Purpose of the Study: Normal values of cardiac mechanical synchrony parameters in gated myocardial perfusion single-photon emission computed tomography (GMPS) are well established in literature from the Western population. The aim of the study is to establish normal values of mechanical synchrony with GMPS in Indian population and to find out whether it differs significantly from established values. Procedure: We retrospectively analyzed 1 day low-dose stress/high-dose rest GMPS studies of 120 patients (sixty males, 52 ± 11.7 years) with low pretest likelihood of coronary artery disease and having normal GMPS study. In GMPS, first-harmonic fast Fourier transform was used to extract a phase array using commercially available software. Phase standard deviation (PSD) and phase histogram bandwidth (PHB) were used to quantify cardiac mechanical dyssynchrony. Results: The values obtained were as follows, PSD: In men, 14.3 ± 4.7 (stress) and 8.9 ± 2.9 (rest), in women 11 ± 4 (stress) and 7.7 ± 2.7 (rest), and PHB: In men, 40.1 ± 11.9 (stress) and 30.6 ± 7.6 (rest), in women, 34.7 ± 12.6 (stress) and 25.3 ± 8.6 (rest). The value of PSD and PHB was significantly less in Indian population as compared with established values in literature. We also observed that synchrony indices derived from the low-dose stress studies are higher than high-dose rest studies. Conclusions: The value of synchrony parameters differs significantly according to population and methodology suggesting that specific population and methodology-based normal database for assessment of cardiac mechanical dyssynchrony should be established.

Objectives: 67-Gallium-citrate three-phase bone scan (Ga-TPBS), a new approach for the diagnosis of bone infection is evaluated. The interpretation of TPBS is based on the normal physiological vascular endothelial-related response noted in infection. Materials and Methods: Three cases of suspected bone infection as determined by clinical, laboratory, and radiological examinations were further subjected to conventional technetium-99m-TPBS (Tc-99m-TPBS) and Ga-TPBS. Nuclear scan diagnosis of bone infection was made by the presence of generalized vasodilatation with increased capillary permeability noted on the flow and the pool phase of the TPBS and the comparative evaluation of the 4 h delayed Tc-TPBS and 24–48 h delayed Ga-TPBS. Diagnosis of bone infection was confirmed in all three cases on histopathologcal examination of the surgically excised tissues. Results: The data clearly indicated that all three cases of bone infection (osteomyelitis) had generalized massive flow and pool pattern. Infection could be diagnosed only on the Ga-TPBS by noting generalized vasodilatation with increased capillary permeability on the flow and the pool phase with focal retention of the radiotracer on the delayed scan. Conclusions: By incorporating the concept of vascular endothelial-related response causing massive vasodilatation in infection, the interpretation of the Ga-TPBS can be more précised as it is based on the normal physiology. In comparison to two Tc-99m scans (white blood cell scan + bone marrow scan), a single Ga-TPBS is also cost-effective and compliance friendly. Larger, comparative, and statistically unbiased studies are needed. Advances in Knowledge: 67-Ga-TPBS is a new concept for the diagnosis of bone infection. Places where radiolabeled leukocyte imaging is not possible, this new approach may prove to be very useful.

Aim: In order to develop a possible tracer for L-type calcium channel imaging, we here report the development of a Ga-68 amlodipine derivative for possible PET imaging. Materials and Methods: Amlodipine DOTA conjugate was synthesized, characterized and went through calcium channel blockade, toxicity, apoptosis/necrosis tests. [⁶⁸Ga] DOTA AMLO was prepared at optimized conditions followed by stability tests, partition coefficient determination and biodistribution studies using tissue counting and co incidence imaging up to 2 h. Results: [⁶⁸Ga] DOTA AMLO was prepared at pH 4–5 in 7–10 min at 95°C in high radiochemical purity (>99%, radio thin layer chromatography; specific activity: 1.9–2.1 GBq/mmol) and was stable up to 4 h with a log P of −0.94. Calcium channel rich tissues including myocardium, and tissues with smooth muscle cells such as colon, intestine, and lungs demonstrated significant uptake. Co incidence images supported the biodistribution data up to 2 h. Conclusions: The complex can be a candidate for further positron emission tomography imaging for L type calcium channels.

Perineural spread in HNSCC is associated with dismal prognosis and decreased overall survival. Clinical diagnosis of this relatively asymptomatic entity is usually delayed and made incidentally on imaging. MRI is gold standard imaging for early diagnosing of this condition owing to its excellent anatomic resolution. With the ever increasing use of PET/CT in commonly encountered cancer such as HNSCC for staging and re-staging, observing perineural spread on PET/CT is not infrequent. Through this pictorial essay we demonstrate the common patterns of perineural spread in HNSCC on PET/CT with the aim of improving reporting accuracy across readers.

In nuclear medicine, ⁹⁹mTc-methylene diphosphonate. (MDP) bone scan is one of the most commonly performed procedures. MDP uptake in nonosseous tissues is occasionally found in bone scan, and the knowledge of these kinds of extraosseous uptakes is of much clinical relevance. We report here two cases where bone scan showed extraosseous MDP uptake either hepatic or splenic apart from the physiological skeletal uptake.

Idiopathic pulmonary fibrosis (IPF) is a progressive interstitial lung disease with median survival of 2–3 years. It is described as fibroproliferative rather than pro-inflammatory disorder with limited treatment options. IPF diagnostics and therapeutics are a hot topic of current research. We describe a case elaborating the utility of the whole body positron emission tomography with 2-deoxy-2-(fluorine-18) fluoro-D-glucose (F-18 FDG) integrated with computed tomography technique in IPF. The area of most intense pulmonary F--18 FDG uptake corresponded to regions of honeycombing suggesting metabolically active disease amenable to pharmacologic intervention. Additional F--18 FDG uptake was seen in mediastinal nodes implying an extrapulmonary component of disease.

