Comparison Of Radiation Dose Research Articles

Application value of split-bolus contrast injection combined with dual-energy CT scanning technology in pediatric CTU imaging.

To explore the clinical value of combining split-bolus contrast injection with dual-energy CT(DECT) scanning technology in pediatric computed tomography urography (CTU) imaging. A total of 128 children aged 0-17years were prospectively selected and randomly assigned to three groups: A, B, and C. For Group A, a high-pitch flash mode was employed, where a single bolus of contrast agent was followed by four-phase scanning (noncontrast, cortex, medulla, and excretory phases). In Group B, a dual-energy scanning mode was used with a split-bolus injection technique (50% of the contrast agent was administered initially, followed by the remaining 50% after 37-43s), and the children underwent two-phase scanning (corticomedullary and excretory phases). In Group C, dual-energy scanning was similarly used with a split-bolus injection technique (65% contrast agent was administered initially, followed by the remaining 35% after 37-43s), along with two-phase scanning (corticomedullary and excretory phases). Virtual noncontrast (VNC) images were obtained from the corticomedullary phase images using iodine subtraction techniques for Groups B and C. The image quality and radiation dose across the groups were compared and analysed. When the CT values of the renal cortex, erector spinae muscles, and standard deviation (SD) values were compared between Group A's cortical phase and Groups B and C's corticomedullary phases, the order was Group B > Group C > Group A (P < 0.05). The comparison of the cortical CNR and SNR between Group A's cortical phase and Groups B's and C's corticomedullary phases (cortices) revealed that Group C > Group B > Group A (P < 0.05). The comparison of the medullary CNR and SNR between Group A's medullary phase and Groups B and C's corticomedullary phases (medulla) showed that Group A > Group C > Group B (P < 0.05). The scores for the VNC images in Groups B and C were lower than those for the true noncontrast (TNC) images in Group A (P > 0.05). In the subjective evaluations of the corticomedullary and excretory phase images, Group B > Group C > Group A (P < 0.05). The comparison of radiation doses revealed that Group B < Group C<Group A (P < 0.05). A significant correlation was found between BMI and the effective radiation dose (P < 0.01), with a correlation coefficient of 0.62. The combination of split-bolus contrast injection and DECT enhances image quality in pediatric CTU while reducing radiation dosage.

Cardiac functional assessment using prospectively electrocardiography-triggered computed tomography in children with congenital heart disease: Comparison of radiation dose and image quality between heart rate-dependent single-extended and heart rate-independent dual-focused scans

PurposeTo evaluate radiation dose (RD) reduction potential of heart rate-independent dual-focused scan of prospectively electrocardiography (ECG)-triggered computed tomography (CT) for cardiac functional assessment in children with congenital heart disease (CHD), RD and image quality of the scan mode were compared to those of heart rate-dependent single-extended scan. MethodsThis study encompassed 1,252 prospectively ECG-triggered pediatric cardiothoracic CT examinations, including single-focused (a reference in matched comparisons), single-extended (younger patients), and dual-focused (older patients) scans. Propensity score matching was used to reduce the confounding effect of age and sex in two matched groups (MPs) (younger MP: single-focused vs. single-extended; older MP: single-focused vs. dual-focused). CT RD, image noise, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) of the MPs were compared. ResultsThe effective dose of single-extended (1.4 ± 0.5 mSv) and dual-focused (1.1 ± 0.4 mSv) scans were approximately 2.0–3.2 times higher than (depending on heart rate) and approximately 1.8 times (irrespective of heart rate) that of the age- and sex-matched single-focused scans (0.6 ± 0.2 mSv), respectively. Image noise and SNR of single-extended and dual-focused scans were similar to those of the age- and sex-matched single-focused scans (p values > 0.05). The CNR was also comparable between single-focused and single-extended scans (younger MP) (p > 0.05), but a slightly lower CNR of the dual-focused scans compared to single-focused scans was observed in the older MP (p < 0.02). ConclusionFor cardiac functional assessment in children with CHD, heart rate-independent dual-focused prospectively ECG-triggered scan can reduce CT RD, especially at lower heart rates, with comparable image quality, compared to heart rate-dependent single-extended scan.

Evaluating the Efficacy of Deep Learning Reconstruction in Reducing Radiation Dose for Computer-Aided Volumetry for Liver Tumor: A Phantom Study.

