Introduction: In early operable stages of cervical an endometrial malignancies, surgical staging of lymph nodes is advocated as contrast-enhanced computed tomography (CECT) has limited sensitivity and accuracy. Although fluorine-18 (F-18) fluorodeoxyglucose (FDG)/positron emission tomography (PET)-CT has potential to identify subcentimeter-sized nodal metastases, higher prevalence of pelvic inflammatory disease in developing countries could result in lower accuracy. The present study was undertaken to assess the incremental value of PET scan over CECT for nodal staging before radical surgery. Methods: Forty-four patients with the International Federation of Gynecology and Obstetrics (FIGO) Stage IA2–IIb carcinoma cervix and 28 patients of FIGO Stage I–II carcinoma endometrium underwent F-18 FDG-PET-CECT scan. A SUV_maxvalue >2.5 g/ml based on body weight was considered as positive. An enhancing node with >1 cm size in the shortest dimension, with loss of fatty hilum was considered positive on CT images. The histological findings were considered the gold standard against which the two modalities were compared. Results: All 1226 pelvic nodes were dissected, of which 65 were found to be metastatic (i.e., 5.3%). Of the 72 patients, 15 (20.83%) had pelvic nodal metastases. The overall accuracy of PET and CECT for assessment of pelvic nodal metastases was comparable (i.e., 86% vs. 85%). Conclusion: PET and CECT scans have similar accuracy in pelvic nodal staging of operable uterine malignancies. Granulomatous inflammation may not be a major cause of false-positive results. The sensitivity and negative predictive values are not high enough to obviate need of surgical nodal staging.

Aim: Utility of Ga68 DOTATATE PETCT imaging to localise cause for oncogenic osteomalacia (OOM). Materials and Methods: Retrospective analysis between March 2015 to March 2018 of all patients with a clinical diagnosis (based on a combination of clinical history, hypophosphatemia and elevated FGF-23 values) of OOM who underwent Ga-68 DOTATATE PET/CT. Results: Total of 27 patients had undergone Ga-68 DOTATATE PET/CT imaging in our centre from March 2015 to March 2018. Of these 16 patients with clinically suspected oncogenic osteomalacia were included in our study. Age range 18-61 years of which 12 were males. Total of 13 (81.25%) patients were found to be positive on imaging for a possible mesenchymal tumour. Most common site of tumour was the lower limb (76%). Most common presenting symptom was bone pain (81%) followed by muscle weakness (19%). Overall, 10 patients underwent surgery, all of whose biopsy was reported as phosphaturic mesenchymal tumour. During the three month follow up, serum phosphorous measured in 15/16, post-surgical/ medical treatment had normalised in all except two patients who had undergone only medical therapy with neutral phosphate. Fall in FGF-23 was more pronounced in surgically treated patients as compared to those who received medical treatment. Conclusion: Ga68-DOTATE PET/CT is a useful investigatory modality for localizing cause for oncogenic osteomalacia.

Aim: Gastric emptying (GE) scintigraphy is commonly used as a standard diagnostic procedure for the assessment of functional dyspepsia (FD). Results of the study are often reported as either normal or delayed GE times. The aim of this study was to recognize various patterns of scintigraphy among both normal and abnormal emptying times. Materials and Methods: Fifty patients with suspected FD were included in the study. GE study was performed with a standardized vegetarian solid meal. Results: Out of 50 patients, 33 patients had deranged GE. Thirty patients had delayed GE. Three patients demonstrated gastric hurrying. Five different patterns were demonstrated in patients having similar emptying and retention times such as reduced fundus compliance, decreased fundic accommodation, antral dysmotility, gastric hurrying, and gastroesophageal reflux. Conclusion: According to our findings, it may be suggested that visual assessment of GE and identification of various pattern is a very important aspect of the GE study. It not only subcategorized patients but also decreases the number of “normal” studies. This finding may have an impact on patient management in the era of personalized medicine.

