Brain CT Research Articles

Evaluating performance of a near-infrared-spectroscopy-based and machine-learning-powered bio-optical sensitivity parameters in identifying intracranial hemorrhages in TBI across different age-groups

ABSTRACT Primary objective To evaluate the accuracy of an innovative machine-learning-powered near-infrared spectroscopy (mNIRS)-based bio-optical sensitivity parameters, namely specific tissue optical index (STOI) and intracranial tissue optical index (ITOI) for effective triaging of patients with suspected traumatic brain injury (TBI) across different age-groups to facilitate timely intervention and curtail the silent epidemic. Research design Prospective, observational, double-blinded, cross-sectional single-center. Methods A total of 240 subjects suspected with TBI and recommended for head CT scan were enrolled. Findings of CT were compared with the bio-optical sensitivity parameters (STOI+ITOI) generated by the mNIRS system to detect intracranial hemorrhages (ICHs). Statistical Software used: SPSS (IBM version 21.0) Results Bio-optical sensitivity parameters (STOI+ITOI) analysis of 1288 scanned lobes showed high specificity of 97% (CI 95–98%), sensitivity of 96% (CI 92–99%), and accuracy of 97% (CI 96–98%) across all ages, maintaining robust performance for detecting subdural, epidural, subarachnoid hemorrhages, and contusions. Also, the reliability in the diagnosis of ICH was evidenced by Youden’s index of 0.93 and positive and negative likelihood ratios of 29.13 and 0.04, respectively. Conclusion The mNIRS-based STOI+ITOI proves to be an effective triage tool for TBI, exhibiting superior diagnostic performance across all age-groups.

The Relationship Between Craniocervical Morphology and the Presence and Level of Cervical Facet Joint Degeneration.

To investigate the relationship between craniocervical morphology and the presence and level of cervical facet joint degeneration (FJD). A total of 108 consecutive female patients aged 45-55 years who had undergone neck + brain CT angiography were included in this retrospective sectional study. Only patients of a certain age and of the same gender were included in order to eliminate the differences that create a disposition to the development of spinal degeneration. The presence of facet joint (FJ) arthritis (grade ≥2 degeneration in at least one affected facet joint) and the grade of the facet joint degeneration for each patient were recorded. A total of 20 lengths and 3 angles of craniocervical morphology were measured. The differences between the individuals with and without FJ arthritis were investigated with the independent-sample t test, and the relationship between the FJD grade and craniocervical morphology was investigated using the Spearman correlation test. Individuals with FJ arthritis were found to have longer Grabb-Oakes measurement, shorter FM AP length, lower ADI, lower EOP thickness, higher clivus length, higher crista gall-ATS distance, lower CCA angle, lower distance between the C1 vertebra lateral masses, and higher BAI than those without FJ arthritis (P ˂ 0.05). Besides, we found that the FJD grade increased as the Grabb-Oakes measurement increased, ADI distance decreased, FM AP length decreased, EOP thickness decreased, clivus length increased, basal angle increased, distance between the C1 vertebra lateral masses decreased, and BAI increased (P ˂ 0.05). Differences in craniocervical morphology are statistically associated with degenerative processes that result in degenerative changes in the facet joint. Therefore, some morphological changes in craniocervical anatomy cause changes in the momentum and distribution of the load on the facet joints, predisposing the patient to facet arthropathy and osteoarthritis.