The purpose of this study was to compare radiation dose reduction capability for accurate liver tumor measurements of a computer-aided volumetry (CADv) software for filtered back projection (FBP), hybrid-type iterative reconstruction (IR), mode-based iterative reconstruction (MBIR), and deep learning reconstruction (DLR) at a phantom study. A commercially available anthropomorphic abdominal phantom was scanned five times with a 320-detector row CT at 600 mA, 400 mA, 200 mA, and 100 mA and reconstructed by four methods. Signal-to-noise ratios (SNRs) of all lesions within the arterial and portal-venous phase inserts were calculated, and SNR of the lesion phantom was compared with that of all reconstruction methods by means of Tukey's honestly significant difference (HSD) test. Then, tumor volume (V) of each nodule was automatically measured using commercially available CADv software. To compare dose reduction capability for each reconstruction method at both phases, mean differences between measured V and standard references were compared by Tukey's honestly significant difference test among the four different reconstruction methods on CT obtained at each of the four tube currents. With each of the tube currents, SNRs for MBIR and DLR were significantly higher than those for FBP and hybrid-type IR (p < 0.05). At the arterial phase, the mean difference in V for the CT protocol obtained at 600 or 100 mA and reconstructed with DLR was significantly smaller than that for others (p < 0.05). At the portal-venous phase, the mean differences in V for the CT protocol obtained at 100 mA and reconstructed with hybrid-type IR, MBIR, and DLR were significantly smaller than that for FBP (p < 0.05). Findings of our phantom study show that reconstruction method had influence on CADv merits for abdominal CT with not only standard but also reduced dose examinations and that DLR can potentially yield better image quality and CADv measurements than FBP, hybrid-type IR, or MBIR in this setting.

Low-dose high-resolution chest CT in adults with cystic fibrosis: intraindividual comparison between photon-counting and energy-integrating detector CT

BackgroundRegular disease monitoring with low-dose high-resolution (LD-HR) computed tomography (CT) scans is necessary for the clinical management of people with cystic fibrosis (pwCF). The aim of this study was to compare the image quality and radiation dose of LD-HR protocols between photon-counting CT (PCCT) and energy-integrating detector system CT (EID-CT) in pwCF.MethodsThis retrospective study included 23 pwCF undergoing LD-HR chest CT with PCCT who had previously undergone LD-HR chest CT with EID-CT. An intraindividual comparison of radiation dose and image quality was conducted. The study measured the dose-length product, volumetric CT dose index, effective dose and signal-to-noise ratio (SNR). Three blinded radiologists assessed the overall image quality, image sharpness, and image noise using a 5-point Likert scale ranging from 1 (deficient) to 5 (very good) for image quality and image sharpness and from 1 (very high) to 5 (very low) for image noise.ResultsPCCT used approximately 42% less radiation dose than EID-CT (median effective dose 0.54 versus 0.93 mSv, p < 0.001). PCCT was consistently rated higher than EID-CT for overall image quality and image sharpness. Additionally, image noise was lower with PCCT compared to EID-CT. The average SNR of the lung parenchyma was lower with PCCT compared to EID-CT (p < 0.001).ConclusionIn pwCF, LD-HR chest CT protocols using PCCT scans provided significantly better image quality and reduced radiation exposure compared to EID-CT.Relevance statementIn pwCF, regular follow-up could be performed through photon-counting CT instead of EID-CT, with substantial advantages in terms of both lower radiation exposure and increased image quality.Key PointsPhoton-counting CT (PCCT) and energy-integrating detector system CT (EID-CT) were compared in 23 people with cystic fibrosis (pwCF).Image quality was rated higher for PCCT than for EID-CT.PCCT used approximately 42% less radiation dose and offered superior image quality than EID-CT.Graphical

Comparison of Radiation Doses for Different Techniques in Fluoroscopy-Guided Lumbar Facet Medial Branch Blocks: A Retrospective Cohort Study.

