Computed Tomography Examinations Research Articles

Relationship Between Clinical Parameters and Histological Features of Epicardial Adipose Tissue and Aortic Valve Calcification Assessed on Computed Tomography.

The relationships of the clinical and biological attributes of epicardial adipose tissue (EAT) with aortic valve calcification (AVC) have not been characterized. We evaluated the relationships of the clinical and histological features of EAT with AVC assessed using computed tomography (CT).Methods and Results: We enrolled 43 patients undergoing cardiac CT examination prior to elective cardiac surgery in whom AVC was identified on CT. EAT volume and density, coronary calcium score (CCS), AVC score (AVCS), and coronary atherosclerosis on CT angiography were evaluated in each patient. During cardiac surgery, 2 EAT samples were obtained for immunohistochemistry. The number of CD68- and CD11c-positive macrophages and osteocalcin-positive cells was counted in 6 random high-power fields of EAT sections. EAT density, but not EAT volume normalized to body surface area, was positively correlated with the number of macrophages and osteocalcin-positive cells in EAT. There was a positive correlation between ln(AVCS), but not ln(CCS+1), and the number of macrophages and osteocalcin-positive cells in EAT. Multivariate analysis revealed significant positive correlations for ln(AVCS) with EAT density (β=0.42; P=0.0072) and the number of CD68-positive macrophages (β=0.57; P=0.0022), CD11c-positive macrophages (β=0.62; P=0.0003), and osteocalcin-positive cells (β=0.52; P=0.0021) in EAT. Inflammation and osteogenesis in EAT, reflected by high CT density, are associated with the severity of AVC representing aortic valve degeneration.

Relationship between assistant’s lens exposure and dose information during computed tomography examinations

According to International Commission of Radiological Protection, the equivalent dose limit for the eye lens for occupational exposure is recommended to be 20 mSv yr−1, averaged over 5 years, with no single year above 50 mSv. Some studies reported the measurement of assistant’s lens exposure in diagnostic computed tomography (CT) examinations, but further investigation is still required in the association between the lens dose for assistants and various dose parameters. Therefore, we measured the assistant’s lens exposure using small optically stimulated luminescence dosimeters. The type of occupation, type of assistance, total scan time, total mAs, total scan length, and dose-length product (DLP) were recorded and analyzed in association with air kerma at the lens position. The assistance was classified into four types: ‘assisted ventilation,’ ‘head holding,’ ‘body holding,’ and ‘raising patient’s arm.’ The air kerma of lens position was not significantly different for each assistance type (p < 0.05, Kruskal–Wallis test). Further, the lens doses for assistants correlated with DLP, but with various strengths of correlation with the assistance type and were influenced by the distance from the CT gantry. In conclusion, lens dose during assistance and DLP demonstrated the strongest correlation. ‘Raising patient’s arm’ and ‘head holding’ exhibited stronger correlations, which required less table movement during the CT scan than ‘assisted ventilation’ and ‘body holding’.

Fetal Hepatic Hemangioma Diagnosed in Utero Using Doppler Microvascular Imaging.

A 35-year-old pregnant woman was referred to our institution at 33 weeks' gestation for evaluation of a fetal abdominal tumor. B-mode ultrasonography demonstrated a massive lesion. Bidirectional power Doppler mode showed abundant blood flow surrounding the tumor. On superb micro-vascular imaging, various Doppler signal patterns were observed within the tumor, including diffuse fine dotted-like signals, linear flow, and internal shunt flow. Sequential observations of the tumor and cardiac cycles also revealed pulsatile flow beneath the edges of the tumor and continuous fine flow in the central area, resembling a 'centripetal fill-in' appearance on contrast computed tomography. Therefore, we assumed the fetal tumor to be a hepatic hemangioma. Fetal heart failure was detected at 37 weeks' gestation, and a 2,484-g female infant was delivered with 1- and 5-min Apgar scores of 7 and 8, respectively. A postnatal contrast computed tomography examination showed a progressive centripetal fill-in appearance, leading to a diagnosis of hepatic hemangioma. Kasabach-Merritt syndrome was also noted. Intensive treatment was performed, and the infant was discharged at 3 months after birth. In summary, we experienced a case of hepatic hemangioma diagnosed in utero using superb micro-vascular imaging. And basing seamless postnatal treatments on prenatal imaging findings may help to reduce the perinatal mortality.