Abstract We127: Infective Endocarditis in COVID-19 - An Unusual Suspect

Introduction: The COVID-19 pandemic globally overwhelmed healthcare systems and the complications associated with this illness have contributed to poor outcomes. The hypercoagulable state associated with COVID-19 is well recognized in the literature. Thromboembolic complications such as left ventricular thrombus (LVT), deep venous thrombosis (DVT) and pulmonary embolism (PE) have been increasingly reported. Dhakal et al. published an association between COVID-19 and cardiovascular disease, including possible complication by infective endocarditis (IE) which was confirmed by Amir et al. reporting the first case. Since then, there have been few reported cases. We present a case of COVID-19 in a patient who developed LVT, complicated by non-valvular IE by an underreported organism, Granulicatella adiacens. Case Presentation: A 55-year-old male with history of dental caries, provoked DVT/PE, NSTEMI x2 and STEMI in-stent restenosis requiring thrombectomy presented to the hospital with a 2-day history of shortness of breath, fatigue, cough, change in mentation and right-sided weakness. He tested positive for COVID-19 by NAAT. CXR revealed cardiomegaly and multiple bilateral infiltrates. CT head demonstrated acute ischemic stroke of the left occipital, parietal and posterior temporal lobes, also confirmed on MRI. CTA neck showed 30% stenosis of left ICA. Blood cultures x2 resulted positive for G. adiacens. Echocardiogram was obtained, demonstrating reduced EF of 35% and the presence of a large, 2.7 x 2.2cm mobile thrombus in the apical-septal region of the left ventricle, not visualized on previous echocardiogram 6 months earlier. Methods: Data was collected from direct patient care and electronic medical records. Discussion: G. adiacens is a fastidious gram-positive coccus, part of the nutritionally variant streptococci (NVS) species, and part of the normal oral and gastrointestinal flora. It is also found in dental plaques and endodontic abscesses. NVS account for less than 5% of cases of bacteremia and IE. G. adiacens account for even fewer cases. Two separate meta-analyses conducted by Quintero-Martinez et al. and George et al. failed to reveal any cases of IE attributable to G. adiacens in the setting of COVID-19 infection. In conclusion, we believe that the hypercoagulable state of COVID-19 infection led to endocardial damage and development of LVT, thereby creating a nidus for microorganism adherence from underlying dental carries resulting in thromboembolic stroke.

Mild Traumatic Brain Injury by the Glasgow Coma Scale Score and Early CT-Brain Findings in Acute Alcohol Intoxication Patients: A Prospective Observational Study.

Introduction Traumatic brain injuries (TBI) in recent years have proved to be a significant public health problem, with potentially life-changing consequences for the individual and their family. Alcohol consumption is a regular, well-documented problem among persons sustaining TBIdue to road traffic accidents and accidental falls. The primary objective of this study was to find out the correlation between the Glasgow Coma Scale (GCS) score and CT brain findings among mild TBI patients under acute alcohol intoxication and determine if early CT-brain is indicated in this group. Methods A prospective observational study was conducted involving 111 alcohol-intoxicated patients with mild head injuries admitted to the surgical wards of Thanjavur Medical College Hospitalover a period of three months. The Glasgow Coma Scale was used to assess the patient'sneurological status and determine the severity of the brain injury. A semi-structured CT-brain findings chart and a severity of alcohol intoxication objective-based scoring system were developed and validated by experts. Descriptive statistics tools such as frequency, percentage, and mean were used, along with inferential statistics tools like the Chi-squared test, Fisher exact test, and Pearson's correlation coefficient test. Results The study findings showed that the comparison of GCS with early CT-brain was significant at a p-value of 0.012, and a negative correlation (r=-0.253) was found between GCS and CT-brain findings. A comparison of CT-brain findings with the severity of alcohol intoxication was non-significant at a p-value of 0.433. Conclusions Early CT-brain in intoxicated mild TBI patients may have a positive impact on early diagnosis and management, even in centers with limited resources catering to low-income population groups. The results of our short-term study show that early CT-Brain picks up lesions and helps initiate early management while it is up to the attending physician to keep in mind an adverse cost-benefit ratio in overuse of hospital resources and misdiagnosis leading to undertreatment causing long-term sequelae and morbidity before prescribing early CT-brain in this cohort of patients.

Longitudinal analysis of cranial growth using comprehensive craniometric measurements after fronto-orbital advancement in coronal craniosynostosis.

