Papers by esmaeil gharepapagh
Iranian South Medical Journal
Background: The present study aims to assess the impact of various image reconstruction methods i... more Background: The present study aims to assess the impact of various image reconstruction methods in 18 F-FDG PET/CT imaging on the quantification performance of the proposed technique for joint compensation of respiratory motion and partial volume effects (PVEs) in patients with non-small cell lung cancer. Materials and Methods: An image-based deconvolution technique was proposed, incorporating wavelet-based denoising within the Lucy-Richardson algorithm to jointly compensate for PVEs and respiratory motion. The method was evaluated using data from 15 patients with 60 non-small cell lung cancer. In these patients, the lesions were classified by size, location and Signal-to-Background Ratios (SBR). In each study, PET images were reconstructed using four different methods: OSEM with timeof-flight (TOF) information, OSEM with point spread function modelling (PSF), OSEM with both TOF and PSF (TOFPSF), and OSEM without PSF or TOF (OSEM). The Contrast to Noise Ratio (CNR), Coefficient of Variation (COV) and Standardized Uptake Values (SUV) were measured within the lesions and compared to images that were not processed using the joint-compensation technique. Furthermore, variabilities arising due to the choice of the reconstruction methods were assessed. Results: Processing the images using the proposed technique yielded significantly higher CNR and SUV, particularly in small spheres, for all the reconstruction methods and all the SBRs (P<0.05). Overall, the incorporation of wavelet-based denoising within the Lucy Richardson algorithm improved COV and CNR in all the cases (P<0.05(. In the patient data, the median values of the relative difference (%) of CNR for the compensated images in comparison to the uncompensated images were 40.9%, 41.2%, 45.3% and 40.8% for OSEM, PSF, TOF, and TOFPSF, respectively, in the small lesions (equivalent diameter <15 mm), 31.0%, 25.9%, 34.1% and 28.2% in the average-sized lesions (equivalent diameter<30 mm), 35.7%, 33.7%, 37.8% and 33.2% in the lesions in the lower lung lobes, 33.5%, 31.0%, 35.7% and 30.6% in the lesions in the upper lung lobes, 39.7%, 37.9%, 45.1% and 39.0% in the low-SBR lesions and 28.8%, 27.8%, 34.8% and 25.7% in the high-SBR lesions. Changes in motion amplitude, target size and SBRs in the patient data resulted in significant inter-method differences in the images reconstructed using different methods. Specifically, in a small target size, quantitative accuracy was highly dependent on the choice of the reconstruction method. Conclusion: Our results showed that joint compensation, and incorporation of wavelet-based denoising, yielded improved quantification from PET images. Quantitative accuracy is greatly affected by SBR, lesion size, breathing motion amplitude, as well as the choice of the reconstruction protocols. Overall, the choice of reconstruction algorithm combined with compensation method needs to be determined carefully.
World Journal of Nuclear Medicine
Transurethral lithotripsy (TUL) procedure via ureteroscopy as an invasive method for nephrolithia... more Transurethral lithotripsy (TUL) procedure via ureteroscopy as an invasive method for nephrolithiasis treatment would lead to urinary tract injuries. In this reported case, the procedure caused severe damage to the left ureter that was detected by 99mTc-diethylenetriaminepentaacetic acid (99mTc-DTPA) scan. Generally, the TUL procedure through the ureter scope is used to manage urinary tract stones. In this case, the TUL was performed on a patient with a history of nephrolithiasis. Following that, she was accompanied with abdominal pain and discomfort, so 99mTc-DTPA scintigraphy was performed to evaluate the urinary tract system. The scintigraphy showed a severe damage to the left ureter that finally resulted in autotransplantation. The control 99mTc-DTPA scintigraphy performed 3 weeks after revealed no visible urinary leakage. In this case, the 99mTc-DTPA scan prevented the patient from dangerous complications. So, 99mTc-DTPA scan could be performed after TUL and ureteroscopy to dete...
