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Introduction: Strategies for achieving high resolution varies between manufacturers. In CT, the helical mode with narrow collimation has long been considered as the gold standard for high-resolution imaging. More recently, incremental modes with small dexels and focal spot, have been developed but have not been compared with helical acquisitions under optimal conditions. The aim of this work is to compare the high-resolution acquisition strategies currently proposed by recent MSCT., Methods: Three CT systems were compared. A phantom was used to evaluate geometric accuracy, uniformity, scan slice geometry, and spatial resolution. Human dry bones were used to test different protocols on real bone architecture. A blind visual analysis was conducted by trained CT users for classifying the different acquisitions (p-values)., Results: All systems give satisfactory results in terms of geometric accuracy and uniformity. The in-plane MTF at 5% were respectively 13.4, 15.9 and 18.1 lp/cm. Dry-bones evaluation confirms that acquisition#3 is considered as the best., Conclusions: The incremental acquisition coupled with à small focal spot, and a high-sampling detector, overpasses the reference of low-pitch helical acquisitions for high-resolution imaging. Cortical bone, bony vessels, and tumoral matrix analysis are the very next challenges that will have to be managed to improve normal and pathologic bone imaging thanks to the availability UHR-CT systems., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Introduction: This study aims to construct learning curves related to the realization of standardized postprocessing by radiographer students and to discuss their exploitation and interest., Materials and Methods: This study was carried out in 21 French students in their 3rd year of training. Two postprocessing protocols in CT (#1 traumatic shoulder; #2 petrous bone) were repeated 15 times by each student. Each achievement was timed to obtain overall learning curves. The realization accuracy was also assessed for each student at each repetition., Results: The learning rates for the two protocols are 63% and 56%, respectively. The number of repetitions to reach the reference time for each protocol is 11 and 12, respectively. In both protocols, the standard deviations are significantly reduced and stabilized during repetitions. The mean accuracy progresses more quickly in protocol #1., Discussion: The measured learning rates reflect a rapid learning process for each protocol. The analysis of the standard deviations shows that students have reached a homogeneous level. The average times and accuracies measured during the last repetitions show that the group has reached a high level of performance. Building learning curves helps students measure their progress and motivates them., Conclusion: Obtaining learning curves allows trainers/supervisors to qualify the learning difficulty of a task while motivating students/radiographers. The use of learning curves is inline with the competency-based training paradigm., (Copyright © 2020. Published by Elsevier Inc.)

History An otherwise healthy 18-year-old man was admitted to the emergency department with a closed displaced fracture of the left femoral shaft ( Fig 1 ) after a high-velocity motorbike accident. At admission, other physical examination findings were unremarkable. Initial unenhanced and contrast material-enhanced (120 mL of Iomeron 400; Bracco Imaging, Milan, Italy) computed tomography (CT) was performed in the arterial and venous phases from the head to the knees. No abnormalities were noted in the brain or chest at initial CT. [Figure: see text] Within a few hours, the patient developed sudden mental confusion and severe hypoxemia, with rapidly worsening tachypnea and perturbed arterial blood gas with low partial pressure of oxygen (61 mmHg [8.1 kPa]; normal range, 75-100 mmHg [10.0-13.3 kPa]) and low partial pressure of carbon dioxide (32 mmHg [4.3 kPa]; normal range, 38-42 mmHg [5.1-5.6 kPa]). A second contrast-enhanced chest CT examination and initial brain magnetic resonance (MR) imaging were performed. Femoral fracture was stabilized with external fixation, and the patient was admitted to the intensive care unit, with progressive neurologic recovery at day 3 and respiratory improvement at day 4. Treatment included intubation with mechanical ventilation and intravenous administration of steroids and noradrenaline. Afterward, the femoral fracture was stabilized with an intramedullary nail. The patient made a full neurologic recovery 1 month after the accident.

