MDCT imaging of traumatic brain injury

Deep Learning-Based Denoising Enables High-Quality, Fully Diagnostic Neuroradiological Trauma CT at 25% Radiation Dose

RATIONALE AND OBJECTIVES

Traumatic neuroradiological emergencies necessitate rapid and accurate diagnosis, often relying on computed tomography (CT). However, the associated ionizing radiation poses long-term risks. Modern artificial intelligence reconstruction algorithms have shown promise in reducing radiation dose while maintaining image quality. Therefore, we aimed to evaluate the dose reduction capabilities of a deep learning-based denoising (DLD) algorithm in traumatic neuroradiological emergency CT scans.

MATERIALS AND METHODS

This retrospective single-center study included 100 patients with neuroradiological trauma CT scans. Full-dose (100%) and low-dose (25%) simulated scans were processed using iterative reconstruction (IR2) and DLD. Subjective and objective image quality assessments were performed by four neuroradiologists alongside clinical endpoint analysis. Bayesian sensitivity and specificity were computed with 95% credible intervals.

RESULTS

Subjective analysis showed superior scores for 100% DLD compared to 100% IR2 and 25% IR2 (p < 0.001). No significant differences were observed between 25% DLD and 100% IR2. Objective analysis revealed no significant CT value differences but higher noise at 25% dose for DLD and IR2 compared to 100% (p < 0.001). DLD exhibited lower noise than IR2 at both dose levels (p < 0.001). Clinical endpoint analysis indicated equivalence to 100% IR2 in fracture detection for all datasets, with sensitivity losses in hemorrhage detection at 25% IR2. DLD (25% and 100%) maintained comparable sensitivity to 100% IR2. All comparisons demonstrated robust specificity.

CONCLUSIONS

The evaluated algorithm enables high-quality, fully diagnostic CT scans at 25% of the initial radiation dose and improves patient care by reducing unnecessary radiation exposure.

Integrated Assessment of GFAP and UCH-L1 for their utility in severity assessment and outcome prediction in Traumatic Brain Injury

OBJECTIVES

This study aimed to explore the potential of glial fibrillary acidic protein (GFAP) and ubiquitin C-terminal hydrolase-L1 (UCH-L1) as biomarkers for diagnosis and prognosis in mild and severe TBI cases, including TBI-related deaths.

METHODS

This prospective cohort study includes 40 cases each of mild, severe, fatal TBI cases, and 40 healthy controls. Serum samples were collected from live patients at 8 and 20 h post injury for UCH-L1 and GFAP respectively, and from deceased patients within 6 h of death.

RESULTS

Elevated levels of both GFAP and UCH-L1 were observed in patients with severe and fatal TBI cases. These biomarkers exhibited promising potential for predicting various Glasgow Outcome Scale Extended (GOSE) categories. Combining GFAP and UCH-L1 yielded higher predictive accuracy both for diagnosis and prognosis in TBI cases. The study additionally established specific cut-off levels for GFAP and UCH-L1 stratified according to the severity and prognosis.

CONCLUSION

GFAP and UCH-L1 individually demonstrated moderate to good discrimination capacity in predicting TBI severity and functional outcomes. However, combining these biomarkers is recommended for improved diagnostic and prognostic utility. This precision tool can enhance patient care, enabling tailored treatment plans, ultimately reducing morbidity and mortality rates in TBI cases.

Intramyelinic edema manifesting as central white matter diffusion restriction associated with brain contusion in pediatric patients

In traumatic brain injury, white matter diffusion restriction can be an imaging manifestation of non-hemorrhagic axonal injury. In this article, a different pattern of widespread white matter diffusion restriction associated with ipsilateral cortical damage, all noted in pediatric and young adult TBI patients, is presented. Its atypical pattern of distribution and extensive scope on imaging suggest excitotoxicity and intramyelinic edema as possible underlying mechanisms.

