The association between fetal intracranial hemorrhages detected on MRI and neurodevelopment.

PURPOSE: Fetal intracranial hemorrhage is rarely identified in prenatal imaging. When identified, sparse data regarding neurodevelopmental outcomes worsens prenatal dilemmas. This MRI-based study aimed to assess prenatal characteristics and neurodevelopmental outcomes of fetal intracranial hemorrhage. METHODS: A historical cohort study which identified fetal intracranial hemorrhage in 22 individual fetal MRI scans, as part of the assessment of abnormal prenatal sonographic findings. Severity was graded by the grading system commonly used in neonates, with modifications. Prenatal data was collected. Neurodevelopmental outcome was assessed clinically by Vineland-II Adaptive Behavior Scales. RESULTS: Eight fetuses had intraventricular hemorrhage grade I-II, twelve had intraventricular hemorrhage grade III-IV, and two had infratentorial hemorrhage. The most prevalent risk factors were maternal chronic diseases and chronic use of medications. There was male predominance. Pregnancy was terminated in eleven cases. No surviving child who participated in the Vineland assessment had a grade IV hemorrhage. Vineland scores were normal in 9/11 children and moderately low in 2/11. The mean composite score of the cohort was not different from the mean score expected for age. Clinically, one child had hypotonia. CONCLUSIONS: Prognosis for fetuses with ICH without parenchymal involvement is potentially more favorable than expected from the intraventricular hemorrhage grading-scale adopted from the preterm neonates. Parenchymal involvement may predict a worse outcome, but it is not the sole predicting feature. This information may be valuable during prenatal counseling.

Pathological changes in the lenticulostriate artery indicate the mechanisms leading to intracranial hemorrhage in Moyamoya disease: a case report.

This case report details the pathological findings of a vessel wall identified as the bleeding point for intracranial hemorrhage associated with Moyamoya disease. A 29-year-old woman experienced intracranial hemorrhage unrelated to hyperperfusion following superficial temporal artery-middle cerebral artery bypass surgery. A pseudoaneurysm on the lenticulostriate artery (LSA) was identified as the causative vessel and subsequently excised. Examination of the excised pseudoaneurysm revealed a fragment of the LSA, with a disrupted internal elastic lamina and media degeneration. These pathological findings in a perforating artery, akin to the circle of Willis, provide insights into the underlying mechanisms of hemorrhage in Moyamoya disease.

Tenecteplase for Stroke at 4.5 to 24 Hours with Perfusion-Imaging Selection.

BACKGROUND: Thrombolytic agents, including tenecteplase, are generally used within 4.5 hours after the onset of stroke symptoms. Information on whether tenecteplase confers benefit beyond 4.5 hours is limited. METHODS: We conducted a multicenter, double-blind, randomized, placebo-controlled trial involving patients with ischemic stroke to compare tenecteplase (0.25 mg per kilogram of body weight, up to 25 mg) with placebo administered 4.5 to 24 hours after the time that the patient was last known to be well. Patients had to have evidence of occlusion of the middle cerebral artery or internal carotid artery and salvageable tissue as determined on perfusion imaging. The primary outcome was the ordinal score on the modified Rankin scale (range, 0 to 6, with higher scores indicating greater disability and a score of 6 indicating death) at day 90. Safety outcomes included death and symptomatic intracranial hemorrhage. RESULTS: The trial enrolled 458 patients, 77.3% of whom subsequently underwent thrombectomy; 228 patients were assigned to receive tenecteplase, and 230 to receive placebo. The median time between the time the patient was last known to be well and randomization was approximately 12 hours in the tenecteplase group and approximately 13 hours in the placebo group. The median score on the modified Rankin scale at 90 days was 3 in each group. The adjusted common odds ratio for the distribution of scores on the modified Rankin scale at 90 days for tenecteplase as compared with placebo was 1.13 (95% confidence interval, 0.82 to 1.57; P = 0.45). In the safety population, mortality at 90 days was 19.7% in the tenecteplase group and 18.2% in the placebo group, and the incidence of symptomatic intracranial hemorrhage was 3.2% and 2.3%, respectively. CONCLUSIONS: Tenecteplase therapy that was initiated 4.5 to 24 hours after stroke onset in patients with occlusions of the middle cerebral artery or internal carotid artery, most of whom had undergone endovascular thrombectomy, did not result in better clinical outcomes than those with placebo. The incidence of symptomatic intracerebral hemorrhage was similar in the two groups. (Funded by Genentech; TIMELESS ClinicalTrials.gov number, NCT03785678.).

Endovascular embolisation of posterior condylar canal dural arteriovenous fistula.

