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.

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 (CTDI_vol 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 CTDI_vol 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 CTDI_vol 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 CTDI_vol was 16.15 mGy and for the DLP 851.77 mGy.cm. The local median values of CDTI_vol and DLP are higher than DRL in two hospitals.

CONCLUSION

Comparison of local median values of CDTI_vol and DLP with DRL suggests the needs of an optimization strategy in some hospitals.

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.

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.

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.

Referral Physicians’ Knowledge of Radiation Dose: A Cross-sectional Study

AIM: The purpose of the study was to evaluate the knowledge of referring physicians of general practitioners, residents, and medical specialists in Jordan and the Middle East on radiation dose and its impact on vulnerable patients. MATERIALS AND METHODS: The Institutional Review Board approved this study before data collection. A cross-sectional study employed questionnaire that was distributed to respondents (n = 293) of general practitioners, residents, specialists, and therapists. The questionnaire consisted of 29 questions. Nine questions concerned with demographics and the remaining 20 questions were divided into five sections: Radiation dose, ionizing radiation, pediatric radiation, pregnant women radiation, and radiation risks. The mean score was computed out of 20. Chi-squared test of independence was utilized to analyze each question. To compare the responses between the demographic variables groups, Kruskal–Wallis and Mann–Whitney tests were used. RESULTS: Out of the 293 respondents, 128 (43.7%) were aware of radiation. The average score of the questionnaire was 9.5 out of 20 (47.5%). Within each section, the level of knowledge varied. Physicians had the highest level of knowledge in radiation risk (85.7%) followed by ionizing radiation (62.1%). The questionnaire revealed lower levels of knowledge in the areas of pediatric radiation, pregnant women radiation, and radiation dose. The percentages of respondents, (with fair to good level of knowledge), were 47.1%, 34.5%, and 24.6%, respectively. CONCLUSION: The results of this study were consistent with previous studies that demonstrated a poor level of general knowledge in referring physicians regarding radiation dose, ionizing radiation, pediatric radiation, pregnant women radiation, and radiation risks.

To repeat or not to repeat: Radiologists demonstrated more decisiveness than their fellow radiographers in reducing the repeat rate during mobile chest radiography

INTRODUCTION

Radiologists and radiographers play a complementary role in providing an optimal image quality with decrease radiation dose and proper diagnosis during chest radiographs. We aim Investigate years of experience among radiologists and radiographers on perception of image quality and its impact on repeat rate when evaluating portable pediatric chest radiographs.

METHODS

IRB approved retrospective study consisted of randomly selected images (n = 131) of pediatric portable chest radiographs. Images were blindly assessed by four radiologists and four radiographers. Readers were asked to assess qualitative and quantitative image quality by rating: image quality, decision to repeat and image technique. All data was compared employing Pearson's Correlation, Visual grading characteristic (VGC) and Cohens' kappa analyses.

RESULTS

Image quality: Radiologists (88.4%) rated images as excellent significantly more than radiographers (11.6%), and radiographers (90.1%) as poor significantly more than radiologists (9.9%) (p < 0.05). Repeat: Radiologists (57%) decided not to repeat images significantly more than radiographers (43%) (p < 0.05). Image technique: Radiologists rated images as acceptable (65%) and excellent (97.7%) significantly more than radiographers (35% and 2.3% respectively) (p < 0.05), whereas radiographers (84%) assessed image technique as poor significantly more than radiologists (16%) (p < 0.05). VGC: radiographers had slightly better qualitative evaluation of image quality than radiologists. An association between image quality (p < 0.002) and repeat decision (p < 0.044) with years of experience was established when comparing years of experience with image assessment rubric, while no association was noted with image technique (p < 0.9).

CONCLUSION

Radiologists demonstrated more decisiveness than their fellow radiographers in reducing the repeat rate of portable pediatric chest radiographs. Interestingly, years of experience only seem to affect image technique and image quality assessment among radiologists.

IMPLICATIONS FOR PRACTICE

Continuous education of radiographers and close collaboration with radiologists is crucial to achieve optimal image quality and low radiation doses.

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 (CTDI_vol) 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 CTDI_vol 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.

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.

Staying abreast of imaging - Current status of breast cancer detection in high density breast

OBJECTIVES

The aim of this paper is to illustrate the current status of imaging in high breast density as we enter a new decade of advancing medicine and technology to diagnose breast lesions.

