The Diverse Utility of Contrast Media Delivery and Dosing During Computed Tomography: An International Assessment of Knowledge and Practices.

BACKGROUND: Despite the escalated production rate, the Iodinated Contrast Media (ICM) shortage continues, and demand outweighs supply. AIM: The aim of this study is to investigate the knowledge and practice of ICM delivery in computed tomography (CT) among radiographers and radiologic technologists worldwide. METHODS: An IRB-approved cross-sectional survey used Google Forms for data collection. It involved 94 CT radiographers from 27 countries and was divided into five sections. The first section gathered demographic information, followed by sections on experience, self-assessment of ICM reactions, and delivery technique. The third section explored ICM knowledge and its relation to CT parameters. The fourth and fifth sections focus on practices during pulmonary angiography CT and renal CT scans. Data analysis involved descriptive statistics, the Chi- Square test, and ANOVA. RESULTS: Knowledge was assessed with seven questions, and a score of at least 3.5 was needed for categorization. The median score was two, indicating low knowledge. Specifically, 64.9% of the participants scored lower than the two scores. Years of experience are strongly correlated with the level of knowledge, with 51.6% of radiographers having more than 10 years of experience demonstrating adequate knowledge. 41.7% of respondents demonstrated adequate knowledge when their duty was focused on CT. Furthermore, wide practice variability exists in all CT pulmonary angiography protocols among radiographers with adequate and inadequate knowledge. CONCLUSION: Inexperienced individuals showed knowledge gaps, leading to varied practices and highlighting the need for educational programs. The study underscores establishing standardized Protocols and Practice Guidelines (PPGs) for contrast media administration in Radiology Departments. Additionally, it emphasizes the importance of regular training programs, and international knowledge sharing. The potential for self-selection bias in the online survey sample is highlighted.

Empowering Radiographers: A Call for Integrated AI Training in University Curricula.

Background: Artificial intelligence (AI) applications are rapidly advancing in the field of medical imaging. This study is aimed at investigating the perception and knowledge of radiographers towards artificial intelligence. Methods: An online survey employing Google Forms consisting of 20 questions regarding the radiographers' perception of AI. The questionnaire was divided into two parts. The first part consisted of demographic information as well as whether the participants think AI should be part of medical training, their previous knowledge of the technologies used in AI, and whether they prefer to receive training on AI. The second part of the questionnaire consisted of two fields. The first one consisted of 16 questions regarding radiographers' perception of AI applications in radiology. Descriptive analysis and logistic regression analysis were used to evaluate the effect of gender on the items of the questionnaire. Results: Familiarity with AI was low, with only 52 out of 100 respondents (52%) reporting good familiarity with AI. Many participants considered AI useful in the medical field (74%). The findings of the study demonstrate that nearly most of the participants (98%) believed that AI should be integrated into university education, with 87% of the respondents preferring to receive training on AI, with some already having prior knowledge of AI used in technologies. The logistic regression analysis indicated a significant association between male gender and experience within the range of 23-27 years with the degree of familiarity with AI technology, exhibiting respective odds ratios of 1.89 (COR = 1.89) and 1.87 (COR = 1.87). Conclusions: This study suggests that medical practices have a favorable attitude towards AI in the radiology field. Most participants surveyed believed that AI should be part of radiography education. AI training programs for undergraduate and postgraduate radiographers may be necessary to prepare them for AI tools in radiology development.

The effect of macrocyclic ionic and non-ionic gadolinium agents on neuronal injury and myelin loss in the spinal cords of rats with and without diabetes mellitus.