"NeuroVanguard": a contemporary strategy in neuromonitoring for severe adult brain injury patients

Severe acute brain injuries, stemming from trauma, ischemia or hemorrhage, remain a significant global healthcare concern due to their association with high morbidity and mortality rates. Accurate assessment of secondary brain injuries severity is pivotal for tailor adequate therapies in such patients. Together with neurological examination and brain imaging, monitoring of systemic secondary brain injuries is relatively straightforward and should be implemented in all patients, according to local resources. Cerebral secondary injuries involve factors like brain compliance loss, tissue hypoxia, seizures, metabolic disturbances and neuroinflammation. In this viewpoint, we have considered the combination of specific noninvasive and invasive monitoring tools to better understand the mechanisms behind the occurrence of these events and enhance treatment customization, such as intracranial pressure monitoring, brain oxygenation assessment and metabolic monitoring. These tools enable precise intervention, contributing to improved care quality for severe brain injury patients. The future entails more sophisticated technologies, necessitating knowledge, interdisciplinary collaboration and resource allocation, with a focus on patient-centered care and rigorous validation through clinical trials.

"COAGULATION": a mnemonic device for treating coagulation disorders following traumatic brain injury-a narrative-based method in the intensive care unit

Introduction

Coagulopathy associated with isolated traumatic brain injury (C-iTBI) is a frequent complication associated with poor outcomes, primarily due to its role in the development or progression of haemorrhagic brain lesions. The independent risk factors for its onset are age, severity of traumatic brain injury (TBI), volume of fluids administered during resuscitation, and pre-injury use of antithrombotic drugs. Although the pathophysiology of C-iTBI has not been fully elucidated, two distinct stages have been identified: an initial hypocoagulable phase that begins within the first 24 h, dominated by platelet dysfunction and hyperfibrinolysis, followed by a hypercoagulable state that generally starts 72 h after the trauma. The aim of this study was to design an acronym as a mnemonic device to provide clinicians with an auxiliary tool in the treatment of this complication.

Methods

A narrative analysis was performed in which intensive care physicians were asked to list the key factors related to C-iTBI. The initial sample was comprised of 33 respondents. Respondents who were not physicians, not currently working in or with experience in coagulopathy were excluded. Interviews were conducted for a month until the sample was saturated. Each participant was asked a single question: Can you identify a factor associated with coagulopathy in patients with TBI? Factors identified by respondents were then submitted to a quality check based on published studies and proven evidence. Because all the factors identified had strong support in the literature, none was eliminated. An acronym was then developed to create the mnemonic device.

Results and conclusion

Eleven factors were identified: cerebral computed tomography, oral anticoagulant & antiplatelet use, arterial blood pressure (Hypotension), goal-directed haemostatic therapy, use fluids cautiously, low calcium levels, anaemia-transfusion, temperature, international normalised ratio (INR), oral antithrombotic reversal, normal acid-base status, forming the acronym "Coagulation." This acronym is a simple mnemonic device, easy to apply for anyone facing the challenge of treating patients of moderate or severe TBI on a daily basis.

Right-to-Left Displacement of an Airgun Lead Bullet after Transorbital Entry into the Skull Complicated by Posttraumatic Epilepsy : A Case Report

Penetrating head injury is a serious open cranial injury. In civilians, it is often caused by non-missile, low velocity flying objects that penetrate the skull through a weak cranial structure, forming intracranial foreign bodies. The intracranial foreign body can be displaced due to its special quality, shape, and location. In this paper, we report a rare case of right-to-left displacement of an airgun lead bullet after transorbital entry into the skull complicated by posttraumatic epilepsy, as a reminder to colleagues that intracranial metal foreign bodies maybe displaced intraoperatively. In addition, we have found that the presence of intracranial metallic foreign bodies may be a factor for the posttraumatic epilepsy, and their timely removal appears to be beneficial for epilepsy control.

Long-term Tractography Evaluation of Corpus Callosum Impairment After Severe Traumatic Brain Injury in Patients With Isolated Intraventricular Hemorrhage on Admission CT: Two Illustrative Cases and a Literature Review

Severe traumatic brain injury (TBI) is often associated with diffuse axonal injury. Diffuse axonal injury affecting the corpus callosum may present with intraventricular hemorrhage on baseline computed tomography (CT) scan. Posttraumatic corpus callosum damage is a chronic condition that can be diagnosed over the long term using various magnetic resonance imaging (MRI) sequences. Here, we present two cases of severe survivors of TBI with isolated intraventricular hemorrhage detected on an initial CT scan. After acute trauma management, long-term follow-up was performed. Diffusion tensor imaging and subsequent tractography revealed a significant decrease in the fractional anisotropy values and the number of corpus callosum fibers compared with those in healthy control patients. This study presents a possible correlation between traumatic intraventricular hemorrhage on admission CT and long-term corpus callosum impairment detected on MRI in patients with severe head injury by presenting demonstrative cases and conducting a literature review.