KEY FINDINGS

Early detection of breast cancer has become the chief focus of research from governments to individuals. However, with varying breast densities across the globe, the explosion of breast density information related to imaging, phenotypes, diet, computer aided diagnosis and artificial intelligence has witnessed a dramatic shift in new screening recommendations in mammography, physical examination, screening younger women and women with comorbid conditions, screening women at high risk, and new screening technologies. Breast density is well known to be a risk factor in patients with suspected/known breast neoplasia. Extensive research in the field of qualitative and quantitative analysis on different tissue characteristics of the breast has rapidly become the chief focus of breast imaging. A summary of the available guidelines and modalities of breast imaging, as well as new emerging techniques under study that can potentially provide an augmentation or even a replacement of those currently available.

CONCLUSION

Despite all the advances in technology and all the research directed towards breast cancer, detection of breast cancer in dense breasts remains a dilemma.

IMPLICATIONS FOR PRACTICE

It is of utmost importance to develop highly sensitive screening modalities for early detection of breast cancer.

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.

State of the art of coronary computed tomography angiography

OBJECTIVES

The aim of this paper is to evaluate contrast media (CM) bolus geometry and opacification patterns in the coronary arteries with particular focus on patient, scanner and safety considerations during coronary computed tomography angiography (CCTA).

KEY FINDINGS

The rapid evolution of computed tomography (CT) technology has seen this imaging modality challenge conventional coronary angiography in the evaluation of coronary artery disease. Increases in spatial and temporal resolutions have enabled CCTA to become the modality of choice when evaluating the coronary vascular tree as an alternative in the diagnostic algorithm for acute chest pain. However, these new technologic improvements in scanner technology have imposed new challenges for the optimisation of CM delivery and image acquisition strategies.

CONCLUSION

Understanding basic CM-imaging principles is essential for designing optimal injection protocols according to each specific clinical scenario, independently of scanner technology.

IMPLICATIONS FOR PRACTICE

With rapid advances in CT scanner technology including faster scan acquisitions, the risk of poor opacification of coronary vasculature increases significantly. Therefore, awareness of CM delivery protocols is paramount to consistently provide optimal image quality at a low radiation dose.

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.

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.

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.

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

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.

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.

Establishment of diagnostic reference levels in cardiac computed tomography

The aim of this study was to determine diagnostic reference levels (DRLs) for cardiac computed tomography (CCT) in Jordan. Volume computed tomography dose index (CTDI_vol) and dose–length product (DLP) were collected from 228 CCTs performed at seven Jordanian hospitals specialized in cardiac CT. DRLs for cardiac CT were defined at the 75th percentile of CTDI_vol and DLP. CTDI_vol and DLP were collected from 30 successive cardiac CT in each center except for one center (18 scans). The 75th percentile of the CTDI_vol and the DLP of the centers calculated from mixed retrospective and prospective gated modes were 47.74 milligray (mGy) and 1035 mGy/cm, respectively. This study demonstrated wide dose variations among the surveyed hospitals for cardiac CT scans; there was a 5.1‐fold difference between the highest and lowest median DLP with a range of 223.2–1146.7 mGy/cm. Differences were associated with variations in the mAs and kVp. This study confirmed large variability in CTDI_vol and DLP for cardiac CT scans; variation was associated with acquisition protocols and highlights the need for dose optimization. DRLs are proposed for CCT; there remains substantial potential for optimization of cardiac CT examinations for adults in Jordan.

Diagnostic reference levels for paediatric CT in Jordan

This study aimed to investigate the current status of Diagnostic Reference Levels (DRLs) in paediatric CT across Jordan. The dose data for four main CT examinations (brain, chest, abdominopelvic, and chest, abdomen and pelvis (CAP)) in hospitals and imaging centres (n = 4) were measured. The volume CT dose index (CTDIvol) and Dose Length Product (DLP) values were compared within the different hospitals and age groups (<1 year, 1-4 years, 5-10 years and 11-18 years). DRLs in Jordan were compared to international DRLs. The paediatric population consisted of 1818 children; 61.4% of them were male. There were significant variations between the DRLs for each CT scanner with an up to four-fold difference in dose between hospitals. There were apparent significant differences between Jordan and other countries with the DLPs in Jordan being relatively high. However, for CTDIvol, the values in Jordan were close to those of other countries. This study confirmed variations in the CTDIvol and DLP values of paediatric CT scans in Jordan. These variations were attributed to the different protocols and equipment used. There is a need to optimise paediatric CT examinations doses in Jordan.