The objective of this study was to investigate the longitudinal changes in cranial growth following fronto-orbital advancement (FOA) surgery in patients with unilateral and bilateral coronal craniosynostosis. This retrospective review analyzed head circumference (HC) and CT data during preoperative (T0), immediate postoperative (T1), and final follow-up (T2) visits in 40 patients (23 female, 17 male) who underwent FOA using either the open approach or distraction osteogenesis (DO) between 1987 and 2018. The mean follow-up period was 90.62 months. The z-scores of HC, CT-based intracranial volume, anteroposterior diameter (APD), biparietal diameter (BPD), and cranial height (CH) were calculated using sex- and age-specific standards. Logistic regression analysis was performed. While the z-scores of HC, intracranial volume, and BPD remained within the normal range, the z-scores of APD fluctuated between -2 and -1, and the z-scores of CH were > 2, indicating a substantial elevation compared with norms from T0 to T2. Age at surgery significantly influenced the z-scores of HC, BPD, and CH at T2 (all p < 0.05). Delayed surgical timing was correlated with increased BPD and CH z-scores from T1 to T2 (p = 0.007 and 0.019, respectively). The DO for FOA resulted in elevated HC z-scores at T2 and increased APD from T0 to T1, followed by a significant APD relapse from T1 to T2. These findings suggest that delayed surgical timing may support better cranial growth, as indicated by increased HC at long-term follow-up. However, delayed timing is also associated with worsening abnormally elevated CH. Despite the immediate APD expansion and long-term HC increase with DO, potential relapse warrants caution. While intentional overcorrection of APD is recommended, careful consideration of surgical timing and planning is essential.

Safety and accuracy of stereoelectroencephalography for pediatric and young adult patients with prior craniotomy.

The authors assessed the safety and accuracy of stereoelectroencephalography (SEEG) electrode implantation in pediatric patients who had previously undergone craniotomy compared to those without prior cranial surgery. The authors performed a retrospective analysis of patients under 25 years of age with medically refractory epilepsy at a single institution who underwent SEEG electrode placement between March 2016 and July 2023. Surgical history and demographic characteristics were collected from the electronic medical records. The coordinates of the anchor bolts and their respective SEEG electrode contacts were manually annotated using postoperative head CT scans. Bolt coordinates were used to calculate the initiated electrode trajectory set by the bolt by using the least-squares method to define a line along the bolt, projected along the length of the electrode. The shortest distance from each electrode contact to this line was calculated to obtain the error measurement. Statistical analysis was conducted using the Kolmogorov-Smirnov test to compare the distribution of errors between groups, the Student t-test was used for continuous variables, and the chi-square/Fisher's exact test was used for categorical variables. Fifty-eight patients underwent a total of 60 SEEG placements and met the inclusion criteria. Eighteen had a history of prior craniotomy and 40 without prior surgery, indicating entirely native cranial bone. Mean age, sex, and mean number of electrodes implanted per surgery were similar between groups. For the electrode contact furthest from the bolt, a mean (IQR) deviation of 1.32 (0.73-2.53) mm was noted for the prior craniotomy group and 1.08 (0.65-1.55) mm for the native bone group (p < 0.0001). A greater number of outliers for the contact furthest from the bolt, defined as > 6 mm from the initiated electrode trajectory, was seen in the prior craniotomy group (p < 0.0001). The complication rate was low and not statistically different between groups. The authors' analysis draws attention to the effect of the intracranial biomechanical environment along the path of the electrode after traversing past the anchor bolt and found that prior craniotomy was associated with a higher number of contacts with a significant deviation from the initiated trajectory. Despite these deviations, we did not find a difference in the overall low complication rate in both groups. Therefore, the authors conclude that SEEG electrode placement is a safe option in pediatric patients even after prior craniotomy.

Brain CT to MRI medical image transformation based on U-Net

Brain CT to MRI medical image transformation based on U-Net

No association of brain CT blend sign with functional outcomes in patients with spontaneous supratentorial intracerebral hemorrhage after craniotomy

ObjectiveThis study retrospectively analyzed the association of blend sign with long-term outcomes in patients who underwent craniotomy following spontaneous supratentorial intracerebral hemorrhage. MethodsA retrospective analysis was conducted on a cohort comprising 259 patients. Initially, patients were stratified into two groups: the blend sign group and the non-blend sign group. Subsequently, the neurological status of these patients was assessed using the NIHSS, GCS, and mRS following craniotomy. Furthermore, at six months post-craniotomy, patients were categorized into either the “good outcome group” or the “poor outcome group”. A multivariate regression analysis was applied to ascertain the independent correlation between the CT blend sign and prognosis. ResultsNo statistically significant disparities were observed in the proportion of patients experiencing favorable outcomes during the follow-up period between the two groups. Nevertheless, it is noteworthy that the incidence of the blend sign was higher among patients in the good outcome group compared to those in the poor outcome group. Multivariate regression analysis disclosed that poor outcomes following craniotomy was not associated with the blend sign. ConclusionsThe presence of the blend sign may not serve as a reliable predictor of functional outcomes in patients undergoing craniotomy for spontaneous supratentorial ICH.

