Head Scans Research Articles

Peripapillary ovoid mass-like structure (PHOMS): prevalence, risk factors, and development over time in Danish myopic children

BackgroundOn optical coherence tomography (OCT) scans of the optic nerve head, peripapillary hyperreflective ovoid mass-like structures (PHOMS) are sometimes seen as a sign of axonal distension. The phenomenon has been reported more frequently in myopic subjects. We investigated PHOMS-prevalence in a myopic pediatric cohort, associated risk factors, and PHOMS development over 18 months during low-dose atropine treatment. MethodsIn this post hoc analysis of an investigator-initiated, placebo-controlled, randomized clinical trial, 97 6- to 12-year-old myopic participants were randomized to 0.1% atropine for 6 months, then 0.01% for 18 months (N = 33), 0.01% for 24 months (N = 32) or placebo for 24 months (N = 32). Primary outcome was presence of PHOMS. Secondary outcome was mean nasal PHOMS diameter measured on OCT B-scan. Outcomes were reported at baseline, 6, and 18 months. Logistic regression and linear mixed modelling were performed. ResultsPHOMS were present in 26% of participants (n = 25), and 52% (n = 13) had bilateral presentation. Optic disk tilt (OR = 10.81; 95% CI, 3.58-32.58 [P < 0.001]) and longer axial length (AL) (OR = 2.06; 95% CI, 1.02-4.17 [P = 0.04]) increased the risk of having PHOMS. Greater increase in nasal peripapillary choroidal thickness over time was associated with smaller PHOMS diameter at 18 months (P = 0.05). ConclusionsPHOMS were common in our cohort of children with myopia. Longer AL increases the risk of, but not size of, PHOMS. The diameter of PHOMS seemed stable over time and unaffected by low-dose atropine.

Comparison of classical and drone based hard-target methodologies applied to scanning lidar for offshore wind

Abstract Hard target testing is a crucial part of the commissioning process of scanning lidar measurement systems. The correct alignment of the scan head and understanding of the pointing accuracy is crucial to reducing uncertainties in wind speed measurements by scanning lidar especially in dual-scanning configuration. This paper presents a comparison between traditional hard targeting technique and the use of drone based hard targets. A procedure is presented to minimise measurement error and hence increase confidence in the pointing accuracy.

Evaluating the Risk of Traumatic Brain Injury in Adults Following a Fall With Concomitant Use of Anti-Coagulation: A Retrospective Cohort Study.

Introduction Falls and fractures are major health challenges for older adults in England. Despite the advantages of anticoagulants, their use in the elderly is often restricted due to concerns about fall-related injuries. However, there is a lack of clear data on the risk of discontinuing anticoagulation therapy solely due to fall risk. NICE guidelines (2021) advise that anticoagulation should not be withheld solely based on age or fall risk. This study aims to assess the incidence of significant brain injuries or intracranial haemorrhages in patients on anticoagulant therapy, also comparing the independent risk factors for traumatic brain injury. Objective This study aims to assess the incidence of TBI following falls in patients on anticoagulant therapy, comparing outcomes between those using DOACs and Vitamin K antagonists. Methods A retrospective cohort study was conducted at Queen Alexandra Hospital, University Hospitals Portsmouth NHS Trust, from November 2023 to May 2024. Data were collected from 3,468 CT head scans performed on patients with a history of falls, including 801 on anticoagulation therapy. Results Of the 801 patients on anticoagulation, 763 (95.2%) were aged 65 or older, with a mean age of 83.1 years. Acute hemorrhage was detected in 3.1% (25/801) of patients. Patients on Warfarin and Dabigatran had significantly higher TBI risk compared to those on Apixaban (6.7%, p=0.02; and 7.6%, p=0.01, respectively), while Edoxaban and Rivaroxaban showed no significant difference. Also, older age (≥65 years) and higher frailty scores (CFS 6 and 7) were associated with increased TBI risk (p<0.05). All patients with acute hemorrhage received conservative management, and two patients experienced mortality within six months. Discussion The study indicates that the risk of TBI following falls in anticoagulated patients is 3.1% relatively low, aligning with existing literature. This underscores the need for careful consideration before discontinuing anticoagulation therapy solely based on fall risk. Hence, discontinuation of anticoagulation should be a patient-specific decision that carefully considers the balance between the risk of traumatic brain injury (TBI) and the benefits of anticoagulation therapy. Factors such as age, frailty, and the type of anticoagulant should all be taken into account. Clinical judgment and selective CT imaging can help balance patient safety with healthcare costs. Conclusion The incidence of adverse outcomes following head injury in patients on anticoagulant therapy is 3.1% and relatively low. Careful decision-making regarding the discontinuation of anticoagulation therapy, informed by patient background and presentation and selective CT imaging, is essential to manage risks effectively and optimize healthcare resource utilization.