BACKGROUND: The effect of gadolinium-based contrast agents (GBCA) on the spinal cord is not established, especially in patients with diabetes mellitus. PURPOSE: To investigate neuronal and myelin loss in the spinal cord when employing macrocyclic ionic Gadoterate Meglumine (Gd-DOTA) and non-ionic Gadobuterol (Gd-BT-DO3A) GBCA in rats with and without diabetes mellitus. MATERIALS AND METHODS: This study was performed between November 2018 and February 2020. Sixty young Sprague Dawley white rats (n = 6/group) were given injections of two macrocyclic GBCA: 0.5 mmol/ml Gd-DOTA and 1 mmol/ml Gd-BT-DO3A, using volumes based of the recommended doses (0.1 ml and 0.2 ml) for 42 days in both healthy and diabetic rats. Control groups received saline injections. Morphological assessment of spinal cord tissues was performed on three spinal segments. Neuronal counts in the ventral horns and myelin sparing percentage in the white matter were determined and compared in each group employing one-way ANOVA and Dunnett test for each category followed by three-way factorial analysis. RESULTS: Low neuronal count and myelin percentage-area were obtained in groups receiving 0.2 ml Gd-DOTA (p = .001;p = .002;p < .001 neurons; and p < .001;p = .007;p = .001 myelin %) and Gd-BT-DO3A (p = .01;p = .048;p = .006 neurons; p < .001;p = .01;p = .001 myelin %). Similarly, neuronal loss was seen in diabetics receiving low volume-injection (0.1 ml) of Gd-DOTA (p = .04;p = .03;p = .42), Gd-BT-DO3A (p = .002;p = .007;p = .01); or high volume-injection (0.2 ml) of Gd-DOTA (p = .001;p = .003;p = .01) or Gd-BT-DO3A (p < .001,p = .002;p = .002), with associated decrease in myelin sparing for each category with low dose Gd-DOTA (p < .001, p = .001; p. = 09),Gd-BT-DO3A (p = .003;p = .003;p = .007); or the higher dose counterparts of Gd-DOTA (p < .001; p < .00; p = .001) and Gd-BT-DO3A (p < .001, p < .001, p < .001). Damage was observed using the standard dose (equivalent of 0.1 mmol/kg for rats) of Gd-DOTA (0.2 ml) but not that of Gd-BT-DO3A (0.1 ml) in healthy rats. CONCLUSION: Multiple high-volume injections of gadoterate meglumine and gadobuterol are associated with neuronal and myelin injury in the spinal cord, more so in rats with diabetes mellitus.

Diagnostic reference levels in spinal CT: Jordanian assessments and global benchmarks.

BACKGROUND: To reduce radiation dose and subsequent risks, several legislative documents in different countries describe the need for Diagnostic Reference Levels (DRLs). Spinal radiography is a common and high-dose examination. Therefore, the aim of this work was to establish the DRL for Computed Tomography (CT) examinations of the spine in healthcare institutions across Jordan. METHODS: Data was retrieved from the picture archiving and communications system (PACS), which included the CT Dose Index (CTDI (vol) ) and Dose Length Product (DLP). The median radiation dose values of the dosimetric indices were calculated for each site. DRL values were defined as the 75th percentile distribution of the median CTDI (vol)  and DLP values. RESULTS: Data was collected from 659 CT examinations (316 cervical spine and 343 lumbar-sacral spine). Of the participants, 68% were males, and the patients' mean weight was 69.7 kg (minimum = 60; maximum = 80, SD = 8.9). The 75th percentile for the DLP of cervical and LS-spine CT scans in Jordan were 565.2 and 967.7 mGy.cm, respectively. CONCLUSIONS: This research demonstrates a wide range of variability in CTDI (vol)  and DLP values for spinal CT examinations; these variations were associated with the acquisition protocol and highlight the need to optimize radiation dose in spinal CT examinations.

Establishment of diagnostic reference levels in low-dose renal computed tomography.