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.

Multimodality approach to imaging giant multilocular cystadenoma of the prostate: A rare entity

Giant multilocular cystadenomas of the prostate or seminal vesicles are rarely reported in literature. We present a case of a 76-year-old male presenting with lower urinary tract symptoms initially perceived as symptoms of benign prostatic hyperplasia. The patient was investigated by employing a multimodality imaging approach of the prostate that included ultrasound, computed tomography, and magnetic resonance imaging, which resulted in an incidental finding of large multiloculated benign cysts originating from the prostate, confirmed by pathological study. This case report highlights the multimodality imaging approach in the detection and diagnosis of this rare disease.

Crohn's disease: A retrospective analysis between computed tomography enterography, colonoscopy, and histopathology

INTRODUCTION

To investigate the spectrum of computed tomography enterography (CTE) findings of active Crohn's disease (CD) in comparison to endoscopic, histopathologic and inflammatory markers.

METHODS

Hospital records of 197 patients with known or suspected CD who underwent CTE over a period of 5 years were reviewed. Eighty-nine patients fulfilled the inclusion criteria. Three-point severity scores for endoscopy, pathology, and haematologic inflammatory markers were recorded. The findings on CTE were identified by three readers and correlated with endoscopic, pathologic, and haematologic severity scores. Statistical analysis was carried out employing a Pearson Chi square test and Fisher exact test. Receiver operating characteristic (ROC), visual grading characteristic (VGC) and Cohens' kappa analyses were performed.

RESULTS

The CTE findings which were significantly correlated with the severity of active disease on endoscopy include bowel wall thickening, mucosal hyperenhancement, bilaminar stratified wall enhancement, transmural wall enhancement, and mesenteric fluid adjacent to diseased bowel (p < 0.05). Only bowel wall thickening and bilaminar stratified wall enhancement correlated with the pathological severity of active CD. ROC and VGC analysis demonstrated significantly higher areas under the curve (p < 0.0001) together with excellent inter-reader agreement (k = 0.86).

CONCLUSION

CTE is a reliable tool for evaluating the severity of active disease and helps in the clinical decision pathway.

Body Weight-Based Protocols During Whole Body FDG PET/CT Significantly Reduces Radiation Dose without Compromising Image Quality:Findings in a Large Cohort Study

RATIONALE AND OBJECTIVES

To investigate radiation dose reduction during whole body fluorodeoxyglucose (¹⁸F-FDG) positron emission tomographic (PET)/computed tomography (CT) by employing weight-based protocols.

MATERIALS AND METHODS

One thousand and twenty-eight patients were referred for ¹⁸F-FDG PET/CT study with one of two protocols: conventional protocol I; 120 kVp, 120 mAs, 0.5 second rotation time, pitch 0.8 mm/rot across all body weights; four-tier body weight protocol II all used 140 kVp, 0.75 seconds rotation time and pitch 0.8 mm/rot: Protocol A (≤60 kg): 35 mAs, Protocol B (61-80 kg): 50 mAs, Protocol C (81-100 kg): 65 mAs, and Protocol D: (>101 kg): 100 mAs. All protocols employed tube current modulation. Quantitative and qualitative image visual grading characteristics assessed image quality.

RESULTS

Patient demographics demonstrated no significant difference between each protocol except for patient weight in weight protocol IIB (p < 0.009). Mean effective dose in all protocols were significantly lower in Protocol B compared to A (p < 0.009). Contrast-to-noise ratio demonstrated no differences between each protocol (p < 0.21) except for weight protocol in protocol IIA (<60 kg, p = 0.035) with the visual grading characteristics demonstrating preference over protocol II compared to I.

CONCLUSION

Significant reduction in radiation dose can be achieved using patient-specific body weight-based protocols during whole-body ¹⁸F-FDG PET/CT without compromising image quality when employing weight-based protocols.

Reduced Contrast Volume and Radiation Dose During Computed Tomography of the Pancreas: Timing-Specific Contrast Media Protocol

RATIONALE AND OBJECTIVE

To investigate the opacification of the pancreatic vasculature and parenchyma during computed tomography utilizing a patient-specific contrast formula.