Head injuries in prehospital and Emergency Department settings: a prospective multicenter cross-sectional study in France

BackgroundHead injuries are the leading cause of trauma in Emergency Departments (EDs). Recent studies have shown epidemiological changes in patients consulting ED for head injuries. The main objective of this study was to describe the profile of head injury patients consulting in the EDs in France and assess i) head injury severity across age groups; ii) the delay between the occurrence of head injury and ED arrival; iii) factors associated with traumatic intracranial hemorrhage (ICH).MethodsThis cross-sectional study collected patient data over a three-day period in March 2023. All adult patients (≥ 18 years old) admitted to the ED with a head injury (defined as a trauma to the head) were included. TBI severity was classified according to patients’ initial Glasgow Coma Scale score in the ED: severe (3–8); moderate (9 -12); mild (13–15); and simple head trauma in the absence of transient or persistent neurological symptoms.ResultsAmong the 71 participating EDs, 26,008 patients visited EDs and a total of 1070 patients (4.1%, IC 95 3.9—4.4) presented a head injury were included in the study, with a median age of 68.5 [37–85] years old. Most of the patients (66.7%) were referred to ED after a call to the Emergency Medical Dispatcher (EMD). The median time from head injury to ED visit was 2 h [1.0 – 5.5]. Ground-level falls were the leading cause of head injury (60.3%). Most of patient presented a simple head trauma (n = 715, 66.8%) followed by mild TBI (n = 337, 31.5%). CT head scans were performed for 636 patients (59.6%), of which 58 were positive. Traumatic ICH prevalence was 5.4% (95% CI: 4.1–6.9) and three patients (0.3%) required an urgent neurosurgical intervention. Neither preinjury anticoagulant (p = 0.97) nor antiplatelet (p = 0.93) use was associated with an increased risk of traumatic ICH.ConclusionsOne head injury patient out of two presenting in the ED is aged over 65 years. Patients referred by EMD were more likely to visit ED promptly. The majority of older patients underwent a head CT scan and preinjury anticoagulant use was not associated with increased risk of traumatic ICH.

Optimal weighting strategies for maximizing contrast-to-noise ratio in photon counting CT images.

Photon counting detectors (PCDs) with energy discrimination capabilities have the potential to generate grayscale CT images with improved contrast-to-noise ratio (CNR) through optimal weighting of their spectral measurements. This study evaluates the CNR performance of grayscale CT projections and images generated from spectral measurements of PCDs using three energy-weighting strategies: pre-log weighting, post-log weighting, and material decomposition (MD) weighting. This study provides the expressions of optimal weights and maximum achievable CNR of these energy-weighting strategies, which only require the knowledge of detected bin counts and do not require information of PCD energy responses or imaging techniques. We defined and solved a generalized eigenvalue problem to obtain the maximum achievable CNR in the projection domain for low-contrast tasks using three energy-weighting strategies: pre-log weighting (weighted sum of energy bin counts), post-log weighting (weighted sum of line integrals), and MD weighting (weighted sum of basis material thicknesses, which is equivalent to virtual monoenergetic images [VMIs]). These expressions only contain energy bin counts from PCD measurements. We used a realistic PCD energy response model to simulate the detected bin counts and conducted Monte Carlo simulations of different contrast tasks and phantoms to evaluate the projection- and image-domain CNR performance of these energy-weighting strategies. Additionally, the total counts method (a special case of pre-log weighting with unity weights) was included for comparison. We also conducted Gammex head and body phantom scans on an edge-on-irradiated silicon PCCT prototype to evaluate the image-domain CNR performance of these energy-weighting strategies. The results show that pre-log, post-log, and MD weighting strategies generate approximately equal projection-domain maximum achievable CNR, with a difference of less than 2%, and outperform the total counts method. These three energy-weighting strategies also generate approximately equal image-domain maximum CNR when the contrast task is located at the center of a homogeneous phantom. Pre-log weighting generates the highest image-domain CNR for an off-center contrast task location or inhomogeneous phantoms while also outperforming the total counts method. We derived the expression of projection-domain maximum achievable CNR using three energy-weighting strategies. Our results suggest that using pre-log weighting strategies enables fast grayscale CT image generation with high CNR from spectral PCD measurements for inhomogeneous phantoms and off-center region of interests (ROIs).