BACKGROUND: Increased radiation doses from computed tomography (CT) examinations is well known with proven risks of inducing cancers for effective dose >100 mSv (according to some studies >50 mSvs). PURPOSE: To establish the diagnostic reference level (DRL) for low-dose renal CT examinations in the evaluation of renal stones. MATERIAL AND METHODS: Patient demographics, CT parameters, and dosimetric indices (CTDIvol and dose length product [DLP]) were collected from 12 tertiary hospitals that routinely perform renal CT in the detection and evaluation of renal stones over a period of 12 weeks. Data obtained from 1418 average-sized patients in each category were recorded. The median values of dosimetric indices for each site were calculated. The DRL values were defined as the 75th percentile of the distribution of the median values of CTDIvol and DLP. RESULTS: There were no significant differences between patient demographics. Mean kVp and mAs for protocols were 121.67 ± 11.56 and 226.91 ± 78.44, respectively. The CTDIvol values were in the range of 2-36.2 mGy, while the DLP values were in the range of 43-1942 mGy.cm. The DRL for the CTDIvol was 16.15 mGy and for the DLP 851.77 mGy.cm. The local median values of CDTIvol and DLP are higher than DRL in two hospitals. CONCLUSION: Comparison of local median values of CDTIvol and DLP with DRL suggests the needs of an optimization strategy in some hospitals.

Sclerosing Stromal Tumor of the Ovary Presenting as Meigs Syndrome During Childhood.

Meigs syndrome is a rare disorder characterized by a triad of benign ovarian tumor, ascites, and pleural effusion. Despite its benign nature, its presentation can be similar to metastatic malignancy, making preoperative diagnosis often challenging. The differential diagnosis includes serious and even life-threatening conditions. Meigs syndrome is most common in postmenopausal women and is extremely rare in children. It is often undiagnosed until an invasive surgery is performed. The fact that surgery includes a unilateral salpingo-oophorectomy in females of reproductive age raises concerns for future fertility and other risks associated with this intervention. Familiarity of radiologists and pediatric surgeons with clinical and imaging findings is beneficial to improve preoperative planning, thereby minimizing invasive surgery and preserving ovarian tissue.

Weight-Based Protocols Offer Significant Reduction in Radiation Dose Without Affecting PET-CT Image Quality.

PURPOSE: To investigate the use of weight-based protocols during full- and half-body fluorodeoxyglucose F 18 (FDG) positron emission tomography-computed tomography (PET-CT) and their effect on image quality, radiation dose, and lifetime attributable risks. METHODS: A total of 1817 patients were referred for FDG PET-CT studies. Each scanning group (4 total: full-body groups A and C and half-body groups B and D) was randomly allotted into conventional or weight-based CT. Groups A and B followed a conventional protocol of 120 kVp, 120 mA, 0.5 second rotation time, and pitch 0.8 mm/rotation for all body weights. Groups C and D were scanned using 1 of 4 weight-based CT protocols. All 4 weight-based protocols used 140 kVp, 0.75 seconds rotation time, and pitch 0.8 mm/rotation. Milliamperage varied by body weight as follows: protocol I (≤ 60kg [132.3 lb]), 35 mA; protocol II (61-80 kg [134.5-176.4 lb]), 50 mA; protocol III (81-100 kg [178.6-220.5 lb]), 65 mA; and protocol IV (> 100kg [222.7 lb]), 100 mA. All protocols (weight based and conventional) employed tube current modulation. CT quantitative image quality measurements were evaluated for each protocol, and lifetime attributable risks were calculated for each age group and sex. RESULTS: Patient demographics demonstrated no significant differences between groups. Mean effective dose was significantly lower for group C (full body, weight based) compared with A (full body, conventional) (P < .001), as were lifetime attributable risks (P < .001). Mean effective dose and lifetime attributable risks also were significantly lower (P < .001) for group D (half body, weight based) compared with B (half body, conventional). Contrast-to-noise ratios showed no difference between groups (P = .12), supporting a preference for the weigh-based protocols used for groups C and D. For half-body, weight-based protocols (group D), the lifetime attributable risks decreased for men by 91.9% and for women by 38.9%. For full-body, weight-based protocols (group C), the lifetime attributable risks decreased by 72.5% and 66.3% for men and women, respectively. DISCUSSION: Radiologists and radiologic technologists face the challenge of balancing the potential risks of radiation-induced cancer against providing diagnostic-quality images and uncompromised disease detection. Weight-based protocols address this challenge without compromising image quality or pathology detection. CONCLUSION: Significant reductions in radiation dose and lifetime attributable risks can be achieved using CT weight-based protocols during half- and whole-body FDG PET-CT without compromising CT image quality.