MATERIALS AND METHODS

This hybrid prospective and retrospective study was approved by the institution review board. In 220 consecutive patients, pancreatic CT was performed with one of two protocols: protocol A, 100mL of contrast material injected via timed bolus triggering technique; or protocol B, employing a patient-specific contrast media protocol specifically timed at the gastroduodenal artery; both protocols employed 4.5 mL/s contrast media and 100mL saline chaser. Attenuation of pancreatic parenchymal, arterial, and venous vasculature supplying the pancreas was measured. Effective dose was calculated. Data were compared to the independent two-sample t test. Receiver operating characteristic, visual grading characteristic, and Cohens' kappa analyses were performed.

RESULTS

Mean pancreatic density measurements in each of the pancreatic segments during the arterial and venous phase were significantly higher in Protocol B (mean ± standard deviation, art: 96.59 HU ± 27.37; venous: 91.28 HU ± 20.88) compared to A (art: 77.86 HU ± 21.14; venous: 73.99 HU ± 14.75) (p < 0.0001). Mean arterial opacification was significantly higher in protocol B compared to A with the abdominal aorta (p < 0.007), superior mesenteric (p < 0.0002), gastroduodenal (proximal segment only p < 0.014), and splenic arteries (p < 0.036). In the venous circulation, the inferior vena cava, superior mesenteric, portal and splenic veins (all segments) demonstrated significant reduction in vascular opacification protocol B compared to A (p < 0.001). The contrast media volume in protocol B (57.60 ± 12.25 mL) was significantly lower than in protocol A (100 ± 1 mL) (p < 0.001). Effective dose was significantly reduced in protocol B (2.75 ± 0.63 mSv) compared to A (4.015 ± 0.89 mSv) (p < 0.001). Receiver operating characteristic and visual grading characteristic analysis demonstrated significantly higher area under the curve for protocol B (p < 0.0001) (p < 0.034) respectively, with inter-reader agreement increasing from good to excellent in pancreatic lesion detection.

CONCLUSION

Timing-specific contrast media protocol enhances image quality at reduced contrast volume and radiation dose during computed tomography of the pancreas.

High comorbidity index is not associated with high morbidity and mortality when employing constrained arthroplasty as a primary treatment for intertrochanteric fractures in elderly patients

AIM

The aim of our study is to investigate the results of constrained total hip arthroplasty as a primary treatment of intertrochanteric fractures (ITF) in elderly patients with high comorbidities.

MATERIALS AND METHODS

Total hip replacement (THR) with a retentive cup was performed on 73 patients with ITF over the age of 54 years who had high comorbidities and a Charlson score above five. Short- and long-term complications were determined by follow-up. Bivariate analysis was conducted in order to determine the possible determinants of mortality and factors associated with comorbidity as measured by the Charlson comorbidities index.

RESULTS

Patient demographics that consisted of females (58.9%) (p < 0.04) with the mean age of both males and females demonstrated no statistical significance. The mean hospitalization time and weight bearing time were 11 and 2.67 days, respectively. Only 4.1% needed re-intervention due to re-fracture and none due to prosthesis failure. There was a statistical significance between the comorbidity index and the mortality rate. However, no statistical significance was identified between the comorbidity index and the functional status after constrained THR.

CONCLUSION

High comorbidity index is not associated with high morbidity and mortality when employing constrained arthroplasty as a primary treatment for ITF in elderly patients.

Sarcopenic obesity derived from PET/CT predicts mortality in lymphoma patients undergoing hematopoietic stem cell transplantation

BACKGROUND

Sarcopenic Obesity (SO) is associated with worse survival among chemotherapy recipients. Research on SO is scarce among lymphoma patients receiving Hematopoietic Stem Cell Transplantation (HSCT).

AIM

assess prevalence of SO pre-HSCT (T0) and 3 months post-HSCT (T1) in lymphoma patients and determine the power of SO at T0 and T1 in predicting survival.

METHODS

Consecutive patients (age ≥16 years) having B and T cell lymphoma who underwent SCT and who had PET/CT scan pre-SCT and 3 months post SCT were included in the study. A cross sectional image was analyzed at the level of the 3rd Lumber Vertebrae to assess body composition parameters.

