An 80-year-old male with a previous history of thymoma and kidney cancer underwent a ¹⁸F fluorodeoxyglucose (FDG) positron emission tomography (PET)/contrast-enhanced computed tomography (CT) scan: two pulmonary nodules were discovered, both characterized by an increased glucose uptake. Of them, only one showed mild contrast enhancement. Both nodules were surgically resected: the first nodule was a benign meningioma and the second one was a malignant meningioma. This case study shows that malignancy of meningioma in the lung is not correlated with ¹⁸F FDG uptake and the contrast enhancement, thus suggesting that PET/CT may represent a suboptimal imaging modality for the evaluation of these lesions.

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Aim: This study aims to assess the diagnostic performance of ¹⁸F-fluorodeoxyglucose-positron emission tomography/computerized tomography (¹⁸FDG-PET/CT) compared to whole body (WB) magnetic resonance diffusion-weighted imaging (DWI) with background body signal suppression (MR/DWIBS) in lesions detection in patients with recurrent breast cancer. Materials and Methods: Twenty-three female patients with suspected breast cancer recurrence by clinical, laboratory, or conventional imaging underwent both ¹⁸FDG-PET/CT and WB MR/DWIBS. WB ¹⁸FDG-PET/CT was performed using the standard technique. WB MR/DWIBS acquired sequences were WB DWI with short tau inversion recovery (STIR), coronal T1, and coronal STIR. Both ¹⁸FDG-PET/CT and WB-magnetic resonance imaging/DWIBS were independently interpreted using visual qualitative and quantitative analysis. Pathological findings and combined clinical/radiological follow-up data were used as a reference standard. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and overall accuracy were calculated for both techniques. Results: PET/CT demonstrated higher specificity and sensitivity indices than MR/DWIBS in the detection of the nodal and distant lesions, while the latter displayed higher sensitivity in the detection of local breast lesions. The overall sensitivity, specificity, NPV, PPV, and accuracy of PET/CT were 84.8%, 86.3%, 90.4%, 78.7%, and 85.4% versus 82.1%, 78.0%, 85.2%, 74.0%, and 80.5% for MR/DWIBS. A high degree of agreement existed between PET/CT and MR-DWIBS. Conclusion: ¹⁸FDG-PET/CT is more sensitive and has superiority in the assessment of nodal and distant lesions than DWIBS that has a potential superior role in the assessment of local breast lesions. DWIBS has a promising and helpful complementary tool for ¹⁸FDG-PET/CT in the evaluation of patients with proven malignancies.

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Objectives: The objective of this study was to correlate maximum standardized uptake value (SUV_max) with different immunohistochemical subtypes of breast cancer and other prognostic factors in breast cancer. Subjects and Methods: This was a retrospective study including 219 consecutive patients undergoing whole-body fluorodeoxyglucose positron emission tomography/computed tomography scan for the staging of breast cancer. Out of 219 patients, two were male and 217 were female; age ranged from 26 to 85 years with mean age of 54 years. On histopathological examination (HPE), 197 patients were of invasive ductal carcinoma type and two of lobular type. Histopathological grades, immunohistochemistry (IHC) types, and ki-67 values were compared with SUV_max values. Results: The mean SUV_max of the population was 11.39 (±6.05). The mean SUV_max in different HPE grades was Grade 1 = 6.81 ± 5.6, Grade 2 = 11.4 ± 6.12, and Grade 3 = 13.14 ± 5. The mean SUV_max values in different IHC types were Luminal A = 7.75 ± 4.2, Luminal B = 10.01 ± 5.3, triple negative = 15.26 ± 5.6, and HER2 enriched = 11.27 ± 5.2. The mean SUV_max in high ki-67 patients was 11.97 ± 5.85 compared with 7.25 ± 3.43 patients with low ki-67. Univariate analysis showed significant difference in SUV_max in patients with different grades (P = 0.013), hormone receptor positivity (P ≤ 0.001), ki-67 (P < 0.001), and axillary lymph node positivity (P ≤ 0.001). In multivariate regression analysis, there was significantly higher SUV_max value in triple-negative patients after correcting for tumor size, ki-67 value, axillary lymph node status, and grade of tumor. Conclusion: High SUV_max values were noted in high-grade, high ki-67, triple-negative, and axillary lymph node positive tumors.

