Computed Tomography Examinations Research Articles

Clinical imaging guidelines: current status and challenges

Background: Advances in medical technology and health insurance coverage policies have significantly promoted radiological examinations in Korea. In 2019, the number of computed tomography examinations performed in Korea was approximately 1.5-times higher than the Organisation for Economic Co-operation and Development average. This surge in radiological examinations has raised concerns regarding inappropriate imaging practices that may lead to unnecessary radiation exposure and increased healthcare cost.Current Concepts: Two fundamental principles guide the radiation safety practices in medicine: Optimization and justification. Optimization, represented by the “As Low As Reasonably Achievable” principle, minimizes the radiation dose while maintaining the diagnostic quality. Justification ensures that the benefits of radiological procedures outweigh their potential risks. Evidence-based clinical imaging guidelines, such as the UK iRefer guidelines and USA American College of Radiology Appropriateness Criteria, have been internationally proposed to implement these principles. In Korea, collaborative efforts between the National Evidence-based Healthcare Collaborating Agency and Korean Society of Radiology have led to the development of Korean evidence-based clinical imaging guidelines.Discussion and Conclusion: Implementation of evidence-based imaging guidelines is crucial to reduce unnecessary radiation exposure and optimize resource utilization. However, various challenges, including the adaptation of the guidelines to individual patient needs and successful integration of rapidly advancing medical technologies, remain. Continuous updates, professional education, and system-wide support are essential to ensure the effective implementation of these guidelines. Future studies should focus on enhancing the precision and applicability of these guidelines in clinical practice to improve the patient safety and healthcare efficiency.

Introduction and evaluation of size-specific DLP for radiation dose estimation in CT examinations.

The increased utilization of computed tomography (CT) has raised concerns about patient radiation exposure. Effective dose (ED), which requires precise estimation, is crucial for assessing and managing these risks. Traditional ED estimation methods, which are based on the dose-length product (DLP), often lack accuracy due to variations in patient size and anatomy. This study aims to evaluate the efficacy of size-specific DLP (SS-DLP), a novel metric that combines the size-specific dose estimate (SSDE) with scan length, to provide a more accurate estimation of radiation exposure from CT examinations. Focusing on adult chest-abdomen-pelvis (CAP) scans, we calculated SSDE and SS-DLP and utilized two simulation tools, Radimetrics and WAZA-ARI, for a detailed analysis. Our findings indicate that SS-DLP is highly correlated with EDs from Monte Carlo simulations, suggesting its reliability. Additionally, SS-DLP showed a moderate reduction in errors based on patient sex and body mass index compared to traditional DLP-based methods. Thus, SS-DLP offers a more accurate and personalized radiation exposure estimate, potentially enhancing patient safety.

Clinical Impact of Radiologist’s Alert System on Patient Care for High-risk Incidental CT Findings: A Machine Learning-Based Risk Factor Analysis

Rationale and ObjectivesEfficient communication between radiologists and clinicians ordering computed tomography (CT) examinations is crucial for managing high-risk incidental CT findings (ICTFs). Herein, we introduced a Radiologist’s Alert and Patient Care Follow-up System (APCFS) for high-risk ICTFs. This study aimed to analyze the ICTFs detected by this system and the factors associated with them. Materials and MethodsThis retrospective study was approved by the institutional review board. We analyzed 52,331 CT examinations conducted between 2019 and 2021. In cases where high-risk ICTFs were identified, radiologists utilized APCFS to prompt ordering clinicians for further patient care. We assessed the frequency, affected body organs, presence or absence of therapeutic interventions, and diagnoses of high-risk ICTFs. An automated machine learning platform was employed to analyze the factors associated with high-risk ICTFs. ResultsAmong the 52,331 CT examinations, 507 (0.96%) revealed high-risk ICTFs, primarily affecting the lung (18.0%). Of these 507 high-risk ICTFs, 117 (23.1%) underwent therapeutic interventions, while 362 (71.4%) required only follow-up. Of the 117 cases undergoing interventions, 61 (52.1%) required surgery. Of the 219 high-risk ICTFs leading to a confirmed diagnosis, 146 (66.7%) were neoplastic lesions, including 88 (60.3%) malignancies, and 73 (33.3%) were non-neoplastic lesions. The top three risk factors associated with high-risk ICTFs in the regularized logistic regression model were the imaging protocol (especially aortic valve implantation planning protocol), imaging area (especially whole-body imaging), and clinical department (especially cardiology). ConclusionUtilizing APCFS, high-risk ICTFs were detected in approximately 1% of all CT examinations, likely associated with specific imaging protocols, areas, and clinical departments.