Heterotopic High-Grade Salivary duct Carcinoma Likely Arising within Cervical Lymph Nodes

Abstract Introduction/Objective Salivary duct carcinoma arising in heterotopic salivary gland tissue is an extremely rare occurrence, with less than five cases reported in the literature. We present a unique case of heterotopic high-grade salivary duct carcinoma likely arising within cervical lymph nodes. Methods/Case Report A 56-year-old male presented with enlarged cervical lymph nodes for few months. Physical examination was unremarkable. Computerized tomography (CT) scan of head and neck showed two enlarged level 1B lymph nodes, measuring 1.0 and 1.4 cm, with unremarkable salivary glands. Patient had left cervical level II lymph node biopsy that showed metastatic poorly differentiated carcinoma. Immunohistochemically, the tumor cells were positive for GATA3, cytokeratin 903, androgen receptor, p16 (variable nonspecific), and were negative for TTF-1, p40, p63, ER, PR and NKX3.1, favoring salivary gland ductal carcinoma. Positron emission tomography (PET) CT scan showed a hypermetabolic left submandibular gland and level 2A lymph nodes. Subsequently, the patient underwent left modified radical neck dissection. Sectioning of the submandibular gland revealed no discrete lesions. Multiple, firm to rubbery lymph nodes ranging from 0.4 cm to 2.3 cm, with tan-pink cut surfaces were identified. Microscopic examination showed normal submandibular salivary gland parenchyma. However, eight out of nineteen lymph nodes were positive for metastatic high-grade salivary duct carcinoma comprising tumor cells forming nests and cords with ample eosinophilic cytoplasm, pleomorphic round to oval nuclei and numerous mitotic figures. Several benign and malignant lymph nodes in levels I, II and IV showed heterotopic salivary gland tissue. Immunohistochemical stains for androgen receptor and p40 were positive and negative respectively, supported the final diagnosis of high-grade salivary duct carcinoma. Results (if a Case Study enter NA) NA Conclusion Given the absence of carcinoma in the completely sampled submandibular gland, the origin of the intra- nodal tumor deposits was most likely to be heterotopic salivary gland tissue. This case emphasizes the importance of meticulous pathological sampling required for definitive diagnosis.

Utility of routine postoperative imaging in adults undergoing primary ventriculoperitoneal shunts.

There is currently no consensus on the usefulness of postoperative imaging after ventriculoperitoneal (VP) shunt insertion in adults. The aim of this study was to investigate the utility of routine postoperative imaging (CT head scans and radiographs) following primary VP shunt insertion in a general adult population treated at a tertiary neurosurgical centre. Patients undergoing primary VP shunt insertion between 2017-2021 were included. Actions taken based on routine postoperative imaging and need for subsequent shunt revision were recorded. 236 patients were included. The median age was 63years (range 17-90). There was a slight female preponderance (121/236, 51.3%). The median follow-up was 38.5months (3.1 - 60.5months). Acute intervention was employed in 9 patients (3.9%) on the basis of routine postoperative CT head scan. Routine postoperative radiographs did not result in reoperation. Around a quarter (28.8%) of patients had a shunt revision, most of whom underwent urgent primary shunt insertions. Postoperative ventricular catheter characteristics (position of shunt tip, tip relation to septum pellucidum, and intraventricular catheter distance) were not predictive of shunt revision. Surgical urgency (emergency vs. elective procedures) was associated with long-term shunt revision (OR = 2.80, 95% CI 1.42 - 5.53, p = 0.003). Routine postoperative imaging rarely led to reoperation in adult patients undergoing primary VP shunt insertion. Patients undergoing emergency shunt insertions were at the highest risk for requiring revision.