We describe a rare case of dural arteriovenous fistula (dAVF) of the posterior condylar canal in a man in his 30s who presented with recent onset headache and neck pain and subsequently acute intracranial haemorrhage. Radiological workup showed a medulla bridging vein draining dAVF of the right posterior condylar canal supplied by a meningeal branch of the right occipital artery. A dilated venous sac was seen compressing over cerebellar tonsil on the right side. There was acute haemorrhage in the posterior fossa and fourth ventricle. He was successfully managed with transarterial endovascular embolisation via a supercompliant balloon microcatheter without any complication. The balloon microcatheter effectively prevented reflux of the liquid embolic agent into the parent artery and vasa nervosa of lower cranial nerves.

AI assisted reader evaluation in acute CT head interpretation (AI-REACT): protocol for a multireader multicase study.

INTRODUCTION: A non-contrast CT head scan (NCCTH) is the most common cross-sectional imaging investigation requested in the emergency department. Advances in computer vision have led to development of several artificial intelligence (AI) tools to detect abnormalities on NCCTH. These tools are intended to provide clinical decision support for clinicians, rather than stand-alone diagnostic devices. However, validation studies mostly compare AI performance against radiologists, and there is relative paucity of evidence on the impact of AI assistance on other healthcare staff who review NCCTH in their daily clinical practice. METHODS AND ANALYSIS: A retrospective data set of 150 NCCTH will be compiled, to include 60 control cases and 90 cases with intracranial haemorrhage, hypodensities suggestive of infarct, midline shift, mass effect or skull fracture. The intracranial haemorrhage cases will be subclassified into extradural, subdural, subarachnoid, intraparenchymal and intraventricular. 30 readers will be recruited across four National Health Service (NHS) trusts including 10 general radiologists, 15 emergency medicine clinicians and 5 CT radiographers of varying experience. Readers will interpret each scan first without, then with, the assistance of the qER EU 2.0 AI tool, with an intervening 2-week washout period. Using a panel of neuroradiologists as ground truth, the stand-alone performance of qER will be assessed, and its impact on the readers' performance will be analysed as change in accuracy (area under the curve), median review time per scan and self-reported diagnostic confidence. Subgroup analyses will be performed by reader professional group, reader seniority, pathological finding, and neuroradiologist-rated difficulty. ETHICS AND DISSEMINATION: The study has been approved by the UK Healthcare Research Authority (IRAS 310995, approved 13 December 2022). The use of anonymised retrospective NCCTH has been authorised by Oxford University Hospitals. The results will be presented at relevant conferences and published in a peer-reviewed journal. TRIAL REGISTRATION NUMBER: NCT06018545.

Imaging of intracranial hemorrhage in photon counting computed tomography using virtual monoenergetic images.

PURPOSE: To determine the optimal virtual monoenergetic image (VMI) for detecting and assessing intracranial hemorrhage in unenhanced photon counting CT of the head based on the evaluation of quantitative and qualitative image quality parameters. METHODS: Sixty-three patients with acute intracranial hemorrhage and unenhanced CT of the head were retrospectively included. In these patients, 35 intraparenchymal, 39 intraventricular, 30 subarachnoidal, and 43 subdural hemorrhages were selected. VMIs were reconstructed using all available monoenergetic reconstruction levels (40-190 keV). Multiple regions of interest measurements were used for evaluation of the overall image quality, and signal, noise, signal-to-noise-ratio (SNR), and contrast-to-noise-ratio (CNR) of intracranial hemorrhage. Based on the results of the quantitative analysis, specific VMIs were rated by five radiologists on a 5-point Likert scale. RESULTS: Signal, noise, SNR, and CNR differed significantly between different VMIs (p < 0.001). Maximum CNR for intracranial hemorrhage was reached in VMI with keV levels > 120 keV (intraparenchymal 143 keV, intraventricular 164 keV, subarachnoidal 124 keV, and subdural hemorrhage 133 keV). In reading, no relevant superiority in the detection of hemorrhage could be demonstrated using VMIs above 66 keV. CONCLUSION: For the detection of hemorrhage in unenhanced CT of the head, the quantitative analysis of the present study on photon counting CT is generally consistent with the findings from dual-energy CT, suggesting keV levels just above 120 keV and higher depending on the location of the hemorrhage. However, on the basis of the qualitative analyses, no reliable statement can yet be made as to whether an additional VMI with higher keV is truly beneficial in everyday clinical practice.

mcTFI QSM MRI ABC/2 intracranial hemorrhage to noncontrast head CT volume measurement equivalence.