Image quality and radiation dose from pediatric abdomen-pelvis CT scans

Introduction: The aim of this study is to assess the organ doses, effective dose, image quality, and the potential risk of developing radiation-related cancer in children undergoing computed tomography (CT) scans of the abdomen-pelvis. Methods: The research involved 219 pediatric patients (129 males and 90 females) who underwent an abdomen-pelvic CT examination. The patients were categorized into four age groups: <1, 1-4, 5-9, and 10-14 years old. The NCICT software version 3.0 was utilized to estimate the organ doses and effective dose. Estimation of cancer incidence risks were conducted according to the Biological Effects of Ionizing Radiation (BEIR) VII report. The image quality was evaluated by measuring the level of noise, as well as the signal-to-noise ratio, and contrast-to-noise ratio. Results: The colon received the highest organ dose in all age groups. The risk of all cancers was 75.38 per 100,000 for the <1 age group, and it decreased to 56.10 for the 10-14 age group. The cancer risks were statistically higher for females (p < 0.05). The mean noise values for the liver, aorta, and paraspinal muscle were found to be 9.08, 11.04, and 8.21, respectively. Conclusion: The findings of present study indicate that pediatric abdomen-pelvis CT examinations carry a potential risk of cancer that should not be disregarded. Consequently, it is crucial to prioritize radiation protection measures in children compared to adults.

Rapid patient-specific organ dose estimation in computed tomography scans via integration of radiomics features and neural networks.

Computed tomography (CT) offers detailed cross-sectional images of internal anatomy for disease detection but carries a risk of solid cancer or blood malignancies due to exposure to X-ray radiation. This study aimed to develop a new method to quickly predict patient-specific organ doses from CT examinations by training neural networks (NNs) based on radiomics features. CT Digital Imaging and Communications in Medicine (DICOM) image data were exported to DeepViewer, a clinical autosegmentation software, to segment the regions of interest (ROIs) for patient organs. Radiomics feature extraction was performed based on the selected CT data and ROIs. Reference organ doses were computed using Monte Carlo (MC) simulations. Patient-specific organ doses were predicted by training a NN model based on radiomics features and reference doses. For the dose prediction performance, the relative root mean squared error (RRMSE), mean absolute percentage error (MAPE), and coefficient of determination (R2) were evaluated on the test sets. The robustness of the NN model was evaluated via the random rearrangement of patient samples in the training and test sets. The maximal difference between the reference and predicted doses was less than 1 mGy for all investigated organs. The range of MAPE was 1.68% to 5.2% for head organs, 11.42% to 15.2% for chest organs, and 5.0% to 8.0% for abdominal organs; the maximal R2 values were 0.93, 0.86, and 0.89 for the head, chest, and abdominal organs, respectively. The radiomics feature-based NN model can achieve accurate prediction of patient-specific organ doses at a high speed of less than 1 second using a single central processing unit, which supports its use as a user-friendly online clinical application.