New intraoral digital impression with pneumatic gingival retraction used in the restoration of crown for posterior teeth: a case report

In fixed prosthodontics, clear exposure of the preparation margin is the prerequisite for obtaining accurate digital impressions and improving the marginal fit of restorations. To resolve the issues associated with the cord retraction technique, such as pain, acute injury, and prolonged procedural time, this study proposes a new technology for intraoral digital impression taking with pneumatic gingival retraction. The new scanning head blows a high-speed airflow that instantaneously separates the free gingiva, locally exposing the subgingival preparation margin. Combined with the farthest point preservation stitching algorithm based on the distance from the normal vector and high-speed laser scanning photography, it achieves global preparation edge data and gingival reconstruction, realizing painless, non-invasive, and efficient precise acquisition of the preparation margin. Using this new technique, a patient with a full porcelain crown restoration on a posterior tooth was treated. The digital impression revealed a clear margin of the preparation, and the crown made from this data has a good marginal fit.

7183 Histoplasmosis Of Adrenal In An Immunocompetent Patient From Arizona: A Surprising Biopsy

Abstract Disclosure: R. Habibi: None. S. Penquite: None. N. Ebrahimi: None. R. Cardenas Lara: None. Introduction: Histoplasmosis of adrenal gland in the context of disseminated infection is a rare entity in a non-endemic area. Early diagnosis and treatment can save one’s life. Here we present a case of a patient from Arizona who was referred to us with a large adrenal mass initially resembling malignancy. Presentation: A 58-year-old male with no significant medical history from Bisbee Arizona presented to our clinic with significant weight loss of 120 pounds in 8months, jaundice, fatigue, nausea and vague abdominal pain. He had an abdominal CT scan in a rural area hospital which showed a left adrenal 4.2 x 4.3 x 3.7 cm mass with average HU=40, with interval development from a CT scan 6months prior to that which showed left adrenal 1.5 x 1.3 x 1.3 cm mass. He had the initial CT scan after a mechanical fall. He was experiencing sweating, dizziness and low blood pressure of 90/60 mmhg, but used to have hypertension. Physical examination revealed diffuse jaundice in an ill appearing cachectic individual. Laboratory data were significant for total bilirubin of 4.9, direct bilirubin 0.7. Plasma metanephrines and normetanephrines, 24-hour urine free cortisol, morning cortisol levels and DHEA sulfate were normal. Other findings on the CT scans of head, chest and abdomen were soft tissue thickening between the right posterior 10th and 11th ribs along with hepatosplenomegaly, nodular lung lesions with calcified granuloma, sub centimeter brain lesions within the left putamen/external capsule junction with corresponding mild edema. During the following month after initial visit he developed bilateral tongue masses with dysphagia along with enlarging bilateral adrenal lesions, measuring up to 4.4 cm on the right and 5.2 cm on the left. The patient was admitted to hospital for further extensive work up. He underwent biopsies of left adrenal mass and tongue lesions which demonstrated necrotizing granulomatous inflammation with fungal elements compatible with histoplasmosis. Liposomal amphotericin B was started, which was quickly switched to itraconazole 200mg twice a day once lumbar puncture result was normal. His transient low blood pressures resolved. He was seen in clinic after few weeks with overall improving symptoms. Follow up with imaging of adrenal in few months is planned. He is currently in his third month of treatment for histoplasmosis with itraconazole. Discussion: The presentation of disseminated histoplasmosis can resemble malignancy as illustrated in this case. Southwest of the United States is an unusual geographical area for such infection. Initial unilateral involvement of adrenal as a mass in an immunocompetent individual is also uncommon. Considering dramatic response to antifungal treatment, a clinician should suspect such rare infections when seeing a nonfunctional adrenal mass with rapidly progressive constitutional symptoms. Presentation: 6/3/2024

A cadaveric study of induced isolated orbital floor fractures and implications for surgical decision-making: comparison of two preoperative imaging modalities

