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2.
Indian J Nucl Med ; 38(1): 87-88, 2023.
Article in English | MEDLINE | ID: mdl-37180182

ABSTRACT

Trichoptysis or coughing of hairs is a rare symptom, but is pathognomonic for a teratoma with tracheobronchial communication. We present such a rare case with 18F-flurodeoxyglucose positron emission tomography/computed tomography (PET-CT) imaging findings in a 20-year-old female. The diagnosis was made with PET-CT and she underwent curative surgical resection after that.

4.
Nucl Med Rev Cent East Eur ; 26(0): 1-10, 2023.
Article in English | MEDLINE | ID: mdl-36286203

ABSTRACT

BACKGROUND: To evaluate the effect of patient-related factors such as age, gender, body mass index (BMI), blood glucose (BG), diabetes, serum creatinine and injected dose on 18F-Fluorodeoxyglucose ([18F]FDG) uptake of tumor and normal organs, as well impact of [18F]FDG uptake of tumor on normal organs, in clinical positron emission tomography-computed tomography (PET/CT). MATERIAL AND METHODS: In this retrospective study, data of 200 patients who underwent clinical [18F]FDG PET/CT with (n = 192) and without (n = 8) intravenous contrast was evaluated. Ten target organs and tumor [18F]FDG uptake were measured with a standardized uptake value maximum (SUVmax). Pearson correlation coefficient was calculated for continuous variables while t-test/Wilcoxon rank sum tests were used to compare continuous outcomes. Multivariate linear regression analysis was done to exclude covariates, followed by posthoc multiple linear regression analysis after adjusting the levels of significance. RESULTS: Significant but weak positive correlation was seen between tumor [18F]FDG uptake with uptake in the pancreas (r = 0.43, p < 0.001) and heart (r = 0.19, p = 0.049), but not other organs. With age, a significant negative correlation was seen with the brain (r = -0.183, p = 0.009) and a positive correlation was seen with the blood pool (r = 0.205, p = 0.003). With BG, significant negative correlation was seen with the brain (r = -0.449, p < 0.0001) and heart (r = -0.15, p = 0.033), while a positive correlation was seen with fat (r = 0.143, p = 0.043). BMI showed a significant positive correlation with [18F]FDG uptake of all organs except the pancreas and heart, as well as tumor. No significant correlation was seen with serum creatinine and injected [18F]FDG dose. Significantly higher uptake was seen in the brain, spleen, and muscles of females. Between obese and non-obese, a significant difference was seen for all organs except for the pancreas and heart, and tumor. Comparison between non-diabetic and diabetic patients showed significant differences only for bone. Multivariate linear analysis adjusting for cofactors showed only BMI (p = 0.0009) and BG (p = 0.0002) to be independently correlated with [18F]FDG uptake. Post-hoc multiple regression analysis showed a significant positive correlation between [18F]FDG uptake of the brain (ß = 0.118, p < 0.001), liver (ß = 0.02, p = 0.002), and fat (ß = 0.01, p < 0.0006) with BMI, and significant negative correlation of brain uptake with BG (ß = 0.03, p < 0.0001). CONCLUSIONS: Tumor [18F]FDG uptake has no significant effect on the uptake in organs, except for the pancreas and heart. Age, gender, BMI, and BG, but not creatinine and injected [18F]FDG dose show correlation with uptake in tumor and organs. BG and BMI are independent significant factors, with a positive correlation of BMI with the brain, hepatic and fat uptake, and a negative correlation of BG with brain uptake.


Subject(s)
Fluorodeoxyglucose F18 , Neoplasms , Female , Humans , Fluorodeoxyglucose F18/metabolism , Positron Emission Tomography Computed Tomography/methods , Radiopharmaceuticals , Retrospective Studies , Creatinine , Positron-Emission Tomography/methods , Neoplasms/diagnostic imaging
5.
Indian J Nucl Med ; 38(4): 396-397, 2023.
Article in English | MEDLINE | ID: mdl-38390533

ABSTRACT

While extranodal involvement of diffuse large B-cell lymphoma (DLBCL) is common, skeletal muscle involvement is extremely rare. Isolated skeletal muscle involvement in lymphoma is even rarer. We present here the case of a 26-year-old woman, who was diagnosed to have a solitary isolated skeletal muscle relapse of DLBCL on surveillance 18F-fluorodeoxyglucose positron emission tomography-computed tomography, after completing first-line treatment, that was subsequently confirmed with biopsy.