CT texture analysis of vertebrobasilar artery calcification to identify culprit plaques

ObjectivesThe aim of this study was to extract radiomic features from vertebrobasilar artery calcification (VBAC) on head computed tomography (CT) images and investigate its diagnostic performance to identify culprit lesions responsible for acute cerebral infarctions.MethodsPatients with intracranial atherosclerotic disease who underwent vessel wall MRI (VW-MRI) and head CT examinations from a single center were retrospectively assessed for VBAC visual and textural analyses. Each calcified plaque was classified by the likelihood of having caused an acute cerebral infarction identified on VW-MRI as culprit or non-culprit. A predefined set of texture features extracted from VBAC segmentation was assessed using the minimum redundancy and maximum relevance method. Five key features were selected to integrate as a radiomic model using logistic regression by the Aikaike Information Criteria. The diagnostic value of the radiomic model was calculated for discriminating culprit lesions over VBAC visual assessments.ResultsA total of 1,218 radiomic features were extracted from 39 culprit and 50 non-culprit plaques, respectively. In the VBAC visual assessment, culprit plaques demonstrated more observed presence of multiple calcifications, spotty calcification, and intimal predominant calcification than non-culprit lesions (all p &amp;lt; 0.05). In the VBAC texture analysis, 55 (4.5%) of all extracted features were significantly different between culprit and non-culprit plaques (all p &amp;lt; 0.05). The radiomic model incorporating 5 selected features outperformed multiple calcifications [AUC = 0.81 with 95% confidence interval (CI) of 0.72, 0.90 vs. AUC = 0.61 with 95% CI of 0.49, 0.73; p = 0.001], intimal predominant calcification (AUC = 0.67 with 95% CI of 0.58, 0.76; p = 0.04) and spotty calcification (AUC = 0.62 with 95% CI of 0.52, 0.72; p = 0.005) in the identification of culprit lesions.ConclusionCulprit plaques in the vertebrobasilar artery exhibit distinct calcification radiomic features compared to non-culprit plaques. CT texture analysis of VBAC has potential value in identifying lesions responsible for acute cerebral infarctions, which may be helpful for stroke risk stratification in clinical practice.

Magnetic Resonance Imaging, Computed Tomographic and Radiographic Findings in the Metacarpophalangeal Joints of 31 Warmblood Showjumpers in Full Work and Competing Regularly

There is a limited description of magnetic resonance imaging (MRI) and no information on computed tomographic (CT) findings in the fetlock of non-lame, non-racing sports horses. This study aimed to document comparative CT, MRI and radiographic findings in the metacarpophalangeal joints of showjumpers in full work. Clinical and gait assessments, low-field MRI, fan-beam CT and radiographic examinations of both metacarpophalangeal joints were performed on 31 showjumpers. Images were analysed descriptively. In most limbs (53/62, 85.5%), there were CT and MRI changes consistent with densification in the sagittal ridge and/or condyles of the third metacarpal bone (McIII). Hypoattenuation (subchondral bone resorption) was seen in CT reconstructions in the metacarpal condyle dorsoproximally (n = 2) and dorsodistally (n = 1), in the sagittal groove (n = 2) and medial fovea (n = 1) of the proximal phalanx. The McIII resorptive lesions were detected on MR images but not the proximal phalanx lesions. None were identified on radiographs. In conclusion, MRI and CT abnormalities previously associated with lameness were seen in the front fetlocks of showjumpers without relevant lameness. Densification in the sagittal ridge and the metacarpal condyles likely reflects an adaptive change to exercise. Subchondral bone resorption may indicate an early stage of disease; follow-up information is needed to establish its clinical significance.

A Novel Approach to Detecting Contrast Extravasation in Computed Tomography: Evaluating the Injection Pressure-to-Injection Rate Ratio.