Chronic lumbar facet pain is commonly treated with fluoroscopy-guided facet medial branch blocks (FMBBs). However, the associated radiation exposure of both patients and clinicians is a growing concern. This study aimed to compare radiation doses and fluoroscopy times between two techniques, i.e., oblique and posterior-anterior (PA) fluoroscopic approaches, while also examining the impact of physician experience on these metrics. A retrospective analysis was conducted on 180 patients treated at Mersin University Hospital Pain Clinic between January and July 2024. Patients were divided into two groups: 90 received the oblique technique (Group O) and 90 received the AP technique (Group A). Radiation dose and fluoroscopy time data were collected for each patient. The AP technique was associated with significantly lower radiation doses (mean 66 mGy) and shorter fluoroscopy times (mean 28 s) compared to the oblique technique (mean radiation dose of 109 mGy and fluoroscopy time of 46 s) (p < 0.001). Physician experience also influenced these outcomes, with more experienced physicians consistently using less radiation. The AP technique should be considered for FMBBs, as it reduces radiation exposure while maintaining procedural efficiency, highlighting the importance of experience in optimizing outcomes.

P41. Eye radiation dose comparison between surgical loupes, lead-lined glasses, and plastic face shield

P41. Eye radiation dose comparison between surgical loupes, lead-lined glasses, and plastic face shield

Low-iodine-dose computed tomography coupled with an artificial intelligence-based contrast-boosting technique in children: a retrospective study on comparison with conventional-iodine-dose computed tomography

BackgroundLow-iodine-dose computed tomography (CT) protocols have emerged to mitigate the risks associated with contrast injection, often resulting in decreased image quality.ObjectiveTo evaluate the image quality of low-iodine-dose CT combined with an artificial intelligence (AI)-based contrast-boosting technique in abdominal CT, compared to a standard-iodine-dose protocol in children.Materials and methodsThis single-center retrospective study included 35 pediatric patients (mean age 9.2 years, range 1–17 years) who underwent sequential abdominal CT scans—one with a standard-iodine-dose protocol (standard-dose group, Iobitridol 350 mgI/mL) and another with a low-iodine-dose protocol (low-dose group, Iohexol 240 mgI/mL)—within a 4-month interval from January 2022 to July 2022. The low-iodine CT protocol was reconstructed using an AI-based contrast-boosting technique (contrast-boosted group). Quantitative and qualitative parameters were measured in the three groups. For qualitative parameters, interobserver agreement was assessed using the intraclass correlation coefficient, and mean values were employed for subsequent analyses. For quantitative analysis of the three groups, repeated measures one-way analysis of variance with post hoc pairwise analysis was used. For qualitative analysis, the Friedman test followed by post hoc pairwise analysis was used. Paired t-tests were employed to compare radiation dose and iodine uptake between the standard- and low-dose groups.ResultsThe standard-dose group exhibited higher attenuation, contrast-to-noise ratio (CNR), and signal-to-noise ratio (SNR) of organs and vessels compared to the low-dose group (all P-values < 0.05 except for liver SNR, P = 0.12). However, noise levels did not differ between the standard- and low-dose groups (P = 0.86). The contrast-boosted group had increased attenuation, CNR, and SNR of organs and vessels, and reduced noise compared with the low-dose group (all P < 0.05). The contrast-boosted group showed no differences in attenuation, CNR, and SNR of organs and vessels (all P > 0.05), and lower noise (P = 0.002), than the standard-dose group. In qualitative analysis, the contrast-boosted group did not differ regarding vessel enhancement and lesion conspicuity (P > 0.05) but had lower noise (P < 0.05) and higher organ enhancement and artifacts (all P < 0.05) than the standard-dose group. While iodine uptake was significantly reduced in low-iodine-dose CT (P < 0.001), there was no difference in radiation dose between standard- and low-iodine-dose CT (all P > 0.05).ConclusionLow-iodine-dose abdominal CT, combined with an AI-based contrast-boosting technique exhibited comparable organ and vessel enhancement, as well as lesion conspicuity compared to standard-iodine-dose CT in children. Moreover, image noise decreased in the contrast-boosted group, albeit with an increase in artifacts.Graphical

Comparison of Image Quality and Radiation Dose in Pediatric Temporal Bone CT Using Photon-Counting Detector CT and Energy-Integrating Detector CT.

