Medical Imaging Technology تكنولوجيا التصوير الطبي
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- ItemMeasurement of liver fat concentration using dual-source dual-energy computed tomography(Al-Quds University, 2024-08-01) Mahmoud Maher Mohammad Fakhoury; محمود ماهر محمد فاخوريThe increase in NAFLD prevalence in the Mediterranean region, which is closely associated with diet, obesity, and metabolic syndrome, justifies research about assessing liver fat accumulation and evaluating liver fat fraction using dual-source DECT. This research outlines how DECT can be used as a safe and noninvasive alternative to liver biopsy, the current method for measuring liver fat content. Liver biopsy is not only the gold standard but also an invasive procedure that is not practical for repeated monitoring. Five portions of fresh cow liver samples were obtained, minced, and supplemented with different amounts of melted sheep fat and iodinated contrast medium (OmnipaqueTM 300) to simulate different fat concentrations. Data were acquired using a Siemens SOMATOM Force dual-source dual-energy computed tomography (DECT) scanner with Siemens Healthineers Syngo.via using mixed image analysis and the Liver Virtual Non-Contrast (VNC) application on a VB60 workstation for fat fraction quantification. The results showed a good correlation between the actual fat added to samples and the fat fraction percentages calculated using the DECT software. For example, when we added 5g of fat (2.4% of the total sample's weight), we obtained a 3% fat fraction, and when we inserted 20g of fat (9% of the total sample's weight), we obtained a 10% fat fraction. The study confirmed a reliable quantification of liver fat content with DECT, with high specificity and accuracy. These findings indicate that DECT may serve as an important clinical tool for the early diagnosis and monitoring of NAFLD, facilitating a noninvasive and cost-effective alternative to MRI and liver biopsy. They also indicate the important role of DECT in the evaluation and follow-up of liver health, especially in regions endemic to NAFLD, where there may be an increased liver donation pool. Future studies utilizing larger sample sizes and cross-modality comparisons are needed to improve the trustworthiness and clinical relevance of these findings.
- ItemCharacterization of two variants in OSTM1 gene inosteopetrosis-affected Palestinian families.(Al-Quds University, 2025-01-15) Maram Ali Shawkat Eid; مرام علي عيدBackground: Osteopetrosis is a rare genetic disorder characterized by increased bone density and brittle bones. Most cases result from mutations affecting lysosome-related organelle genes. One of the genes associated with osteopetrosis is the OSTM1 gene. Mutations in OSTM1 gene are linked to severe forms of the disease. Whole Exome Sequencing (WES) test was conducted on a group of affected Palestinian families, revealing two new variants c.365T>A (p.Val122Asp) and c.108C>T (p.Gly36Gly) in the OSTM1 gene. To our knowledge, these two variants have not been previously reported as pathogenic. Therefore, the study aims to determine their contribution to osteopetrosis. Methods: In order to evaluate the pathogenicity of these two genetic variants, whole blood samples were collected from each family member of the inflicted families. DNA and RNA were extracted from each sample. Variant segregation was performed following Sanger sequencing on the obtained samples from the affected volunteers and their extended families’ members. For the c.108 C>T (p.Gly36Gly) variant, which is hypothesized to create a donor splicing site, analysis was undertaken to look for splicing events that could result from the indicated variant. Primers flanking exons one and two were used to determine whether this variant results in abnormal splice variants of the OSTM1 gene. Results: Segregation of the two variants was assessed by examining their inheritance in 36 participants. The results revealed that unaffected individuals possess both variants either in a heterozygous or wild-type genotype, while affected individuals are homozygous for both variants, indicating a recessive inheritance pattern. RNA analysis of the c.108 C>T (p.Gly36Gly) variant in the OSTM1 gene was also performed. The findings demonstrated that this variant does not affect splicing, contrary to claims made in a 2013 case report by Mahmoud et al., suggesting that the variant might create a donor splice site. This also goes against the predictions made by splicing prediction tools, indicating that the c.108 C>T (p.Gly36Gly) variant could potentially function as a splice site. Conclusion: This study provided an opportunity to uncover the genetic variant responsible for the disease in the included families. Our results indicate that the variant c.365T>A (p.Val122Asp) segregates well between affected and unaffected family members, however, c.108C>T (p.Gly36Gly) variant does not affect splicing and thus seems to be a benign or neutral variant. This knowledge can help identify those at risk and provide preventative interventions, improving patient counselling and raising awareness about the importance of premarital screening for the pathogenic variant of the OSTM1 gene.