Introduction: The choice of the radionuclide has a key role in nuclear medicine which appearing the lowest scatter fraction. In addition, the presence of penetrated and scattered photons from collimator in single-photon emission computed tomography images degrades resolution and contrast. Thus, image quality depends on sensitivity and resolution of the collimator–detector system. The goal of this study was to compare the image quality that can be achieved by three radionuclides: technetium-99 m (Tc-99 m), iodine-123 (I-123), and samarium-153 (Sm-153). Materials and Methods: Tc-99 m and Sm-153 were imaged with low-energy high resolution (LEHR) collimator, while I-123 was imaged with medium-energy (ME) collimator. We modeled the Siemens Symbia Medical system using Monte Carlo simulation code SIMIND. The imaging characteristics of each radionuclide were investigated by simulated data: point spread function, sensitivity (Cps/MBq) and geometric, penetration and scattering distribution. Results: Tc-99 m and Sm-153 give best and results with LEHR collimator for spatial resolution (full width at half maximum [FWHM] = 3.19 mm; full width at tenth maximum [FWTM] = 6.73 mm) and (FWHM = 3.22 mm; FWTM = 7.39 mm), respectively. Whereas, I-123 provided with ME collimator a lower resolution (FWHM = 4.89 mm; FWTM = 9.89 mm). The sensitivity recorded by Tc-99 m, Sm-153, and I-153 were (31.21 Cps/MBq), (10.16 Cps/MBq), and (51.22 Cps/MBq), respectively. Conclusion: Tc-99 m and Sm-153 give the best and generally similar imaging properties with LEHR. For I-123, the ME collimator helps lowering the influence of high-energy gamma rays.

Skin metastases are rare from systemic malignancy, and incidence reported is between 0.7% and 9% in various malignancies and usually occur in advanced stage. Here, we report three cases, one each of carcinoma esophagus, carcinoma breast, and carcinoma lung, where patients presented with metastatic cutaneous lesions and positron-emission tomography-computed tomography (PET-CT) scan whole body helped in localizing the primary site. Whole-body fluorodeoxyglucose PET-CT scan helps in scanning whole body at once and detect occult primary and metastatic sites.

Fibrodysplasia ossificans progressiva is a rare genetic disease believed to occur in approximately 1 in 2 million people worldwide and is characterized by progressive extraosseous ossification over the course of a lifetime in an inevitable and unpredictable episodic manner, with most patients being confined to a wheelchair by the third decade of life and requiring life-long care. The extraosseous calcification involves ligaments, tendons, muscles, and connective tissue leading to severe restriction of movements. Another hallmark of this condition is abnormal great toes. The diagnosis is often made on clinical and radiological examination, but Technetium-99m methylene diphosphonate (Tc-99m MDP) bone scan is usually indicated to determine the extent of the disease. We hereby present a case series comprising of four patients suffering from this debilitating illness who underwent Tc99m MDP bone scan for initial diagnosis and localizing sites of heterotopic ossification.

Prostate cancer (PCa) is the second most frequent malignancy in men. Most common sites of disease involvement other than the prostate gland include abdominopelvic lymph nodes and the skeleton. The detection of nodal metastases is of utmost importance to determine prognosis and choice of treatment in patients with PCa. Conventional imaging focuses on morphologic information and takes size criteria for decision-making. Early detection of metastases is further relevant in terms of prognosis and therapy management. Molecular imaging of PCa with Ga-68 prostate-specific membrane antigen (PSMA) positron emission tomography–computed tomography (PET-CT) has recently received significant attention and frequently used with a signature to PCa-specific remark. We presented the case of a 69-year-old male presenting with biochemical recurrence after undergoing surgery and in remission for about a year, where Ga-68 PSMA PET-CT identified additional sites of disease apart from the expected regional bed.

Carcinoid tumor of the mesentery has a classical imaging morphology. A specific diagnosis can often be provided on the basis of clinical history, elevated serum neuroendocrine markers, and uptake on somatostatin receptor-based radiotracer studies. Although a number of inflammatory and neoplastic conditions may mimic carcinoid tumor on many of these modalities, uptake on ⁶⁸Ga-DOTANOC positron emission tomography/computed tomography (PET/CT) is considered specific. We report a case of a 28-year-old male presenting with a mesenteric mass along with elevated serum neuroendocrine markers and uptake on DOTANOC PET/CT, all suggestive of carcinoid tumor. However, the histopathologic examination after surgical resection revealed necrotizing granulomas consistent with tuberculosis (TB). This case highlights the great masquerader that TB can be and stresses the importance of keeping a high index of suspicion for TB, especially in endemic areas.

Metastases to thyroid cartilage are rare entities and can often easily be missed on computed tomography (CT) scan alone. Positron emission tomography (PET)-CT imaging has overcome this diagnostic dilemma due to its ability to provide for both anatomical and functional imaging. We report two rare cases of thyroid cartilage metastases on F-18 fluorodeoxyglucose PET-CT from breast and papillary thyroid malignancies as primaries.

