No Abstract.

Purpose: Radiology examinations are growing significantly every year. Analysis of the CT scan reports can highlight defects and is a good way to develop safety in healthcare. This study aimed to evaluate the rate of normal head Computed Tomography (CT) scans at a hospital radiology department in Shahroud and estimate the cancer risk associated with these normal CT scans.

Materials and Methods: In total, the data of 400 patients referred to the emergency radiology center of Imam Hossein hospital in Shahroud from November 23 to December 10, 2021, were collected. CT scan reports were categorized into three groups according to the interpretation of the radiologist. The BEIR VII model was used to estimate the radiation cancer risk.

Results: Among the 400 patients, 248 (62%) were males and the average age of the patients was 49.05 ± 22.60 years. CT scans in 270 (67.5%) cases were reported normal. The average age of the patients with normal, and abnormal CT scans were 41.86 ± 20.27, and 63.03 ± 20.27 years, respectively and the difference was significant (p-value <0.001). The average effective dose was obtained 1.72±0.09, 1.31±0.11, and 0.87±0.09 mSv for different age groups of 1-5, 5-10, >10-year-old. The average risks of all solid cancers were 7.82 cases per 100,000 patients, while the average risk of leukemia was 0.71 cases per 100,000 patients.

Conclusion: A large percentage of CT examinations are normal in our country which leads to many public health issues in the future years. Therefore, efforts should be made to establish predictor clinical factors to reduce unnecessary radiology examinations.

Purpose: Multiple Sclerosis (MS) is an acute, autoimmune, and inflammatory disease in the central nervous system. This study investigated the effect of sagittal Short Tau Inversion Recovery (STIR) and T2-W Fluid Attenuated Inversion Recovery (FLAIR) sequences rather than sagittal T2-W as complementary sequences in patients with cervical spinal cord lesions and suspected MS.

Materials and Methods: This cross-sectional study was performed on all individuals referred to the Shahid Ghazi MRI center in Sanandaj for six months. Sixty patients with a cervical spine MRI request that were suspected of having MS were examined. The number of MS plaques in the sagittal T2-W FSE, sagittal STIR, and sagittal T2-W FLAIR were recorded separately. A comparison between routine sequences and sequence supplementation has been made for characterizing MS plaque in the spine.

Results: Results showed that the greatest agreement was related to sagittal STIR, and sagittal FLAIR (Cohen’s kappa = 0.56). Whereas the least agreement values were from sagittal T2-W and sagittal FLAIR, STIR and FLAIR, T2-W and FLAIR, T2-W and STIR (Cohen’s kappa = 0.20, 0.33, 0.48, 0.55), respectively. Sagittal STIR and sagittal FLAIR were excellent predictors for MS plaques diagnosis due to the area under the ROC curve = 0.56; sensitivity (95% CI) = [0.85 (0.73426 to 0.929044)] and specificity (95% CI) = [0.46 (0.336699 to 0.600035)].

Conclusion: Results show that FLAIR T2-W images in sagittal sequence are appropriate for detecting lesions around spinal cord lesions. Furthermore, using thresholds obtained via statistical analysis, plaques in the cervical spinal cord can be identified in sagittal STIR images.

This study aimed to design an improved form of a composite shield with different materials and shapes and simultaneously reduce the radiation dose to both the patient and operator. A female phantom study was performed with and without bismuth belt-shaped composite shields on the breast region at different beam projections used in coronary angiography. Dose measurements were conducted using GR-200 thermo-luminescence dosimeters, dose area product (DAP), and air kerma (AK) over regular and large breast locations, with and without using bismuth shields. An electronic personal dosimeter was used for operator dose assessment. Patients received doses between 2.27 mSv and 3.38 mSv, depending on the size and strength of beam projections. The use of the developed shields caused a dose reduction of 18%–25% of sensitive breast tissue due to breast size and shield type. During coronary angiography, the mean values of DAP and AK were 2.02 (1.24-2.80)  and 314.1 (202.8-500) mGy, respectively. The highest recorded dose was at the LAO/CRA and LAO/CAU beam projections for both the patient and operator. After applying a belt shield, the operator's radiation dose was decreased by approximately 32%. We found a statistically significant correlation between the radiation dose received by the operator and the patient's breast radiation exposure dose (p<0.001, r²=0.93). The designed belt shield can be a potentially promising protective device for decreasing the radiation risk to the patient's breast and the operator during coronary angiography. However, further studies will be considered before application of this shield in standard clinical practice.