Preoperative Planning for Shoulder Arthroplasty is Feasible with Computed Tomography at Lower-Than-Conventional Radiation Doses

Computed tomography (CT) offers a detailed assessment of the shoulder for preoperative shoulder arthroplasty planning; however, this technique exposes the patient to ionizing radiation. The purpose of this study was to prospectively evaluate the practicality of reducing the CT radiation dose compared to conventional dose levels for manual and preoperative planning software measurements for shoulder arthroplasty. A total of 10 shoulder CT examinations were performed for preoperative planning purposes on a dual x-ray source CT scanner. A specialized dose-split scan technique was utilized to reconstruct CT images corresponding to 100%, 70%, and 30% radiation dose relative to our institution's standard of care imaging protocol. Glenoid version, inclination, and humeral head subluxation were measured manually by three authors and by commercially available software platforms. These measurements were analyzed for agreement between the 100%, 70%, and 30% dose levels for each patient. Tolerances of 5° of glenoid version, 5° of glenoid inclination, and 10% humeral head subluxation were used as equivalent for preoperative planning. Automated measurements of 70% dose images were within 5° of version, 5° of inclination, and 10% subluxation in 95.0% of cases. Manual measurements of 70% RD images were within 5° of version for 90.0% of cases, 5° of inclination in 86.7% of cases, and 10% subluxation in 100% of cases. Automated measurements from the 30% dose images were within 5° of version, 5° of inclination, and 10% subluxation for 100% of cases. Manual measurements from the 30% dose images were within 5° of version for 86.7% of cases, 5° of inclination in 76.7% of cases, and 10% subluxation in 100% of cases. The mean absolute difference in software measurement of glenoid version (p = 0.96), glenoid inclination (p = 0.64), or humeral head subluxation (p = 0.09) or in aggregated manual mean absolute difference of version (p = 0.22), inclination (p = 0.31), or humeral head subluxation (p = 0.56) was not significant. Good to excellent reliability was determined by interclass correlation coefficients among the manual observers and automatic software platforms for measurements at all doses (P<0.001) CONCLUSIONS: The results indicate that both preoperative planning software platforms and human observers produced similar measurements of glenoid version, inclination, and humeral head subluxation from reduced-dose images compared to standard of care doses. By implementing reduced dose techniques in preoperative shoulder CT, the potential risks associated with radiation exposure could be reduced for patients undergoing shoulder arthroplasty.

Efficacy and safety of oral versus intravenous cyclophosphamide in treatment of connective tissue disease-related interstitial lung disease.

Interstitial lung disease (ILD) resulting from connective tissue disease (CTD) greatly undermines people's health. Cyclophosphamide (CYC) is a widely used agent in treating CTD-ILD. We compared the efficacy and safety of oral and intravenous CYC in CTD-ILD treatment. The retrospectively enrolled CTD-ILD patients were divided into the oral and intravenous CYC groups. The chest high-resolution computed tomography examination, forced vital capacity (FVC), lung carbon monoxide diffusion capacity (Dlco) determinations, and 6 min walk test (6MWT) were performed pre-treatment and at the 3rd, 6th, and 12th months posttreatment. Radiographic ILD severity was assessed using the Warrick score. Krebs Von den Lungen-6, surfactant protein A (SP-A), SP-D, and erythrocyte sedimentation rate (ESR) before and at the 12th month post-treatment were determined. CYC cumulative dose and occurrence of adverse reactions during treatment were recorded. CYC cumulative dose in the intravenous CYC group was reduced. Compared with oral CYC treatment, intravenous CYC caused decreased Warrick score and increased FVC and 6MWT at the 6th month, and elevated DLco at the 3rd and 6th months posttreatment. SP-A, SP-D and ESR levels in both groups were reduced 12 months posttreatment, with a more evident decrease in the intravenous CYC group. Intravenous CYC had lower total adverse reaction incidence. Compared with oral CYC, intravenous CYC decreases Warrick score and increases FVC and 6MWT at 6 months posttreatment, and reduces SP-A, SP-D, and ESR levels after 12 months of treatment, which shows low CYC cumulative dose and adverse reaction incidence in treating CTD-ILD.