An atypical manifestation of idiopathic retroperitoneal fibrosis: A case report.

A 58-year-old male patient, previously healthy, presented with right flank pain of few hours duration. Initial workup showed an elevated creatinine and right hydroureteronephrosis. Computed tomography imaging revealed a retroperitoneal soft tissue mass encasing the right common iliac artery which is a first reported case in its anatomical distribution. Patient was referred to interventional radiology service where a percutaneous nephrostomy tube was placed followed by double J stenting. Subsequently, treatment with steroids was started. Follow up imaging a few months later revealed progressive resolution of the inflammatory process.

Impact of various iodine concentrations of iohexol and iodixanol contrast media on image reconstruction techniques in a vascular-specific contrast media phantom: quantitative and qualitative image quality assessment.

PURPOSE: The aim of our study is to investigate the impact of iodine quantification on image reconstruction when employing a vascular-specific contrast media phantom with varying iodine concentrations. MATERIALS AND METHODS: A 30-cm phantom simulating arterial and venous blood vessel diameters was manufactured. Small (9 mm) and medium (12 mm) cylinders contained iodine concentrations from 10 to 100% while large (21 mm) cylinders were in quartiles from 25 to 100% diluted in blood equivalent medium. Each phantom was filled with either iohexol 350 mgI/mL (Group A) or iodixanol 320 mgI/mL (Group B) and then scanned separately. For each group, tube potential (80-140 kVp) and current (50-400 mAs) were changed and all image series were reconstructed with filtered back projection (FBP), hybrid-based iterative reconstruction (HBIR) and model-based iterative reconstruction (MBIR). Mean opacification was measured in all groups. All data were compared employing an independent t test and Pearson's correlation. Visual grading characteristic (VGC) and Cohens' kappa analyses were performed. RESULTS: At 80 kVp, mean opacification using HBIR was significantly higher in Group B (2165 ± 1108 HU) than in Group A (2040 ± 1036 HU) (p < 0.009). At 140 kVp, MBIR and HBIR were greater in Group A (1704 ± 1033 HU and 1685 ± 1023 HU) versus Group B (1567 ± 1036 HU and 1567 ± 1034 HU) (p < 0.022). CNR using FBP, HBIR and MBIR was higher in Group B (46 ± 42 HU, 70 ± 163 HU and 83 ± 74 HU, respectively) than in Group A (43 ± 39 HU, 174 ± 130 HU and 80 ± 65 HU, respectively) (p < 0.0001-0.035). Qualitative image analysis demonstrated no difference in Cohen's kappa analysis. VGC was higher in Group A at all image reconstruction groups. CONCLUSION: Iohexol outperforms iodixanol in observer performance when assessing image reconstruction techniques and iodine concentrations in a vascular-specific contrast media phantom.

Radiation dose reduction considerations and imaging patterns of ground glass opacities in coronavirus: risk of over exposure in computed tomography.

This article aims to summarize the available data on the severe acute respiratory syndrome coronavirus 2 (SAR-CoV-2) imaging patterns as well as reducing radiation dose exposure in chest computed tomography (CT) protocols. First, the general aspects of radiation dose in CT and radiation risk are discussed, followed by the effect of changing parameters on image quality. This article attempts to highlight some of the common chest CT signs that radiologists and emergency physicians are likely to encounter. With the increasing trend of using chest CT scans as an imaging tool to diagnose and monitor SAR-CoV-2, we emphasize that pattern recognition is the key, and this pictorial essay should serve as a guide to help establish correct diagnosis coupled with correct scanner parameters to reduce radiation dose without affecting imaging quality in this tragic pandemic the world is facing.

Development of a computational tool for estimating computed tomography dose parameters.