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Background: Insulinoma is an islet-cell neoplasm that secretes insulin. It is usually localized to the pancreas and is often the most common cause of endogenous hyperinsulinemic hypoglycaemia in non-diabetic adult patients. Surgical excision with a curative intent is the standard modality of treatment, and it requires precise localization of tumor tissue. Ga-68 DOTA-exendin-4 PET/CT scan is a clinically reasonable and sensitive scan for the identification of insulinoma. The aim of this prospective cohort study was to determine the overall accuracy of Ga-68 DOTA-exendin-4 PET/CT scan in the detection of insulinoma. Materials and Methods: Eight patients with fasting hyperinsulinemic hypoglycaemia with neuroglycopenic symptoms were enrolled in this study which was conducted during October 2016 to October 2017. Whole body PET/CT scan was performed on a Philips time of flight PET/CT scanner, 60 minutes after injection of Ga-68 DOTA-exendin-4 (and also Ga-68 DOTANOC). The imaging findings were compared to the histopathological diagnosis in six out of eight patients and to subsequent follow up in the remaining two patients who did not undergo surgery. Results: The sensitivity of Ga-68 DOTA-Exendin-4 PET/CT scan in insulinoma detection was found to be 75%. Conclusion: Ga-68 DOTA-Exendin-4 PET/CT scan is highly sensitive for identification and exact localization of insulinoma which can guide better surgical exploration. However, randomised controlled trials are needed to assess the accuracy of Ga-68 DOTA-Exendin PET/CT scan in localization of insulinoma.

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Pancytopenia due to thyrotoxicosis is a rare but serious complication. In this report, we describe a rare case of Graves' disease confirmed on thyroid scintigraphy presented with coexisting pancytopenia and liver dysfunction. There was complete recovery of blood counts and hepatic enzyme level to normal after antithyroid treatment and radioiodine ablation.

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We present a case of suspected idiopathic Parkinson's disease in whom extrastriatal accumulation of Technetium-99m labeled tropane derivatives in a pituitary macroadenoma interfered with image quality and interpretation. Subsequent F-18 fluoro-dihydroxyphenylalanine positron emission tomography/computed tomography was useful to demonstrate the absence of presynaptic dopaminergic dysfunction.

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Occipital condyle syndrome is a rare cause of pain in the head which is characterized by severe and persistent unilateral suboccipital headache with unilateral hypoglossal nerve palsy. We report an elderly female who presented with dysarthria and suboccipital headache. On further evaluation, she was found to have a solitary bone metastases from thyroid cancer. She was treated with local radiation therapy for pain relief, total thyroidectomy, and high-dose radioiodine therapy. The patient is presently free of pain with very good control of the thyroid cancer status.

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Adenoid cystic carcinoma of the buccal mucosa has an increased propensity for recurrence and distant metastases. Due to the poor prognosis at late detection of distant metastases, it is advisable to keep a close follow-up. In the present case, ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography proved invaluable in the comprehensive workup of the patient, including detection of local recurrence, distant metastases, and in assessing treatment response.

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Purpose of the Study: This study aims to compare glomerular filtration rate (GFR) estimated by Gates method using gamma camera (GC) with single plasma sample method (SPSM) in people with normal and abnormal body mass index (BMI) using SPSM as gold standard. Materials and Methods: It was single-center prospective study including 60 voluntary kidney donors. Technetium-99m labeled Diethylene Triamine Pentaacetic Acid (^99mTc-DTPA) was administered intravenous under GC. GFR was calculated using Gates Method. After the scan, the subjects were called again after 180 min of injection of ^99m Tc-DTPA. Then, a 3 ml venous blood sample was obtained from the contralateral arm. Russell's formula was used to determine the GFR by SPSM. Results: Mean GFR calculated by SPSM and Gates' method, was 94.0 ± 15.2 ml/min/1.73 m² and 87.3 ± 16 ml/min/1.73 m² respectively. Moderate correlation noted between two methods (r = 0.71, P < 0.0001). Significant correlation noted between GFR calculated by SPSM and Gates method in people with normal BMI (r = 0.92) with no significant statistical difference (P = 0.8). However, only moderate correlation noted between GFR calculated by SPSM and Gates method in people with BMI outside normal range (r = 0.71) with a significant statistical difference (P = 0.0002). Conclusion: Gates method of GFR estimation using GC shows significant correlation with plasma sample technique in people with normal BMI. In people with BMI outside normal range, it significantly underestimates GFR.