Purpose: This study aimed to evaluate the lumbar annular tears prevalence regarding the patient’s history factors, and Magnetic Resonance Imaging (MRI) recorded data.

Materials and Methods: In this study, 218 patients (106 men and 112 women) were evaluated; 136 cases (63 men and 73 women, 20-80 years, mean: 45.4±14.8 years) with Lower Back Pain (LBP) and High-Intensity Zone (HIZ) were diagnosed based on MR images. The diagnosed annular tears from the MRI data, Body Mass Index (BMI, kg/m²), and physical activity of the patients were recorded, and the prevalence of lumbar annular tears was evaluated regarding the mentioned parameters.

Results: The prevalence of annular tears was 31.6% at L5/S1 (43/136 patients), 43.4% at L4/L5 (59/136 patients), 16.9% at L3/L4 (23/136 patients), 4.4% at L2/L3 (6/136 patients), and 3.7% at L1/L2 spinal disc space (5/136 patients). Most patients with annular tears had LBP (>60%). Based on the patient's history, 25% of patients had BMI above 30, 8.8% had post-traumatic history, 15.4% had a history of falling down, 19.1% had slipped down history, 16.2% were athletes, and 15.4% performed heavy work.

Conclusion: The prevalence of lumbar annular tears was higher in patients having LBP and a BMI over 30, which should be considered possible risk factors. This study demonstrated that annular tears are more likely to occur in lower lumbar discs, especially in L4/L5 and L5/S1 discs.

In this study, a deep learning-based model for ADHD diagnosis in children has been presented. For this purpose, the dataset of the ‘First_National_EEG_Data_Analysis_Competition_with_Clinical_Application’. After preprocessing, data was segmented to 3-second epochs and the frequency features of these epochs were extracted. The Fourier transform was applied to each of the channels separately and, finally, the two-dimensional matrix obtained (channel x frequency) for each epoch is considered to be the input of the Convolutional Neural Network (CNN). The CNN is made up of two convolutional layers, two max pooling layers and two fully connected layers as well as the output layer (totally 9 layers) for classification. In order to improve the performance of the method, the output of the classification of each input variable was examined. In other words, the role of each channel / frequency in the final classification has been investigated using the Layer-wise Relevance Propagation (LRP) algorithm. According to the results of LRP algorithm, only efficient channels have been used as the Convolutional Neural Network (CNN) inputs in the next step. The final accuracy obtained by this approach was 94.52% for validation data. The findings indicate that the proposed technique can be utilized for ADHD diagnosis.

The capacity of transmission electron microscopy (TEM) to distinguish ultrastructure morphology at the nanometer scale makes it useful for a wide range of biomedical imaging applications. TEM has long been a vital tool in the virologist's toolbox because of its capacity to directly visualize virus particles. When used in HIV-1 research, TEM is essential for assessing the actions of inhibitors that obstruct the maturation and morphogenesis phases of the virus lifecycle. However, TEM micrograph fabrication and analysis both involve tedious manual effort. We have built an 8-layer convolutional neural network backbone capable of categorizing HIV-1 virions at various phases of maturity and morphogenesis via the devoted application of computer vision frameworks and machine learning techniques. On a wide range of micrographs made up of various experimental samples and magnifications, our results surpassed both typical CNN backbones and deep residual networks, obtaining 91.33 percent testing accuracy and 85.83 percent validation accuracy. We anticipate that this tool will be useful to a variety of studies.