The purpose of this study was to evaluate the usefulness of the injection pressure-to-injection rate (IPIR) ratio for the early detection of contrast extravasation at the venipuncture site during contrast-enhanced computed tomography. We retrospectively enrolled 57,528 patients who underwent contrast-enhanced computed tomography examinations in a single hospital. The power injector recorded the contrast injection pressure at 0.25-second intervals. We constructed logistic regression models using the IPIR ratio as the independent variable and extravasation occurrence as the dependent variable (IPIR ratio models) at 1, 2, 3, 4, 5, and 6 seconds after the start of contrast administration. Univariate logistic regression models in which injection pressure is used as an independent variable (injection pressure models) were also constructed as a reference baseline. The performance of the models was evaluated with the area under the receiver operating characteristic curves. Of the 57,528 cases, 46,022 were assigned to the training group and 11,506 were assigned to the test group, which included 112 extravasation cases (0.24%) in the training group and 28 (0.24%) in the test group. The area under the receiver operating characteristic curves for the IPIR ratio models and injection pressure models were 0.555 versus 0.563 at t = 1 (P = 0.270), 0.712 versus 0.678 at t = 2 (P = 0.305), 0.758 versus 0.693 at t = 3 (P = 0.032), 0.776 versus 0.688 at t = 4 (P = 0.005), 0.810 versus 0.699 at t = 5 (P = 0.002), and 0.811 versus 0.706 at t = 6 (P = 0.002). The IPIR ratio models perform better in detecting contrast extravasation at 3 to 6 seconds after the start of contrast administration than injection pressure models.

Lower incisor position in skeletal Class III malocclusion patients: a comparative study of orthodontic camouflage and orthognathic surgery

ABSTRACT Objectives To determine the difference between orthodontic camouflage and orthodontic-orthognathic surgery using the traditional cephalometric measurement IMPA and the newly proposed IA/PAMD, the angle between the long axis of the lower incisor (IA) and the principal axis of the mandibular alveolus (PAMD). Materials and Methods This study included 40 cases each in the orthodontic camouflage group (OG) and orthodontic-orthognathic surgery group (SG). The differences between the IMPA and IA/PAMD before and after treatment were compared between the two groups. T0 lateral cephalometric images of the 10 cases with the highest and lowest increase in the IA/PAMD were analyzed to identify characteristics associated with a higher risk of overdecompensation of the lower incisors during presurgical orthodontic treatment. Results Both the OG and SG showed a significant improvement in hard- and soft-tissue measurements. However, in the OG, there was significant lingual inclination of the lower incisor but only a small change in the IA/PAMD. In the surgical group, the IMPA was close to 90° after treatment, but the IA/PAMD significantly increased. Conclusions In orthodontic camouflage, the lower anterior teeth were significantly moved lingually with a better root-bone relationship. However, this relationship deteriorated in some surgical patients. Therefore, it is important to conduct cephalometric or cone-beam computed tomography examinations during preoperative orthodontics to identify and prevent possible periodontal risks.

Increased adiposity to muscle ratio and severity of sinusitis affect quality of life in asthma—Computed tomographic analysis—

BackgroundDeteriorated sinusitis and increased adiposity relative to muscle mass may affect the quality of life(QoL) in patients with asthma. However, whether these effects are observed regardless of intra-pulmonary pathology is unknown. ObjectivesTo evaluate the correlation of the cross-sectional ratio of abdominal visceral fat (VF) to erector spinae muscle (ESM) and sinus findings based on Lund-Mackey scoring system (LMS) on computed tomography (CT) with the impaired score of the Asthma Quality of Life Questionnaire (AQLQ), regardless of airway and parenchymal disease, in patients with asthma. MethodsParticipants from the Hokkaido-based severe asthma cohort who had completed AQLQ and CT examination at the entry. The participants were divided into high (highest) and low (other quartiles) groups based on the extra-pulmonary indices. The multivariate analysis examined the association of VF/ESM for the adiposity-to-muscle ratio, LMS with AQLQ, after adjusting for the airway fractal dimension for airway index, %low attenuation volume for parenchymal index. ResultsNo significant differences were observed in VF/ESM and LMS in terms of sex. The AQLQ score in the high VF/ESM group and high LMS group was lower than those in low VF/ESM group and low LMS group (N:Male/Female, 63/100). High VF/ESM (estimate [95% confidence interval], (-0.43[-0.61,-0.25]) and high LMS scores (-0.22(-0.41, -0.03)) were associated with low AQLQ scores, adjusted for age, body mass index, smoking status, blood eosinophil counts, and intra pulmonary CT indices. ConclusionsIncreased VF relative to ESM mass and high LMS may deteriorate asthma related QoL, regardless of intra-pulmonary disease.

