significantly and therefore bone scan done within first 1–2 days may give spurious results.

Excessive skeletal radioisotope uptake in relation to soft tissues along with absent or faint activity in the genitourinary tract on skeletal scintigraphy is known as a “superscan.” Prostate cancer is the most common cause of superscan in skeletal scintigraphy due to diffuse skeletal metastases. However, prostate cancer may cause secondary renal osteodystrophy leading to metabolic superscan also. Differentiating between these two entities are important as treatment options are different. We, hereby, describe a case of prostatic adenocarcinoma presented with metabolic superscan on methylene diphosphonate skeletal scintigraphy and demonstrate the utility of single emission computed tomography-computed tomography in differentiating between two entities.

Nested stromal-epithelial tumor (NSET) is a very rare nonhepatocytic and nonbiliary primary tumor of the liver. An 8-year-old boy was incidentally detected with hepatic lesions, involving both lobes of the liver for which he later underwent orthotopic liver transplant. The hepatic lesions were confirmed to be NSET following histopathological examination of explant liver specimen. He later developed recurrence with multiple metastatic lesions, including multi-station nodal and right talar bone involvement. We here present the case highlighting the importance of ¹⁸F-fludeoxyglucose positron emission tomography/computed tomography in the management of this rare tumor, in particular for monitoring disease progression and/or recurrence.

A 60-year-old female with triple negative breast cancer, postsurgery, neoadjuvant chemotherapy and radiotherapy, on follow-up had facial puffiness and giddiness. ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT) done for suspected recurrence evaluation revealed a large tumor thrombus (TT) in superior vena cava (SVC) with radiological evidence of SVC obstruction. ¹⁸F-FDG PET/CT also showed evidence of FDG avid brain metastases, lymph nodal metastases, and metastatic soft tissue deposits. This case of unusually large TT in SVC detected on ¹⁸F-FDG PET/CT highlights the ability of ¹⁸F-FDG PET/CT to identify TT and clearly demonstrate the pattern of disease in suspected recurrence in triple negative breast cancer patients.

Disseminated cryptococcosis without pulmonary involvement is a very rare phenomenon. Patterns of organ involvement in cryptococcosis resemble various other infective conditions as well as malignant conditions on fluorodeoxyglucose positron emission tomography–computed tomography. We present a case of a 43-year-old male patient who had disseminated cryptococcosis. The rarity of the case being noninvolvement of lungs and meninges and resembling more like lymphoma due to the diffuse involvement of the lymph nodes on both sides of the diaphragm.

Cardiac paragangliomas are rare tumors of neural crest origin, most frequently seen in the left atrium. There are mixed opinions regarding the most appropriate imaging study for diagnosis and evaluation. We describe the novel utility of 18-F-Fluorodeoxyglucose positron emission tomography/magnetic resonance imaging in the case of a 42-year-old male with cardiac paraganglioma.