Computed tomography (CT) is the gold standard for the diagnosis of isolated orbital floor fractures, while cone beam computed tomography (CBCT) is an alternative. The aim of this study was to compare the diagnostic accuracy of CT and CBCT for isolated orbital floor fractures. Forty-eight isolated orbital floor fractures were systematically induced in cadaver orbits. CBCT and CT scans of each cadaver head were performed and the image data imported into ProPlan CMF for analysis. The orbital floor area (OFA), orbital defect area (ODA), and peri-orbital tissue herniation were evaluated. Surgical decision-making differed significantly according to the imaging modality (P = 0.031). The odds of decision discrepancy between CBCT and CT were higher with increasing ODA/OFA ratios, when adjusted for peri-orbital tissue herniation and fracture localization (P = 0.026). An ODA/OFA ratio cut-off value of >36.25% had a sensitivity of 100% and specificity of 71% (area under the curve 0.83, P = 0.011) for predicting discrepancies between CBCT and CT in surgical decision-making. In this cadaveric study, CT and CBCT were diagnostically equivalent for isolated orbital floor fractures with an ODA/OFA ratio ≤36.25%. However, fractures exceeding this threshold may be better evaluated by CT to avoid discrepancies in surgical decision-making.

225 - Radiation dose of non-contrast head scan in multi slice computed tomography

225 - Radiation dose of non-contrast head scan in multi slice computed tomography

Association between rare, genetic variants linked to autism and ultrasonography fetal anomalies in children with autism spectrum disorder

BackgroundRecent evidence suggests that certain fetal anomalies detected upon prenatal ultrasound screenings are associated with autism spectrum disorder (ASD). In this cross-sectional study, we aimed to identify genetic variants associated with fetal ultrasound anomalies (UFAs) in children with ASD.MethodsThe study included all children with ASD who are registered in the database of the Azrieli National Center of Autism and Neurodevelopment and for whom both prenatal ultrasound and whole exome sequencing (WES) data were available. We applied our in-house integrative bioinformatics pipeline, AutScore, to these WES data to prioritize rare, gene-disrupting variants (GDVs) probably contributing to ASD susceptibily. Univariate statistics and multivariable regression were used to assess the associations between UFAs and GDVs identified in these children.ResultsThe study sample comprised 126 children, of whom 43 (34.1%) had at least one UFA detected in the prenatal ultrasound scan. A total of 87 candidate ASD genetic variants were detected in 60 children, with 24 (40%) children carrying multiple variants. Children with UFAs were more likely to have loss-of-function (LoF) mutations (aOR = 2.55, 95%CI: 1.13–5.80). This association was particularly noticeable when children with structural anomalies or children with UFAs in their head and brain scans were compared to children without UFAs (any mutation: aOR = 8.28, 95%CI: 2.29–30.01; LoF: aOR = 5.72, 95%CI: 2.08–15.71 and any mutation: aOR = 6.39, 95%CI: 1.34–30.47; LoF: aOR = 4.50, 95%CI: 1.32–15.35, respectively). GDVs associated with UFAs were enriched in genes highly expressed across all tissues (aOR = 2.76, 95%CI: 1.14–6.68). There was a weak, but significant, correlation between the number of mutations and the number of abnormalities detected in the same children (r = 0.21, P = 0.016).ConclusionsThe results provide valuable insights into the potential genetic basis of prenatal organogenesis abnormalities associated with ASD and shed light on the complex interplay between genetic factors and fetal development.

Lamina Cribrosa Microstructure in Nonhuman Primates With Naturally Occurring Peripapillary Retinal Nerve Fiber Layer Thinning.

The lamina cribrosa (LC) is hypothesized to be the site of initial axonal damage in glaucoma with the circumpapillary retinal nerve fiber layer thickness (RNFL-T) widely used as a standard metric for quantifying the glaucomatous damage. The purpose of this study was to determine in vivo, 3-dimensional (3D) differences in the microstructure of the LC in eyes of nonhuman primates (NHPs) with naturally occurring glaucoma. Spectral-domain optical coherence tomography (OCT) scans (Leica, Chicago, IL, USA) of the optic nerve head were acquired from a colony of 50 adult rhesus monkeys suspected of having high prevalence of glaucoma. The RNFL-T was analyzed globally and in quadrants using a semi-automated segmentation software. From a set of 100 eyes, 18 eyes with the thinnest global RNFL-T were selected as the study group and 18 eyes with RNFL-T values around the 50th percentile were used as controls. A previously described automated segmentation algorithm was used for LC microstructure analysis. Parameters included beam thickness, pore diameter and their ratio (beam-to-pore ratio [BPR]), pore area and shape parameters, beam and pore volume, and connective tissue volume fraction (CTVF; beam volume/total volume). The LC microstructure was analyzed globally and in the following volumetric sectors: quadrants, central and peripheral lamina, and three depth slabs (anterior, middle, and posterior). Although no significant difference was detected between groups for age, weight, or disc size, the study group had significantly thinner RNFL than the control group (P < 0.01). The study group had significantly smaller global and sectoral pore diameter and larger BPR compared with the control group. Across eyes, the global RNFL-T was associated positively with pore diameter globally. BPR and CTVF were significantly and negatively associated with the corresponding RNFL-T in the superior quadrant. Global and sectoral microstructural differences were detected when comparing thin and normal RNFL-T eyes. Whether these LC differences are the cause of RNFL damage or the result of remodeling of the LC requires further investigation. Our findings indicate structural alterations in the LC of NHP exhibiting natural thinning of the RNFL, a common characteristic of glaucomatous damage.