The Journal of Alternative and Complementary Medicine, 2009
Introduction: Reiki is an ancient form of Japanese healing. While this healing method is widely u... more Introduction: Reiki is an ancient form of Japanese healing. While this healing method is widely used for a variety of psychologic and physical symptoms, evidence of its effectiveness is scarce and conflicting. The purpose of this systematic review was to try to evaluate whether Reiki produces a significant treatment effect. Methods: Studies were identified using an electronic search of Medline, EMBASE, Cochrane Library, and Google Scholar. Quality of reporting was evaluated using a modified CONSORT Criteria for Herbal Interventions, while methodological quality was assessed using the Jadad Quality score. Data extraction: Two (2) researchers selected articles based on the following features: placebo or other adequate control, clinical investigation on humans, intervention using a Reiki practitioner, and published in English. They independently extracted data on study design, inclusion criteria, type of control, sample size, result, and nature of outcome measures. Results: The modified CONSORT Criteria indicated that all 12 trials meeting the inclusion criteria were lacking in at least one of the three key areas of randomization, blinding, and accountability of all patients, indicating a low quality of reporting. Nine (9) of the 12 trials detected a significant therapeutic effect of the Reiki intervention; however, using the Jadad Quality score, 11 of the 12 studies ranked ''poor.'' Conclusions: The serious methodological and reporting limitations of limited existing Reiki studies preclude a definitive conclusion on its effectiveness. High-quality randomized controlled trials are needed to address the effectiveness of Reiki over placebo.
iranian journal of nuclear medicine, 2018
Introduction: Myocardial perfusion SPECTby 99mTc-Sestamibi and 99mTc-Tetrofosmin radiopharmaceuti... more Introduction: Myocardial perfusion SPECTby 99mTc-Sestamibi and 99mTc-Tetrofosmin radiopharmaceuticals usually presents a false significant increase in the radiotracer uptake in the inferior myocardium due to the uptake in organs such as liver, bowel, stomach and biliary system. The present study evaluated a suitable Slit angle for differentiating extra-cardiac activities by Slit Slat collimation. Methods: The Siemens E.CAM gamma camera equipped with a Low Energy High Resolution (LEHR) collimator was simulated with the Simulating Medical Imaging Nuclear Detectors (SIMIND) Monte Carlo program. Following the verification of the simulation, a Slit Slat collimator was simulated for SPECT imaging of a NURBS-based Cardiac Torso (NCAT) phantom with different Slit angels ranged from 0 to 30 degrees. The reconstructed images were qualitatively assessed with blinded observer method by three nuclear medicine specialists. Results:The improved differentiation of the bowel activity from the cardia...
Medical journal of Tabriz University of Medical Sciences and Health Services, 2016
Background & Objectives: The complexity of determining presence and distribution of bone metastas... more Background & Objectives: The complexity of determining presence and distribution of bone metastases is due to morphological, time-related and location-related variations. Different imaging modalities have been used in this regard, with benefits and shortcomings of each. This study aims to study the correlation between isotope scanning, magnetic resonance imaging (MRI), and computer tomography (CT) findings and bone metastases. Material and Methods: Of 152 patients with cancer, 46 patients with bone metastases were investigated within 10 months in Imam Reza educational Center in a cross-sectional study. Conformity and nonconformity between the findings obtained by radioisotope scanning, MRI and CT scanning with the presence or absence of bone metastases were investigated. Results: 20 men and 26 women with the mean age of 61.02±12.63 (range 35-84) years were studied. Radioisotope scanning yielded positive results for bone metastases in 42 out of 46 patients (91.3%), MRI was positive i...
Cancer Cell International
Glioblastoma, WHO grade IV astrocytoma, is the most aggressive type of brain tumors. These cancer... more Glioblastoma, WHO grade IV astrocytoma, is the most aggressive type of brain tumors. These cancerous cells have a rapid growth rate, tendency to penetrate vital brain structures, molecular heterogeneity, etc. and this cancer is associated with a poor prognosis and low survival rate. Due to the resistance of glioblastoma cells to conventional therapeutic modalities (such as radiation therapy and chemotherapy) as well as the adverse effects of these modalities, the researchers have attempted to discover an appropriate alternative or adjuvant treatment for glioblastoma. Resveratrol, as an herbal and natural polyphenolic compound, has anti-tumoral property and has shown to be effective in GBM treatment. Resveratrol exerts its anti-tumoral effect through various mechanisms such as regulation of cell cycle progression and cell proliferation, autophagy, oxidant system, apoptosis pathways, and so on. Resveratrol in combination with radiation therapy and chemotherapy has also been used. In t...