Objective: Nowadays, post-mortem computed tomography (PMCT) has become an integral part of Forensic practice. The purpose of the study was to determine PMCT impact on diagnosis of the cause of death within the context of the external examination of the body, when autopsy has, at first, not been requested., Material and Methods: We reviewed the records of 145 cases for which unenhanced PMCT was performed in addition to the external examination of the body from January 2014 to July 2015 at the Institute of Forensic medicine in Strasbourg (France). We confronted final reports from forensic pathologist to the corresponding PMCT reports. Data were collected in a contingency table and the impact of PMCT on the final conclusions of the forensic pathologist was evaluated via a Chi 2 test., Results: PMCT results significantly impact the final conclusions of forensic pathologist (p<0,001). In some cases, PMCT permits etiological diagnosis by revealing a cause of death hidden from external examination (mainly natural death) or by supporting the clinical findings of the forensic pathologist. In other cases (traumatic death), PMCT enables fast and exhaustive lesion assessment. Lastly, there are situations where PMCT may be ineffective (intoxication, hanging or some natural deaths)., Conclusion: Performing PMCT within the context of the external examination of the body when autopsy has, at first, not been requested could bring significant benefits in diagnosing the cause of death. The impact of PMCT varies depending on the circumstances of death., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Purpose To determine if the obliteration of a cervical space, the paraspinal fat pad (PFP), can be used as an indicator at computed tomography (CT) of an injury of cervical spine posterior ligamentous complex (PLC). Materials and Methods This retrospective study was approved by the institutional board review; written informed consent was obtained from healthy subjects and was waived for patients. First, PFP appearance was evaluated in an anatomic specimen and in 10 healthy subjects on spine CT scans by three radiologists (readers 1, 2, and 3) working in consensus. Then, in 85 patients with suspicion of cervical spine trauma following high-velocity trauma, readers 2 and 3 reviewed in consensus the cervical spine CT (reference for fracture and luxation) and 1.5-T magnetic resonance images (T1, T2, and short inversion time inversion-recovery sequences; reference for ligament and disk injuries and contusion or occult fracture) for traumatic injuries. CT appearance of PFP was independently analyzed by readers 1 and 2, and interobserver agreement (weighted kappa) was calculated. Relationships between PFP changes and injuries and descriptive analysis were calculated by using logistic regression and Fisher test, respectively. Results The PFP could be identified as a well-circumscribed fatty area between cervical spine and posterior muscles. Interobserver agreement was 0.76. An abnormal PFP was associated with PLC (P < .001) and arch (P = .006) injuries but not with body (P = .056), longitudinal ligaments (P = .412), or disk (P = .665) injuries. Sensitivity, specificity, positive predictive value, and negative predictive value for PLC injuries were 55% (11 of 20), 97% (38 of 39), 92% (11 of 12), and 81% (38 of 47), respectively. Conclusion PFP changes on CT scans are significantly associated with injuries of PLC in patients with spine cervical trauma. © RSNA, 2016 Online supplemental material is available for this article.

Objective: To prospectively evaluate the performance of virtual non-calcium (VNC) dual-energy CT (DECT) images for the demonstration of trauma-related abnormal marrow attenuation in collapsed and non-collapsed vertebral compression fractures (VCF) with MRI as a reference standard., Materials and Methods: Twenty patients presenting with non-tumoral VCF were consecutively and prospectively included in this IRB-approved study, and underwent MRI and DECT of the spine. MR examination served as a reference standard. Two independent readers visually evaluated all vertebrae for abnormal marrow attenuation ("CT edema") on VNC DECT images; specificity, sensitivity, predictive values, intra and inter-observer agreements were calculated. A last reader performed a quantitative evaluation of CT numbers; cut-off values were calculated using ROC analysis., Results: In the visual analysis, VNC DECT images had an overall sensitivity of 84%, specificity of 97%, and accuracy of 95%, intra- and inter-observer agreements ranged from k = 0.74 to k = 0.90. CT numbers were significantly different between vertebrae with edema on MR and those without (p < 0.0001). Cut-off values provided sensitivity of 85% (77%) and specificity of 82% (74%) for "CT edema" on thoracic (lumbar) vertebrae., Conclusions: VNC DECT images allowed an accurate demonstration of trauma-related abnormal attenuation in VCF, revealing the acute nature of the fracture, on both visual and quantitative evaluation.