CT Utilization in a Level One Trauma Center in South Africa

Introduction

Computed tomography (CT) imaging forms an important component in the evaluation and management of patients with traumatic injuries. Many South African emergency departments (EDs) have a significant trauma-related workload, especially in the public sector, where there are limitations in resources relating to CT scanners. It is important to gauge the impact of traumatic injuries on CT utilization. The primary objectives were to quantify the number and type of CT imaging studies trauma patients received, as well as to determine the frequency of radiologically significant findings in a level one trauma center. The secondary objectives were to determine the CT utilization rate and describe the demographics of patients who received imaging.

Methods

This was a retrospective, quantitative, descriptive, cross-sectional study undertaken over two months at the level one trauma center of a tertiary, academic, public sector teaching hospital in Johannesburg, South Africa. The radiology department’s picture archiving and communication system (PACS) was used to evaluate the reports of trauma patients who were referred for a CT scan. The trauma center register was used to calculate the CT utilization rate.

Results

There were 5,058 trauma patients seen in the two months. A total of 1,277 CT scans were performed on 843 patients. CT brain accounted for 52% of all scans performed. Radiologically significant findings were demonstrated in 407 scans (354 patients), i.e. 31.9% of scans and 42% of patients. CT chest and peripheral angiogram demonstrated radiologically significant findings in 60.5% and 50.9% of scans respectively. Assault accounted for 55.8% of the injuries sustained and road traffic accidents accounted for 33.2%. The overall CT utilization rate was 16.7% i.e. 843 out of the 5,058 trauma patients underwent a CT scan.

Conclusions

South Africa has a substantial trauma burden which commonly necessitates CT utilization. It is concerning that blunt and penetrating assault continues to dominate these traumatic presentations. Worldwide, there is a broad range of described CT utilization rates and the findings at this level one trauma center fall within that range. ED clinicians are encouraged to continue carefully using this scarce resource in the trauma setting. 

Automatic hemorrhage segmentation on head CT scan for traumatic brain injury using 3D deep learning model

The most common cause of long-term disability and death in young adults is a traumatic brain injury. The decision for surgical intervention for craniotomy is dependent on the injury type and the patient's neurologic exam. The potential subtypes of intracranial hemorrhage that may necessitate surgical intervention include subdural hemorrhage, epidural hemorrhage, and intraparenchymal hemorrhage. We proposed a novel automatic method for segmenting the hemorrhage subtypes on a CT scan by integrated CT scan with bone window as input of a deep learning model. Brain CT scans were collected from adult patients and annotated regions of subdural hemorrhage, epidural hemorrhage, and intraparenchymal hemorrhage by neuroradiologists. Their raw DICOM images were preprocessed by two different window settings i.e., subdural and bone windows. The collected CT scans were divided into two datasets namely training and test datasets. A deep-learning model was modified to segment regions of each hemorrhage subtype. The model is a three-dimensional convolutional neural network including four parallel pathways that process the input at different resolutions. It was trained by a training dataset. After the segmentation result was produced by the deep-learning model, it was then improved in the post-processing step. The size of the segmented lesion was considered, and a region-growing algorithm was applied. We evaluated the performance of the proposed method on the test dataset. The method reached the median Dice similarity coefficients higher than 0.37 for each hemorrhage subtype. The proposed method demonstrates higher Dice similarity coefficients and improved segmentation performance compared to previously published literature.

Association of frontal and maxillary bone fractures and concomitant craniocerebral injuries in patients presenting with head trauma

Background

Maxillofacial fractures and craniocerebral injuries are common in patients with head trauma. These are injuries with high mortality and morbidity. Therefore, patients with head trauma should be evaluated early with a multidisciplinary approach.

Aim

The association between frontal and maxillary bone fractures and concurrent craniocerebral injuries were investigated in patients presenting with head trauma in this study. The data of the patients were analyzed retrospectively.

Methods and Material

Age and gender distributions were evaluated in frontal and maxillary fractures. Concomitant craniocerebral injuries were investigated. Craniocerebral injuries were grouped as pneumocephalus, extra-axial, intra-axial injuries and brain edema. Craniocerebral injuries in frontal and maxillary fractures were compared statistically.