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Majority of ovarian cancer (OC) patients are usually diagnosed at advanced stage and present with peritoneal spread/ascites. Some patients develop pleural deposits/effusion secondary to transdiaphragmatic spread of peritoneal disease/ascites. However, pleural deposits/effusion from OC in the absence of peritoneal disease/ascites are very rare. We present a case of serous carcinoma of the left ovary with fluorodeoxyglucose (FDG) avid right pleural deposits and effusion in the absence of peritoneal disease/ascites on FDG positron emission tomography (PET)/computed tomography (CT), showing excellent response to chemotherapy in subsequent PET/CT. We also discuss the pathophysiology of pleural abnormalities in patients with ovarian diseases, a characteristic disease spread pattern and recognition of which would help in the imaging interpretation.

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Papillary carcinoma thyroid is the most common type of thyroid cancer. Papillary thyroid cancer metastasizes commonly to regional lymph nodes, distant organ involvement is to lungs and bone are rare and is associated with poor prognosis. Metastases to intra-abdominal organs are extremely rare. Here, we report a case of 50-year-old female diagnosed with papillary microcarcinoma thyroid who initially treated total thyroidectomy, later presented with metastasis to liver, bone, left adrenal gland, and bilateral lungs. The functioning metastasis was diagnosed by Iodine-131 whole-body scan and later treated with radioiodine.

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Cherubism, a rare hereditary fibro-osseous lesion characterized by painless expansion of jaws, starts early in life manifesting itself fully in the second decade of life and is almost regressed in the third decade. Here, we report a sporadic case of Cherubism with clinico-radiological and scintigraphic presentation of its classical features for its disease rarity and single-photon emission computed tomography/computed tomography findings with review the literature.

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We present a case with space-occupying lesion in cirrhotic liver, diagnosed as hepatocellular carcinoma on immunohistochemistry, who underwent F-18 fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) and showed FDG-avid lesions in liver as well as in the prostate. These findings guided in establishing the diagnosis of prostate cancer, metastasizing to liver by performing additional immunohistochemical markers. PET/CT was also useful in identifying coexisting non-Hodgkin's lymphoma.

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^99mTc-EC (Technetium-99m-ethylenedicysteine) is a renal tubular imaging agent introduced as an alternative to ^99mTc-MAG3 (Technetium-99m-mercaptoacetyltriglycine) (1). This radiopharmaceutical can be easily labeled at room temperature and has high radiochemical purity and long stability for at least 8 h. Within 1 h 70% of ^99mTc-EC is excreted in the urine (2). ^99mTc-EC provides the same Scintigraphic information as ^99mTc-MAG3. The Hepato biliary excretion of ^99mTc-EC is very low and usually does not affect image interpretation on routine imaging, the possibility of visualization of the gall bladder should be kept in mind while reporting the 99mTc-EC renogram (1). We present a case of ^99mTc-EC renogram, a suspected case of hypoplastic/ectopic right kidney, to look for ectopic kidney. In this case, there was unexpected visualization of gallbladder in delayed images. We herewith present this case, so that physician should be careful while reporting ^99mTc-EC renogram, as there may be chances for gall bladder to be masquerading as Ectopic kidney.

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Introduction: In iodine-131 (I-131) imaging, the image quality is degraded by scatter and penetration in a collimator. In this work, we assessed the penetrated and the scattered photon fractions in the photopeak energy window using Monte Carlo Simulation code. Materials and Methods: The Siemens Medical System equipped with high-energy collimator was simulated. We evaluated the acceptance angle values on geometric, penetration, and scatter components in a separate file. Binary images in a data file are obtained and each one of them was imported in software ImageJ. Full-width at half-maximum (FWHM) and sensitivity were calculated and compared. Results: The simulation data show that for the acceptance angle value equal to 4.845°, the geometric, scatter, and penetration components were 93.20%, 4.13%, and 2.67%, respectively. Moreover, the resolution is improved (FWHM = 7.21 mm, full width at tenth maximum = 12.36 mm) for a point source at 12 cm from the detector. Conclusion: The small acceptance angle has a major impact on the image quality in I-131 single photon emission computed tomography.