BACKGROUND/OBJECTIVES: Intracranial hemorrhage (ICH) volume assessment is an important part of patient management and is routinely obtained by non-contrast head CT (NCHCT) using the validated ABC/2 measurement method. Because conventional MRI imaging sequences demonstrate variability in ICH appearance, volumetric analyses for MRI bleed volume in a standardized manner using ABC/2 is not possible. The recently introduced multiecho-complex total field inversion quantitative susceptibility mapping (mcTFI QSM) MRI technique, which maps brain tissue susceptibility to both depict brain tissue structures and quantify tissue susceptibility, may provide a viable alternative. In this study we evaluated mcTFI QSM ABC/2 ICH volume assessment relative to NCHCT. METHODS: Patients with ICH who had undergone NCHCT and MRI brain scans within 48 h were recruited for this retrospective study. The ABC/2 method was applied to estimate the bleed volume for both NCHCT and MRI by a CAQ-certified neuroradiologist with 10 years of experience and a trained laboratory assistant. Results were analyzed via Bland-Altman (B-A) and linear regression. RESULTS: 54 patients (27 females) who had undergone NCHCT and MRI within 48 h (<24 h., n = 31, 24-48 h, n = 10) were enrolled. mcTFI QSM ICH volume measurement method showed a positive correlation (99.5%) compared to NCHCT. B-A plot comparing ABC/2 ICH volume on NCHCT and mcTFI MRI done for patients within 24 h demonstrates a bias of -0.09%. CONCLUSIONS: ICH volume calculation using ABC/2 on mcTFI QSM showed a high correlation with NCHCT measurement. These results suggest mcTFI QSM is a promising MRI method for ABC/2 for bleed volume measurement.

Examination-Level Supervision for Deep Learning-based Intracranial Hemorrhage Detection on Head CT Scans.

Purpose To compare the effectiveness of weak supervision (ie, with examination-level labels only) and strong supervision (ie, with image-level labels) in training deep learning models for detection of intracranial hemorrhage (ICH) on head CT scans. Materials and Methods In this retrospective study, an attention-based convolutional neural network was trained with either local (ie, image level) or global (ie, examination level) binary labels on the Radiological Society of North America (RSNA) 2019 Brain CT Hemorrhage Challenge dataset of 21 736 examinations (8876 [40.8%] ICH) and 752 422 images (107 784 [14.3%] ICH). The CQ500 (436 examinations; 212 [48.6%] ICH) and CT-ICH (75 examinations; 36 [48.0%] ICH) datasets were employed for external testing. Performance in detecting ICH was compared between weak (examination-level labels) and strong (image-level labels) learners as a function of the number of labels available during training. Results On examination-level binary classification, strong and weak learners did not have different area under the receiver operating characteristic curve values on the internal validation split (0.96 vs 0.96; P = .64) and the CQ500 dataset (0.90 vs 0.92; P = .15). Weak learners outperformed strong ones on the CT-ICH dataset (0.95 vs 0.92; P = .03). Weak learners had better section-level ICH detection performance when more than 10 000 labels were available for training (average f1 = 0.73 vs 0.65; P < .001). Weakly supervised models trained on the entire RSNA dataset required 35 times fewer labels than equivalent strong learners. Conclusion Strongly supervised models did not achieve better performance than weakly supervised ones, which could reduce radiologist labor requirements for prospective dataset curation. Keywords: CT, Head/Neck, Brain/Brain Stem, Hemorrhage Supplemental material is available for this article. © RSNA, 2023 See also commentary by Wahid and Fuentes in this issue.

Evaluating artificial intelligence software for delineating hemorrhage extent on CT brain imaging in stroke: AI delineation of ICH on CT.

BACKGROUND: The extent and distribution of intracranial hemorrhage (ICH) directly affects clinical management. Artificial intelligence (AI) software can detect and may delineate ICH extent on brain CT. We evaluated e-ASPECTS software (Brainomix Ltd.) performance for ICH delineation. METHODS: We qualitatively assessed software delineation of ICH on CT using patients from six stroke trials. We assessed hemorrhage delineation in five compartments: lobar, deep, posterior fossa, intraventricular, extra-axial. We categorized delineation as excellent, good, moderate, or poor. We assessed quality of software delineation with number of affected compartments in univariate analysis (Kruskall-Wallis test) and ICH location using logistic regression (dependent variable: dichotomous delineation categories 'excellent-good' versus 'moderate-poor'), and report odds ratios (OR) and 95 % confidence intervals (95 %CI). RESULTS: From 651 patients with ICH (median age 75 years, 53 % male), we included 628 with assessable CTs. Software delineation of ICH extent was 'excellent' in 189/628 (30 %), 'good' in 255/628 (41 %), 'moderate' in 127/628 (20 %), and 'poor' in 57/628 cases (9 %). The quality of software delineation of ICH was better when fewer compartments were affected (Z = 3.61-6.27; p = 0.0063). Software delineation of ICH extent was more likely to be 'excellent-good' quality when lobar alone (OR = 1.56, 95 %CI = 0.97-2.53) but 'moderate-poor' with any intraventricular (OR = 0.56, 95 %CI = 0.39-0.81, p = 0.002) or any extra-axial (OR = 0.41, 95 %CI = 0.27-0.62, p<0.001) extension. CONCLUSIONS: Delineation of ICH extent on stroke CT scans by AI software was excellent or good in 71 % of cases but was more likely to over- or under-estimate extent when ICH was either more extensive, intraventricular, or extra-axial.