Results

Frontal bone and maxillary bone fractures were detected in 24% and 95% of the patients. Coexistence of pneumocephalus and intra-axial injuries in frontal bone fracture was statistically significant. The association of frontal posterior wall fractures with pneumocephalus and parenchymal contusion was found to be statistically significant. In addition, the association of craniocerebral injuries were evaluated and statistically significant ones were determined.

Conclusion

The presence of maxillofacial fractures in patients presenting with head trauma increases mortality and morbidity. Craniocerebral injuries can be life-threatening and delay the treatment of facial fractures. Upper facial bone fractures are significantly more common in craniocerebral injuries.

Head CT for the intensivist: 10 tips and pearls

Head imaging is an essential diagnostic tool for the management of patients with most acute neurological emergencies involving the brain. While numerous modalities including magnetic resonance imaging and catheter angiography play a role, computed tomography (CT) of the brain is far and away the most widely utilized technique because of its widespread availability and the fact that it is usually easier to implement in critically ill and potentially unstable patients. CT is particularly useful in identifying acute intracranial hemorrhage and this makes it often indispensable in the management of patients with traumatic brain injury and hemorrhagic stroke. However, shortcomings in identifying early ischemia on non-contrast CT mean that care must be taken in considering findings early after symptom onset, with newer CT sequences such as CT angiography and CT perfusion adding value. The critical role played by intensivist in managing neurocritical care patients necessitates familiarity and ability with viewing and understanding the advantages and shortcomings of head CT imaging and under which circumstances other modalities may be appropriate to obtain. This manuscript provides ten different circumstances commonly encountered in neurocritical care and how intensivists can use CT for the benefit of their patients.

Inner Ear Symptoms Are Prevalent in Patients with High Head Abbreviated Injury Scale Scores after Blunt Head Trauma

INTRODUCTION

The purpose of this article was to determine the prevalence of inner ear symptoms in patients with blunt head trauma and to explore whether the severity of head trauma was associated with the incidence of such symptoms.

METHODS

We performed a retrospective review of 56 patients admitted with blunt head trauma who underwent audiovestibular evaluation within 1 month after injury. Two scales were used to measure the severity of trauma; these were the Glasgow Coma Scale (GCS) and the Head Abbreviated Injury Scale (H-AIS). Patients with sensorineural-type hearing loss, or dizziness with nystagmus, were considered to have inner ear symptoms.

RESULTS

About half of all patients (45%) with blunt head trauma showed trauma-related inner ear symptoms. Patients with inner ear symptoms were significantly more likely to have H-AIS scores ≥4 than those without inner ear symptoms (p = 0.004), even without concomitant temporal bone fracture (p > 0.05). Also, patients with inner ear symptoms required a statistically significantly longer time (measured from admission) before undergoing their ontological evaluations than did those without such symptoms (p = 0.002), possibly due to prolonged bed rest and use of sedatives.

CONCLUSION

Thus, detailed history-taking and early evaluation using trauma scales are essential for all patients suffering from severe head trauma. It may be necessary to initiate early treatment of traumatic inner ear diseases.

Radiology and A Radiologist: A Keystone in the Turmoil of Trauma Setting

Traumatic injuries are one of the leading causes of morbidity and mortality. Precise diagnosis and management in the golden hour are key to decrease morbidity and mortality. History and physical examination alone are insufficient to avoid misdiagnosis. In this article, we tried to determine the role of a radiologist and an appropriate imaging modality in a trauma setting. We conducted a literature review of published research articles. We used the keywords imaging, trauma, imaging and trauma, and trauma imaging essentials were used on PubMed and Google Scholar. The articles published in the English language from 2015 to 2020 with full free text available were included. Using the medical subject heading (MeSH) strategy, "diagnostic imaging" (Major {Majr}) and "multiple trauma/diagnostic imaging" (Mesh) on PubMed, we identified 34 papers after applying the inclusion and exclusion criteria. Twenty articles were finally selected which included studies from 2015 to 2020 with articles focusing on the adult population and acute cases. A radiologist and imaging modalities are the essential parts of a trauma setting to lower morbidity and mortality. X-rays and Extended Focussed Assessment with Sonography for Trauma (eFAST) are the first-line imaging modality in the acute trauma setting. However, the CT scan is the most sensitive modality that should be done to avoid misdiagnosis depending upon the patient's history and physical examination.