Prevalence of accessory carpal ossicles - a CT-based survey

This observational study aimed to determine the prevalence of accessory carpal ossicles (ACO) using a computerized tomography examination. The digital imaging database of the authors’ institution was retrospectively reviewed, and all wrist computerized tomography examinations for any indication were identified between 2014 and 2021. Patients with previous wrist surgery and severely impaired carpal anatomy, such as severe osteoarthritis or congenital or acquired deformities that may preclude evaluation and identification of accessory carpal ossicles, were excluded from the study. Four orthopedic surgeons reviewed the computerized tomography scans and identified patients with accessory carpal ossicles on two-dimensional (coronal, axial, and sagittal planes) and three-dimensional computerized tomography reconstructions. Two thousand two hundred thirteen patients, with a mean age of 36.8±12.8 years, were identified and included. Accessory carpal ossicles were detected in 156 (7.1%) subjects, with 186 ACOs identified. The most common accessory carpal ossicles were os praetrapezium (n:34, 1.536%), os triquetrum secundarium (n:28, 1.265%), os epitriquetrum (n:20, 0.903%), os hamuli proprium (n:18, 0.813%), os ulnostyloideum (n:16, 0.723%), os epilunatum (n:12, 0.542%) and os styloideum (n:11, 0.497%) respectively. The study provides valuable information on the prevalence and distribution of accessory carpal ossicles, which can aid in accurately diagnosing and managing wrist pathologies. Further research is warranted to explore the clinical significance and potential impact of rare accessory carpal ossicles on wrist disorders.

Decreased portal vein attenuation and liver enhancement with reduced intravenous contrast dosage during the national iodinated contrast shortage of 2022.

The worldwide shortage of intravenous (IV) Omnipaque iodinated contrast (Iohexol, GE Healthcare; Milwaukee, WI, USA) forced institutions to adopt various policies regarding contrast allocation. We sought to evaluate the impact of our hospital's response to the shortage, which was to decrease the dose of IV contrast from 100 mL to 75 mL for patients weighing between 45.4 and 136 kg (100-300 lbs) undergoing abdominal computed tomography (CT) examinations. The main objective was to assess for any differences in liver attenuation and enhancement between contrast dosages. Secondary outcomes included assessing differences in aortic and portal vein attenuation, the variance in attenuation measurements, and whether radiology reports included the correct IV contrast dose. Consecutive CT abdomen or CT abdomen and pelvis examinations without and with contrast were analyzed for the 3 months before the contrast shortage and for 3 months during the contrast shortage. Attenuation in Hounsfield units (HUs) was measured in the liver on pre-contrast and portal venous phase images. Vessel attenuation was measured in the aorta (arterial phase) and main portal vein (portal venous phase). Standard deviation of liver attenuation measurements was recorded as an indicator of signal-to-noise. Liver enhancement was calculated as the difference between liver portal venous phase attenuation and pre-contrast attenuations. Thirty-nine fixed dose (100 mL) and 36 reduced dose (75 mL) consecutive CT studies were included in the study. There were no significant differences between the two groups with respect to baseline characteristics such as age, weight, body mass index, and gender. There was no significant difference in pre-contrast liver attenuation between groups, but there was statistically significant greater liver attenuation (99.6 vs. 91.2 HU, P = 0.04) and liver enhancement (51.5 vs. 39.1 HU, P < 0.0001) during the portal venous phase for the fixed-dose group compared to the reduced dose group. There was significantly greater main portal vein opacification during the portal venous phase for the fixed dose group (146.6 vs. 122.2 HU, P < 0.0001). No significant difference was found in aortic opacification during the arterial phase (245 vs. 254 HU, P = 0.52). There was no difference in the standard deviation of liver attenuation measurements on the portal venous phase between the groups. The dose was reported correctly in all the patients receiving the fixed dose and in 92% of patients receiving the reduced dose, which was not statistically significant (P = 0.11). Reducing the IV contrast dose from 100 mL to 75 mL Omnipaque 350 in patients weighing 45.4-136 kg (100-300 lbs) undergoing an abdominal CT examination resulted in significantly decreased portal vein opacification and liver enhancement. In particular, liver enhancement and calculated iodine concentrations fell below suggested thresholds for adequate conspicuity of liver lesions. The change in contrast administration protocol also led to more errors in contrast dose reporting in the radiologist's report. These findings are broadly applicable to many practice settings and can help inform strategies in response to any potential future-iodinated contrast shortage.

