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Showing 4 results for Gharepapagh
Impact of Various Image Reconstruction Methods on Joint Compensation of Respiratory Motion and Partial Volume Effects in Whole-Body 18F-FDG PET/CT Imaging: Patients with Non-Small Cell Lung Cancer
Pardis Ghafarian , Sahar Rezaei , Esmaeil Gharepapagh , Saeid Sarkar , Mohammad Reza Ay ,
Volume 25, Issue 4 (Iranian South Medical Journal 2022)
Abstract
Background: The present study aims to assess the impact of various image reconstruction methods in 18F-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 time- of-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.

Evaluation of Radioiodine Therapy in the Refractory Hyperthyroidism
Samira Rahimlou , Sahar Rezaei , Noushin Milanchian , Esmaeil Gharepapagh ,
Volume 25, Issue 5 (Iranian South Medical Journal 2023)
Abstract
Background: Thyrotoxicosis is a clinical state with potentially multiple etiologies, clinical presentations, and treatments. Thyrotoxicosis is a clinical condition that results from inappropriate function of thyroid hormone in the body tissues. During the early 1950s, radioactive iodine was used as a definitive treatment method. During the last two decades, radioactive iodine has been recognized as an effective treatment for thyrotoxicosis because of its simplicity, repeatability, inexpensiveness, and low recurrence rate.
Method and materials: One hundred patients with refractory hyperthyroidism (40 men and 60 women) were enrolled according to the inclusion criteria from 2017 to 2021. The data was extracted considering the ethical principles of examining patients' medical files. Patients' information including age, gender, type of hyperthyroidism, serum levels of TSH, and free T4 were collected before and 2, 6, and 12 months after treatment.
Results: The results showed that 61% of the patients had toxic nodular goiter and 39% had diffuse toxic goiter. The mean ± standard deviation values of patient’s TSH and free T4 before treatment were 0.91±0.07 and 2.9±0.8, respectively. Six months after treatment, 49% of the patients became hypothyroid. Also 43% revealed euthyroid state and 5% showed no response (recurrence). One year follow-up of these patients after repetitive radioiodine therapy showed 6% hypothyroidism and 2% euthyroidism.
Conclusion: Our results indicated that radioactive iodine therapy is an effective and definitive treatment for patients with refractory hyperthyroidism.

Evaluation of D-dimer Test Correlation with Lung Perfusion-Ventilation Scan in Patients Suspected Pulmonary Embolism
Mahkameh Nasirian , Esmaeil Gharepapagh , Ashraf Fakhari , Mohammad Reza Ghaffari Bavil , Neda Gilani ,
Volume 25, Issue 6 (Iranian South Medical Journal 2023)
Abstract
Background: Pulmonary embolism refers to the blockage of pulmonary arteries or a condition in which blood flow to the lungs is interrupted by a blood or fat clot. This phenomenon eventually leads to ische-mia and respiratory failure, which, without diagnosis and treatment, will result in the lungs losing their efficiency. Along with other diagnostic methods such as CT angiography and the D-dimer test, nuclear medicine scans are very helpful in embolism cases as a non-invasive diagnostic method. Specifically, the purpose of this study is to compare D-dimer tests with perfusion-ventilation scans in patients suspected of having pulmonary embo-lisms.
Materials and Methods: According to the Nuclear Medicine Association protocol, 112 patients underwent lung scintigraphy (V/Q) with SPECT imaging systems (Siemens Ecam models). D-dimer tests were admin-istered to all patients before the scan, at the discretion of the attending physician. Data were collected and the distribution of embolism probability (normal, low, high, and intermediate probabilities) among refer-ring patients was evaluated using Modified PIOPED criteria. In addition, D-dimer test values were evalu-ated and compared with possible pulmonary embolism diagnoses and clinical conditions (age, surgery, pregnancy, and underlying diseases).
Results: This study showed that 26.2% of patients with normal V/Q and 15.4% of patients with V/Q with a low probability of embolism had positive D-dimer tests. Accordingly, patients with intermediate and high probabilities of pulmonary embolism had 33.3% and 50% positive D-dimer tests, respectively. Addi-tionally, the results of the studies showed that the correlation with D-dimers negative (positive) in individ-uals less than or equal to 60 years, who had a normal scan and a low, intermediate, or high embolism probability was 74% (26%), 92.3% (7.7%), 83.3% (16.7%), and 0% (100%) respectively. Over 60-year-olds showed the same correlation with 73.3% (26.7%), 76.9% (23.1%), 55.6% (44.4%), and 100% (0%) respectively.
Conclusion: A higher D-dimer level does not correspond to a positive pulmonary embolism finding on V/Q scans. Furthermore, according to the obtained results, high D-dimer values are significantly correlated with V/Q scan findings in patients less than or equal to 60 years old, but there is no significant statistical correlation between high D-dimer values in patients with surgery, underlying diseases and pregnant wom-en with V/Q scan findings
 
Prevalence and Intensity of Vesicoureteral Reflux in Children with UTI based on Direct Radionuclide Cystography
Esmaeil Gharepapagh , Fariba Aryanpour , Ashraf Fakhari , Shahram Dabiri Oskui ,
Volume 26, Issue 4 (Iranian South Medical Journal 2024)
Abstract
Background: Urinary tract infection (UTI) is considered one of the most common types of infection in children. Vesicoureteral reflux (VUR) is one of the major risk factors of UTI leading to renal scarring. Cur-rently, two diagnostic methods are used for the evaluation of VUR, including voiding cystourethrography (VCUG) and radionuclide cystourethrography (DRNC). The present study examines the prevalence and intensity of VUR using direct radionuclide cystography (DRNC) in children referred to the Nuclear Medi-cine Division of Imam Reza Hospital in Tabriz, Iran.
Materials and Methods: The referred patients were studied by DRNC in filling, post filling, voiding and post voiding phases if there was confirmed VUR or not. Furthermore, VCUG, sonography and urine cul-ture had been performed for all the patients prior to our investigation. Both dynamic and static imaging were performed from the bladder, ureters and kidneys. The results were studied by a nuclear medicine physician to assess VUR and grade it. 
Results: The prevalence of VUR among all 300 patients was calculated to be 29.3%. Most of the cases of VUR were unilateral (63.6%), among which involvement of the left kidney (42%) was significantly more frequent (p=0.022). The most common grade in the cases with unilateral involvement was grade B, and in those with bilateral involvement, grade C. The highest frequency of VUR was observed in the age group below 1 year (10%, n=30), followed by 1-4 years and 5-8 years, each with the frequency of 8.67% (n=26).  There was no significant difference in terms of frequency of VUR based on age (p=0.198).
Conclusion: Our study showed that there is no significant association between VUR and urine culture results, but there is significant association between sonography/clinical findings and VUR. Moreover, the results demonstrated that DRNC is more sensitive than VCUG in the detection of VUR.

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