Cutaneous metastasis may be the first evidence of internal malignancy or a sign of recurrence of malignancy and is considered a grave prognostic sign. There are various morphological variants of cutaneous metastases, with the most common being solitary to multiple erythematous infiltrating papules and nodules and the rarer variants being carcinoma erysipeloides, carcinoma en cuirasse, carcinoma telangiectaticum, alopecia neoplastica, metastasis to the inframammary crease, and zosteriform pattern. FDG PETCT is an established imaging modality in the identification of an unknown primary malignancy and also has an important role in the therapeutic decision-making.

Laryngeal cancer is the second most common type of head and neck malignancy, representing approximately 45% of all head and neck cancers. Hematogenous spread to the liver rarely occurs without evidence of pulmonary and bone disease. We report a patient who had been treated 7 years earlier for laryngeal squamous cell cancer and who had isolated liver metastasis on fluorodeoxy D-glucose positron emission tomography-computed tomography.

Paraneoplastic neurological syndromes (PNSs) are commonly encountered with underlying malignant pathology. Though anti--neuronal antibodies play a major role in the diagnosis of the underlying malignant pathology but at many times it becomes inconclusive. As early detection of the primary cause and its treatment gives the best result in such situations, there arises an early and accurate diagnostic need. We present a 65--year--old patient presenting with rapidly progressive quadriparesis with both distal and proximal involvement. With all routine work--up tests within normal limits, 18F-fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) was done which revealed multiple findings that suggested a diagnosis of lymphoma. In our case, PET/CT proved to be an important modality for finding the underlying malignant pathology in a suspected case of PNS.

Bone scintigraphy (BS) is a well--established commonly used imaging modality for staging and follow--up evaluation of cancer patients. Occasionally, BS may show asymptomatic unusual extraosseous lesions in the body which may or may not be related to primary disease. We here present an interesting case of carcinoma cervix in whom ¹⁸F sodium fluoride positron emission tomography-computerized tomography (PET-CT) bone scan detected an intracranial lesion. Initially, this lesion was suspected as brain metastasis; however, later on, combined PET--CT images and contrast-enhanced CT confirmed this lesion as calcified falcine meningioma in the right posterior parietal region.

We present a case of a 17-year-old football player who had previously received multiple facet joint injections for presumed secondary osteoarthritis. ⁹⁹mTc-methylene diphosphonate single-photon emission computed tomography/computed tomography imaging of the cervical spine demonstrated focal increased radiopharmaceutical activity in the right C2 lamina, which was associated with an osteolytic lesion with a central irregular sclerotic nidus. Surgical pathology confirmed an osteoid osteoma.

Primary hyperparathyroidism is a common endocrine disorder of the parathyroid gland. It is mostly seen as a single gland adenoma in up to 85% of the cases with the excess production of parathyroid hormone. Double adenomas although reported are very rare and double giant parathyroid adenomas are even rarer. We possibly report the second case in the literature of primary hyperparathyroidism caused by double giant parathyroid adenomas, presenting with severe symptomatic hypercalcemia and review the diagnostic and therapeutic challenges in its management. The presentation with severe hypercalcemia and the presence of atypia in one of the adenomas added to its uniqueness. A combination of the neck ultrasound and a parathyroid scintigraphy should be used for preoperative localization and selection of the right surgical approach for patients undergoing parathyroidectomy. The parathyroid scintigraphic protocols keep getting refined; it is hence vitally important and practical to adapt the diagnostic algorithms in accordance with local availability and expertise.

Fludeoxyglucose positron emission tomography/computed tomography is valuable in the identification of tumor thrombus and differentiating it from bland thrombus which has implications in initiating anticoagulation. We present a rare case of tumor thrombosis in ovarian vein, in a recurrent case of uterine carcinosarcoma.

The role of fluorine-18 fluorodeoxyglucose. (¹⁸F-FDG) positron emission tomography. (PET)/computed tomography. (CT) in the initial staging of various malignancies is now well established. However, nonspecificity of FDG occasionally results in tracer uptake in benign lung lesions. The authors describe a complicated case of carcinoma stomach with multiple nodules and a cavitary lesion in lungs where ¹⁸F-FDG PET CT done for initial staging revealed FDG avid mass in stomach, FDG avid multiple mediastinal lymph nodes and multiple intensely FDG avid bilateral lung lesions. The FDG avid lung lesions turned out to be due to silicosis as confirmed by histopathology.

Tc-99m TRODAT is cocaine analog and binds to the dopamine transporter in vivo. Tc-99m TRODAT single-photon emission computed tomography/computed tomography. (SPECT/CT) is useful for demonstrating presynaptic dopaminergic dysfunction in patients with Parkinsonism. However, few reports have shown extrastriatal uptake of Tc-99m TRODAT. We present the case of a 67-year-old male who underwent Tc-99m TRODAT SPECT/CT for evaluation of Parkinsonism. In addition to tracer binding in the striatum, tracer uptake was noted in an osteoid tumor of the clivus. Integrated SPECT/CT enabled precise localization and characterization of the extrastriatal site of tracer binding and emphasizes the importance of such coincidental findings.

⁹⁹mTc macroaggregated albumin (MAA) scintigraphy is always performed before administration of ⁹⁰Y--microspheres for the treatment of liver tumors for hepatopulmonary shunt calculation. Tumor thrombus visualization in the hepatic vasculature is an infrequent finding on the ⁹⁹m Tc--MAA single photon emission computed tomography. We present a rare case of a hepatocellular carcinoma extending as a tumor thrombus through hepatic vein, inferior vena cava into the right atrium.