Implementation of a new EGSnrc particle source class for computed tomography: validation and uncertainty quantification

Objective. Personalized dose monitoring and risk management are of increasing significance with the growing number of computer tomography (CT) examinations. These require high-quality Monte Carlo (MC) simulations that are of the utmost importance for the new developments in personalized CT dosimetry. This work aims to extend the MC framework EGSnrc source code with a new particle source. This, in turn, allows CT-scanner-specific dose and image calculations for any CT scanner. The novel method can be used with all modern EGSnrc user codes, particularly for the simulation of the effective dose based on DICOM images and the calculation of CT images. Approach. The new particle source can be used with input data derived by the user. The input data can be generated by the user based on a previously developed method for the experimental characterization of any CT scanner (doi.org/10.1016/j.ejmp.2015.09.006). Furthermore, the new particle source was benchmarked by air kerma measurements in an ionization chamber at a clinical CT scanner. For this, the simulated angular distribution and attenuation characteristics were compared to measurements to verify the source output free in air. In a second validation step, simulations of air kerma in a homogenous cylindrical and an anthropomorphic thorax phantom were performed and validated against experimentally determined results. A detailed uncertainty evaluation of the simulated air kerma values was developed. Main results. We successfully implemented a new particle source class for the simulation of realistic CT scans. This method can be adapted to any CT scanner. For the attenuation characteristics, there was a maximal deviation of 6.86% between the measurement and the simulation. The mean deviation for all tube voltages was 2.36% (σ = 1.6%). For the phantom measurements and simulations, all the values agreed within 5.0%. The uncertainty evaluation resulted in an uncertainty of 5.5% ( k=1 ).

Imaging of congenital heart defects with a focus on magnetic resonance imaging and computed tomography

Due to advances in diagnostics and therapy, the survival rate of patients with congenital heart defects is continuously increasing. The aim of this review is to compare various imaging modalities that are used in the diagnosis of congenital heart defects. Transthoracic echocardiography is the imaging method of choice in the presence of acongenital heart defect because of its wide availability and non-invasiveness. It can be complemented by transesophageal echocardiography, cardiac catheterization, computed tomography (CT), and magnetic resonance imaging (MRI) of the heart and vessels close to the heart. The radiation exposure of CT examinations of the heart is continuously decreasing because of improved technologies. MRI is also being continuously optimized, e.g., by the acquisition of MR angiographies without contrast medium application or athin three-dimensional (3D) visualization of the entire heart with the possibility of reconstruction in all spatial planes (whole-heart technique) as well as 2D to 4D flow. Due to the complexity of congenital heart defects and the variety of possible pathologies, the choice of imaging modality and its exact performance has to be coordinated in an interdisciplinary context and individually adapted.

Age-based diagnostic reference levels and achievable doses for paediatric CT: a survey in Shanghai, China

Computed tomography (CT) is extensively utilised in medical diagnostics due to its notable radiographic superiority. However, the cancer risk associated with CT examinations, particularly in children, is of significant concern. The assessment of cancer risk relies on the radiation dose to examinees. Diagnostic reference levels (DRLs) and achievable doses (ADs) were used to assess the level of radiation dose in CT examinations widely. Although the national DRLs of paediatric CT have been explored in China, few local DRLs at the city level have been assessed. To set up the local DRLs and ADs of paediatric CT, we investigated the radiation dose level for paediatric CT in Shanghai. In this survey, a total of 3061 paediatric CT examinations underwent in Shanghai in 2022 were selected by stratified sampling, and the dose levels in terms of volume CT dose index (CTDIvol) and the dose-length product (DLP) were analysed by 4 age groups. The DRLs and ADs were set at the 75th and 50th percentile of the distribution and compared with the previous studies at home and abroad. The survey results revealed that, for head scan, the DRLs of CTDIvol were from 25 to 46 mGy, and the levels of DLP were from 340 to 663 mGy·cm. For chest, the DRLs of CTDIvol were from 2.2 to 8.3 mGy, and the levels of DLP were from 42 to 223 mGy·cm. For abdomen, the DRLs of CTDIvol were from 6.3 to 16 mGy, and the levels of DLP were from 181 to 557 mGy·cm. The ADs were about 60% lower than their corresponding DRLs. The levels of radiation doses in children-based hospitals were higher than those in other medical institutions (P < 0.001). In conclusion, there was still potential for reducing radiation dose of paediatric CT, emphasising the urgent need for optimising paediatric CT dose in Shanghai.