BACKGROUND: Computed Tomographic (CT) imaging procedures have been reported as the main source of radiation in diagnostic procedures compared to other modalities. To provide the optimal quality of CT images at the minimum radiation risk to the patient, periodic inspections and calibration tests for CT equipment are required. These tests involve a series of measurements that are time consuming and may require specific skills and highly-trained personnel. OBJECTIVE: This study aims to develop a new computational tool to estimate the dose of CT radiation outputs and assist in the calibration of CT scanners. It may also provide an educational resource by which radiological practitioners can learn the influence of technique factors on both patient radiation dose and the produced image quality. METHODS: The computational tool was developed using MATLAB in order to estimate the CT radiation dose parameters for different technique factors. The CT radiation dose parameters were estimated from the calibrated energy spectrum of the x-ray tube for a CT scanner. RESULTS: The estimated dose parameters and the measured values utilising an Adult CT Head Dose Phantom showed linear correlations for different tube voltages (80 kVp, 100 kVp, 120 kVp, and 140 kVp), with R2 nearly equal to 1 (0.99). The maximum differences between the estimated and measured CTDIvol were under 5 %. For 80 kVp and low tube currents (50 mA, 100 mA), the maximum differences were under 10%. CONCLUSIONS: The prototyped computational model provides a tool for the simulation of a machine-specific spectrum and CT dose parameters using a single dose measurement.

Radiologists' Knowledge and Attitudes towards CT Radiation Dose and Exposure in Saudi Arabia-A Survey Study.

Computed tomography (CT) is a key imaging technique in diagnostic radiology, providing highly sensitive and specific information. While its use has increased dramatically in recent years, the quantity and associated risks of radiation from CT scans present major challenges, particularly in paediatrics. The fundamental principles of radiation protection require that radiation quantities be as low as reasonably achievable and CT use must be justified, particularly for paediatric patients. CT radiation knowledge is a key factor in optimising and minimising radiation risk. The objective of this study was to analyse knowledge level, expertise, and competency regarding CT radiation dose and its hazards in paediatrics among radiologists in Saudi Arabian hospitals. A self-reported, multiple-choice questionnaire assessed the attitudes and opinions of radiologists involved in imaging studies using ionising radiation. Among the total respondents, 65% ± 13.5% had a good comprehension of the dangers of carcinogenicity to the patient resulting from CT scans, with 80% presuming that cancer risks were elevated. However, only 48.5%, 56.5%, and 65% of the respondents were aware of specific radiation risks in head, chest, and abdominal paediatric examinations, respectively. Regular, frequent, and specific training courses are suggested to improve the fundamental knowledge of CT radiation among radiologists and other physicians.

Lung density in the trajectory path is a strong indicator of patients sustaining a pneumothorax during CT-guided lung biopsy.

INTRODUCTION: The purpose is to evaluate the prognostic significance of lung parenchymal density during percutaneous coaxial cutting needle lung biopsy (PNLB). MATERIALS AND METHODS: Retrospective analysis of 179 consecutive patients (106 males, 73 females; mean age 59.16 ± 16.34 years) undergoing PNLB was included. Mean lobar parenchymal lung density, mean densities anterior to the lesion and posterior to the chest wall in the needle trajectory path were measured in HU. Lesion location and needle trajectory were also measured. Fisher's exact test and Chi-square test were conducted to analyze the categorical variables. ANOVA test was done to examine continuous and normally distributed variables. Statistical significance was considered when p < 0.05. RESULTS: Mean lobar parenchymal lung density (p < 0.05) and mean parenchymal lung density relative to the needle trajectory path were below -800 HU in patients who sustained a pneumothorax. Increase in the number of pleural passes was significantly associated with the risk of patients having pneumothorax (p < 0.05). The mean distance from the skin to the lesion and needle trajectory angle were not statistically different among patients with and without pneumothorax (p > 0.05). CONCLUSION: Lobar parenchymal density and lung parenchymal density anterior to the lesion and posterior to the chest wall in the needle trajectory path could be used as predicting parameters in patients undergoing PNLB who sustained a pneumothorax. These findings can help interventional radiologist further assess risk of pneumothorax when preforming such procedure.