RESULTS

93 patients [mean age: 38 (range: 17-70 years), 52 (55.9%) males, 45 (48%) Hodgkin and 48 (52%) Non-Hodgkin lymphoma, 81 (87%) autologous and 12 (13%) allogeneic SCT)] met the inclusion criteria. From T0 to T1, Sarcopenia rates increased (27% at T0 to 38% at T1, p = 0.013), Visceral adiposity decreased (46% at T0 to 30% at T1, p = 0.03) and SO decreased (42% at T0 to 20% at T1, p < 0.01). Length of stay, overall survival and progression free survival were significantly better in patients without sarcopenic obesity at T1. Cox-regression revealed SO at T1 was a risk factor for mortality [Adjusted Hazards Ratio = 8.2 (95% Confidence Interval: 1.9-36.2)].

CONCLUSION

Sarcopenic obesity, prevalent in 42% of patients pre-HSCT, decreased 3 months post HSCT as lymphoma patients lost skeletal muscle and visceral adipose tissues. SO at T1 was the most impactful risk factor for mortality.

Gadolinium and Multiple Sclerosis: Vessels, Barriers of the Brain, and Glymphatics

The pathogenesis of multiple sclerosis is characterized by a cascade of pathobiologic events, ranging from focal lymphocytic infiltration and microglia activation to demyelination and axonal degeneration. MS has several of the hallmarks of an inflammatory autoimmune disorder, including breakdown of the BBB. Gadolinium-enhanced MR imaging is currently the reference standard to detect active inflammatory lesions in MS. Knowledge of the patterns and mechanisms of contrast enhancement is vital to limit the radiologic differential diagnosis in the staging and evaluation of MS lesion activity. The aim of this review was the following: 1) to outline the pathophysiology of the effect of lymphocyte-driven inflammation in MS, 2) to describe the effects of gadolinium on the BBB and glymphatic system, and 3) to describe gadolinium enhancement patterns and artifacts that can mimic lesions in MS.

Split-bolus contrast injection protocol enhances the visualization of the thoracic vasculature and reduced radiation dose during chest CT

OBJECTIVE

To investigate the visualization of mediastinal lymph nodes during thoracic CT employing a multiphasic contrast media (CM) protocol.

METHODS

Institutional review board approved retrospective study consisting of 300 patients with known chest malignancy. Patients were allocated to one of two CM protocols: Protocol A, consisted of dual bolus (Phase 1:100 ml CM followed by 100 ml saline chaser) i.v. injected at 2.5 ml s^-1; Protocol B employed 100 ml of CM using a multiphasic injection protocol (Phase 1 and 2:60 ml contrast and saline, followed by Phase 3 and 4:40 ml contrast and saline injected at 2.5 ml s^-1) with a fixed scan delay of 70 s for each acquisition. Attenuation profiles of the thoracic arteries and veins were calculated as well as the arterio-venous contrast ratios (AVCR). Receiver operating characteristic (ROC), visual grading characteristic (VGC), and Cohen's kappa analysis were assessed.

RESULTS

Arterial opacification was up to 24% (p < 0.032) higher in protocol B than A, whereas, in the veins it was significantly lower in protocol B than A, with a maximum reduction of up to 84% (p < 0.0001). There was no statistical significance between the central and peripheral pulmonary arteries [>263 Hounsfield units (HU)] in each protocol. Protocol B, demonstrated significant improvement in AVCR at various anatomical sites (p < 0.002). Radiation dose was significantly reduced in protocol B compared to A (p < 0.004). Both ROC and VGC demonstrated significantly higher Az score for protocol B compared to A (p < 0.0001) with an increased inter reader agreement from poor to excellent.

CONCLUSION

Employing a multiphasic CM protocol significantly improves opacification of the thoracic vasculature and visualization of mediastinal lymph nodes during thoracic CT.

ADVANCES IN KNOWLEDGE

Uniform opacification between thoracic arteries and veins increases the delineation between vasculature and lymph nodes, reduces radiation dose when employing a multiphase contrast media injection protocol.

Knowledge and practice of computed tomography exposure parameters amongst radiographers in Jordan

OBJECTIVE

To investigate the knowledge and practice of computed tomography (CT) radiographers working in Jordan.

MATERIALS AND METHODS

This Institutional Review Board (IRB) approved study disseminated a questionnaire via social media and recruited 54 Jordanian CT radiographers. The questionnaire comprised 36 questions divided into four sections: demographics; an evaluation of knowledge regarding CT exposure; modifications to CT exposure for paediatric patients; dose units and diagnostic reference levels (DRLs). Descriptive and inferential statistics including Chi-square tests, Mann-Whitney U tests, independent samples t-tests and Kruskal-Wallis H tests were employed. Statistical significance was considered below p < 0.05.