A study of clinical &amp; radiological outcomes of small single enhancing lesions in CT brain - in a tertiary care hospital

Introduction Small single enhancing lesion in CT (SSECT) scan as an entity came into existence in India in early 1980, with the advent of CT scan. Tandon et al3 labeled them as intracranial tuberculomas. They identified two types of lesions based on the appearance of the lesion in the C T Scan brain. Small ring and disc lesions were called as immature tuberculomas and large lobulated lesions were called as mature tuberculomas. ATT was invariably started in these patients. Sethi et al5 &amp; Bansal et al6 noted that these lesions disappeared spontaneously without treatment. Natarajan and Arjundas et al37 at the Institute of Neurology, Chennai also noted spontaneous disappearance of these lesions without specific treatment. The exact cause of these lesions could not be deciphered because apart from tuberculoma, cysticercus granuloma, pyogenic abscess, metastases, fungal granuloma, and glioma had been reported to cause similar appearance in CT scan brain as more centers acquired C.T. Scan facility. Hence the exact aetiology of these lesions became a subject of speculation. A significant breakthrough came in 1987 at Vellore 8 when stereo tactic biopsy was done on 15 patients with SSECT. Most of the lesions were identified as cysticercus and none were of tuberculous etiology. Bhargava and Tandon in 1988 and Wadia, Makhalle in 19863,4, found evidence of tuberculous lesions in histopathology. However they failed in defining the size of the lesion. Rajshekhar et al8 then defined a small single lesion based on CT appearance as “A solitary, contrast-enhancing lesion of less than 20- mm diameter lesion without severe cerebral edema (no midline shift)”.this definition is often equated to cysticercous granuloma but there is every possibility that these lesions could be a tuberculoma.

Analisis Hasil Safire pada Imaging CT Scan Kepala

Background: Iterative Reconstruction (IR) method was first applied to CT in 1960 and successfully used for the first time in clinical research by reconstructing 128 x 128 images according to image metrics and using high-resolution images of 512 x 512 for special research activities such as image evaluation. artifacts and noise. In 2008, the development of IR can improve image quality and reduce the amount of radiation in clinical CT diagnosis. Iterative reconstruction promises to improve image quality while reducing radiation dose. This has been demonstrated in CT of the thorax, coronary arteries, abdomen, spine and neck, paranasal sinuses, and head. Sinogram-Afirmed Iterative Reconstruction (SAFIRE) is one of the iterative algorithm reconstruction methods that uses noise modeling techniques, Sinogram-Afirmed Iterative Reconstruction (SAFIRE), promises to improve Cranial CT (CCT). In this new technique, raw data-based iteration for artifact reduction is combined with image-based iteration using smooth regularization that estimates the variance of image noise in various directions at each image pixel and adjusts it with a spatial variance regularization function simultaneously. Methods: This study is a literature review, where literature exploration is carried out on various databases with keywords such as, Reference sources used in compiling this article include google scollar, as well as articles in English and Indonesian scientific journals. Results: Itarative Reconstruction (IR) Head CT Scan, SAFIRE includes reducing or adding noise to the image results, artifacts, acquisition time, increasing SNR and CNR and reducing dose in the examination. Conclusion: Analysis of Safire results in Head CT-Scan Imaging has an Itarative Reconstruction (SAFIRE) procedure, the role of safire in head CT scans is to optimize noise in the Reconstructed image and can reduce artifacts in the image and increase SNR, CNR in the Reconstructed results so that it can provide better information.

Development of Acceptable Quality Dose (AQD) and image quality-related diagnostic reference levels for common computed tomography investigations in a tertiary care public sector hospital of Khyber Pakhtunkhwa, Pakistan.