Assessing abdominal aortic aneurysm growth using radiomic features of perivascular adipose tissue after endovascular repair

ObjectivesThe study aimed to investigate the relationship between the radiomic features of perivascular adipose tissue (PVAT) and abdominal aortic aneurysm (AAA) growth after endovascular aneurysm repair (EVAR).MethodsPatients with sub-renal AAA who underwent regular follow-up after EVAR between March 2014 and March 2024 were retrospectively collected. Two radiologists segmented aneurysms and PVAT. Patients were categorised into growing and non-growing groups based on volumetric changes observed in two follow-up computed tomography examinations. One hundred seven radiomic features were automatically extracted from the PVAT region. Univariable and multivariable logistic regression was performed to analyse radiomic features and clinical characteristics. Furthermore, the performance of the integrated clinico-radiological model was compared with models using only radiomic features or clinical characteristics separately.ResultsA total of 79 patients (68 ± 9 years, 89% men) were enroled in this study, 19 of whom had a growing aneurysm. Compared to the non-growing group, PVAT of growing AAA showed a higher surface area to volume ratio (non-growing vs growing, 0.63 vs 0.70, p = 0.04), and a trend of low dependence and high dispersion manifested by texture features (p < 0.05). The area under the curve of the integrated clinico-radiological model was 0.78 (95% confidence intervals 0.65–0.91), with a specificity of 87%. The integrated model outperformed models using only radiomic or clinical features separately (0.78 vs 0.69 vs 0.69).ConclusionsHigher surface area to volume ratio and more heterogeneous texture presentation of PVAT were associated with aneurysm dilation after EVAR. Radiomic features of PVAT have the potential to predict AAA progression.Clinical relevance statementRadiomic features of PVAT are associated with AAA progression and can be an independent risk factor for aneurysm dilatation to assist clinicians in postoperative patient surveillance and management.Key PointsAfter EVAR for AAA, patients require monitoring for progression.PVAT surrounding growing AAA after EVAR exhibits a more heterogeneous texture.Integrating PVAT-related features and clinical features results in better predictive performance.Graphical

Prehospital computed tomography in a rural district for rapid diagnosis and treatment of stroke.

Early diagnosis and triage of patients with ischemic stroke is essential for rapid reperfusion therapy. The prehospital delay may be substantial and patients from rural districts often arrive at their local hospital too late for disability-preventing thrombolytic therapy due to prolonged transport times. Hallingdal District Medical Centre (HDMC) is located in a rural area of Norway and is equipped with a computed tomography (CT) scanner. We established emergency pathways of CT imaging and thrombolytic treatment of patients with acute ischemic stroke at HDMC. During office hours these pathways were managed by a radiographer and a general physician supported by videoconference from the Primary Stroke Centre. Outside office hours we remotely controlled the CT exam and supported telestroke guided paramedics handling and examining the patients. With a primary aim of demonstrating the feasibility of this de novo concept we enrolled patients in the period 2017-2021 into a comparative cohort observational study. We compared patients treated at HDMC (the Rural CT group) to patients from two other rural regions in Norway with similar distances to their local hospital but without access to a rural CT scanner (the Reference group). A total of 86 patients were included in the Rural CT group (mean age 74, 52% male, 43% stroke mimics), and 69 patients were included in the Reference group (mean age 70, 42% male, 28% stroke mimics). Median time from onset of symptoms to completed CT examination was 93 min in the Rural CT group as compared to 240 min in the Reference group (p < 0.05). In patients receiving intravenous thrombolysis time from onset of symptoms to treatment was median 124 min in the Rural CT group and 213 min in the Reference group, p < 0.05. The frequency of thrombolysis for ischemic stroke did not significantly differ between the two groups. Combining prehospital rural CT examination with telestroke guided diagnosis and thrombolytic treatment by paramedics may facilitate earlier initiation of thrombolysis for patients with ischemic stroke.