Advancements in opportunistic intracranial aneurysm screening: The impact of a deep learning algorithm on radiologists' analysis of T2-weighted cranial MRI

(1) Background: Unruptured Intracranial Aneurysms (UIAs) are common blood vessel malformations, occurring in up to 3 % of healthy adults. Magnetic Resonance Angiography (MRA) is frequently used for the screening of UIAs due to its high resolution in vascular anatomy. However, T2-Weighted Magnetic Resonance Imaging (T2WI) is a standard sequence utilized for the majority of outpatient head scans. By employing a sequence such as T2WI, there is a possible shift towards early detection of UIAs through opportunistic screening. Here, we assess a Deep Learning Algorithm (DLA) developed to assist radiologists in identifying and reporting UIAs on T2WI in a routine clinical setting. (2) Methods: A DLA was trained on a set of 110 patients undergoing an MR head scan with the gold standard set by two radiology experts. Eight radiologists were given a cohort of 50 cranial T2WI studies and asked for a routine report. After a 10-day washout period, they reviewed the same cases randomized and supported by the DLA predictions. We assessed changes in sensitivity, specificity, accuracy, and false positives. (3) Results: During routine reporting, the models’ assistance improved the sensitivity of the eight participants by an average of 36.19 and the accuracy by 10.00 percentage points. (4) Conclusion: Our results indicate the potential benefit of deep learning to improve radiologists' detection of UIAs during routine reporting. From this, we can infer that the combination of T2WI with our DLA supports opportunistic screening, suggesting potential approaches for future research and application.

Accuracy and longitudinal consistency of PET/MR attenuation correction in amyloid PET imaging amid software and hardware upgrades.

Integrated PET/MR allows the simultaneous acquisition of PET biomarkers and structural and functional MRI to study Alzheimer disease (AD). Attenuation correction (AC), crucial for PET quantification, can be performed using a deep learning approach, DL-Dixon, based on standard Dixon images. Longitudinal amyloid PET imaging, which provides important information about disease progression or treatment responses in AD, is usually acquired over several years. Hardware and software upgrades often occur during a multiple-year study period, resulting in data variability. This study aims to harmonize PET/MR DL-Dixon AC amid software and head coil updates and evaluate its accuracy and longitudinal consistency. Tri-modality PET/MR and CT images were obtained from 329 participants, with a subset of 38 undergoing tri-modality scans twice within approximately three years. Transfer learning was employed to fine-tune DL-Dixon models on images from two scanner software versions (VB20P and VE11P) and two head coils (16-channel and 32-channel coils). The accuracy and longitudinal consistency of the DL-Dixon AC were evaluated. Power analyses were performed to estimate the sample size needed to detect various levels of longitudinal changes in the PET standardized uptake value ratio (SUVR). The DL-Dixon method demonstrated high accuracy across all data, irrespective of scanner software versions and head coils. More than 95.6% of brain voxels showed less than 10% PET relative absolute error in all participants. The median [interquartile range] PET mean relative absolute error was 1.10% [0.93%, 1.26%], 1.24% [1.03%, 1.54%], 0.99% [0.86%, 1.13%] in the cortical summary region, and 1.04% [0.83%, 1.36%], 1.08% [0.84%, 1.34%], 1.05% [0.72%, 1.32%] in cerebellum using the DL-Dixon models for the VB20P-16-channel-coil, VE11P-16-channel-coil and VE11P-32-channel-coil data, respectively. The within-subject coefficient of variation and intra-class correlation coefficient of PET SUVR in the cortical regions were comparable between the DL-Dixon and CT AC. Power analysis indicated that similar numbers of participants would be needed to detect the same level of PET changes using DL-Dixon and CT AC. DL-Dixon exhibited excellent accuracy and longitudinal consistency across the two software versions and head coils, demonstrating its robustness for longitudinal PET/MR neuroimaging studies in AD. AC = attenuation correction; AD = Alzheimer disease; HU = Hounsfield unit; ICC = intraclass correlation coefficient; MAE = mean absolute error; MRAE = mean relative absolute error; pCT = pseudo-CT; PiB = Pittsburgh Compound B; SD = standard deviation; SUVR = standardized uptake value ratio; wCV = within-subject coefficient of variation.