Peristaltic Contrast Media Injection Improved Image Quality and Decreased Radiation and Contrast Dose When Compared With Direct Drive Injection During Liver Computed Tomography.

PURPOSE: The aim of this study was to compare hepatic vascular and parenchymal image quality between direct and peristaltic contrast injectors during hepatic computed tomography (HCT). METHODS: Patients (n = 171) who underwent enhanced HCT and had both contrast media protocols and injector systems were included; group A: direct-drive injector with fixed 100 mL contrast volume (CV), and group B: peristaltic injector with weight-based CV. Opacification, contrast-to-noise ratio, signal-to-noise ratio, radiation dose, and CV for liver parenchyma and vessels in both groups were compared by paired t test and Pearson correlation. Receiver operating characteristic curve, visual grading characteristics, and Cohen κ were used. RESULTS: Contrast-to-noise ratio: compared with hepatic vein for functional liver, contrast-to-noise ratio was higher in group B (2.17 ± 0.83) than group A (1.82 ± 0.63); portal vein: higher in group B (2.281 ± 0.96) than group A (2.00 ± 0.66). Signal-to-noise ratio for functional liver was higher in group B (5.79 ± 1.58 Hounsfield units) than group A (4.81 ± 1.53 Hounsfield units). Radiation dose and contrast media were lower in group B (1.98 ± 0.92 mSv) (89.51 ± 15.49 mL) compared with group A (2.77 ± 1.03 mSv) (100 ± 1.00 mL). Receiver operating characteristic curve demonstrated increased reader in group B (95% confidence interval, 0.524-1.0) than group A (95% confidence interval, 0.545-1.0). Group B had increased revenue up to 58% compared with group A. CONCLUSIONS: Image quality improvement is achieved with lower CV and radiation dose when using peristaltic injector with weight-based CV in HCT.

A systematic review on the current status of adult diagnostic reference levels in head, chest and abdominopelvic Computed Tomography.

Computed tomography (CT) is a routinely employed diagnostic tool for the detection and diagnosis of disease processes. Despite the primary focus of radiation dose reduction and improvements in CT scanners, radiation dose exposure remains an ever-increasing concern. Scanning protocol optimisation relative to body weight and scanner manufacturer still lags behind the diagnostic reference levels (DRLs) that are set on an international scale. The aim of this systematic review is to evaluate the current status of adult DRLs in head, chest and abdominopelvic CT over time on a global scale. A search was carried out in early 2019 using the Medline, PubMed, EMBASE, SCOPUS and manual databases. The reference lists of published articles were also assessed to identify further articles. The preferred reporting items for systematic reviews and meta-analyses (PRISMA) methodology was employed to evaluate articles for relevance. Articles were included if they assessed the DRL in head, chest and abdominopelvic scans. The search resulted in 6079 articles, of which 67 were included after a thorough screening process. The literature demonstrates a wide dose variation in reported head, chest and abdominopelvic dose length product (DLP) DRL, ranging from 700-1359, 330-707 and 550-1486 mGy·cm, respectively. Where reported, the volumed CT dose index (CTDIvol) DRL in the head, chest and abdominopelvic studies ranged from 30.4-85.5, 9-15 and 12.3-31 mGy·cm, respectively. The global means were shown to be slightly lower and significantly lower than the reported values of DLP and CTDIvol values for the American College of Radiology and European Commission, respectively. This review emphasises the need for an international standardisation for head and body DRL establishment methods, to provide a more comparable global measurement of dose variations across CT sites as well as regular monitoring of delivered radiation dose to patients.

The value of diffusion weighted imaging and apparent diffusion coefficient in primary Osteogenic and Ewing sarcomas for the monitoring of response to treatment: Initial experience.