To describe the first experience of patient dose optimization in developing AQD, SSDE and image quality-related DRLs for common CT examinations in the adult age group using the concept of AQD. The recent published IQSC from 0 to 4 were used by radiologists for the assessment of image quality. The entire data were collected for five types (brain CT, chest CT, chest HRCT, abdomen KUB CT and abdomen + pelvic CT) CT investigations based on anatomic region (head, chest and abdomen + pelvic). The entire datasets of 264 patients were categorized into three groups based on their weights: group-1 (41-60kg), group-2 (61-80kg) and group-3 (81-100kg). Only score-3 images were considered to assess median and 75th percentile values of CTDIvol and DLP to obtain AQDs and DRLs, respectively. Following the practical training of four radiologists on image quality scoring criteria for CT images, 264 (92%) out of 288 patient images were clinically acceptable as per IQSC for the study. The AQD (median) values in terms of CTDIvol for the mentioned weight groups were 25.8, 2.7, and 30.6mGy, while the median DLP values for these groups were 496, 510 and 557 mGycm, respectively, for brain CT. The 75th percentile values in terms of CTDIvol were 30.2, 35.3 and 36.2mGy, while in terms of DLP, they were 583, 619 and 781 mGycm for brain CT, respectively. Similar results are presented for the above-mentioned procedures, as well as in terms of SSDE. The first ever experience in obtaining AQD, SSDE and DRLs values for specific CT procedures couples image quality with dose indices, showing comparable values with other relevant studies. Hence, it will provide a baseline for comparison within the facility for future studies and facilitate dose optimization for other facilities aiming for improvement.

The Consequences of a Heart Condition: Acute Stroke and Limb Ischemia Secondary to Massive Intracardiac Thrombus in a Young Female with Dilated Cardiomyopathy

Background: Dilated cardiomyopathy (DCM) is associated with the increased occurrence of left ventricular (LV) thrombosis caused by cardiac dysfunction. This condition is associated with significant mortality and morbidity because of its significance as a potential source of systemic emboli. We are reporting a case of Acute Stroke and Limb Ischemia in a Young Female Patient with DCM. Case Illustration: A 20-year-old female was referred to our hospital due to pain in her right lower extremities and weakness in her right limb. She had been diagnosed with peripartum cardiomyopathy five years earlier. A general physical examination found her right lower limbs to be cold and pulseless. A neurological examination revealed hemiparesis involving the right side of her body. The chest radiograph showed cardiomegaly. Electrocardiography indicated sinus rhythm with LVH. The transthoracic echocardiograms revealed significant LV systolic failure with a massive thrombus at LV. The Duplex ultrasound showed a thrombus at the right dorsal pedis artery, and a head CT scan revealed an acute infarct. The patient was started on heparin and bridged with warfarin 5mg orally daily, and she was uneventfully discharged after one week. Conclusion: DCM had been associated with thrombosis, stroke, and an increased risk of thromboembolism. Previous studies had documented decreased thromboembolic events due to administering anticoagulants. Keyword: Acute Stroke, Dilated Cardiomyopathy, Limb Ischemia, Massive Intracardiac Thrombus.

The Effect of Scan Length on Effective Dose in Emergency Brain CT Scans in Pediatric Patients

The Effect of Scan Length on Effective Dose in Emergency Brain CT Scans in Pediatric Patients