High Rate of Return to Sport in Contact and Collision Athletes After Arthroscopic Latarjet With Cortical Button Fixation

Background: Contact and collision athletes face a higher risk of recurrent anterior shoulder instability after surgical stabilization. The Latarjet procedure is often preferred given the high incidence of bony lesions. However, this stabilizing procedure, performed either open or arthroscopically, is met with concerns regarding complications and revision surgery rates. Purpose: To evaluate the return to sport (RTS) and assess complication and instability recurrence rates in contact/collision athletes undergoing the arthroscopic Latarjet procedure using a guided technique with suture buttons for coracoid fixations. Study Design: Case series; Level of evidence, 4. Methods: A retrospective analysis was conducted on contact/collision athletes who underwent the arthroscopic Latarjet procedure for recurrent anterior shoulder instability between January 2011 and March 2018. All patients were operated on arthroscopically using glenoid and coracoid guides and suture button fixation of the transferred coracoid. RTS was defined as the patient being able to participate in his or her activity without any restriction postoperatively. Two independent observers assessed patients using postoperative computed tomography (CT) scans to evaluate coracoid positioning and healing. A multivariate analysis was performed to identify predictive factors associated with persistent apprehension. A group comparison was performed to assess RTS failure risk factors. Results: In 136 contact/collision athletes (mean age, 25 ± 7 years), 93% were satisfied, and 98% achieved shoulder stability at a mean follow-up of 60 months (range, 24-117 months). No suture button–related complications or neurovascular issues were reported. Overall, 82% (112/136) returned to contact/collision sports. The mean time to RTS was 5.3 ± 1.2 months (range, 3-7.3 months). In a CT study performed 2 weeks after surgery, 87% (118/136) of bone grafts were positioned below the equator and 93% (126/136) were flush to the glenoid surface. At the 6-month postoperative CT examination, complete bone block healing was achieved in 84% (114/136). On clinical examination at the latest follow-up, 36 patients (26%) reported some anterior apprehension on testing. On multivariate analysis, patients with severe humeral bone defects (medium to large Hill-Sachs lesions, Calandra grade 2 or 3) had a higher risk of postoperative persistent apprehension. On group comparison, a visual analog scale score >3 and persistent anterior apprehension were found to be associated with failure of RTS. Conclusion: The arthroscopic Latarjet procedure with suture button fixation allowed 82% of athletes with recurrent anterior shoulder instability to return to contact or collision sports. Patients with severe humeral bone defects have a higher risk of persistent anterior apprehension and decreased RTS. The arthroscopic-guided procedure with suture button fixation is safe; accurate, with a high rate of anatomic graft positioning and healing; and reliable, with a low recurrence rate.

Computed tomographic findings of a medically managed canine renal cortical abscess

AbstractA 10‐year‐old, neutered, male labrador retriever was referred for acute history of abdominal pain and distention, pyrexia and pelvic limb ataxia. Peritoneal free fluid with intracellular bacteria was confirmed, and subsequent abdominal computed tomography revealed a hypoattenuating and rim‐enhancing focal lesion in the cortex of the left kidney, with associated regional inflammation. The dog underwent fine‐needle aspiration of the lesion with ultrasound guidance confirming the presence of a renal abscess with growth of Escherichia coli on culture of the acquired purulent intralesional fluid. Medical management was commenced, and on repeat clinical examination and computed tomography imaging, the clinical signs and renal lesion had resolved. To the authors’ best knowledge, this is the first report of confirmation of complete resolution of a cortical renal abscess, treated with only medical management, using computed tomography examination.

Risk factors for proximal and distal aortic events after type A acute aortic dissection.

Type A acute aortic dissection (TAAAD) is a life-threatening condition often requiring emergency surgery, with approximately 30% of patients needing reoperation. This study aimed to identify predictors of long-term aortic events from early postoperative computed tomography (CT) examinations. A total of 336 cases underwent TAAAD surgery at two institutions between 2002 and 2018. Of these, 302 patients received CT examinations immediately after initial TAAAD surgery. Predictors of aortic events were evaluated from these early postoperative CT exams. Aortic events were defined as any events involving aortic-related death, open surgery, reoperation, endovascular stenting, or thoracic aorta diameter enlargement to ≥ 55mm. Excluding 34 in-hospital deaths (10.1%; 34/336), the 1-, 5-, and 10-year actuarial survival rates after primary TAAAD surgery were 98.2%, 88.6%, and 81.7%, respectively. Over a mean follow-up period of 7.4 ± 5.1years, 67 aortic events (proximal: 19, distal: 45, both: 3) were observed. Freedom from proximal aortic events was 98.6%, 93.9%, and 85.2% at 1, 5, and 10years, respectively. Proximal anastomosis new entry was identified as a significant risk factor for aortic events, with a 92% vs. 42% incidence at 10years (p < 0.001). Freedom from distal aortic events was 99.6%, 84.5%, and 67.2% at 1, 5, and 10years, respectively. A false/true area ratio greater than 1 and distal anastomosis new entry were significant risk factors for aortic events (low-risk group: 83.3% vs. high-risk group: 42.3% at 10years, p < 0.001). Detailed analysis of early postoperative CT scans following primary TAAAD surgery may help identify predictors of subsequent aortic events, potentially improving long-term patient management and outcomes.