PURPOSE: To assess the value of using Apparent Diffusion Coefficient (ADC) mapping in Diffusion Weighted Imaging (DWI) when monitoring treatment response in pediatric Osteogenic and Ewing sarcomas and to correlate with level of necrosis on post-surgical excision pathology. METHOD: This retrospective study includes 7 Osteosarcoma and 8 Ewing sarcoma patients. Pre-treatment and post-treatment focal MRIs were evaluated for ADC values, tumor volumes and variability of both measurements. We also compared the measurement between Ewing and Osteosarcoma groups, as well as between good (=/>90 % necrosis post-excision) and poor (<90 % necrosis post-excision) responders. RESULTS: All measurements except Maximum ADC (p = 0.20) showed a statistically significant difference when comparing them before and after treatment. When we segregated our population according to pathologic complete response, there was no difference in ADC measurements, volumetric measurements or either variability between good (8 Patients) and poor responders (7 Patients). When comparing the before-after changes in our measurement between the Ewing sarcoma and Osteosarcoma cases, there was no significant difference in the change between pre and post treatment (Δ) Mean or Maximum ADC, or in Δtumor-volume when measured on STIR or SPIR T1 post-contrast sequences. Only the ΔMinimum-ADC showed a statistically significant difference (p < 0.02) in this group. CONCLUSIONS: ADC can potentially reflect cellular changes associated with chemotherapy use, reflecting a response to treatment. However, quantitative use of those parameters to dictate a change in management, treatment regimen or chemotherapy dose in order to target a good response (>/ = 90 % necrosis post-excision) needs further investigation.

Balancing act between quantitative and qualitative image quality between nonionic iodinated dimer and monomer at various vessel sizes during computed tomography: a phantom study.

PURPOSE: Investigate the impact of nonionic dimer and monomer on iodine quantification in different vessel sizes when employing a vascular specific phantom and varying iodinated contrast media (ICM) concentrations during computed tomography (CT). MATERIALS AND METHODS: We created a vascular specific phantom (30 cm) to simulate human blood vessel diameters (25 cylinders of different diameters: 10 × 9mm, 10 × 12mm and 5 × 21mm). The phantom was filled with two ICM separately: Group: Iohexol(monomer)350 mg ml-1 and B: Iodixanol(Dimer)320 mg ml-1. Cylinders of same size were filled with increasing ICM concentration(10%-100%) while large cylinders were filled in quartiles(25%-100%). Phantom was scanned with different tube potential (80-140kVp), current (50-400mAs), reconstruction method [filtered back projection (FBP), hybrid-based iterative reconstruction (HBIR) and model-based iterative reconstruction (MBIR)] for each ICM. Chi-square was employed to compare mean opacification, contrast/noise ratio (CNR) and noise. Qualitative analysis was assessed by Visual grading characteristic (VGC) and Cohens-kappa analyses. RESULTS: At 80 and140kVp significant difference in opacification between Group A (2054 ± 1040HU and 1696 ± 1027HU) and B (2169 ± 1105HU and 1568 ± 1034HU) was demonstrated (p < 0.001). However, at 100 and 120kVp no difference was noted (p > 0.05). When comparing image noise, it was higher in Group A compared to B (p < 0.05). CNR was higher in Group B (119.99 ± 126.10HU) than A (107.09 ± 102.56HU) (p < 0.0001). VGC: Group A outperformed B in image opacification in all vessel sizes and ICM concentrations except at medium vessels with concentration group 2(0.4-0.6 mg ml-1). Cohens'-kappa: agreement in opacification between each ICM group and iodine concentration 1(0-0.3 mg ml-1): κ = 0.253 and 0.014 respectively, concentration 2(0.4-0.6 mg ml-1):κ = -0.017 and -0.005 respectively and concentration 3(0.7-1 mg ml-1):κ = 0.031 and 0.115 respectively. CONCLUSION: Nonionic dimer (Iodixanol) surpasses monomer (Iohexol) in quantitative image quality assessment by having lower image noise and higher CNR during CT.

The acute scrotum: Frequency and range of etiologies in a Middle Eastern setting.