6.
Nanotechnology ; 33(43)2022 Aug 03.
Article in English | MEDLINE | ID: mdl-35850090

ABSTRACT

Understanding the linear and nonlinear optical (NLO) responses of two-dimensional nanomaterials is essential to effectively utilize them in various optoelectronic applications. Here, few-layer MoS2and WS2nanoflakes with lateral size less than 200 nm were prepared by liquid-phase exfoliation, and their linear and NLO responses were studied simultaneously using experimental measurements and theoretical simulations. Finite-difference time-domain (FDTD) simulations confirmed the redshift in the excitonic transitions when the thickness was increased above 10 nm indicating the layer-number dependent bandgap of nanoflakes. WS2nanoflakes exhibited around 5 times higher absorption to scattering cross-section ratio than MoS2nanoflakes at various wavelengths. Open aperture Z scan analysis of both the MoS2and WS2nanoflakes using 532 nm nanosecond laser pulses reveals strong nonlinear absorption activity with effective nonlinear absorption coefficient (ßeff) of 120 cm GW-1and 180 cm GW-1, respectively, which was attributed to the combined contributions of ground, singlet excited and triplet excited state absorption. FDTD simulation results also showed the signature of strong absorption density of few layer nanoflakes which may be account for their excellent NLO characteristics. Optical limiting threshold values of MoS2and WS2nanoflakes were obtained as ∼1.96 J cm-2and 0.88 J cm-2, respectively, which are better than many of the reported values. Intensity dependent switching from saturable absorption (SA) to reverse SA was also observed for MoS2nanoflakes when the laser intensity increased from 0.14 to 0.27 GW cm-2. The present study provides valuable information to improve the selection of two-dimensional nanomaterials for the design of highly efficient linear and nonlinear optoelectronic devices.

7.
J Laryngol Otol ; 136(11): 1081-1086, 2022 Nov.
Article in English | MEDLINE | ID: mdl-35135641

ABSTRACT

OBJECTIVE: This study aimed to evaluate the long-term hearing outcomes in stapedotomy surgery using skeeter oto-drill and to assess safety in difficult situations. METHOD: A retrospective study was conducted with 944 patients who underwent 1007 stapedotomy procedures over 16 years, performed by a single surgeon using a trans-canal approach and a self-retaining ear canal retractor. Hearing thresholds were calculated over four frequencies. Air-bone conduction hearing thresholds were obtained at 1, 5 and 10 years post-operatively and compared to the pre-operative records. RESULTS: Out of 1007 operated ears with one year follow up, 98.61 per cent of cases showed a negligible air-bone gap of equal to or less than 5 dB, 1.19 per cent of cases showed an air-bone gap equal to or more than 5 dB but less than 10 dB, and only 0.2 per cent of cases showed an air-bone gap of more than 10 dB. CONCLUSION: In this study, using skeeter drill with a 0.6 mm diamond burr to make the fenestra was constant in all the cases and one of the safest techniques, showing persistent long-term hearing results.


Subject(s)
Otosclerosis , Stapes Surgery , Surgeons , Humans , Otosclerosis/surgery , Retrospective Studies , Ear Canal , Stapes Surgery/methods , Bone Conduction , Treatment Outcome , Audiometry, Pure-Tone
8.
Indian J Nucl Med ; 37(4): 370-372, 2022.
Article in English | MEDLINE | ID: mdl-36817201

ABSTRACT

High 18F-Fluorodeoxyglucose (18F-FDG) uptake in a cardiac mass is considered to be a marker of malignancy, but that is not always true. We here present such a case of incidentally detected 18F-FDG cardiac mass on staging positron emission tomography-computed tomography in a woman with head-and-neck cancer, confirmed to be myxoma on contrast-enhanced magnetic resonance imaging and subsequent histopathology.