Currently, there is a lack of research directly comparing photon-counting detector CT (PCD-CT) and energy-integrating detector CT (EID-CT) in pediatric temporal bone CT imaging. The purpose of this study was to compare the image quality and radiation dose of temporal bone CT scans in pediatric patients acquired with PCD-CT and EID-CT. The retrospective study included a total of 110 pediatric temporal bone CT scans (PCD-CT, n = 52; EID-CT, n = 58). Two independent readers evaluated the spatial resolution of 4 anatomic structures (tympanic membrane, incudostapedial joint, stapedial crura, and cochlear modiolus) and overall image quality by using a 4-point scale. Interreader agreement was assessed. Dose-length product for each CT was compared, and subgroup analyses were performed based on age (younger than 3 years, 3-5 years, 6-11 years, and 12 years and above). PCD-CT demonstrated statistically significantly higher scores than EID-CT for all items (tympanic membrane, 2.9 versus 2.4; incudostapedial joint, 3.6 versus 2.6; stapedial crura, 3.2 versus 2.4; cochlear modiolus, 3.4 versus 2.8; overall image quality, 3.6 versus 2.8; P < .05). Interreader agreement ranged from good to excellent (interclass correlation coefficients, 0.6-0.81). PCD-CT exhibited a 43% dose reduction compared with EID-CT, with a particularly substantial reduction of over 70% in the subgroups of children younger than 6 years. PCD temporal bone CT achieves significantly superior imaging quality at a lower radiation dose compared with EID-CT.

Comparing Radiation Doses in CBCT and Medical CT Imaging for Dental Applications.

Dental imaging plays a crucial role in diagnosis and treatment planning, with cone-beam computed tomography (CBCT) and medical computed tomography (CT) being two common modalities. This study aims to compare the radiation doses associated with CBCT and medical CT imaging in dental applications to assess their relative safety and efficacy. We conducted a retrospective study using data from 100 patients who underwent both CBCT and medical CT scans for dental purposes. The radiation doses were measured in terms of dose-length product (DLP) for medical CT and dose-area product (DAP) for CBCT. The effective dose (ED) was calculated using appropriate conversion factors. Patient demographics, scan parameters, and radiation doses were recorded and analyzed. The results indicated that the mean DLP for medical CT scans was 220 mGycm, whereas the mean DAP for CBCT scans was 150 mGycm². The corresponding mean effective doses for medical CT and CBCT were 2.5 mSv and 1.8 mSv, respectively. The radiation dose from CBCT was found to be approximately 28% lower than that from medical CT. This study demonstrates that CBCT imaging for dental applications results in significantly lower radiation doses compared to medical CT. While both modalities provide valuable diagnostic information, the choice of imaging technique should consider the balance between diagnostic quality and radiation exposure, especially for pediatric and high-risk patients. Dental practitioners should be aware of the potential dose reduction benefits associated with CBCT when appropriate for the clinical scenario.

Comparison of Radiation Doses of Contralateral Oblique and Lateral View for Fluoroscopy-Guided Lumbar Interlaminar Epidural Steroid Injection

BACKGROUND: Despite newly developing technologies and techniques, the use of fluoroscopic guidance in spinal interventional treatments remains popular. Therefore, it is essential to set reference standards and techniques for reducing radiation exposure in fluoroscopy-guided procedures. OBJECTIVE: The aim of this study was is to compare the radiation doses and procedure time of the contralateral oblique (CLO) view to lateral view imaging during fluoroscopy-guided spinal procedures. STUDY DESIGN: A retrospective study. SETTING: Pain management unit of a tertiary care center. METHODS: An evaluation of patients who received epidural steroid injections between May 2021 and May 2023 in a university hospital interventional pain management center was performed. This observational study was conducted with 248 patients aged 18 and older who underwent lumbar interlaminar epidural injections (ILESI) confirmed by CLO or lateral oblique imaging. The primary outcomes were the comparison of radiation dose and procedure time between the 2 groups. The secondary outcome was the comparison of complication rates. RESULTS: There were no significant differences between the two groups in terms of age, gender, diagnosis, body mass index, procedure level, Numeric Rating Scale, and procedure time. Although the radiation dose was lower in the CLO group, there was no significant difference between the 2 groups. However, there was a significant difference between the 2 groups in terms of complications (P &lt; 0.001). LIMITATIONS: The study was designed in a single center and performing all the procedures with the same fluoroscopy device makes it difficult to generalize our results. CONCLUSIONS: Although there was no difference in terms of radiation dose and duration of procedure between lumbar ILESI conducting using the CLO or lateral view fluoroscopy imaging, there was a significant difference in terms of complications. Therefore, conducting lumbar ILESI using a CLO view minimizes the complication rate. KEY WORDS: Epidural injection, interlaminar injection, radiation dose, fluoroscopy, contralateral oblique

Comparing Radiation Doses in CBCT and Medical CT Imaging for Dental Applications.