Feasibility, Clinical Potential, and Limitations of Trans-Burr Hole Ultrasound for Postoperative Evaluation of Chronic Subdural Hematoma: A Prospective Pilot Study.

Chronic subdural hematoma (CSDH) is commonly managed through burr hole surgery. Routine follow-up using computed tomography (CT) imaging is frequently used at many institutions, contributing to significant radiation exposure. This study evaluates the feasibility, safety, and reliability of trans-burr hole sonography as an alternative postoperative imaging modality, aiming to reduce radiation exposure by decreasing the frequency of CT scans. We conducted a prospective pilot study on 20 patients who underwent burr hole surgery for CSDH. Postoperative imaging included both CT and sonographic examinations through the burr hole. We assessed the ability to measure residual subdural fluid thickness under the burr hole sonographically compared with CT, the occurrence of complications, and the potential factors affecting sonographic image quality. The Pearson correlation coefficient was used to demonstrate relationships between CT and ultrasound and axial and coronal ultrasound. Sonography through the burr hole was feasible in 73.5% of cases, providing measurements of residual fluid that closely paralleled CT findings, with an average discrepancy of 1.2 mm for axial and 1.4 mm for coronal sonographic views. A strong positive correlation was found between axial and coronal ultrasound (r = 0.955), CT and axial ultrasound (r = 0.936), and CT and coronal ultrasound (r = 0.920). The primary obstacle for sonographic imaging was the presence of air within the burr hole or the subdural space, which typically resolved over time after surgery. Trans-burr hole sonography emerges as a promising technique for postoperative monitoring of CSDH, with the potential to safely reduce reliance on CT scans and associated radiation exposure in selected patients. Our results support further investigation into the extended use of sonography during the follow-up phase. Prospective multicenter studies are recommended to establish the method's efficacy and to explore strategies for minimizing air presence postsurgery.

Intracranial extra-axial chondromas: clues to computed tomography and magnetic resonance imaging diagnosis.

We aimed to describe the computed tomography (CT) and magnetic resonance (MR) imaging findings of intracranial extra-axial chondroma. We retrospectively evaluated the imaging findings of CT and MR examinations of six patients (three men and three women, aged 21-66 years) with histopathological diagnoses of intracranial extra-axial chondroma. Four tumors were located in the frontal region and two in the cavernous sinus. All the tumors showed low signals on diffusion-weighted images and high signals on apparent diffusion coefficient maps without restricted diffusion. There was no perifocal edema in all the tumors. Cavernous sinus chondromas were associated with bone erosion and anterior displacement of the internal carotid arteries, but without calcification. Calcification was present in all frontal chondromas. All the tumors revealed low signals on T1-weighted MR images. Frontal chondromas revealed mixed signals, but cavernous sinus chondromas were brightly hyperintense on T2-weighted MR images. No enhancement was detected in the two chondromas. An intense homogeneous enhancement was detected in a cavernous sinus chondroma. The imaging appearances of frontal extra-axial chondromas and cavernous sinus chondromas may have different imaging appearances. Although there is a wide range of imaging findings, the absence of restricted diffusion, perifocal edema, enhancement, and presence of low signals on T1-weighted MR images in a well-circumscribed calcified extra-axial mass should suggest an intracranial chondroma.

No trauma-related diagnosis in emergency trauma room whole-body computer tomography of patients with inconspicuous primary survey.