RESULTS

The 54 participants had various qualifications, with the majority holding a Bachelor's degree (n = 35, 64.8%) and the rest holding a Diploma (n = 19, 35.2%). In order to pass the questionnaire, participants needed to score 13 correct answers. The overall number of radiographers who correctly passed the questionnaire was 48 (88.9%). None of the participants correctly stated all the DRL values for chest, abdomen and brain CT. However, four out of 54 respondents (7.4%) knew the chest DRL value, three (5.6%) participants correctly estimated the abdominal DRL value but only two (3.7%) knew the DRL for the brain.

CONCLUSION

Good general knowledge was found amongst radiographers regarding the relationship of each exposure parameter to the image quality and patient dose. However, there was poor knowledge of diagnostic reference levels and the order of the organ radiation sensitivity. The need for CT radiographers to undertake further education that focuses on radiation exposure in CT is highlighted.

Knowledge, attitude and practice regarding clinical and self breast examination among radiology professionals

Aim: This study aims to assess the knowledge, attitudes and practices of radiology professionals in Jordan in regard to breast cancer (BC) screening. Methods: An IRB approved, online-based study was carried out in Jordan. The participants were radiologists (n = 8) and radiographers (n = 64). Results: The results showed that although 61.8% of participants were knowledgeable about BC prevention, only 65.7% (n = 48) of respondents performed breast self-examinations (BSE) on themselves, 28.7% (n = 21) underwent clinical breast examination (CBE) and 15.1% (n = 5) underwent either diagnostic or screening mammography. Conclusion: Radiology professionals are generally aware of the benefits of BC screening and its ability to facilitate early diagnosis of BC. Although some practitioners advise their relatives to perform BSEs and attend CBE, low percentages of respondents performed BSEs themselves or undergo CBE.

Intestinal obstruction caused by a strangulating adnexa: a rare complication of ovarian sparing hysterectomy

Intestinal obstruction caused by a remnant fallopian tube from previous hysterectomy is a rare entity that has been reported once in the literature. We report the case of a 61-year-old woman who presented with both small and large bowel obstructions caused by a strangulating remnant fallopian tube. She had an ovarian sparing hysterectomy 16 years ago and was diagnosed with antiphospholipid syndrome. Our case report will discuss the clinical presentation, imaging and outcome of the patient. It will also briefly tackle other rare causes of bowel obstruction.

Anomalous origin of the right coronary artery from the mid-left anterior descending coronary artery: association with acute myocardial infarction

Congenital abnormalities of the coronary arteries are uncommon but can be associated with important cardiac events depending on their location and the course of the aberrant artery. Conventional angiography has been the gold standard for the diagnosis of these anomalies. The recent development of cardiac CT has allowed accurate and non-invasive depiction of coronary artery anomalies in terms of their origin, course and termination. We describe the case of a patient presenting with acute inferior myocardial infarction who was found to have a very rare congenital abnormality consisting of an anomalous origin of the right coronary artery from the mid-segment of the left anterior descending. Coronary angiography and cardiac CT angiographic images are shown and discussed.

Swine Atrioventricular Node Ablation Using Stereotactic Radiosurgery: Methods and In Vivo Feasibility Investigation for Catheter-Free Ablation of Cardiac Arrhythmias

Background

Linear accelerator–based stereotactic radiosurgery delivered to cardiac arrhythmogenic foci could be a promising catheter‐free ablation modality. We tested the feasibility of in vivo atrioventricular (AV) node ablation in swine using stereotactic radiosurgery.

Methods and Results

Five Large White breed swine (weight 40–75 kg; 4 females) were studied. Single‐chamber St Jude pacemakers were implanted in each pig. The pigs were placed under general anesthesia, and coronary/cardiac computed tomography simulation scans were performed to localize the AV node. Cone beam computed tomography was used for target positioning. Stereotactic radiosurgery doses ranging from 35 to 40 Gy were delivered by a linear accelerator to the AV node, and the pigs were followed up with weekly pacemaker interrogations to observe for potential electrocardiographic changes. Once changes were observed, the pigs were euthanized, and pathology specimens of various tissues, including the AV node and tissues surrounding the AV node, were taken to study the effects of radiation. All 5 pigs had disturbances of AV conduction with progressive transition into complete heart block. Macroscopic inspection did not reveal damage to the myocardium, and pigs had preserved systolic function on echocardiography. Immunostaining revealed fibrosis in the target region of the AV node, whereas no fibrosis was detected in the nontargeted regions.