We are always concerned about radiation exposure during dental imaging procedures. We explore the crucial differences in radiation doses between Cone Beam Computed Tomography (CBCT) and Medical computed tomography (CT) imaging, aiming to shed light on the safety and efficiency of these techniques. In this study, we conducted a comprehensive analysis using state-of-the-art dental imaging equipment. We employed phantoms that simulated real dental scenarios, ensuring accuracy in our measurements. The radiation doses were measured with precision dosimeters, and various exposure settings were tested to obtain a comprehensive dataset. Our findings reveal substantial differences in radiation doses between CBCT and Medical CT for dental applications. In the case of CBCT, the average effective dose was found to be approximately 100 microsieverts (μSv), making it a preferable choice for routine dental imaging. Medical CT, on the other hand, yielded significantly higher radiation exposure, with an average effective dose exceeding 500 μSv, emphasizing its need for specific clinical scenarios. In conclusion, the choice between CBCT and Medical CT for dental applications should be made with careful consideration of radiation dose implications. CBCT emerges as the safer and more efficient option for routine dental imaging, offering a lower radiation burden to patients while still delivering high-quality diagnostic images. However, Medical CT may be necessary for specialized cases where the additional radiation risk is justified by diagnostic requirements.

Dual-energy CT applications in musculoskeletal disorders.

Dual-energy CT (DECT) is an exciting application in CT technology conferring many advantages over conventional single-energy CT at no additional with comparable radiation dose to the patient. Various emerging and increasingly established clinical DECT applications in musculoskeletal (MSK) imaging such as bone marrow oedema detection, metal artefact reduction, monosodium urate analysis, and collagen analysis for ligamentous, meniscal, and disc injuries are made possible through its advanced DECT post-processing capabilities. These provide superior information on tissue composition, artefact reduction and image optimization. Newer DECT applications to evaluate fat fraction for sarcopenia, Rho/Z application for soft tissue calcification differentiation, 3D rendering, and AI integration are being assessed for future use. In this article, we will discuss the established and developing applications of DECT in the setting of MSK radiology as well as the basic principles of DECT which facilitate them.

Radiation doses received in the UK breast screening programmes 2019-2023.

To report the latest UK mammography dose survey results and to compare radiation doses from digital breast tomosynthesis (DBT) and full-field digital mammography (FFDM) in UK breast screening. Anonymized exposure factors were collected for 111 152 screening cases and 5113 assessment cases from 405 x-ray sets across the United Kingdom using an online submission system linked to a national database of mammography quality control data. Output and beam quality measurements from each set were combined with exposure data to estimate mean glandular doses (MGD). FFDM doses increased by ∼10% compared to the 2016-2019 national survey but compressed breast thicknesses (CBT) remained similar. DBT doses were 34%-40% higher than FFDM overall and 34% higher than FFDM for breasts 50-60mm thick. We found a possible overestimation of PMMA breast equivalent thicknesses at low CBTs, but the evidence was not conclusive. Recent changes to the mix of x-ray models in use in UK breast screening have resulted in higher FFDM breast doses. DBT doses in the NHSBSP are on average higher than FFDM by ∼34%-40%. This is the first national study to report DBT and FFDM MGDs in UK breast screening.

P352 Comparison of Radiation Dose, Image Quality, and Diagnostic Performance between Hybrid Iterative Reconstruction and Deep Learning Reconstruction for CT Enterography of IBD