Objective: To determine the prevalence of infection diagnosed by percutaneous computed tomography (CT)-guided sternoclavicular (SC) sampling in cases of suspected joint infection., Materials and Methods: A retrospective search was performed in reports of SC joint CT-guided biopsies in adults from July 1992 to July 2012. We reviewed medical records, radiology, microbiology, laboratory, and surgical reports. A positive result was defined as demonstration of a pathogenic organism, either by microscopy or growth in culture, confirming the diagnosis of SC joint infection. A negative result was defined as the absence of such findings. Patients in whom sampling was unsuccessful or not subjected to microbiology were excluded. In addition, CT images were reviewed by the consensus of two musculoskeletal radiologists., Results: A total of 41 patients (mean age 57.1 years) underwent CT-guided SC joint sampling, 27 of whom underwent microbiology studies. Sampling was performed using core biopsy alone in 19%, fine needle aspiration alone in 44%, and aspiration combined with core biopsy in 37%. Positive results were found in 52% (14/27) of patients. Related diseases and predisposing conditions for infection were found in 79% of positive patients. Negative results were found in 48% (13/27) of patients. There were no procedure-related complications. The dominant CT findings were soft tissue swelling (negative group), and effusion and/or capsular hypertrophy/distension (positive group)., Conclusions: CT-guided sampling is a safe procedure with positive microbiological cultures in slightly more than half of cases.

Humoral immunodeficiencies, which are characterized by defective production of antibodies, are the most common types of primary immunodeficiency. Pulmonary changes are present in as many as 60% of patients with humoral immunodeficiency. Chronic changes and recurrent infections in the respiratory airways are the main causes of morbidity and mortality in those affected by a humoral immunodeficiency. Medical imaging, especially computed tomography (CT), plays a crucial role in the initial detection and characterization of changes and in monitoring the response to therapy. The spectrum of abnormalities seen at thoracic imaging includes noninfectious airway disorders, infections, chronic lung diseases, chronic inflammatory conditions (granulomatosis, interstitial pneumonias), and benign and malignant neoplasms. Recognition of characteristic CT and radiographic features, and correlation of those features with clinical and laboratory findings, are necessary to differentiate between the many possible causes of parenchymal and mediastinal disease seen in patients with primary humoral immunodeficiencies.

Objective: We explored the potential for patients with proven venous thromboembolism or pulmonary embolism (PE) to have occult malignancies detected during the same CT examination. To verify this, we compared the presence of occult malignancies identified on pulmonary artery CT angiography (CTA) and CT venography (CTV) when venous thromboembolism (VTE) was present., Subjects and Methods: Pulmonary artery CTA combined with CTV was performed on a 16-MDCT scanner on 186 adult patients suspected of having pulmonary embolism without any known malignancies. CTV was performed from the diaphragm to the knee 180 seconds after CTA. Two radiologists evaluated the presence of VTE, that is PE or deep venous thrombosis (DVT), and tumor lesions on both examinations in consensus. The malignant nature of the possibly identified tumors was confirmed by pathologic examination., Results: VTE was found in 49 patients (26%). Malignant tumors were detected in 24 patients (13%). Eleven patients with malignant tumors had VTE (46% of patients with malignant tumors; 22% with VTE and 6% of all patients). There was correlation with presence of malignancies between both and DVT and DVT associated with PE but not between presence of malignancies and PE only. Patients with DVT and those with DVT associated with PE had a risk ratio of 3.2 and 3.3, respectively, for having a malignant tumor discovered simultaneously., Conclusion: A high number of malignant tumors can be incidentally discovered on pulmonary artery CTA, even more so with additional CTV. Radiologists should scrutinize scans to pick up unknown malignancies, especially in patients with identified VTE.