Application of low-dose CT in image-guided radiotherapy based on CT-linac

BackgroundImage-guided radiation therapy (IGRT) involves online medical imaging systems. CT-guided imaging systems not only have high image quality but also allow for direct dose calculation for radiation treatment planning, making it an ideal image guidance method. However, the imaging dose from CT images may pose additional risks to patients. Therefore, the aim of this study was to evaluate the substitutability of using low-dose CT images for IGRT. Materials and methodsThe CIRS-062 phantom, Catphan 604 phantom, CT dose index phantom were used to obtain the conversion curves of the CT values to the relative electron density (RED), image quality, and imaging dose of the low-dose CT, respectively. Catphan 604 phantom and clinical cases were used to analyze the feasibility of low-dose CT for dose calculation. ResultsNo significant differences were observed in the conversion curves of CT values to RED between low-dose and standard-dose CT scans. In terms of image quality, the geometric distortion of low-dose CT was 0.1 mm, which was the same as that of standard-dose CT. The spatial resolution of the images was 0.42–0.45 lp/mm, which was slightly better than that of standard-dose CT (0.40–0.44 lp/mm). The image uniformity was 98.4%–99.0%, slightly worse than that of standard-dose CT (99.4%–99.5%), but still met the clinical requirements. The imaging dose was 2.96–4.62 mGy, significantly lower than that of standard-dose CT (9.71–26.68 mGy), especially for head CT protocol. In terms of dose calculation, the γ passing rates were not lower than 98% for either the Catphan 604 phantom or the clinical cases. ConclusionLow-dose CT can significantly reduce the imaging dose without a significant loss of image quality and can be directly used for dose calculation in radiation treatment planning, providing a safer and more effective image guidance method for IGRT.

Artificial Intelligence-based automated CT brain interpretation to accelerate treatment for acute stroke in rural India: An interrupted time series study.

In resource-limited settings, timely treatment of acute stroke is dependent upon accurate diagnosis that draws on non-contrast computed tomography (NCCT) scans of the head. Artificial Intelligence (AI) based devices may be able to assist non-specialist physicians in NCCT interpretation, thereby enabling faster interventions for acute stroke patients in these settings. We evaluated the impact of an AI device by comparing the time to intervention (TTI) from NCCT imaging to significant intervention before (baseline) and after the deployment of AI, in patients diagnosed with stroke (ischemic or hemorrhagic) through a retrospective interrupted time series analysis at a rural hospital managed by non-specialists in India. Significant intervention was defined as thrombolysis or antiplatelet therapy in ischemic strokes, and mannitol for hemorrhagic strokes or mass effect. We also evaluated the diagnostic accuracy of the software using the teleradiologists' reports as ground truth. Impact analysis in a total of 174 stroke patients (72 in baseline and 102 after deployment) demonstrated a significant reduction of median TTI from 80 minutes (IQR: 56·8-139·5) during baseline to 58·50 (IQR: 30·3-118.2) minutes after AI deployment (Wilcoxon rank sum test-location shift: -21·0, 95% CI: -38·0, -7·0). Diagnostic accuracy evaluation in a total of 864 NCCT scans demonstrated the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) in detecting intracranial hemorrhage to be 0·89 (95% CI: 0·83-0·93), 0·99 (0·98-1·00), 0·96 (0·91-0·98) and 0·97 (0·96-0·98) respectively, and for infarct these were 0·84 (0·79-0·89), 0·81 (0·77-0·84), 0·58 (0·52-0·63), and 0·94 (0·92-0·96), respectively. AI-based NCCT interpretation supported faster abnormality detection with high accuracy, resulting in persons with acute stroke receiving significantly earlier treatment. Our results suggest that AI-based NCCT interpretation can potentially improve uptake of lifesaving interventions for acute stroke in resource-limited settings.

The impact of pediatric post-cardiac arrest care on survival: A multicenter review from the AHA get with the Guidelines®-resuscitation post-cardiac arrest care registry