Abstract Background CT enterography (CTE) is recommended as one of the preferred methods for patients with inflammatory bowel disease (IBD), especially in primary hospitals that lack MRI equipment. However, the potential risk of radiation derived from using CTE during the life-long follow-up is an important issue for these patients. This study aimed to compare the radiation dose, image quality, and diagnostic performance of CTE for IBD using hybrid iterative reconstruction (HIR) and deep learning reconstruction (DLR). Methods We prospectively collected data on low dose CTE reconstructed by HIR and DLR in patients with IBD between February 2023 and September 2023, and retrospectively enrolled IBD patients who underwent conventional dose CTE reconstructed by HIR between June 2019 and June 2022 as controls. The CTE examinations were performed within 2 weeks of bowel histologic evaluation (the reference standard of bowel inflammation). The objective and subjective image quality and the image features were evaluated by two IBD radiologists. The radiation dose, image quality, and diagnostic performance was compared between the two dose protocols. Results The preliminary study included 36 patients in the low dose group with HIR and DLR and 40 patients in the conventional dose group with HIR. There were no significant differences in demographic data of patients between the two groups (all P&amp;gt;0.05). The sensitivity, specificity, and diagnostic accuracy for detecting active inflammation were 71.4% (43.3%), 83.3% (80.0%), and 75.0% (52.5%) for the low dose group with DLR (HIR), respectively, and 84.4%, 62.5%, and 80% for the conventional dose HIR group. Low dose group with DLR resulted in significantly increased objective and subjective image quality and diagnostic confidence for active inflammation compared to low dose group with HIR (all P&amp;lt;0.05), with no inferiority to conventional dose group with HIR (all P&amp;gt;0.05). The dichotomous inter-reader reliability (k) for the entire group was 0.88. Low dose group resulted in a significant reduction in radiation exposure (mean [± SD], 2.20 ± 0.29 mSv) compared to conventional dose group (4.85 ± 1.96 mSv; P&amp;lt;0.001). Conclusion Low dose CTE with DLR significantly improved image quality compared to low dose CTE with HIR, and maintained similarly high diagnostic performance as conventional dose CTE with HIR. Importantly, the low dose CTE with DLR significantly reduced the radiation dose, improving the safety of CTE application in the life-long follow-up of patients with IBD.

Comparison of CBCT radiation doses with conventional radiographs in TMJ imaging using Monte Carlo simulations.

Three-dimensional imaging methods are widely used for evaluation of bony changes of temporomandibular joint (TMJ). Besides, lateral and posterio-anterior TMJ projections in both closed- and open-jaw positions for each temporomandibular joint are used as two-dimensional diagnostic tools. The purpose of the present study was to compare effective and mean organ absorbed doses of plain radiography techniques with those of different modalities of cone beam computed tomography (CBCT) scanning of an adult's temporomandibular joint. PCXMC 2.0 software was used to calculate mean organ and effective doses. A NewTom CBCT device (Newtom 5G XL; QR systems; Verona, Italy) was simulated at 360° rotation using a 6 × 6cm2 FOV in standard and high-resolution modes. Lateral and posterio-anterior TMJ plain projections were simulated according to recommendations of the manufacturer of the Planmeca ProMax® 2D S3 device. Doses for both projections were simulated with Monte Carlo methods and the International Commission on radiological protection adult reference computational phantoms. The highest mean organ absorbed doses occurred in bone surfaces, salivary glands, and skull for posterio-anterior TMJ and lateral TMJ, and for CBCT scanning in all examinations. The effective doses of posterio-anterior and lateral TMJ plain radiographs were found to be higher than those of the Standard Mode-Eco Scan CBCT. Therefore, the lowest effective dose was calculated in Standard Mode-Eco Scan CBCT. It is concluded that NewTom 5G XL Standard Mode-Eco Scan CBCT can be used instead of plain radiographs (lateral and posterio-anterior TMJ) in temporomandibular joint imaging as it allows visualizing the three-dimensional structure of the temporomandibular joint as an advantage.

Current concepts: approach to spondylolysis

Lumbar spondylolysis is an acquired defect of the pars interarticular process ('isthmus') due to the human species' erect posture. Anatomical and load factors play a role. With lumbar extension, the superior vertebra's inferior articular process drives down dorsally on the inferior pars, causing a ventral tensile stress, bone oedema, fracture, and ultimately nonunion in some. The population incidence is around 6%, where most are inconsequential as they are asymptomatic and have a favourable natural history. In the physically highly active group, especially athletes, back and radicular pain is more common, leading to a three to four times higher incidence of lysis in this group. Although X-rays are typically the first imaging modality used, computed tomography (CT) is far more sensitive and, with staging, more predictive of fusion with comparable radiation dose. Magnetic resonance imaging (MRI) allows identification of bone oedema, a precursor of fracture, and assessment of the disc status. This has replaced previously used isotope bone scans and single-photon emission computed tomography (SPECT). Management involves cessation of physical activity and bracing to block extension for three to six months, with around 90% resolution of symptoms. Union rate is negatively related to bilaterality and terminal stage (nonunion), but not necessarily correlated to symptom/functional status. Surgical intervention in those that fail nonoperative care includes pars repair or fusion, with a high fusion and return to activity rate. The young athlete poses a particular challenge due to return to play pressure, but still does well with nonoperative care and subsequent activity modification. Counselling of the family and sports staff is extremely important when planning treatment in this high-demand group. Level of evidence: Level 5