AIM: To investigate the frequency of different etiologies of acute scrotal pain in males presenting to the emergency department at American University of Beirut Medical Center in Beirut, Lebanon. MATERIALS AND METHODS: In all, 94 patients between the ages 18 and 40 years presenting to the emergency room at American University of Beirut Medical Center with acute scrotum were recruited. The scrotum was inspected with palpation, and Doppler Ultrasound of the testicle was performed by a radiology resident to confirm the diagnosis. The study results were then collected after the official reports were signed by a board-certified radiology attending with expertise in ultrasound. RESULTS: Of the 94 patients presenting with acute scrotal pain, 23.4% (95% confidence interval (0.70-0.87)) had no ultrasound findings and were considered normal. On the other hand, 54.3% (95% confidence interval (0.45-0.66)) were diagnosed with varicocele, 9.6% (95% confidence interval (0.04-0.16)) were diagnosed with epididymo-orchitis, and 9.6% (95% confidence interval (0.04-0.16)) had a history of trauma to the testicle. Patients presenting with acute scrotum had a pain duration of 13.2 ± 4.5 h, with 10.6% (95% confidence interval (0.04-0.17)) having associated urinary symptoms, 18.1% (95% confidence interval (0.09-0.25)) have had sexual activity within 48 h of presentation, and 10.6% (95% confidence interval (0.04-0.17)) were pre-diagnosed with varicocele. CONCLUSION: Varicocele is the most common cause of acute scrotal pain in patients presenting to American University of Beirut Medical Center in Beirut. This should direct varicocele to the top of our differential when a patient with acute scrotum presents to the emergency department. Nevertheless, ruling out torsion remains the first step in the workup.

Intracranial calcifications on CT: an updated review.

Intracranial calcifications are frequently encountered in non-contrast computed tomography scan in both adult and pediatric age groups. They refer to calcifications within the brain parenchyma or vasculature and can be classified into several major categories: physiologic/age-related, dystrophic, congenital disorders/phakomatoses, infectious, vascular, neoplastic, metabolic/endocrine, inflammatory and toxic diseases. In this updated review, we present a wide spectrum of intracranial calcifications from both pediatric and adult populations focusing on their pattern, size and location.

An augmented patient-specific approach to administration of contrast agent for CT renal angiography

ABSTRACT Purpose This hybrid retrospective and prospective study performed on 200 consecutive patients undergoing renal CTA, investigates the opacification of renal vasculature, radiation dose, and reader confidence. Materials and Methods 100 patients were assigned retrospectively to protocol A and the other 100 were allocated prospectively to protocol B. Both protocols implemented a contrast material and saline flow rate of 4.5 mL/sec. Protocol A utilized a 100 mL of low-osmolar nonionic IV contrast material (Ioversol 350 mg I/mL) while protocol B employed a patient-tailored contrast media formula using iso-osmolar non-ionic (Iodixanol 320 mg I/mL). Results Arterial opacification in the abdominal aorta and in the bilateral main proximal renal arteries demonstrated no statistical significance (p>0.05). Only the main distal renal artery of the left kidney in protocol B was statistically significant (p<0.046). In the venous circulation, the IVC demonstrated a significant reduction in opacification in protocol B (59.39 HU ± 19.39) compared to A (87.74 HU ± 34.06) (p<0.001). Mean CNR for protocol A (22.68 HU ± 13.72) was significantly higher than that of protocol B (14.75 HU ± 5.76 p< 0.0001). Effective dose was significantly reduced in protocol B (2.46 ± 0.74 mSv) compared to A (3.07 ± 0.68 mSv) (p<0.001). Mean contrast media volume was reduced in protocol B (44.56 ± 14.32 mL) with lower iodine concentration. ROC analysis demonstrated significantly higher area under the ROC curve for protocol B (p< 0.0001), with inter-reader agreement increasing from moderate to excellent in renal arterial visualization. Conclusion Employing a patient-tailored contrast media injection protocol shows a significant refinement in the visualization of renal vasculature and reader confidence during renal CTA.