AimAdherence to post-cardiac arrest care (PCAC) recommendations is associated with improved outcomes for adults. We aimed to describe the survival impact of meeting American Heart Association (AHA) PCAC guidelines in children after cardiac arrest. MethodsWe conducted a retrospective study using Get With The Guidelines® Resuscitation’s (GWTG®-R) registry to describe the PCAC of patients ≤ 18 years old who suffered an in-hospital or out-of-hospital cardiac arrest (IHCA or OHCA). We evaluated the association between the absence of hypotension and fever in the initial 24 h following return of circulation (ROC) with survival to hospital discharge. We reviewed the utilization of monitoring/evaluation tools recommended in pediatric PCAC guidelines: electrocardiogram (ECG), electroencephalogram (EEG), and neuro-imaging. ResultsWe found 385 pediatric patients who suffered an IHCA or OHCA from 2015 through 2019 and survived at least 6 h post-ROC. Sixty-six percent of patients survived to hospital discharge. Following ROC, 56% of patients had EEG monitoring, 80% had an ECG performed, 47% had a head CT, and 26% had a cerebral MRI. In the initial 24 h post-ROC, 92% of patients did not have hypotension and 79% were afebrile. Patients without hypotension in the initial 24 h post-ROC had higher odds of survival to hospital discharge than those with hypotension (aOR 4.96; 95% CI 2.07, 11.90; p = 0.0003), adjusting for age and cardiac arrest location. Patients without hypotension and without fever in the initial 24 h post-ROC had higher odds of survival to hospital discharge compared to patients who had either hypotension or fever or both (aOR 1.98; 95% CI 1.06,3.71; p = 0.034). ConclusionIn this retrospective multicenter registry study, absence of both post-cardiac arrest hypotension and fever were associated with increased odds of survival to hospital discharge. Further research is needed to understand the full impact of PCAC recommendation compliance on survival outcomes.

Sociodemographic biases in a commercial AI model for intracranial hemorrhage detection.

To evaluate whether a commercial AI tool for intracranial hemorrhage (ICH) detection on head CT exhibited sociodemographic biases. Our retrospective study reviewed 9736 consecutive, adult non-contrast head CT scans performed between November 2021 and February 2022 in a single healthcare system. Each CT scan was evaluated by a commercial ICH AI tool and a board-certified neuroradiologist; ground truth was defined as final radiologist determination of ICH presence/absence. After evaluating the AI tool's aggregate diagnostic performance, sub-analyses based on sociodemographic groups (age, sex, race, ethnicity, insurance status, and Area of Deprivation Index [ADI] scores) assessed for biases. χ2 test or Fisher's exact tests evaluated for statistical significance with p ≤ 0.05. Our patient population was 50% female (mean age 60 ± 19 years). The AI tool had an aggregate accuracy of 93% [9060/9736], sensitivity of 85% [1140/1338], specificity of 94% [7920/ 8398], positive predictive value (PPV) of 71% [1140/1618] and negative predictive value (NPV) of 98% [7920/8118]. Sociodemographic biases were identified, including lower PPV for patients who were females (67.3% [62,441/656] vs. 72.7% [699/962], p = 0.02), Black (66.7% [454/681] vs. 73.2% [686/937], p = 0.005), non-Hispanic/non-Latino (69.7% [1038/1490] vs. 95.4% [417/437]), p = 0.009), and who had Medicaid/Medicare (69.9% [754/1078]) or Private (66.5% [228/343]) primary insurance (p = 0.003). Lower sensitivity was seen for patients in the third quartile of national (78.8% [241/306], p = 0.001) and state ADI scores (79.0% [22/287], p = 0.001). In our healthcare system, a commercial AI tool had lower performance for ICH detection than previously reported and demonstrated several sociodemographic biases.

Optimal image quality and radiation doses with optimal tube voltages/currents for pediatric anthropomorphic phantom brains.

Using pediatric anthropomorphic phantoms (APs), we aimed to determine the scanning tube voltage/current combinations that could achieve optimal image quality and avoid excessive radiation exposure in pediatric patients. A 64-slice scanner was used to scan a standard test phantom to determine the volume CT dose indices (CTDIvol), and three pediatric anthropomorphic phantoms (APs) with highly accurate anatomy and tissue-equivalent materials were studied. These specialized APs represented the average 1-year-old, 5-year-old, and 10-year-old children, respectively. The physical phantoms were constructed with brain tissue-equivalent materials having a density of ρ = 1.07 g/cm3, comprising 22 numbered 2.54-cm-thick sections for the 1-year-old, 26 sections for the 5-year-old, and 32 sections for the 10-year-old. They were scanned to acquire brain CT images and determine the standard deviations (SDs), effective doses (EDs), and contrast-to noise ratios (CNRs). The APs were scanned by 21 combinations of tube voltages/currents (80, 100, or 120 kVp/10, 40, 80, 120, 150, 200, or 250 mA) and rotation time/pitch settings of 1 s/0.984:1. The optimal tube voltage/current combinations yielding optimal image quality were 80 kVp/80 mA for the 1-year-old AP; 80 kVp/120 mA for the 5-year-old AP; and 80 kVp/150 mA for the 10-year-old AP. Because these scanning tube voltages/currents yielded SDs, respectively, of 12.81, 13.09, and 12.26 HU, along with small EDs of 0.31, 0.34, and 0.31 mSv, these parameters and the induced values were expediently defined as optimal. The optimal tube voltages/currents that yielded optimal brain image quality, SDs, CNRs, and EDs herein are novel and essentially important. Clinical translation of these optimal values may allow CT diagnosis with low radiation doses to children's heads.