Conclusions

Catheter‐free radioablation using linear accelerator–based stereotactic radiosurgery is feasible in an intact swine model.

Qualitative and quantitative radiological analysis of non-contrast CT is a strong indicator in patients with acute pyelonephritis

OBJECTIVE

To evaluate the performance of non-contrast computed tomography (CT) by reporting the difference in attenuation between normal and inflamed renal parenchyma in patients clinically diagnosed with acute pyelonephritis (APN).

MATERIAL AND METHODS

This is a retrospective study concerned with non-contrast CT evaluation of 74 patients, admitted with a clinical diagnosis of APN and failed to respond to 48h antibiotics treatment. Mean attenuation values in Hounsfield units (HU) were measured in the upper, middle and lower segments of the inflamed and the normal kidney of the same patient. Independent t-test was performed for statistical analysis. Image evaluation included receiver operating characteristic (ROC), visual grading characteristic (VGC) and kappa analyses.

RESULTS

The mean attenuation in the upper, middle and lower segments of the inflamed renal cortex was 32%, 25%, and 29% lower than the mean attenuation of the corresponding cortical segments of the contralateral normal kidney, respectively (p<0.01). The mean attenuation in the upper, middle, and lower segments of the inflamed renal medulla was 48%, 21%, and 30%, lower than the mean attenuation of the corresponding medullary segments of the contralateral normal kidney (p<0.02). The mean attenuation between the inflamed and non-inflamed renal cortex and medulla was 29% and 30% lower respectively (p<0.001). The AUCROC (p<0.001) analysis demonstrated significantly higher scores for pathology detection, irrespective of image quality, compared to clinical and laboratory results with an increased inter-reader agreement from poor to substantial.

CONCLUSION

Non-contrast CT showed a significant decrease in the parenchymal density of the kidney affected with APN in comparison to the contralateral normal kidney of the same patient. This can be incorporated in the diagnostic criteria of APN in NCCT in the emergency setting.

Renal pseudoaneurysm formation post allograft biopsy: a case report

Renal pseudoaneurysm (PSA) is a rare complication post kidney transplant biopsy that accounts for less than 1% of allograft dysfunction. Imaging guidelines in the diagnosis of renal PSA have not yet been developed owing to the low occurrence and limited data availability. However, contrast-enhanced CT and magnetic resonance angiography (MRA) are the preferred modalities in detecting PSA owing to the high contrast and spatial resolution. However, magnetic resonance angiography is preferred since non-contrast imaging techniques can see blood flow patterns in renal PSA without the use of contrast media that may alter renal function. We present a rare complication in a 48-year-old male receiving a living related kidney transplant and found to have renal PSA post allograft biopsy. We review the clinical features, imaging and treatment outcome with the developed PSA in the transplanted kidney post allograft biopsy.

Synchronisation between contrast media administration and caudocranial scan direction increases visualisation of altered coronary artery blood flow in patients presenting with dual left anterior descending coronary artery

Coronary CT angiography (CCTA) has the advantage over invasive coronary angiography in that its non-invasive nature and minimal risk on patients. CCTA enables accurate assessment of the entire heart, coronary artery system and thorax, displaying three-dimensional information about the spatial relations of the anomalous vessels and surrounding intraluminal and extraluminal anatomy, and thereby contributing clinically important prognostic information. Dual left anterior descending (LAD) coronary artery consists of of two LAD arteries within the anterior interventricular sulcus (AIVS). Type 4 is infrequently reported subtype and differs from the others, with a long LAD originating from the right coronary artery (Mercado, A., Johnson Jr, G., Calver, D., & Sokol, R. J. (1989). Cocaine, pregnancy, and postpartum intracerebral hemorrhage. Obstetrics & Gynecology, 73(3, Part 2), 467-468. and the short LAD originating from the left main coronary artery. However, the radiological features between the short LAD and septal coronary arteries remain a controversy, with the latter being determined by CCTA. We present a case report based on short LAD terminating proximally in the AIVS and the long LAD originating from the RCA and terminating into the distal AIVS with the later having a long septal travelling parallel to the long LAD.