Pharmaceutical Sciences
UTI (urinary tract infection) is a leading case of renal scarring. Most of nephrons are found in ... more UTI (urinary tract infection) is a leading case of renal scarring. Most of nephrons are found in kidney cortex, so it is important for early diagnosis of scarring. In this study, we investigated if scarring affects GFR (glomerular filtration rate) and serum level of creatinine through dual multipurpose 99mTc-GH (99mTc-Glucoheptonate) scintigraphy in patients with UTI. Methods: During this study 21 patients with UTI were studied by 99mTc-GH scan. For performing scintigraphy, the patient was injected by 370-555 MBq of 99mTc-GH and studied through two steps including dynamic (immediately after injection) and static (2-3h after injection) phases. The results were evaluated by appropriate analytical methods. Moreover, five patients were studied by both 99mTc-DMSA/GH (99mTc-dimercaptosuccinic acid and 99mTc-Glucoheptonate) to show 99mTc-GH scan is beneficial for detection of additional problems. Results: The results showed that there is an association between right/left kidney scarring an...
New Journal of Chemistry
Preparation, dosimetry and biodistribution study of 99mTc-(N-GQDs) as multipurpose nanoparticles.
Medical Journal of The Islamic Republic of Iran
Background: Cancer antigen 15-3 (CA15-3) is a common tumor marker and the serum level of this tum... more Background: Cancer antigen 15-3 (CA15-3) is a common tumor marker and the serum level of this tumor marker is evaluated during the treatment period (periodically) in breast cancer patients. Assuming that the elevated serum levels of this tumor marker can be a potential risk, this study was conducted to determine the association between CA15-3 and bone metastasis and CA15-3 and metastasis spreading rate in breast cancer patients. Methods: In this study, 70 women with the mean of age 51.69 (10.77) years who suffered from breast cancer were studied by performing both bone scintigraphy and measuring CA15-3. Independent sample t test, Fisher's exact test, Spearman rho correlation, and logistic regression were used for inferential section. To determine the new cross section, Roc curve and coordinates of the curve were applied. Also, significance level was set at p<0.05. Data were analyzed by SPSS 16 software. Results: There was no difference among patients in age (p=0.123). Assuming the CA15-3 (≥ 30 U/mL) as a potential risk, there was no association between CA15-3 and bone metastases (p=0.167). Based on Spearman's rank correlation coefficient, there was no significant correlation between CA15-3 and metastasis spreading rate (r=-0.07, p=0.851). Based on ROC curve and Youden's J statistic index, the new cutoff was pointed at CA15-3 ≥21.76 Unit/mL, which correlated with bone metastases (p<0.001). Conclusion: This study found a decreased cutoff point at CA15-3 (≥21.76) against 30 (routine value). Based on CA15-3 (≥21.76), there was a correlation between bone metastases and CA15-3, indicating that patients with CA15-3 (≥21.76) were most likely to experience bone metastases.