Camurati–Engelmann disease (CED) or progressive diaphyseal dysplasia is a rare autosomal dominant inherited condition which belongs to the group of craniotubular hyperostosis. A 24-year-old man presented with insidious onset, progressive pain over both legs, and forearms for 3 years. He was born as the second child of a nonconsanguineous union by vaginal delivery at term without any complications. The clinical, radiological, and histopathological features were suggestive of CED. Transforming growth factor-β1 sequence analysis revealed a missense mutation (c.652C>T; p. Arg218Cys) confirming the diagnosis. He had a good response to treatment with Losartan. CED should be considered in the differential diagnosis of patients presenting with nonspecific limb pains and radiological features of skeletal dysplasia. Early recognition and diagnosis play a crucial role in management. This case discuss regarding the potential benefits of the drug losartan in the management of a rare bone disease for which the evidence from previous literature is scarce.

Sarcoidosis is a systemic chronic granulomatous disease. It mostly involves the lungs and hilar lymph nodes and produces epithelioid granulomas. Granulomatous (sarcoid) reaction is known to be associated with malignancies; however, it is uncommonly seen with colon carcinomas. Furthermore, systemic sarcoidosis following cancer diagnosis is less commonly seen. To the best of our knowledge, cutaneous sarcoidosis related with an underlying colon carcinoma has not been reported previously in the literature. In this report, we present a very rare case with sarcoidosis development after resection of sigmoid adenocarcinoma, presenting with multiorgan involvement including the skin, eye, joints, and lymph nodes. 18F-fluorodeoxyglucose-positron emission tomography/computed tomography (18F-FDG-PET/CT) images showed the skin, lung, spleen, mediastinal, and hilar lymph node involvement. Histopathological examination of skin lesions demonstrated granulomatous dermatitis. This case demonstrates that sarcoidosis can cause intensely FDG-avid lesions on 18F-FDG-PET/CT scans, mimicking metastasis in colon cancer patients. Histopathological evaluation is essential for confirming the diagnosis. 18F-FDG-PET/CT scan provides important information for evaluation of disease extension, progression, and clinical follow-up.

Ectopic thyroid is a rare embryological aberration due to defective migration. Most patients with ectopic thyroid tissue have absent thyroid gland in normal anatomical position and present with hypothyroidism. We present a patient with Graves' disease in the eutopic thyroid with ectopic thyroid tissue in the mediastinum and usefulness of single-photon emission computed tomography-computed tomography.

FDG uptake is an unreliable tool when it comes to distinguish between infectious and malignant etiology particularly in conditions involving the lymph nodes. We describe a case of a 42-year-old man who has been operated for ileal lymphoma two decades back and now developed ileostomy site infection which masqueraded as lymphoma recurrence on ¹⁸F FDG positron emission tomography-computed tomography.

During follow-up of thyroid cancer, ¹³¹I whole-body scan showed intense tracer uptake in the right hemithorax of a patient previously submitted to thyroidectomy and radioiodine therapy for differentiated thyroid cancer. Thyroglobulin was undetectable at the time of the scan. Single-photon emission computed tomography/computed tomography (SPECT/CT) of the thorax correctly identified widespread bronchiectasis ¹³¹I-avid in the middle lobe of the right lung. After bronchoalveolar lavage, a bronchial specimen was positive for Mycobacterium avium infection. Hybrid imaging with SPECT/CT allowed to correctly identify a false-positive case of ¹³¹I uptake due to inflammation in a single diagnostic session, minimizing patient discomfort or misdiagnoses.

Demyelinating lesions of the central nervous system (CNS) are classically known to be hypometabolic on ¹⁸F-Flurodeoxyglucose Positron Emission Tomography (¹⁸F-FDG PET). However, demyelinating lesions may show increased tracer uptake on ¹⁸F-FDG PET and can radiologically mimic neoplasm. Delayed tracer uptake on FDG PET is one of the diagnostic hallmarks of primary CNS lymphoma (PCNSL). Here, we present two cases in which the brain lesions showed increased FDG uptake on delayed integrated PET Magnetic Resonance Imaging (MRI), which were pathologically proven as CNS demyelination. Such demyelinating lesions may also act as “sentinel lesions” and potential harbinger of PCNSL on follow-up.

Primary cardiac angiosarcomas although rare neoplasms remain the most common primary malignant neoplasms affecting the heart. We discuss the sequential positron-emission tomography–computed tomography findings of a 50-year-old man who was diagnosed with the metastatic cardiac angiosarcoma at the outset and developed progressive disease despite sorafenib therapy.