Increased image quality and reduced radiation dose and contrast media volume: a holistic approach to intracranial CTA

AIM

To investigate the dose-length product (DLP) during intracranial computed tomography angiography (CTA) using a patient-specific contrast formula.

MATERIALS AND METHODS

Intracranial CTA was performed on 120 patients using 64-channel CT. Patients were subjected in equal numbers to one of two acquisitions/contrast medium protocols. Protocol A, consisted of 80 ml contrast medium and protocol B, involved a novel contrast medium formula. In each protocol, contrast medium and saline were injected at a flow rate of 4.5 ml/s. The DLP and contrast volume (CV) were measured between each protocol and the data obtained were compared using two-tailed independent t-test.

RESULTS

Mean arterial vessel attenuation was up to 56% (p<0.01) higher using protocol B compared with A. In the venous system, the mean vessel attenuation was significantly lower in protocol B than A with a maximum reduction of 93% (p<0.001). The mean CV was significantly lower in protocol B (53±10 ml) compared to A (80±1 ml, p<0.001). The scan time was equal in each protocol (B, 4.22±1.2 seconds; A, 4.01±1.3 seconds). A significant reduction in mean DLP was demonstrated in protocol B (3.99±0.22 mSv) compared to A (4.74±0.22 mSv; p=0.02).

CONCLUSION

A significant reduction in CV and DLP during intracranial CTA can be achieved when employing a patient-specific contrast medium formula.

Magnetic resonance imaging findings of central nervous system in lysosomal storage diseases: A pictorial review

Lysosomal storage diseases (LSD) are a complex group of genetic disorders that are a result of inborn errors of metabolism. These errors result in a variety of metabolic dysfunction and build-up certain molecules within the tissues of the central nervous system (CNS). Although, they have discrete enzymatic deficiencies, symptomology and CNS imaging findings can overlap with each other, which can become challenging to radiologists. The purpose of this paper is to review the most common CNS imaging findings in LSD in order to familiarize the radiologist with their imaging findings and help narrow down the differential diagnosis.

The diagnostic yield of ultrasound of the head in healthy infants presenting with the clinical diagnosis of benign macrocrania

AIM

To investigate the frequency of sonographic findings that required neurosurgical consultation for all referred outpatients suspected to have benign macrocrania (BMC).

MATERIALS AND METHODS

A retrospective review was performed from September 2011 until June 2015 for all outpatients referred to the ultrasound (US) department for BMC. Electronic medical records, US images, and reports were reviewed in conjunction with follow-up imaging. Each review consisted of gender, specialty of referring physician, first head circumference, head circumference at or closest to the time of the head US, the last head circumference, and any neurological issue prior to the US, at the time of US, or following the US, and clinical outcomes. Statistical analysis employed the Kruskal-Wallis rank sum test and Fischer's exact test (chi square test of independence) that compared normal/BMC patients from the patients requiring a neurosurgical consultation.

RESULTS

One hundred and thirty (40.9%) had a normal head US, 181 patients (56.9%) had sonographic findings of BMC, and seven (2.2%) patients had an abnormal head US that required a neurosurgical consultation. Of the 181 patients with BMC, 23 underwent follow-up imaging with 22 patients having unchanged BMC or a normal head US and one patient developing mild ventriculomegaly that was stable on follow-up imaging. Three of the seven patients (1%) aged 1.8, 2.3, and 13.1 months with abnormal head US requiring neurosurgical consultation, had mild ventriculomegaly that was stable on follow-up imaging. Four of the seven patients (1.2%) that required neurosurgical consultation needed a neurosurgical procedure. Between the two US subgroups (normal and BMC), no statistical significance was noted regarding age of patient at US, head circumference at clinical and radiological presentation (p>0.05) except for the first head circumference clinically documented which demonstrated statistical significance (p<0.03).

CONCLUSION

Short interval surveillance including head circumference and assessment for the development of bulging anterior fontanelle and neurological abnormalities may be more cost effective than US in the initial evaluation of patients clinically suspected to have BMC.

Congenital anomalies of lumbosacral spine: A pictorial review

Congenital malformations of the lumbosacral spine include spinal dysraphism and caudal anomalies. Most often, these malformations are discovered prenatally or in early infancy, but some are not diagnosed until late childhood or adulthood. The purpose of this pictorial review is to illustrate the multi-modality imaging characteristics in these complex anomalies and to provide a systematic radiological approach aiming at improving diagnostic accuracy.