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Objective: The aim of this study is to investigate the effect of microbiological characteristics of causative organisms on the scintigraphic patterns of labeled-white blood cells (WBC) scan in cases of proven osteomyelitis. Materials and Methods: Retrospective analysis of 25 patients referred with suspected osteomyelitis and had both bone and labeled-WBC scans performed and complete records of the microbiological culture of the causative organism. The bone and labeled-WBC scans were retrieved and reviewed by two nuclear medicine physicians. Any definite focal accumulation of labeled WBCs within the bone was considered positive for osteomyelitis. Diagnosis of osteomyelitis in the discharge summary was considered the reference standard and was based on a combination of the clinical scenario, imaging, and laboratory findings including microbiology. Correlation of the pattern of labeled WBC and the type of microorganisms was done. Results: A total of 16 patients were included in this study, seven females and nine males. Of these, seven patients had Gram-positive whereas nine patients had Gram-negative organisms. The majority (85.7%) of Gram-positive organisms showed increased accumulation of labeled WBCs, whereas only one-third (33.3%) of patients with Gram-negative organisms had such finding. Conclusion: The pattern observed in this study shows that the false-negative results of labeled-WBC scans were mainly noted in patients with Gram-negative as opposed to Gram-positive infections. This confirms the experimental animal study findings that the secretion of anti-chemotactic factors by Gram-negative organisms, seems to be inhibiting the migration of labeled WBCs to the site of infection. The inhabitation is decreasing the accumulation of labeled WBCs and consequently resulting in a false-negative finding. The study adds to evidence that microbiological characteristics of the causative organisms are another explanation for the false-negative WBC in proven osteomyelitis.

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Presenting known treated case of hepatocellular carcinoma, complaining of non specific backache. 99mTc methylene diphosphonate bone scan showed photopenic area in sternal body, which could be easily thought of osteolytic metastasis from hepatocellular carcinoma; however CT scan revealed it to be sternal foramina- a normal variant of sternum. The possibility of a sternal foramen should be mentioned to the clinician because infiltration, biopsy or acupuncture of this area may lead to fatal cardiac complications. Knowledge of the existence of such anatomic variants is important to avoid misdiagnosis as an osteolytic process.

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Primary uterine non-Hodgkin's lymphomas are extremely rare, and consequently, imaging findings of this disease have rarely been reported in the literature. We present fluorine-18-fluorodeoxyglucose (¹⁸[F] FDG) positron emission tomography/computerized tomography (CT) and iodinated contrast CT findings in a young patient with primary uterine non-Hodgkin's B-cell lymphoma with right ovary involvement.

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Epidermoid cysts are benign rare congenital cysts which typically present between 3^rd and 5^th decade of life. They mostly arise from cerebellopontine angle or parasellar region, but sporadic cases arise from cranial dipole. Here, we present a case of 42-year-old female with painful soft swelling in the left frontal region, which on F-18 fluorodeoxyglucose (FDG) positron emission tomography–computed tomography is well-circumscribed non-FDG avid lesion. The patient underwent total resection of the cyst, and the defect produced by space-occupying lesion was repaired by cranioplasty.

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The POEMS syndrome is a rare and multisystemic disease characterized by the presence of polyneuropathy, organomegaly, endocrinopathy, presence of M protein, and alterations in the skin. The existence of bone lesions is frequent, being generally blastic or mixed and rarely lytic. We present the case of a 54-year-old male patient diagnosed with POEMS syndrome, with atypical presence of lytic lesions, who was referred for an 18F-fluorodeoxyglucose positron emission tomography-computed tomography (PET-CT) study for initial staging of the process. There were several hypermetabolic foci coinciding with bone lesions, reaching a maximum standardized uptake value of 15 at the level of the right iliac bone with associated soft-tissue mass. PET-CT is an adequate tool for evaluation, diagnosis, and monitoring of the pathology. The scan allows the detection and selection for its biopsy of bone lesions and lymphadenopathies.

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Many causes of incidental focal uptake on raw data images using myocardial perfusion imaging, including malignant diseases, metastatic processes, benign pathologies, and physiological conditions, have been reported in the literature. However, iatrogenic ^99mTc sestamibi emboli have not yet been reported. Herein, we demonstrated iatrogenic ^99mTc sestamibi embolization on consecutive rest and stressed myocardial perfusion images at different locations.

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