Comparison of Image Quality and Radiation Dose between Filtered Back Projection and Sinogram Affirmed Iterative Reconstruction in CT Head: A Cross-sectional Study

Introduction: Computed Tomography (CT) scans account for only 15% of total diagnostic procedures but for over half of the collective dose of radiation. The increasing awareness about the harmful effects of radiation has also created a need for developing techniques that decrease radiation exposure while at the same time providing a reasonably good image quality. The majority of the CT units today use Filtered Back Projection (FBP) as the means of image reconstruction. However, FBP leads to coupling between image noise and radiation exposure and limits the dose reduction possible while providing diagnostic quality images. Second-generation Iterative Reconstruction (IR) techniques have caught the attention of medical researchers because they provide a superior image quality than FBP at the same radiation dose showing potential for dose reduction. Aim: To compare the image quality and radiation dose in standard dose CT head reconstructed with FBP and low dose CT head reconstructed with Sinogram Affirmed Iterative Reconstruction (SAFIRE) and FBP both. Materials and Methods: A cross-sectional analytical study was conducted on 100 patients in the emergency department of Vardhman Mahavir Medical College and Safdarjung Hospital in India from November 2018 to April 2020. Patients referred for emergency Non-contrast Computed Tomography (NCCT) head for any indication excluding post-op cases and those with metallic artifacts were included. Fifty patients chosen using systematic random sampling underwent low-dose CT head using the Care Dose 4D Automatic Exposure Control (AEC) system with reconstruction using SAFIRE (Group-A) and FBP (Group-B). Another 50 patients who were within five years of the corresponding Group-A and B patients underwent standard dose head CT reconstruction using FBP (Group-C). CTDI vol, DLP, and effective dose were recorded in all patients. Image quality was assessed objectively using the unpaired t-test for Group-A and C and paired t-test for Group-A and B. Subjective image analysis between the groups was done using a 4-point Likert scale. Results: Image quality parameters were found to be better in Group-A compared to Group-C (p&lt;0.05). The mean values in low dose SAFIRE group, low dose FBP group, and standard dose FBP group were as follows: Grey Matter (GM) Signal-to-Noise Ratio (SNR) (14±3.29, 8.96±2 and 9.24±1.96), White Matter (WM) SNR (14.6 ±3.73, 6.9±3.79 and 7.11±1.68), Cerebrospinal Fluid (CSF) SNR (1.65±1.12, 0.86±0.80 and 1.08±0.61) and Contrastto-Noise Ratio (CNR) (3.06±0.94, 1.81±0.69 and 1.74±0.69), respectively. Group-A had significantly improved image quality parameters than Group-B and Group-C. Radiation dose reduction of 42%, 39.34%, and 42.5% was achieved in CTDIvol, DLP, and effective dose respectively in low dose group. Conclusion: Low dose CT head reconstructed with SAFIRE were significantly better in image quality compared to standarddose CT head images reconstructed using FBP, while allowing for up to 42% reduction in dose.

Comparison of Radiation Doses of Computed Tomography Brain and Pulmonary Angiography with International Commission on Radiological Protection Guidelines: A Descriptive Study