“Don’t miss the globe” – Study of diagnostic accuracy of computed tomography in detecting open globe injury

Abstract: PURPOSE: The purpose is to determine the computed tomography (CT) characteristics of open globe injury and establish the relative accuracy and reliability of various features on CT. Second, to assess the significance of a difference in the anterior chamber depths (ACDs) on CT in cases of open globe injury. METHODS: The diagnostic database of our radiology department was retrospectively reviewed to obtain details of patients with a history of blunt or penetrating injury to the orbit between September 2018 and March 2021. A total of 190 patients (144 males and 46 females) were included. A radiologist analyzed the CT scans without prior knowledge of ophthalmologic findings or surgical outcomes. Operative and ophthalmic examination findings were considered the gold standard for comparison. RESULTS: Out of 190 injured globes, the final clinical diagnosis confirmed 54 (28.4%) open globe injuries and 136 (71.5%) closed globe injuries. Between the two groups, intraocular hemorrhage, lens dislocation, lens injury or absence, intraocular foreign body, intraocular air, wall/contour defect, and ACD change were considered statistically significant (P &lt; 0.05). The average sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of CT in diagnosing open globe injury were 71.3%, 98.5%, 83.6%, 95.75%, and 94.9%, respectively. CONCLUSION: Globe contour deformity or defect, intraocular hemorrhage, and a change in ACD were the three most predictive signs of open globe injury. CT is of valuable help in a multi-trauma setting and in an uncooperative patient for ophthalmological examination to draw attention to globe injury. However, CT examination alone is insufficient in detecting all cases of open globe injury. There is a need for a more collaborative approach among emergency physicians, ophthalmologists, and radiologists.

Machine Learning to Differentiate Malignant and Non-malignant Pleural Effusion Findings

Introduction: This study developed a method using machine learning techniques to differentiate between malignant and non-malignant pleural effusions, analyzing texture parameters in computed tomography scans Method: The study involved forty-one patients, with their computed tomography examinations classified into three groups: True Positive - patients with both cytopathological analysis and pleural biopsy indicating malignancy; True Negative - patients with negative results in both tests; and False Negative - patients with negative cytopathological analysis but positive pleural biopsy results. Four machine learning methods were applied across three analyses: True Positive versus True Negative, True Positive versus False Negative, and True Negative versus False Negative. The logistic regression model demonstrated notable effectiveness, achieving an Area Under the Curve of 0.84 ± 0.02 in the True Positive versus True Negative analysis and 0.81 ± 0.05 in the True Positive versus False Negative comparison. In the True Negative versus False Negative analysis, the Naive Bayes model achieved an Area Under the Curve of 0.72 ± 0.02. Results: Statistically significant differences were observed in the liquid Lactate Dehydrogenase and protein content between the True Positive and True Negative groups (p-values of 0.0390 and 0.0249, respectively), and in the liquid pH level between the True Positive and False Negative groups (p-value of 0.0254). The use of textural features in combination with machine learning techniques provided a reliable classification for investigating suspected pleural effusion findings. This method represents a potential tool for assisting in clinical diagnosis and decision-making, enhancing the accuracy of pleural effusion assessments Conclusion: In conclusion, our approach not only improves diagnostic accuracy but also offers a faster and non-invasive alternative, significantly benefiting clinical decision-making and patient care.