- ItemEvaluation of Organs Absorbed Doses, effective dosesand Cancer risk Following Chest HRCT Scan for COVID-19 Patients(Al-Quds University, 2024-05-24) Hala Yousef Hussein Ahmad Dar-Rabee; هاله يوسف حسين احمد دار ربيعCT imaging is an effective modality for diagnosing a wide range of medical conditions. CT outperforms x-rays in terms of 3D image generation and soft tissue visualization. CT imaging of the lungs is an important diagnostic tool in the fight against pneumonia. The use of the HRCT imaging protocol for the chest has increased during the COVID-19 pandemic. It is possible to use CT scans for both diagnostic and screening purposes. Radiation risk must be considered, and the dosimetric effects of chest HRCT must be assessed. CT imaging could assist with the early detection of COVID-19-related interstitial pneumonia. There is no agreement on the use of CT for diagnosis due to the first stage of the disease can be negative. So, this study aims to evaluate the dosimetric impact of HRCT of the chest for COVID-19 Patients. The mean organ and effective doses will be evaluated. Also, estimation of radiation cancer risk in (lung, stomach, colon, thyroid, and breast) associated with these exposures according to the Biological Effects of Ionizing Radiations (BEIR) VII report. The study's goal was achieved through the use of quantitative retrospective cohort analysis. The study population consists of 49 adult patients (31 males and 17 females), aged 18 to 89 years, who underwent HRCT during the period between April 26th, 2020, and March 20th, 2021. Data was collected using a local picture archiving and communication system (PACS), including patient demographics and anthropometrics, as well as dose descriptive information (CTDIv and DLP). The effective dose was calculated using two methods: first, using the tissue conversion coefficient (k) for the chest CT, and second, using the VirtualDose™ CT software, which also calculates the organ absorbed dose. The software is based on a large database of organ doses generated via Monte Carlo (MC) simulations using a library of 25 anatomically realistic phantoms. Then The life time attributable risk (LAR) of developing cancer in a specific organ (T) was determined by risk coefficients obtained from Biological Effects of Ionizing Radiations (BEIR) VII report. Each dosimetric parameter is defined by its mean, median, standard deviation, and 75th percentile. We used the MV for comparing our results with previously reported values. The mean value of equivalent doses and the cancer risk probability for organs have been established for either or both gender groups. Spearman’s rank-order test was used to test for correlations between, DLP\BMI, EDDLP, and EDMC. The significance level was defined as p < 0.05. The results of the study revealed that the average calculated effective dose for total population 9.7 mSv, and the average effective dose estimated by virtual dose CT software was 13.47 mSv, with female average dose higher than male with a value of 14.75 and 12.7 mSv respectively. The result showed a decreased effective dose for patients with increased patient BMI while increased with increased DLP. Females showed a higher organs dose than males for all organs as well as cancer risk except for colon, the highest risk were found in lungs for both gender as it 51.6 per 100.000 for females and 21.8 per 100.000 per males.it was concluded that the current chest HRCT protocol result in significant radiation doses to the patients compared to reported in previous studies
- ItemA Comparative Study of Six Software Tools Used for Estimating Fetal Radiation Dose from CT Examinations(Al-Quds University, 2024-11-04) Huda Husni Mahmoud Nasser; هدى حسني محمود ناصرThe assessment of fetal radiation dose during computed tomography (CT) examinations is crucial for ensuring the safety of the pregnant women and their fetuses. This study aimed to perform a comparative analysis of six MC-based software tools (VirtualDose CT, FetalDose.org, CODE, Waza-ari, ImPACT, and CT-Expo) for fetal dose estimation in various CT examinations, assessing their reliability and performance. The analysis involved estimating fetal radiation doses for pregnant women in our sample set using these tools. The six software tools were used to estimate fetal radiation doses for twenty-six pregnant participants undergoing twenty-seven different CT examinations, including head, cervical spine, chest, abdomen-pelvis, lumbar spine, and ankle scans. Single measures and average measures Intraclass Correlation Coefficient (ICC) values at 95% Confidence Interval (CI) were calculated, to assess the reliability of the six software tools together, and the pairs of software tools separately as well. Bland-Altman plots were also utilized to assess the agreement between some pairs of software tools. A comparative analysis for the six software tools’ performance in estimating fetal dose from CT examinations was also conducted. Total performance score was calculated for each tool based on the established criteria in this study, which are considered critical in performing dose estimates to fetus, including availability of pregnant phantoms, required inputs, availability of CT procedures, availability of CT scanner models, details of resulting fetal and maternal doses, number of available phantoms, cost, ease of use, and compatibility with mobile systems. The resulting fetal dose estimates were all within the ICRP-recommended threshold for deterministic effects, specifically below 100 milligray (mGy). Average measures ICC value for the six software tools was found to be 0.96 (95% CI: 0.91 – 0.98), indicating excellent reliability, whereas single measures ICC value for the six software tools was found to be 0.80 (95% CI: 0.63 – 0.90), indicating moderate to excellent reliability of an individual software tool with the others. VirtualDose CT and FetalDose.org showed the highest single measures ICC value across all pairs of software tools at 0.98 (95% CI: 0.96 – 0.99), indicating excellent reliability of both tools. Whereas CODE software showed the lowest single measures ICC values with all other software tools, indicating a low reliability of this software tool. Bland-Altman plot showed a mean difference of 0.79 for VirtualDose CT and FetalDose.org software tools, with limits of agreement ranged from – 2.45 to 4.03, indicating a good agreement between both tools, and confirming their reliability as well. For the comparative analysis of the software tools’ performance in calculating fetal dose from CT examinations, VirtualDose CT was identified as the best performer according to the predefined criteria evaluated in this study with a total performance score of 485.25. Ultimately, VirtualDose CT, with its superior performance and high reliability, was recommended as a standout tool for fetal dose estimates from CT examinations.