Whole-body computer tomographic examinations (WBCT) are essential in diagnosing the severely injured. The structured clinical evaluation in the emergency trauma room, according to ATLS® and guidelines, helps to indicate the correct radiological imaging to avoid overtriage and undertriage. This retrospective, single-center study aimed to evaluate the value of WBCT in patients with an inconspicuous primary survey and whether there is any evidence for this investigation in this group of patients. This retrospective, single-center study was conducted with patients admitted to a maximum-care hospital and supraregional trauma center in Germany and part of the TraumaNetwork DGU® in southwest Germany between January 2012 and November 2017. Hospital files were used for evaluation, and WBCT was carried out using a 32-row MSCT device from Siemens Healthineers, Volume Zoom, Erlangen, Germany. For evaluation, non-parametric procedures such as the chi-square test, U test, Fisher test, and Wilcoxon rank sum test were used to test for significance (p < 0.05). From 3976 patients treated with WBCT, 120 patients (3.02%) showed an inconspicuous primary survey. This examination did not reveal any trauma sequelae in any of this group. Additionally, 198 patients (4.98%) showed minor clinical symptoms in the primary survey, but no morphological trauma sequence could be diagnosed in WBCT diagnostics. Three hundred forty-two patients were not admitted as inpatients after WBCT and discharged to further outpatient treatment because there were no objectifiable reasons for inpatient treatment. Four hundred fifteen patients did not receive WBCT for, e.g., isolated extremity trauma, child, pregnancy, or death. Not one of the clinically asymptomatic patients had an imageable injury after WBCT diagnostics in this study. WBCT should only be performed in severely injured patients after clinical assessment regardless of "trauma mechanism." According to guidelines and ATLS®, the clinical examination seems to be a safe and reliable method for reasonable and responsible decision-making regarding the realization of WBCT with all well-known risk factors.

Influence of deep learning image reconstruction algorithm for reducing radiation dose and image noise compared to iterative reconstruction and filtered back projection for head and chest computed tomography examinations: a systematic review.

The most recent advances in Computed Tomography (CT) image reconstruction technology are Deep learning image reconstruction (DLIR) algorithms. Due to drawbacks in Iterative reconstruction (IR) techniques such as negative image texture and nonlinear spatial resolutions, DLIRs are gradually replacing them. However, the potential use of DLIR in Head and Chest CT has to be examined further. Hence, the purpose of the study is to review the influence of DLIR on Radiation dose (RD), Image noise (IN), and outcomes of the studies compared with IR and FBP in Head and Chest CT examinations. We performed a detailed search in PubMed, Scopus, Web of Science, Cochrane Library, and Embase to find the articles reported using DLIR for Head and Chest CT examinations between 2017 to 2023. Data were retrieved from the short-listed studies using Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) guidelines. Out of 196 articles searched, 15 articles were included. A total of 1292 sample size was included. 14 articles were rated as high and 1 article as moderate quality. All studies compared DLIR to IR techniques. 5 studies compared DLIR with IR and FBP. The review showed that DLIR improved IQ, and reduced RD and IN for CT Head and Chest examinations. DLIR algorithm have demonstrated a noted enhancement in IQ with reduced IN for CT Head and Chest examinations at lower dose compared with IR and FBP. DLIR showed potential for enhancing patient care by reducing radiation risks and increasing diagnostic accuracy.

Effectiveness of low dose computed tomography to detect fractures in paediatric suspected physical abuse: a systematic review.

The skeletal survey X-ray series is the current 'gold standard' when investigating suspected physical abuse (SPA) of children, in addition to a non-contrast computed tomography (CT) brain scan. This systematic literature review synthesised findings of published research to determine if low dose computed tomography (LDCT) could detect subtle fractures and therefore replace the skeletal survey X-ray series in the investigation of SPA in children aged under 3 years. Five electronic databases and grey literature were systematically searched from their inception to 28 April 2022. Primary studies were included where the population comprised paediatric patients up to 16 years and LDCT was used to detect fractures associated with SPA. Studies involving imaging investigations of the head, standard dose CT examinations or accidental trauma were excluded. Three studies met the inclusion criteria, all of which were case series. These studies did not report many of the criteria required to compare the accuracy of LDCT to X-ray, i.e. they did not meet the criteria for a diagnostic accuracy test. Therefore, it is difficult to conclude from the case series if LDCT is accurate enough to replace X-rays. Due to the gap in current literature, a phantom study and subsequent post-mortem CT study are recommended as the primary investigative methods to assess the ability of low-dose CT to identify the subtle fractures associated with SPA and to calculate how low the achievable CT dose can be.