Purpose: A new code based on Helmholtz decomposition is presented to separate longitudinal (pressure) and transverse (shear) components of a mixed wave field. This algorithm will help isolate shear or pressure components of an elastic wave to further concentrate on each specific wave and its physical characteristics, particularly in medical imaging instrument development and image processing techniques.

Materials and Methods: Using the combination of Fourier transform and Helmholtz decomposition, first, the mathematical basis of the work is prepared. After reaching a usable formula, this basis is embedded in the Code written in MATLAB program. Then, various test data containing shear and pressure waves were created and fed to the Code to evaluate its ability to decompose the displacements into the shear and pressure waves.

Results: This new algorithm successfully isolated the transverse and longitudinal wavefront of the mixed wavefield. The Code demonstrated 100% accuracy for separating the shear wave and more than 99% for the pressure wave. Moreover, the background noise was kept under 0.03% in every step.

Conclusion: The results show that using Helmholtz decomposition in Fourier space on 3D data can help decompose a displacement field into its irrotational and solenoidal components with high accuracy. A weak dependency on wave thickness and contrast was observed, but the algorithm's accuracy never fell below 99%.

Background and purpose: Prostate cancer is one of the most prevalent malignancies in men and its early detection contributes to the chance for a more sufficient treatment plan and a reduction in its complications. The usual methods for prostate cancer screening include serum PSA levels and digital rectal examination. In case the prostate cancer is suspected, transrectal ultrasound guided biopsy (TRUS) is performed as the gold standard for the diagnosis. The present study is designed to evaluate the potential efficacy of multiparametric-magnetic resonance imaging (mp-MRI) in detection of prostate cancer location.

Materials and methods: a total of 66 subjects were participated in this cross sectional case-controlled study. Based on the results of the TRUS-guided biopsy, 33 of the participants had prostate cancer. All participants underwent MP-MRI imaging prior to the prostate biopsy. findings achieved by the either methods have been investigated and the comparison has been made.

Results: It was revealed that the sensitivity and specificity of the mp-MRI in the diagnosis of prostate cancer were 81.8% and 93.9%, respectively. The positive and negative predictive value were 93.1% and 83.8%, respectively.

Conclusion: The current study indicates that the mp-MRI imaging method has a sufficient sensitivity and specificity for detecting the location of prostate cancer and can potentially be employed as a clue-providing method prior to the TRUS-guided biopsy.

Purpose: The main goal of this study was to determine the optimal collimator in the absence of medium energy collimators along with the impact of Attenuation Correction (AC) and different iterative reconstruction protocols on the quantitative evaluation of Gallium-67 (⁶⁷Ga) SPECT/CT imaging.

Materials and Methods: A GE Discovery 670 dual-head SPECT/CT scanner and a NEMA phantom filled with ⁶⁷Ga solution were used to scan the patients. The projections were acquired with both Low Energy High Resolution (LEHR) and High Energy General Purpose (HEGP) collimators, and CT images were acquired to evaluate the effect of attenuation correction. SPECT data were reconstructed using the ordered subset expectation maximization (OSEM) method with various combinations of iterations and subsets. The performance was quantified, and a clinical study validated the phantom study.

Results: Acquired images by the HEGP collimator yielded higher Contrast Recovery (CR) and Contrast to Noise Ratio (CNR) in images with AC than those without non-AC (41.6% and 74.2%, respectively). The CNR in all spheres after AC was increased by 80.4% (82.1%) for the HEGP collimator against the LEHR collimator. Also, an increase in iterations × subsets from 16 to 48 led to the Coefficient of Variation (COV) increasing by 17.2%, 16.67%, 15.50%, 14.4%, 14.2%, and 14.1% for 10 mm to 37 mm sphere diameter, respectively.