Computed Tomographic Imaging Appraisal of Traumatic Brain Injury in a Tertiary Hospital in South-South Nigeria: A 6-Year Review

Background:

Computed tomography (CT) remains the gold standard in imaging evaluations of traumatic brain injury (TBI). TBI on its own has become a major concern in developing countries with its untoward effects.

Objectives:

The objective was to appraise the craniocerebral computed tomograms of patients who had TBIs.

Materials and Methods:

A retrospective study of patients who underwent craniocerebral CT on account of head injury in the University of Uyo Teaching Hospital, Uyo, Nigeria, from November 13, 2013 to May 31, 2019 was done. The duration was regardless of the disjointed periods of service interruption. Patients' demographic and CT features were evaluated with application of simple analysis of data.

Results:

Two hundred and thirty-two patients were evaluated with minimum and maximum ages of 6 months and 78 years, respectively. Males were predominant with a ratio of 2.74: 1. Most affected age ranges were 30–39 years (23.27%) and 20–29 (22.84%). Normal brain CT was seen in 44 patients (18.97%). The most frequent lesion in patients with abnormal CT was intracranial hemorrhages (n = 188, 81.03%). Here, extra-axial hemorrhages (n = 100, 53.19%) supersede intracerebral hemorrhages (n = 88, 46.81%). Half of the intracerebral hemorrhages were multiple. Calvarial fractures were seen in 34.48% (n = 80) of patients. The most common localization was the facial bones (n = 24, 30.00%), whereas the least site was the occipital bone (n = 4, 5.00%). Fifteen percent of the patients had multiple fractures which also included base of the skull.

Conclusion:

TBIs commonly occur among young active males. The most frequent lesion is intracranial hemorrhages with extra-axial bias.

Two latent classes of diagnostic and treatment procedures among traumatic brain injury inpatients

To characterize latent classes of diagnostic and/or treatment procedures among hospitalized U.S. adults, 18-64 years, with primary diagnosis of TBI from 2004-2014 Nationwide Inpatient Samples, latent class analysis (LCA) was applied to 10 procedure groups and differences between latent classes on injury, patient, hospital and healthcare utilization outcome characteristics were modeled using multivariable regression. Using 266,586 eligible records, LCA resulted in two classes of hospitalizations, namely, class I (n = 217,988) (mostly non-surgical) and class II (n = 48,598) (mostly surgical). Whereas orthopedic procedures were equally likely among latent classes, skin-related, physical medicine and rehabilitation procedures as well as behavioral health procedures were more likely among class I, and other types of procedures were more likely among class II. Class II patients were more likely to have moderate-to-severe TBI, to be admitted on weekends, to urban, medium-to-large hospitals in Midwestern, Southern or Western regions, and less likely to be > 30 years, female or non-White. Class II patients were also less likely to be discharged home and necessitated longer hospital stays and greater hospitalization charges. Surgery appears to distinguish two classes of hospitalized patients with TBI with divergent healthcare needs, informing the planning of healthcare services in this target population.

Pattern Recognition: A Mechanism-based Approach to Injury Detection after Motor Vehicle Collisions

Motor vehicle collisions cause substantial mortality, morbidity, and expense worldwide. Certain types of injuries are more likely to result from frontal versus side-impact collisions, and knowledge of these specific patterns and why they occur aids in accurate and efficient diagnosis of traumatic injuries. Although the proper use of seat belts decreases crash-related mortality during frontal impact, certain injury patterns to the torso are directly attributed to restraint use. The spectrum of seat belt-related injuries ranges from mild skin and soft-tissue contusions to traumatic bowel injuries and unstable spine injuries that require surgery. Impact with the steering wheel or windshield during a frontal crash can cause characteristic injuries to the head, neck, torso, and distal upper extremity. Steering wheel deformity is an independent predictor of serious thoracic and abdominal injury among front-seat passengers. Impact of a flexed knee with the dashboard during a frontal collision can cause knee, thigh, and hip injuries. Distal lower extremity injuries are encountered frequently when the floorboard is driven into the foot. Lateral impact crashes often result in traumatic brain, thoracic, abdominal, and pelvic injuries, which are more often fatal to occupants on the side of the impact. The specific mechanism-based injury patterns are reviewed to establish a structured systematic search pattern that enables the radiologist to identify traumatic injuries with greater accuracy and speed, thereby improving the care of patients who experience acute trauma. ^©RSNA, 2019 See discussion on this article by Ballard and Mellnick .