9.
World J Nucl Med ; 20(3): 309-311, 2021.
Article in English | MEDLINE | ID: mdl-34703401

ABSTRACT

Seborrhoeic keratosis is a common benign skin tumor and can have a variable presentation. Irritated seborrhoeic keratosis can clinically mimic cutaneous malignancy and often warrant biopsy. 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography-computed tomography (PET-CT) can give false-positive results in many cutaneous pathologies. We present an interesting case of irritated seborrhoeic keratosis masquerading as skin cancer, clinically as well as on18F-FDG PET-CT.

10.
Nucl Med Rev Cent East Eur ; 24(2): 108-109, 2021.
Article in English | MEDLINE | ID: mdl-34382677

ABSTRACT

Double primary lung cancer (DPLC) is a rare occurrence of primaries of different histologies or the same histology in different lobes in absence of advanced nodal or distant metastasis. It could be synchronous or metachronous. They are frequently misdiagnosed as metastasis or recurrence. This study presents the staging [¹8F]Fluorodeoxyglucose positron emission tomography-computed tomography findings in a case of a 74-year-old man with DPLC of different histologies.


Subject(s)
Lung Neoplasms , Positron Emission Tomography Computed Tomography , Aged , Fluorodeoxyglucose F18 , Humans , Lung Neoplasms/diagnostic imaging , Male , Neoplasm Recurrence, Local , Neoplasm Staging , Positron-Emission Tomography , Radiopharmaceuticals
11.
Indian J Nucl Med ; 36(2): 173-178, 2021.
Article in English | MEDLINE | ID: mdl-34385789

ABSTRACT

Prosthetic valve endocarditis (PVE) is a sinister complication, with high morbidity and mortality. Diagnosis is conventionally based on modified Duke Criteria. 18F-Fluorodeoxyglucose (18F-FDG) positron emission tomography-computed tomography (PET-CT) has shown high accuracy in diagnosing PVE. Positive 18F-FDG uptake in prosthetic valves on PET-CT is now considered major criteria for diagnosis of PVE. We share our experience of 18F-FDG PET-CT imaging as a problem solving tool in a case of suspected PVE and review the relevant literature.

12.
Indian J Nucl Med ; 36(2): 203-204, 2021.
Article in English | MEDLINE | ID: mdl-34385796

ABSTRACT

Hyperfibrinolysis caused by abnormal over-activation of the fibrinolytic system can be associated with occult cancer. We present an interesting case of a 48-year-old man with paraneoplastic hyperfibrinolysis, where 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography-computed tomography (PET-CT) was able to detect occult prostate-specific antigen-negative metastatic prostate cancer as the underlying etiology. This shows that while 18F-FDG PET-CT has overall poor sensitivity for prostate cancer, it can be useful in certain clinical situations.

13.
Med Biol Eng Comput ; 59(7-8): 1495-1527, 2021 Aug.
Article in English | MEDLINE | ID: mdl-34184181

ABSTRACT

Accurate segmentation and delineation of the sub-tumor regions are very challenging tasks due to the nature of the tumor. Traditionally, convolutional neural networks (CNNs) have succeeded in achieving most promising performance for the segmentation of brain tumor; however, handcrafted features remain very important in identification of tumor's boundary regions accurately. The present work proposes a robust deep learning-based model with three different CNN architectures along with pre-defined handcrafted features for brain tumor segmentation, mainly to find out more prominent boundaries of the core and enhanced tumor regions. Generally, automatic CNN architecture does not use the pre-defined handcrafted features because it extracts the features automatically. In this present work, several pre-defined handcrafted features are computed from four MRI modalities (T2, FLAIR, T1c, and T1) with the help of additional handcrafted masks according to user interest and fed to the convolutional features (automatic features) to improve the overall performance of the proposed CNN model for tumor segmentation. Multi-pathway CNN is explored in this present work along with single-pathway CNN, which extracts simultaneously both local and global features to identify the accurate sub-regions of the tumor with the help of handcrafted features. The present work uses a cascaded CNN architecture, where the outcome of a CNN is considered as an additional input information to next subsequent CNNs. To extract the handcrafted features, convolutional operation was applied on the four MRI modalities with the help of several pre-defined masks to produce a predefined set of handcrafted features. The present work also investigates the usefulness of intensity normalization and data augmentation in pre-processing stage in order to handle the difficulties related to the imbalance of tumor labels. The proposed method is experimented on the BraST 2018 datasets and achieved promising results than the existing (currently published) methods with respect to different metrics such as specificity, sensitivity, and dice similarity coefficient (DSC) for complete, core, and enhanced tumor regions. Quantitatively, a notable gain is achieved around the boundaries of the sub-tumor regions using the proposed two-pathway CNN along with the handcrafted features. Graphical Abstract This data is mandatory. Please provide.