Journal of Radioanalytical and Nuclear Chemistry
Tropical Journal of Pharmaceutical Research
Purpose: To compare the effects of aspirin and captopril on glomerular filtration rate (GFR) duri... more Purpose: To compare the effects of aspirin and captopril on glomerular filtration rate (GFR) during renal perfusion scintigraphy in cats after experimentally-induced unilateral renal-artery stenosis. Methods: Twenty mixed-breed adult cats weighing 3-4 kg were used. After conducting renal scintigraphy operations, their GFRs were measured by the method of Gate. Four days later, renovascular hypertension was induced through renal-artery stenosis by clipping half of the left renalarteries. Renal scintigraphy was conducted after four days. After confirming the presence of hypertension, the cats were divided into two groups of 10 animals each (aspirin and captopril groups, respectively). The drugs were administered orally to the groups. One hour later, scintigraphic operations were repeated under anaesthesia after injecting 2 mCi of the radiopharmaceutical, technetium-99m diethylene triamine pentaacetic acid (99mTc-DTPA), via the femoral vein as a bolus dose. In all groups, regions of interest (ROIs) were drawn and GFRs were measured by Gate method. Results: Mean total GFR (both right and left kidneys) in operated animals treated with captopril was 5.459 ml/min while the mean value for the left kidney and right kidneys were 1.585 and 3.874 ml/min, respectively. In operated animals treated with aspirin, mean total GFR was 5.440 ml/min, while the values for the left kidney and right kidneys were 1.567 and 3.866 ml/min, respectively. Conclusion: These results indicate that aspirin has similar reduction effect on GFRs and similar shape of renograms as captopril in cat renovascular hypertension scintigraphy. Thus, aspirin is a suitable substitute for captopril in the diagnosis of renovascular hypertension in renal scintigraphy.
Iranian Journal of Nuclear Medicine, Dec 4, 1994
World Journal of Nuclear Medicine, 2015
The collimator in single-photon emission computed tomography (SPECT) is a critical component of t... more The collimator in single-photon emission computed tomography (SPECT) is a critical component of the imaging system and plays an impressive role in the imaging quality. In this study, the effect of the collimator material on the radioisotopic image and its functional parameters was studied. The simulating medical imaging nuclear detectors (SIMIND) Monte Carlo program was used to simulate a Siemens E.CAM SPECT (Siemens Medical Solutions, Erlangen, Germany) system equipped with a low-energy high-resolution (LEHR) collimator. The simulation and experimental data from the SPECT imaging modality using 99m Tc were obtained on a point source and Jaszczak phantom. Seventeen high atomic number materials were considered as LEHR collimator materials. In order to determine the effect of the collimator material on the image and functional parameters, the energy resolution, spatial resolution, contrast, and collimator characteristics parameters such as septal penetration and scatter-to-primary ratio were investigated. Energy spectra profiles, full width at half maximums (FWHMs) (mm) of the point spread function (PSF) curves, system sensitivity, and contrast of cold spheres of the Jaszczak phantom for the simulated and experiment systems have acceptability superimposed. The results of FWHM and energy resolution for the 17 collimators showed that the collimator made of 98% lead and 2% antimony could provide the best FWHM and energy resolution, 7.68 mm and 9.87%, respectively. The LEHR collimator with 98% lead and 2% antimony offers the best resolution and contrast when compared to other high atomic number metals and alloys.
Applied Radiation and Isotopes, 2016
World Journal of Nuclear Medicine, 2015
The collimator in single-photon emission computed tomography (SPECT) is a critical component of t... more The collimator in single-photon emission computed tomography (SPECT) is a critical component of the imaging system and plays an impressive role in the imaging quality. In this study, the effect of the collimator material on the radioisotopic image and its functional parameters was studied. The simulating medical imaging nuclear detectors (SIMIND) Monte Carlo program was used to simulate a Siemens E.CAM SPECT (Siemens Medical Solutions, Erlangen, Germany) system equipped with a low-energy high-resolution (LEHR) collimator. The simulation and experimental data from the SPECT imaging modality using 99m Tc were obtained on a point source and Jaszczak phantom. Seventeen high atomic number materials were considered as LEHR collimator materials. In order to determine the effect of the collimator material on the image and functional parameters, the energy resolution, spatial resolution, contrast, and collimator characteristics parameters such as septal penetration and scatter-to-primary ratio were investigated. Energy spectra profiles, full width at half maximums (FWHMs) (mm) of the point spread function (PSF) curves, system sensitivity, and contrast of cold spheres of the Jaszczak phantom for the simulated and experiment systems have acceptability superimposed. The results of FWHM and energy resolution for the 17 collimators showed that the collimator made of 98% lead and 2% antimony could provide the best FWHM and energy resolution, 7.68 mm and 9.87%, respectively. The LEHR collimator with 98% lead and 2% antimony offers the best resolution and contrast when compared to other high atomic number metals and alloys.
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Papers by esmaeil gharepapagh