Abbreviated MRI in the evaluation of dizziness: report turnaround times and impact on length of stay compared to CT, CTA, and conventional MRI.

Neuroimaging is often used in the emergency department (ED) to evaluate for posterior circulation strokes in patients with dizziness, commonly with CT/CTA due to speed and availability. Although MRI offers more sensitive evaluation, it is less commonly used, in part due to slower turnaround times. We assess the potential for abbreviated MRI to improve reporting times and impact on length of stay (LOS) compared to conventional MRI (as well as CT/CTA) in the evaluation of acute dizziness. We performed a retrospective analysis of length of stay via LASSO regression for patients presenting to the ED with dizziness and discharged directly from the ED over 4 years (1/1/2018-12/31/2021), controlling for numerous patient-level and logistical factors. We additionally assessed turnaround time between order and final report for various imaging modalities. 14,204 patients were included in our analysis. Turnaround time for abbreviated MRI was significantly lower than for conventional MRI (4.40h vs. 6.14h, p < 0.001) with decreased impact on LOS (0.58h vs. 2.02h). Abbreviated MRI studies had longer turnaround time (4.40h vs. 1.41h, p < 0.001) and was associated with greater impact on ED LOS than non-contrast CT head (0.58h vs. 0.00h), however there was no significant difference in turnaround time compared to CTA head and neck (4.40h vs. 3.86h, p = 0.06) with similar effect on LOS (0.58h vs. 0.53h). Ordering both CTA and conventional MRI was associated with a greater-than-linear increase in LOS (additional 0.37h); the same trend was not seen combining CTA and abbreviated MRI (additional 0.00h). In the acute settings where MRI is available, abbreviated MRI protocols may improve turnaround times and LOS compared to conventional MRI protocols. Since recent guidelines recommend MRI over CT in the evaluation of dizziness, implementation of abbreviated MRI protocols has the potential to facilitate rapid access to preferred imaging, while minimizing impact on ED workflows.

CT histogram analysis to distinguish between acute intracerebral hemorrhage and cavernous hemangioma

Acute intracerebral hemorrhage (AICH) and cerebral cavernous hemangioma (CCM) are two common cerebral hemorrhage diseases with partially overlapping CT findings and clinical symptoms, making it hard to distinguish between them. The current study used histogram analysis based on CT images to differentiate between CCM and AICH and test its diagnosis performance. This retrospective study included 158 patients with CCM and 137 patients with AICH. The histograms of brain CT plain scan images of both groups were extracted using Python code and included 18 histogram parameters of the lesions. The most effective parameters were selected by univariate logistic regression analysis and Spearman correlation analysis and included in the final multivariate logistic regression model. The sample was randomly divided into the training set and the validation set by 7:3. The ROC curve was constructed to evaluate the discriminant efficiency of the final logistic regression model in distinguishing between AICH and CCM. The univariate analysis identified seven significant histogram parameters with the following final logistic regression model: F=3.731+2.6411×10-9×Energy-1.192×Kurtosis-0.003×Minimum-1.449×Skewness + 2.5002×10-10×Total Energy-1.103×Uniformity+0.009×Variance. The model showed good diagnostic performance in distinguishing between AICH and CCM, with an AUC of 0.876, sensitivity of 70.8%, and specificity of 91.9% in the training set, and an AUC of 0.870, sensitivity of 82.9%, and specificity of 85.1% in the validation set. The histogram analysis of brain CT images can be used as an auxiliary method to distinguish between AICH and CCM effectively.