Subject(s)
Brain Neoplasms , Image Processing, Computer-Assisted , Brain Neoplasms/diagnostic imaging , Humans , Magnetic Resonance Imaging , Neural Networks, Computer
14.
Indian J Nucl Med ; 36(1): 43-45, 2021.
Article in English | MEDLINE | ID: mdl-34040295

ABSTRACT

Fever of unknown origin (FUO) is a convoluted clinical dilemma. It can be caused by infective, inflammatory, malignant, and other pathologies. The identification of etiopathogenesis is essential for instituting definitive management. 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography-computed tomography (PET-CT) is now an integral part of FUO management. We present the case of a 60-year-old female with autosomal dominant polycystic kidney disease (ADPKD), where the infected renal cyst was detected as the cause of FUO on18F-FDG PET-CT.

15.
Nanotechnology ; 32(26)2021 Apr 06.
Article in English | MEDLINE | ID: mdl-33524955

ABSTRACT

In this article, the synthesis of phase pure iron pyrite nanocubes (FeS2NCs) and their various effects on the charge carrier dynamics and photovoltaic performances of P3HT:PC71BM based hybrid bulk-heterojunction solar cells have been studied. The optimum doping concentration of FeS2NCs was found to be 0.3 wt%. For the optimally doped devices, the short-circuit current density was found to have improved from 5.47 to 7.99 mA cm-2leading to an overall cell efficiency improvement from 2.10% to 3.22% as compared to the undoped reference devices. The enhancement in photovoltaic performance is mainly attributed to the formation of localized energy states near the band edges leading to higher carrier generation rate by 72% whereas carrier dissociation probability is also increased by 13%. Urbach energy estimation reveals that the optimally doped devices have achieved a relatively balanced amount of localized states resulting in reduced non-radiative recombination. Such localized defect states formation with FeS2NCs doping was also found to have significant influence over the charge carrier dynamics of the active layer. Transient photocurrent and photovoltage studies revealed that FeS2NCs assist in faster carrier extraction by reducing the transport time from 1.4 to 0.6µs and by enhancing carrier recombination time from 51.7 to 78.9µs for the reference and optimum devices respectively. Such an unorthodox approach of defect state assisted efficiency improvement demonstrates the importance of simultaneously understanding the charge carrier dynamics and photovoltaic performance for rational device optimization, and opens new prospects for developing high-efficiency solution processable hybrid devices.

16.
Nucl Med Rev Cent East Eur ; 24(1): 31-32, 2021.
Article in English | MEDLINE | ID: mdl-33576483

ABSTRACT

Fever of Unknown Origin (FUO) is a vexing clinical problem. Diagnosis of aetiology is essential for definitive management. A wide array of infective, inflammatory, malignant and miscellaneous pathologies can cause FUO. Hybrid imaging with 18F-Fluorodeoxyglucose (18F-FDG) positron emission tomography-computed tomography (PET-CT) is now an integral part of FUO management because of its ability to demonstrate the cause in a large proportion of cases. The authors present the case of a 42-year-old male, where an infected fistula-in-ano was detected as the cause of FUO on 18F-FDG PET-CT.


Subject(s)
Fever of Unknown Origin/diagnostic imaging , Fluorodeoxyglucose F18 , Positron Emission Tomography Computed Tomography , Adult , Fever of Unknown Origin/complications , Fistula/complications , Fistula/microbiology , Humans , Male
17.
Clin Nucl Med ; 46(5): e266-e267, 2021 May 01.
Article in English | MEDLINE | ID: mdl-33315673

ABSTRACT

ABSTRACT: Primitive neuroectodermal tumor (PNET) is an aggressive small cell malignancy. Apart from the central nervous system, they can arise from peripheral sites as well. Ovarian PNETs are extremely rare neoplasms. We here present a case of childhood ovarian PNET, where 18F-FDG PET/CT was efficiently used for staging and response evaluation.