- ItemEvaluation of the Application of Orthopedic Metal Artifact Reduction and Iterative Reconstruction Algorithms in CT Imaging of Hip Prostheses(Al-Quds University, 2021-05-28) Omarah Naser Saed AbdAlqader; عماره ناصر سعيد عبد القادرThe CT imaging of metal hip prosthesis causes metal-related artifacts reducing the overall image quality and clinical value of CT. This study aims to an evaluation of using orthopedic metal artifact reduction (O-MAR) technique and iterative model-based reconstruction (IMR) in CT imaging of bilateral total hip prostheses in a pelvis phantom. The fabricated pelvis phantom has four major components, pelvis bones, muscle, fat, and vascular structures, and was made using different concentrations of respectively calcium sulfate, bee wax, agarose powder, and Iohexol. Two types of hip prosthesis were used total hip and Austen Moore prosthesis. Different types of algorithms, filtered back projection (FBP), iDose4, and IMR with different Kilo-Voltage peak (kVps) settings at 80, 100, 120, and 140, combined with O-MAR were applied on this phantom. The image quality criteria were CT number, noise, and signal to noise ratio (SNR) and were analyzed by five regions of interest (ROIs), while regions R1 and R5 were the primary focusing. The five RIOs representing the following anatomy (right common iliac artery, left common iliac artery, right gluteus medius muscle, fat, and urinary bladder) respectively from R1 – R5. Without the prosthesis, results showed that IMR resulted in lower CT number, noise values, and increased SNRs relative to FBP and iDose4 for regions R1-R5. With the prosthesis, O-MAR improved CT-number precision for region R1 by 49% and 83% for FBP and IMR (p<0.05), relative to iDose4 by 57% without any significant changes at (p<0.05). For region R5, O-MAR improved CT-number precision by 81%, 89%, and 92% towards baseline values for respectively FBP, iDose4, and IMR (p<0.05). Also, O-MAR was most efficient in minimizing noise when integrated with IMR with corrections in the noise in R5 with 79 %, 90 %, and 92 % for respectively FBP, iDose4, and IMR (p<0.05). . Additionally, O-MAR was most effective in correcting SNR deviations when integrated with IMR with absolute SNR corrections in region R5 with 29 ± 1 and 43 ± 4 for FBP and IMR (p<0.05), compared to iDose4 by 37 ± 7 without any significant changes (p>0.05). For region R1, O-MAR improves SNR corrections by 5 ± 1, 23 ± 5, and 42 ± 9 for respectively FBP, iDose4, and IMR (p<0.05). O-MAR paired with IMR revealed an HU correction for region R5 of 90%, 90%, 93%, and 93% for respectively 80, 100, 120, and 140-kVp results. Noise was corrected for with 92%, 91%, 92% and 92% for respectively 80, 100, 120 and 140-kVp results. SNR corrections were 37%, iv 38%, 46% and 52% for respectively 80, 100, 120 and 140-kVp results. For region R1, O-MAR combined with IMR showed an average HU correction of 90%, 68%, 81%, and 93% for respectively 80, 100, 120, and 140-kVp results. Noise was corrected with 89%, 88%, 90% and 89% for respectively 80, 100, 120 and 140-kVp results. SNR corrections were 55%, 42%, 38% and 34% for respectively 80, 100, 120 and 140-kVp results. In conclusion, O-MAR decreases the appearance of metal artifacts using iDose4 and is most efficient in severe artifacts when used in combination with 140-kVp and IMR. CT imaging of a bilateral total hip prosthesis phantom, using IMR together with O-MAR increases image quality by significantly minimizing metal artifacts, reducing noise, and enhancing CT number and SNR.