The sequential development of port site recurrence, followed by recurrence in the axillary lymph node in gallbladder carcinoma is very infrequently reported in the literature. The representing 18F-fluorodeoxyglucose positron emission tomography-computed tomography image shows a metastatic right axillary lymph node in a case of gallbladder cancer developed following surgical removal of port site recurrence and six cycles of chemotherapy. The image also shows coexistence of two incidentally detected vascular anomalies, i.e., aberrant right subclavian artery and left-sided superior vena cava. Coexistence of both the vascular anomalies is rare among the general population and have their own clinical implications as described.

Although ¹⁸F-fluorodeoxyglucose (FDG) is the most extensively used tracer in oncological positron emission tomography/computed tomography (PET/CT) studies, various physiological as well as benign pathological conditions are known to cause false-positive results. This report describes ¹⁸F-FDG PET/CT done in an elderly man with primary hepatocellular carcinoma, revealing a metastasis mimicking lesion in the left inguinal canal, which was identified as the herniated portion of the urinary bladder. Though rare, bladder herniation, especially with a narrow neck, can be a pitfall in the evaluation for metastatic disease. The study also highlights the utility of delayed imaging in the evaluation of pelvic pathology.

Adenoid cystic carcinoma (ACC) of the trachea is the second most common tumor of trachea after squamous cell carcinomas. It arises from the submucosal layer and predominantly has a rapid locoregional spread. We describe the ¹⁸F FDG positron emission tomography-computed tomography findings of a 51-year-old woman, a biopsy-proven case of ACC of trachea who underwent the scan for initial staging.

Proximal metatarsal stress fractures are common at base of the second metatarsal, typically seen in repetitive impact athletes, dancers, and those with cavus feet. It is caused by increased bone resorption rather than formation in a state of abrupt increased physical activity or intensity, leading to repetitive microfractures and eventually stress fracture. It is characterized by swelling and tenderness of a prolonged duration. We report a case of a 40-year-old female having left foot pain diagnosed with stress fracture on Tc-99m HDP single-photon emission computed tomography (SPECT)-CT. We emphasize the use of SPECT/CT in allocating active source of pain in the feet.

Pheochromocytomas are tumors arising from sympathetic lineage-derived cells in adrenal medulla, and ⁶⁸Ga DOTANOC positron emission tomography-computed tomography (PET-CT) has been found to be superior than ¹³¹I MIBG single-photon emission computed tomography-computed tomography (SPECT-CT) for initial localization/diagnosis of the adrenal lesion. We discuss the ⁶⁸DOTANOC PET-CT and ¹³¹I MIBG SPECT-CT findings of a 24-year-old male who presented with clinical and biochemical findings suspicious of pheochromocytoma.

Adductor insertion avulsion syndrome, also known as “thigh splints,” is a painful condition affecting the proximal to mid-femur at the insertion of the adductor muscles of the thigh. ¹⁸F-Sodium fluoride (¹⁸F-NaF) is increasingly used in diagnosing skeletal pain which is not identified on radiographs. We report a case of a 56-year-old morbidly obese woman with left hip pain referred for ¹⁸F-NaF positron emission tomography–computed tomography (PET-CT) as magnetic resonance imaging cannot be performed due to obesity. ¹⁸F-NaF PET-CT shows an increase in tracer uptake at the posteromedial cortex of the upper shaft of left femur. Findings are likely due to adductor insertion avulsion syndrome. ¹⁸F-NaF provides important diagnostic information that might alter treatment options.

Elastofibroma dorsi (EFD) is a relatively rare soft-tissue pseudotumor that arises from mesenchymal tissue. We present a case of 48-year-old woman who underwent ¹⁸F fluorodeoxyglucose (FDG) positron emission tomography-computed tomography for initial staging of suspected carcinoma of the left breast. Incidental detection of soft-tissue masses showing moderate FDG uptake was seen in the bilateral infrascapular location characteristic of EFD.

Neuroendocrine tumors (NETs) of gastrointestinal (GI) tract and lungs are a rare variety of tumors but given their indolent nature are quite prevalent. These tumors are mostly malignant in nature and are often diagnosed in advanced stages. GI tracts are the most common sites of NETs followed by lungs, thymus, and other less common sites being ovaries, testis, and hepatobiliary system. Nuclear medicine imaging modalities include ⁶⁸Ga-DOTANOC positron emission tomography/computed tomography (PET/CT) which is sensitive for low-grade NETs and ¹⁸F-fluorodeoxyglucose (FDG) PET/CT which is more valuable for high-grade NETs. However, intermediate-grade NETs are equally sensitive to both ⁶⁸Ga-DOTANOC PET/CT and 18F-FDG PET/CT.