Subject(s)
Fluorodeoxyglucose F18 , Neuroectodermal Tumors, Primitive/diagnostic imaging , Neuroectodermal Tumors, Primitive/pathology , Ovarian Neoplasms/diagnostic imaging , Ovarian Neoplasms/pathology , Positron Emission Tomography Computed Tomography , Child , Female , Humans , Neoplasm Staging , Neuroectodermal Tumors, Primitive/therapy , Ovarian Neoplasms/therapy , Treatment Outcome
18.
Clin Nucl Med ; 46(3): e141-e150, 2021 03 01.
Article in English | MEDLINE | ID: mdl-33351507

ABSTRACT

PURPOSE: Fibroblast activation protein (FAP) is a cell membrane-bound serine peptidase, overexpressed in cancer-associated fibroblasts and activated fibroblasts at wound healing/inflammatory sites. Recently, molecular PET/CT imaging with radiolabeled FAP inhibitor (FAPI) has been evaluated in different diseases. We aimed to assess its potential role based on the available literature. PATIENTS AND METHODS: We conducted a comprehensive review of the available preclinical and clinical data on FAPI PET/CT in an attempt to summarize its current status and potential future role. Based on that, we have discussed the pathophysiology behind FAP-based imaging, followed by a discussion of FAPI radiopharmaceuticals including their synthesis, biodistribution, and dosimetry. Next, we have discussed studies evaluating FAPI PET/CT in different oncological and nononcological pathologies. The potential of FAPI PET/CT in theranostics has also been addressed. RESULTS: Based on the early scientific evidence available, including preclinical and clinical studies, FAPI PET/CT seems to be a promising molecular imaging tool, especially in oncology. It can be used for imaging different types of cancers and outperforms 18F-FDG PET/CT in some of these. Its potential as a theranostic tool warrants special attention. CONCLUSIONS: Fibroblast activation protein inhibitor PET/CT has the potential to emerge as a powerful molecular imaging tool in the future. However, as of yet, the available evidence is limited, warranting further research and trials in this field.


Subject(s)
Gelatinases/antagonists & inhibitors , Membrane Proteins/antagonists & inhibitors , Positron Emission Tomography Computed Tomography/methods , Serine Proteinase Inhibitors/pharmacology , Endopeptidases , Humans , Neoplasms/diagnostic imaging , Serine Endopeptidases
19.
Clin Nucl Med ; 46(4): e236-e237, 2021 Apr 01.
Article in English | MEDLINE | ID: mdl-32956131

ABSTRACT

ABSTRACT: Testicular metastasis is rare, with prostate cancer followed by lung cancer being the commonest primary site. Usually these are incidentally detected and are rarely symptomatic. We present an unusual case of adenocarcinoma lung, presenting initially with right testicular pain. Further workup with 18F-FDG PET/CT demonstrated primary malignancy of the left lung with nodal and right testicular metastasis.


Subject(s)
Adenocarcinoma of Lung/pathology , Cancer Pain/complications , Fluorodeoxyglucose F18 , Positron Emission Tomography Computed Tomography , Testicular Neoplasms/complications , Testicular Neoplasms/secondary , Humans , Male
20.
Clin Nucl Med ; 46(1): 76-77, 2021 Jan.
Article in English | MEDLINE | ID: mdl-33065622

ABSTRACT

F-FDG PET/CT is now an integral part of management of high-grade B-cell lymphoma. It is used for staging, response evaluation, restaging, and surveillance. Although high-grade B-cell lymphoma most commonly presents with involvement of the lymph nodes, spleen, liver, and bone marrow, chest wall involvement is very rare. We present the staging F-FDG PET/CT findings in a case of an 82-year-old woman with double expressor high-grade B-cell lymphoma of isolated presternal anterior chest wall mass.


Subject(s)
Fluorodeoxyglucose F18 , Lymphoma, B-Cell/diagnostic imaging , Lymphoma, B-Cell/pathology , Positron Emission Tomography Computed Tomography , Thoracic Wall/pathology , Aged, 80 and over , Female , Humans , Neoplasm Grading , Neoplasm Staging , Thoracic Wall/diagnostic imaging
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