Clinical Significance of the Control CT Rotterdam Score Compared With the Admission CT Rotterdam Score in Patients With Isolated Severe Traumatic Brain Injury in the Intensive Care Unit.

The Rotterdam scale is one of the most commonly used radiological scales for evaluating and predicting outcomes in traumatic brain injury (TBI) cases. Given the evolving nature of TBI, our study is designed to compare the Rotterdam score of computed tomography (CT) findings upon admission (Rotterdam score I) with the score after 72 hours (Rotterdam score II) of treatment in the trauma intensive care unit (ICU). A retrospective observational study was conducted on 54 patients who received intensive care treatment for isolated severe TBI over five years. We included severe TBI patients with no age restrictions who required admission to the ICU within 12 hours of the onset of trauma. An initial Rotterdam CT score was obtained via a CT head scan within four hours of the trauma, followed by a control CT head scan 72 hours after ICU admission. It was essential to have documentation on the clinical and laboratory treatment course and access to radiological CT diagnostics. Receiver operating characteristic (ROC) curves were employed in this study to evaluate the accuracy of diagnostic tests, such as the Rotterdam score. The ROC curves provided a graphical representation of the tests' diagnostic performance, which helped assess their effectiveness. There was a significant difference (p < 0.001) in the diagnostic scores of CT scans upon admission (Rotterdam score I) and control CT scans after 72 hours (Rotterdam score II) in the total sample. The Rotterdam score I was notably higher, 3.6 (±0.8), in patients requiring neurosurgical intervention compared to those who did not, 2.8 (±0.9), with significance (p = 0.003). The Rotterdam score I demonstrated a substantial predictive value for unfavorable outcomes (p = 0.048), as did the Rotterdam score II after the 72-hour mark (p = 0.006). The control Rotterdam score 72 hours after admission predicts mortality in isolated TBI patients more significantly than the Rotterdam score determined at the patient's admission to the intensive care unit.

A Survey Study of the 3D Facial Landmark Detection Techniques Used as a Screening Tool for Diagnosis of the Obstructive Sleep Apnea Syndrome.

Obstructive Sleep Apnea (OSA) is a common disorder affecting both adults and children. It is characterized by repeated episodes of apnea (stopped breathing) and hypopnea (reduced breathing), which result in intermittent hypoxia. We recognize pediatric and adult OSA, and this paper focuses on pediatric OSA. While adults often suffer from daytime sleepiness, children are more likely to develop behavioral abnormalities. Early diagnosis and treatment are important to prevent negative effects on children's development. Without the treatment, children may be at increased risk of developing high blood pressure or other heart problems. The gold standard for OSA diagnosis is the polysomnography (sleep study) PSG performed at a sleep center. Not only is it an expensive procedure, but it can also be very stressful, especially for children. Patients have to stay at the sleep center during the night. Therefore, screening tools are very important. Multiple studies have shown that OSA screening tools can be based on facial anatomical landmarks. Anatomical landmarks are landmarks located at specific anatomical locations. For the purpose of the screening tool, a specific list of anatomical locations needs to be identified. We are presenting a survey study of the automatic identification of these landmarks on 3D scans of the patient's head. We are considering and comparing both knowledge-based and AI-based identification techniques, with a focus on the development of the automatic OSA screening tool.