Imaging of Brain Trauma

Conventional imaging in the acute setting of brain trauma, relevant pathophysiology of injury, and advanced imaging techniques that may provide value in understanding the immediate management and long-term sequela of traumatic brain injury are reviewed. Key imaging findings that can guide clinical management related to such injuries as concussions, hematomas, dissections, dural atrioventricular fistula, and diffuse axonal injury are discussed. The role and accuracy of computed tomography, dual-energy computed tomography, computed tomography angiography, and magnetic resonance angiography in the acute setting are evaluated. In addition, caveats related to imaging the elderly and pediatric population are addressed.

Observer Performance in Computed Tomography Head Reporting

AIM

To audit the reporting results of a cohort of radiographers (n = 6) completing an accredited academic program in clinical reporting of computed tomography (CT) head examinations.

METHODS

An audit of retrospective academic image case banks and prospective random clinical workload case banks. Both the academic test banks and clinical workload banks included a wide range of normal and abnormal cases of different levels of difficulty and pathology. Abnormalities included hemorrhage, fractures, lesions, infarctions, degeneration, and normal variants from a variety of referral sources. True positive and negative, as well as false positive and negative fractions were used to mark the reports, which were analyzed for accuracy against a reference standard. Furthermore, interobserver variability was assessed using Cohen's kappa, one-way analysis of variance, and Tukey for multiple comparisons and significance testing at 95% confidence intervals (CI).

RESULTS

The mean accuracy score for all radiographers (n = 6) and reports (n = 3,008) was 90.7% (95% CI, 88.3%-93.0%). Mean sensitivity and specificity rates were 86.9% (95% CI, 85.8%-88.2%) and 94% (95% CI, 89.6%-98.3%), respectively. The most common errors were associated with herniation, lacunar infarctions, and subtle fractures (false negatives) and involutional changes, subtle infarctions, and ventricular dilation (false positives).

CONCLUSIONS

The results suggest appropriately trained radiographers can successfully undertake to report computed tomography head examinations to a high standard. The adoption of both academic and clinical workload image banks that reflect disease examples and the prevalence that may logically be encountered in practice offers the potential for an accurate measure of performance of radiographer's abilities.

Image Quality Required for the Diagnosis of Skull Fractures Using Head CT: A Comparison of Conventional and Improved Reconstruction Kernels

BACKGROUND AND PURPOSE

Although skull fractures are generally assessed on bone images obtained by using head CT, the combined multikernel technique that enables evaluation of both brain and bone through a change in the window settings of an image set has been reported. The purpose of this retrospective study was to determine the image quality required for the accurate assessment of skull fractures by using head CT.

MATERIALS AND METHODS

A random sample of 50 patients (25 nonfracture and 25 simple nondisplaced skull fractures) was selected, and sets of conventional brain and bone images and improved combined multikernel images were reconstructed (4614 images). Three radiologists indicated their confidence levels regarding the presence of skull fractures by marking on a continuous scale for each image set. The mean area under the receiver operating characteristic curve was calculated for each kernel, and the statistical significance of differences was tested by using the Dorfman-Berbaum-Metz method.

RESULTS

Although a difference in the diagnostic performance of the 3 radiologists was suggested, the mean area under the curve value showed no significant differences among the 3 reconstruction kernels (P = .95 [bone versus combined]), P = .91 [bone versus brain]), and P = .88 [brain versus combined]). However, the quality of brain images was distinctly poorer than the quality of the other 2 images.

CONCLUSIONS

There was no significant difference in the diagnostic performance of brain, bone, and combined multikernel images for skull fractures. Skull fracture diagnosis is made possible by brain image assessments. Combined multikernel images offer the advantage of high-quality brain and bone images.

The "Air in the CT X-ray Tube Oil" Artifact-Examples of the Quality Control Images and the Evaluation of Four Potential Clinical Patients' Head Computed Tomography Cases

We present a newly reposted scanner-based artifact-with 4 potential patients' head computed tomography (CT) cases-the "Air in the CT X-ray Tube Oil" artifact with a 64-slice multidetector CT. This artifact mimics diseases, which cause hypodense findings in CT images. It can be difficult to notice in the clinical patient imaging but can be also very difficult to verify in quality control tests.