Arteriosclerotic Calcification and Atrial Fibrillation in the General Population: The Rotterdam Study

Limited population-based data on the gender differences and association between arteriosclerotic calcification at different sites and atrial fibrillation (AF) exist. We aimed to investigate the (gender-specific) associations between arteriosclerotic calcification at different sites with the risk of AF in the general population. Arteriosclerotic calcification was quantified using computed tomography examinations between 2003 and 2006 in 2,259 participants free of AF from the population-based Rotterdam Study. Cox proportional hazards models, adjusted for cardiovascular risk factors, were used to assess the associations of volumes of coronary artery calcification (CAC), aortic arch calcification (AAC), extracranial and intracranial carotid arteries, vertebrobasilar arteries, and the aortic valve with incident AF. During a median follow-up of 8.6 years, 182 incident AF cases occurred. A larger CAC was associated with incident AF (hazard ratio [HR], 95% confidence interval [CI] 1.25 1.09 to 1.44, p = 0.0019). The gender-stratified analyses showed that larger CAC in men (HR 1.43, 95% CI 1.10 to 1.86, p = 0.0068) and larger AAC in women were associated with incident AF (HR1.44, 95% CI 1.04 to 2.01, p = 0.0299). In conclusion, CAC in the general population, especially in men, and AAC in women were significantly associated with new-onset AF. Our findings imply that interventions to lower arteriosclerotic calcification, particularly, CAC, carry potential for the prevention of AF in the general population, especially in men.

Comparison of foci of active inflammation and fatty degeneration according to MRI and CT data of syndesmophytes in patients with ankylosing spondylitis

Introduction. Syndesmophyte, which is the hallmark of ankylosing spondylitis (AS), is a vertically oriented ossification located outside the fibrous ring of the intervertebral disc. In recent decades, the most widespread theory is that after inflammation in the area of attachment of the fibrous ring to the vertebral body, fatty degeneration occurs with reparative processes, as a result of which the growth of new bone – syndesmophyte – begins. It is believed that the likelihood of developing syndesmophyte is two to three times higher in the angles of those vertebrae in which active inflammation or fatty changes were detected on magnetic resonance tomography (MRI) in the previous 2 years, the latter having a stronger association with subsequent pathological bone formation. However, this relationship is ambiguous according to different studies.The aim – comparison of the exact localization of magnetic resonance tomography and computed tomography (CT) signs of lesions on the vertebral endplates, characteristic of axial spondyloarthritis, in patients with ankylosing spondylitis.Material and methods. The cross-sectional study included 10 patients with AS who met the inclusion criteria.All patients underwent a standard examination for AS, as well as MRI and CT examination of the lumbar spine.A special technique for joint assessment of changes detected during MRI and CT examination has been developed.For the primary analysis, changes found on the upper endplates of 5 lumbar vertebrae were taken.Results. On the upper endplates of 5 lumbar vertebrae, a CT examination revealed 35 syndesmophytes (from 1 to 7 syndesmophytes in 1 patient), and MRI revealed 9 foci of acute inflammation and 24 of chronic inflammation (fatty degeneration). When jointly analyzing the MRI foci of detectable inflammation and syndesmophytes transferred to the vertebral diagram, it turned out that in the majority of cases (68%), the latter were not associated with sites of active and/or chronic inflammation. Correlation analysis showed a certain direct relationship only between the number of syndesmophytes and foci of chronic inflammation (r=0.68).Discussion. Preliminary data show that the proposed method for comparing MRI and CT lesions in AS allows us to jointly study the localization of MRI and CT spinal injuries in patients with AS using multidirectional sections. The first results of our one-time study showed that in most cases the localization of developing syndesmophytes does not coincide with the foci of inflammation detected by MRI (both acute and chronic).