Conclusion: CT-based AC and HEGP collimators can yield improved 67Ga SPECT quantification compared to Non-AC and LEHR collimators. The choice of the optimal collimator with the reconstruction protocol led to changes in the image quality and quantitative accuracy, emphasizing the need to carefully select the appropriate combination of data acquisition factors.

Purpose: Evaluating organ radiation doses and also lifetime risk (LAR) of breast cancer from lung CT scans of 735 female patients from the age of 20-50 with Covid19 surveyed by four Corona center hospitals in Tehran, Iran. Patients’ data and exposure information were extracted from dose report pages in picture archiving and communication systems.

Materials and methods: Patients were divided into six age groups 20-25; 25-30; 30-35; 35–40; 40-45 and 45–50 years. Breast, thyroid, lung and heart doses were calculated by NCICT, and LAR of breast cancer incidence has been evaluated by BEIR VII report.

Results: The average dose of breast, thyroid, lung and heart were 3.97, 4.75, 4.10 and 3.37 mGy and also the average of the effective dose was 2.56 mSv. Also, the average LAR of breast cancer in female patients was 7.45 per 100,000 exposures and it decreased with age.

Conclusion: Although CT scan is a useful instrument in the diagnosis and treatment of Corona disease, but it should be recommended with caution due to the increased risk of breast cancer, especially in younger women.

Purpose: The danger of radiation at low doses continues linearly, and without a threshold, investigations concluded that although the risk of cancer from Computed Tomography (CT) scans is low, it is not zero.

This study aims to determine the patient's radiation dose and estimate the Lifetime Attributable Risk (LAR) of cancer incidence for a single chest CT scan in children.

Materials and Methods: We divided 1,105 children into four age groups: 0 years, 5 years, 10 years, and 15 years. Dosimetric data of chest CT scan were plugged in VirtualDoseCT software, and organ dose and effective dose were calculated. The cancer risk based on organ dose is estimated according to the BEIR VII report.

Results: The highest dose in boys was related to lung (5.13 - 6.8 mSv) and heart (5.27-5.97 mSv), and in girls, lung (4.98 - 5.91 mSv), breast (4.24 - 5.21 mSv), and heart (4.9 - 5.71 mSv) had the highest dose. The highest LAR (per 100,000) was obtained for the breast in the age group of 0 years (61.01), followed by the breast for the age group of 5 years (46.16) and lung in the age group of 0 years (43.32) in girls.

Conclusion: This study shows a better concept of radiation dose in the chest CT scan in children and how much effective dose and organ dose values increase the cancer risk.

Autonomous Sensory Meridian Response is a novel phenomenon that is very popular these days on Youtube and Reddit to its anti-anxiety effects. As the name suggests, ASMR is a relaxing warm sensation that begins on the scalp and spreads throughout the body. This technique is also known as "brain massage," and it relies on soothing sights and sounds, like whispers and slow movements.One of the most substantial reasons for investigating these videos is to find out their scientific roots, which can be from different approaches. In this paper, we intended to examine the physiological changes such as Heart Rate (HR) as well as Galvanic Skin Conductance (GSC) levels before and after watching a single session ASMR video. The dependent t-test statistical analysis by SPSS results with P-value <=0.01 indicated that after a single session of ASMR watching, the heart rate decreased significantly comparing the baseline data. In addition, the skin conductance was slightly reduced as well, but not significantly. These physiological findings prove that ASMR could be an affordable, portable, and immediate anxiety relief for those struggling with anxiety-based disorders, especially for patients who do not respond well to medication or seek alternatives to anti-anxiety medications due to the wide range of side effects or would like to try it for better results along with the prescribed drugs.

Purpose: The present study aims to assess the differences in the condyle position for two skeletal classes using Cone-Beam Computed Tomography (CBCT) reconstructions for both sides and genders.