Intracranial calcifications in Post-mortem Computed Tomography and its forensic implications

ABSTRACT Intracranial physiological calcifications are usually seen in Post-mortem Computed Tomography (PMCT) and are difficult to note with naked-eye examination during conventional autopsy. Studies on intracerebral calcifications in PMCT are few. Moreover, such studies may be of interest from the clinical perspective in order to compare physiological and pathological intracranial calcifications. Hence, the authors aimed to calculate the incidence of calcification of the pineal gland and choroid plexus in the lateral ventricle in brain PMCT and its association with age, sex, type of death, and manner of death. The authors studied 620 PMCT head scans of the deceased whose ages ranged from 2 months to 97 years (mean ± SD is 38.83 ± 15.91). A total of 59.68% had pineal calcification, and 47.42% had choroid plexus calcification with a male preponderance. A statistically significant association was present between the studied calcifications and age, sex, type of death, and manner of death. The calcification was higher in the pineal gland than in the choroid plexus until the fifth decade, and post fifth decade the choroid plexus calcification was more common. The presence of calcification was higher among the suicidal deaths when compared with the non-suicidal deaths with a statistically significant association (p < 0.05).

Accuracy and time efficiency of a novel deep learning algorithm for Intracranial Hemorrhage detection in CT Scans

PurposeTo evaluate a deep learning-based pipeline using a Dense-UNet architecture for the assessment of acute intracranial hemorrhage (ICH) on non-contrast computed tomography (NCCT) head scans after traumatic brain injury (TBI).Materials and methodsThis retrospective study was conducted using a prototype algorithm that evaluated 502 NCCT head scans with ICH in context of TBI.Four board-certified radiologists evaluated in consensus the CT scans to establish the standard of reference for hemorrhage presence and type of ICH. Consequently, all CT scans were independently analyzed by the algorithm and a board-certified radiologist to assess the presence and type of ICH. Additionally, the time to diagnosis was measured for both methods.ResultsA total of 405/502 patients presented ICH classified in the following types: intraparenchymal (n = 172); intraventricular (n = 26); subarachnoid (n = 163); subdural (n = 178); and epidural (n = 15). The algorithm showed high diagnostic accuracy (91.24%) for the assessment of ICH with a sensitivity of 90.37% and specificity of 94.85%. To distinguish the different ICH types, the algorithm had a sensitivity of 93.47% and a specificity of 99.79%, with an accuracy of 98.54%. To detect midline shift, the algorithm had a sensitivity of 100%. In terms of processing time, the algorithm was significantly faster compared to the radiologist’s time to first diagnosis (15.37 ± 1.85 vs 277 ± 14 s, p < 0.001).ConclusionA novel deep learning algorithm can provide high diagnostic accuracy for the identification and classification of ICH from unenhanced CT scans, combined with short processing times. This has the potential to assist and improve radiologists’ ICH assessment in NCCT scans, especially in emergency scenarios, when time efficiency is needed.

2229 A review of CT head scans in elderly patients admitted to hospital with falls and adherence to the NICE guidelines.

Abstract Introduction Falls remain the leading reason for elderly people to attend emergency department (ED), which in 2023 led to 250,000 hospital admissions in the UK. A seemingly large number of geriatric patients undergo CT head as an initial workup in ED which might not be necessary, especially in minor head trauma. NICE (National Institute for Health and Care Excellence), recommended risk stratification to reduce unnecessary head scanning which may potentially reduce ED length of stay, hospitalisation and medical expense. Our study evaluated the current practice of adherence to NICE guidance on Head Injury: assessment and early management for performing CT head scans in elderly admitted to Basildon hospital. Methods Two cycles of retrospective data collection were undertaken across three elderly care wards. Elderly patients admitted with falls who had CT head scans were identified. Indication for scanning were evaluated to determine adherence with NICE guidelines for head injury. Between cycles, formal educational sessions were provided to Junior Doctors by departmental teaching and distributing leaflets/posters explaining NICE guidance for indication of CT head scans in head injury. Results Following the interventions implemented, patient compliance to the NICE guidance for undergoing CT head with a history of falls, rose from 77.33% to 93.99%. No significant difference in abnormal CT head findings were demonstrated between cycles. In addition, mortality observed between cycles was near equivalent, 12% and 11.67% respectively. The mean time for CT head scans performed also improved, from 13 hours to 4 hours. Conclusion We demonstrated education regarding the indication for CT head scans in elderly with falls improved the appropriateness of scans performed in accordance with NICE guidance. CT head scans performed which more robustly met NICE guidance demonstrated no difference in adverse findings or patient mortality and may have contributed to reduced mean scan time, thus improving resource allocation.