Preservation of the heart in ancient Egyptian mummies: A computed tomography investigation with focus on the myocardium.

The ancient Egyptians considered the heart to be the most important organ. The belief that the heart remained in the body is widespread in the archeological and paleopathological literature. The purpose of this study was to perform an overview of the preserved intrathoracic structures and thoracic and abdominal cavity filling, and to determine the prevalence and computed tomography (CT) characteristics of the myocardium in the preserved hearts of ancient Egyptian mummies. Whole-body CT examinations of 45 ancient Egyptian mummies (23 mummies from the Ägyptisches Museum und Papyrussammlung, Berlin, Germany, and 22 mummies from the Museo Egizio, Turin, Italy) were systematically assessed for preserved intrathoracic soft tissues including various anatomical components of the heart (pericardium, interventricular septum, four chambers, myocardium, valves). Additionally, evidence of evisceration and cavity filling was documented. In cases with identifiable myocardium, quantitative (measurements of thickness and density) and qualitative (description of the structure) assessment of the myocardial tissue was carried out. Heart structure was identified in 28 mummies (62%). In 33 mummies, CT findings demonstrated evisceration, with subsequent cavity filling in all but one case. Preserved myocardium was identified in nine mummies (five male, four female) as a mostly homogeneous, shrunken structure. The posterior wall of the myocardium had a mean maximum thickness of 3.6 mm (range 1.4-6.6 mm) and a mean minimum thickness of 1.0 mm (range 0.5-1.7 mm). The mean Hounsfield units (HU) of the myocardium at the posterior wall was 61 (range, 185-305). There was a strong correlation between the HU of the posterior wall of the myocardium and the mean HU of the muscles at the dorsal humerus (R = 0.77; p = 0.02). In two cases, there were postmortem changes in the myocardium, most probably due to insect infestation. To our knowledge, this is the first study to investigate the myocardium systematically on CT scans of ancient Egyptian mummies. Strong correlations between the densities of the myocardium and skeletal muscle indicated similar postmortem changes of the respective musculature during the mummification process within individual mummies. The distinct postmortem shrinking of the myocardium and the collapse of the left ventriclular cavity in several cases did not allow for paleopathological diagnoses such as myocardial scarring.

Advancing pediatric head CT dose prediction: correlating patient size metrics with AP and LAT dimensions in Moroccan population

This study aims to establish comprehensive relationships between patient size, focusing on effective diameter (Deff) and water-equivalent diameter (Dw), in conjunction with anterior-posterior (AP) and lateral (LAT) dimensions. The primary goal is to refine precise patient dose estimations in pediatric head computed tomography (CT) examinations. Our examination involved a dataset of 105 pediatric head CT images sourced from a Moroccan pediatric university hospital. These images, selected from the central scanning range, underwent quantification for LAT, AP, Deff, and Dw, with measurements carried out using RadiAnt Dicom Viewer for lateral and anteroposterior dimensions. Our analytical approach encompassed modeling Deff and Dw as functions of LAT, AP, and combined AP + LAT dimensions. Additionally, Dw was modeled as a function of Deff and calculated Size Specific Dose Estimates (SSDE) based on Dw was compared to SSDE computed from one single dimension. The outcomes revealed strong correlations among Deff, Dw, and fundamental geometric dimensions (LAT, AP, and AP + LAT), as indicated by consistently high coefficients of determination (R² > 0.8). SSDE calculated from Dw shows impressive correlation with SSDE computed from a single dimension (R² > 0.9). This study offers insights into the relationships between patient size and critical dimensions, identifying high correlations that can represent a significant advancement in predicting doses for pediatric head CT examinations. This introduces the potential for streamlining the determination of head diameter and dose by relying on a single dimension, thereby enhancing the efficiency of dose predictions by facilitating the monitoring of radiation exposure of this population in clinical routine.