Materials and Methods: In this cross-sectional descriptive study, the CBCT images of 96 patients (20-60 years) were assessed. The participants were divided according to their Angle malocclusion classifications (Angle Classes I and III). The variables of the Anterior-Posterior position of the Condyle (APC), condylar angle in the axial plane (ACA), the Lateral Position of the Condyle in the axial plane (LPC), the Vertical Position of the Condyle (VPC), condylar angle in coronal dimension (CCA), and the difference of APC and VPC on both sides were measured. The measurements were analyzed using a one‑way ANOVA and Tukey’s post hoc test.

Results: The variables of APC, LPC, ACA, VDC, and the difference of the APC on both sides in the two skeletal classes were similar. The VPC and CCA were greater in Class III than in Class I. All variables representing the 3D position of the condyle were similar in men and women, as well as on the right and left in both skeletal classes, I and III.

Conclusion: Based on the 3D evaluation results of the condylar position, the skeletal classes III and I differed in the VPC and CCA; however, for the rest variables, there were no statistical differences.

Abstract

Purpose: We synthesized folic acid-conjugated Fe₃O₄/Au-pralidoxime chloride nanoparticles (Fe-Au-PAM NPs) for use as dual-modal contrast agents for magnetic resonance imaging (MRI) and computed tomography (CT) in the diagnosis of breast cancer.

Methods: Fe-Au-PAMs NPs conjugated or not to folic acid were synthesized and analyzed by dynamic light scattering, transmission electron microscopy, and vibrating sample magnetometry. The ability of these NPs to create image contrast was also investigated in silico and in vitro (in MCF-7 breast cancer cells and A549 lung cancer cells) with CT and MRI.

Results: Dynamic light scattering and transmission electron microscopy revealed that the Fe-Au-PAM NPs were nearly spherical. The average diameter of Fe-Au NPs increased from 11.6 nm to 98 nm after folic acid conjugation. The saturation magnetization values of Fe-Au-PAM NPs with and without folic acid conjugation were 32.6 and 25.6 emu/g, respectively. Conjugation of folic acid to NPs greatly improved their uptake by cancer cells. The additional coating of NPs with Au reduced the T2 relaxation time for MRI from 245 ms for Fe-PAM NPs to 162 ms for Fe-Au-PAM NPs. Folic acid-conjugated NPs had radiodensity measurements of 185.2 Hounsfield units (HU) compared to 153.4 HU for non-conjugated NPs.

Conclusion: Folic acid-conjugated Fe-Au-PAMs NPs can serve as dual CT/MRI contrast agents and improve the sensitivities of both modalities for the detection of cancer cells.

Keywords: Breast Cancer; Computed Tomography; Magnetic Resonance Imaging; Targeted Imaging

Abstract

Purpose: The pathophysiological progression of traumatic spinal cord injury (SCI) includes primary and secondary injury. Secondary injury causes the destruction of the spinal cord tissue and neurological disorders. After primary mechanical damage, inflammation is the most important factor inducing astrogliosis and scar formation. The activation of inflammatory cells in the area of ​​damage causes the production of free radicals, all of which damage cell membranes. A significant level of oxygen free radical production is involved in the pathology of SCI; Therefore, limiting secondary damage is very important in the clinical treatment of acute traumatic spinal cord injury.

Materials and Methods: In this review article, the articles indexed in various databases were used. The collection of articles was evaluated without time constraints using keywords inducing traumatic spinal cord injury (SCI), inflammation, oxidative stress, chitosan, selenium nanoparticles.

Results: Inflammation and oxygen free radicals play a key role in secondary damage after SCI. Therefore, as a new therapeutic approach, the use of - hydrogels based on chitosan has been considered in SCI. The biocompatibility and biological properties of chitosan have made it considered as a suitable material for nerve regeneration.

Conclusion: The use of reactive oxygen species scavengers, including metal nanoparticles, can control inflammation and oxidative stress in spinal cord injuries. Selenium nanoparticles treatment may reduce secondary damage in SCI by using its anti-inflammatory and antioxidant properties. Therefore, the use of selenium nanoparticles in the chitosan hydrogel bed can control the degeneration and functional improvement of the nerve tissue of the spinal cord.