Back pain: diagnostic and therapeutic algorithms in outpatient practice

Back pain is a common reason for seeking primary care from older and younger people. Early spinal imaging by a therapist is indicated to eliminate potentially dangerous causes of pain. Independent magnetic resonance imaging or computed tomography examination at the patient’s initiative in the absence of “red flags” back pain in most cases does not come close to identifying the obvious cause of pain syndrome, and it creates the preconditions for the formation of an exaggerated picture of the disease in the patient himself, driving him into the “trap” of chronic pain. Attention of the polyclinic doctor to the clinical symptoms detailed in the article, following the standard algorithms of diagnosis will allow timely suspicion of “red flags” back pain, avoid hyperdiagnosis of the cause, and minimize the risk of its chronization. The algorithm for treatment of acute and chronic episodes of pain should include informing the patient about the favorable outcome in the vast majority of cases, optimizing the physical activity of the patient, the use of complex drug therapy, the basis of which are nonsteroidal anti-inflammatory drugs (predominantly selective), muscle relaxants and other pathogenetically based medicines.

Computed Tomographic Findings of Liver Cirrhosis in Dogs: Comparison between Compensated and Decompensated Cirrhosis.

This study aimed to describe computed tomography (CT) characteristics of histologically confirmed cirrhosis and to compare these CT characteristics between compensated and decompensated cirrhosis. Sixteen dogs who underwent contrast CT and histopathological examinations were included; eleven dogs were assigned to the compensated group, and five dogs were assigned to the decompensated group. Irregular hepatic contours with a diffuse nodular distribution and hepatic lymph node enlargement are common concomitant features of cirrhotic livers on CT images. The enhancement patterns of the regenerative nodules and hepatic parenchyma were not significantly different from each other. Hypoattenuating areas with delayed contrast enhancement indicating fibrotic tissue were confirmed in 56.3% of cases. Hypoattenuating wedge-shaped area or nodule with minor or no contrast enhancement (histopathologically confirmed as focal necrosis) were confirmed in 37.5% of cases. Among CT variables, only normalized liver volume and portal vein-to-aorta ratio were significantly lower (p = 0.038 and 0.003, respectively) in the decompensated group. In conclusion, this study presented the CT features of cirrhosis and identified CT features that can discriminate between compensated and decompensated cirrhosis. Specifically, lower normalized liver volume and the portal vein-to-aorta ratio might be useful indicators for the progression of cirrhosis to the decompensated phase.

Estimation of Radiation Dose to the Eye Lens in Cranial Computed Tomography Examinations in Federal Neuro-Psychiatric Hospital Maiduguri, Borno State, Nigeria

Estimation of Radiation Dose to the Eye Lens in Cranial Computed Tomography Examinations in Federal Neuro-Psychiatric Hospital Maiduguri, Borno State, Nigeria

The determination of coefficients for size specific effective dose for adult and pediatric patients undergoing routine computed tomography examinations.

The effective dose resulting from computed tomography (CT) scans provides an assessment of the risk associated with stochastic effects but does not account for the patient's size. Advances in Monte Carlo simulations offer the potential to obtain organ dose data from phantoms of varying stature, enabling derivation of a size-specific effective doses (SEDs) representing doses to individual patients. This study aimed to compute size-specific k-conversion factors for SED in routine CT examinations for adult and pediatric patients of different sizes. Radiation interactions were simulated for adult and pediatric phantom models of various sizes using National Cancer Institute CT version 3.0.20211123. Subsequent calculations of SED were performed, and coefficients for SED were derived, considering the variations in body sizes. The results revealed a strong correlation between effective diameter and weight, observed with size-specific k-conversion factors for adult and pediatric phantoms, respectively. While size-specific k-conversion factors for CT brain remained constant in adults, values for pediatric cases varied. When using the tube current modulation (TCM) system, size-specific k-conversion factors increased in larger phantoms and decreased in smaller ones. The extent of this increase or decrease correlated with the set TCM strength. This study provides coefficients for estimating SEDs in routine CT exams. Software utilizing look-up tables of coefficients can be used to provide dose information for CT scanners at local hospitals, offering guidance to practitioners on doses to individual patients and improving radiation risk awareness in clinical practice.