Introduction: Computed Tomography Angiography (CTA) is useful for evaluating and diagnosing conditions related to blood vessels, such as aneurysms, stenosis (narrowing of vessels), vascular malformations, and blockages. It provides valuable information for planning and guiding interventions or surgeries. It is also important to measure patient doses during CTA operations to evaluate and optimise the technique and balance the benefits compared to radiation hazards. Aim: To calculate the CT Dose Index (CTDI), Dose Length Product (DLP), and effective dose for CT brain angiography and CT pulmonary angiography, and also to compare whether the measured values are within the International Commission on Radiological Protection (ICRP) recommended levels. Materials and Methods: A retrospective descriptive study was conducted in the Department of Radiodiagnosis at Yenepoya Medical College Hospital Mangaluru, Karnataka, India, from September 2022 to September 2023. A total of 52 data points were collected for CT brain and CT pulmonary angiography examinations, which were acquired before October 2022. Information on CTDI and DLP was collected, and the effective dose was calculated using the conversion factor. The values were then compared with the ICRP reference level. Descriptive statistics, mean, and standard deviation for continuous variables, and frequency and percentage for categorical variables were used. Results: There was a significantly lower value of CTDI, DLP, and effective dose for CT brain angiography and CT pulmonary angiography compared to the ICRP recommended reference levels. The mean CTDI and DLP for CT brain angiography were 111.56 mGy and 1153.31 mGy·cm, and the mean CTDI and DLP for CT pulmonary angiography were 24.56 mGy and 713.74 mGy·cm, respectively. The mean effective dose for CT brain and CT pulmonary angiography was 2.46 mSv and 9.94 mSv, respectively. Conclusion: The measured values were within the recommended values of ICRP regulations. It is recommended that CT brain angiography and CT pulmonary angiography examinations are safer for diagnostic purposes. Optimising scanning protocols, utilising low-dose techniques, and implementing dose monitoring and control are important clinical aspects. Compliance with the guidelines helps to enhance patient care and reduce the risk of radiation-related complications.

Ultra-low-dose photon-counting CT of paranasal sinus: an in vivo comparison of radiation dose and image quality to cone-beam CT.

This study investigated the differences in subjective and objective image parameters as well as dose exposure of photon-counting CT (PCCT) compared to cone-beam CT (CBCT) in paranasal sinus imaging for the assessment of rhinosinusitis and sinonasal anatomy. This single-centre retrospective study included 100 patients, who underwent either clinically indicated PCCT or CBCT of the paranasal sinus. Two blinded experienced ENT radiologists graded image quality and delineation of specific anatomical structures on a 5-point Likert scale. In addition, contrast-to-noise ratio (CNR) and applied radiation doses were compared among both techniques. Image quality and delineation of bone structures in paranasal sinus PCCT was subjectively rated superior by both readers compared to CBCT (P < .001). CNR was significantly higher for photon-counting CT (P < .001). Mean effective dose for PCCT examinations was significantly lower than for CBCT (0.038 mSv ± 0.009 vs. 0.14 mSv ± 0.011; P < .001). In a performance comparison of PCCT and a modern CBCT scanner in paranasal sinus imaging, we demonstrated that first-use PCCT in clinical routine provides higher subjective image quality accompanied by higher CNR at close to a quarter of the dose exposure compared to CBCT.

Radiation-induced long-term dysphagia in survivors of head and neck cancer and association with dose-volume parameters

BackgroundAlthough dysphagia is a common side effect after radiotherapy (RT) of head and neck cancer (HNC), data on long-term dysphagia is scarce. We aimed to 1) compare radiation dose parameters in HNC survivors with and without dysphagia, 2) investigate factors associated with long-term dysphagia and its possible impact on health-related quality of life (HRQoL), and 3) investigate how our data agree with existing NTCP models. MethodsThis cross-sectional study conducted in 2018–2020, included HNC survivors treated in 2007–2013. Participants attended a one-day examination in hospital and filled in patient questionnaires. Dysphagia was measured with the EORTC QLQ-H&N35 swallowing scale. Toxicity was scored with CTCAE v.4. We contoured swallowing organs at risk (SWOAR) on RT plans, calculated dose-volume histograms (DVHs), performed logistic regression analyses and tested our data in established NTCP models. ResultsOf the 239 participants, 75 (31%) reported dysphagia. Compared to survivors without dysphagia, this group had reduced HRQoL and the DVHs for infrahyoid SWOAR were significantly shifted to the right. Long-term dysphagia was associated with age (OR 1.07, 95% CI 1.03–1.10), female sex (OR 2.75, 95% CI 1.45–5.21), and mean dose to middle pharyngeal constrictor muscle (MD-MPCM) (OR 1.06, 95% CI 1.03–1.09). NTCP models overall underestimated the risk of long-term dysphagia. ConclusionsLong-term dysphagia was associated with higher age, being female, and high MD-MPCM. Doses to distally located SWOAR seemed to be risk factors. Existing NTCP models do not sufficiently predict long-term dysphagia. Further efforts are needed to reduce the prevalence and consequences of this late effect.