Utility of Repeat Head Computed Tomography in Detecting Delayed Intracranial Hemorrhage in Falls on Direct Oral Anticoagulants.

INTRODUCTION: Ground level falls in the elderly often lead to complications due to use of anticoagulants (ACs). Intracranial hemorrhage (ICH), immediate or delayed, is a feared consequence of such falls. The rate of delayed ICH (dICH) in patients taking anticoagulants or antiplatelet (AP) agents ranges from .6% to 6%. Patients on warfarin have a persistent rate of dICH, leading to implementation of routine repeat head CTs at our institution. This policy was extended to direct oral anticoagulants (DOACs). This study aims to determine institutional incidence of DOAC-associated dICH. METHODS: With IRB waiver approval, we conducted a retrospective review of trauma evaluations for falls on DOACs from 2016 to 2018. We reviewed records for neurologic status, DOAC use, and results of initial and delayed head CTs. Exclusion criteria included initial GCS ≤14, new neurologic deficits, traumatic findings on initial CT, concurrent use of additional AC/AP, or absence of repeat head CT. RESULTS: Among 632 patients evaluated for falls on AC/AP therapy, 159 (25%) of patients were included in the review. The age range was 19-98 years old, with 99 females and 60 males. Half of the patients were on apixaban, with the rest on dabigatran or rivaroxaban. Ten patients presented with GCS of 14. No delayed hemorrhages were detected in this population. CONCLUSION: The necessity of a repeat head CT in patients taking DOACs is debated in the literature. Our analysis failed to demonstrate any delayed hemorrhage in neurologically intact patients after head strike on DOAC, suggesting no indication for follow-up imaging in this group.

Spontaneous Intracranial Hemorrhage and Acute Respiratory Distress Syndrome Associated with Dengue: A Case Report.

BACKGROUND: Dengue is a major health burden worldwide, notably in tropical and subtropical countries, with symptoms ranging from asymptomatic infection to severe hemorrhagic or shock syndrome. The clinical and biochemical profile of dengue has been shown in the literature to be expanding as more atypical signs have been added over the past few decades. Most dengue-related symptoms are typically mild to moderate and self-limited. However, intracranial hemorrhage and acute respiratory distress syndrome in severe dengue is an event that has been encountered uncommonly. CASE PRESENTATION: A 30-year-old female presented with complaints of fever, headache, cough, and altered sensorium. Later, she was diagnosed with severe dengue fever complicated by dengue hemorrhagic fever, which manifested as subarachnoid and subdural bleeding and acute respiratory distress syndrome. She was managed conservatively with a positive outcome. CONCLUSION: Atypical manifestation, though rare, should be kept in mind while dealing with severe dengue patients, as early detection based on anticipated risk factors and timely treatment have the potential to save lives.

Derivation of the Falls Decision Rule to exclude intracranial bleeding without head CT in older adults who have fallen.

BACKGROUND: Ground-level falls are common among older adults and are the most frequent cause of traumatic intracranial bleeding. The aim of this study was to derive a clinical decision rule that safely excludes clinically important intracranial bleeding in older adults who present to the emergency department after a fall, without the need for a computed tomography (CT) scan of the head. METHODS: This prospective cohort study in 11 emergency departments in Canada and the United States enrolled patients aged 65 years or older who presented after falling from standing on level ground, off a chair or toilet seat, or out of bed. We collected data on 17 potential predictor variables. The primary outcome was the diagnosis of clinically important intracranial bleeding within 42 days of the index emergency department visit. An independent adjudication committee, blinded to baseline data, determined the primary outcome. We derived a clinical decision rule using logistic regression. RESULTS: The cohort included 4308 participants, with a median age of 83 years; 2770 (64%) were female, 1119 (26%) took anticoagulant medication and 1567 (36%) took antiplatelet medication. Of the participants, 139 (3.2%) received a diagnosis of clinically important intracranial bleeding. We developed a decision rule indicating that no head CT is required if there is no history of head injury on falling; no amnesia of the fall; no new abnormality on neurologic examination; and the Clinical Frailty Scale score is less than 5. Rule sensitivity was 98.6% (95% confidence interval [CI] 94.9%-99.6%), specificity was 20.3% (95% CI 19.1%-21.5%) and negative predictive value was 99.8% (95% CI 99.2%-99.9%). INTERPRETATION: We derived a Falls Decision Rule, which requires external validation, followed by clinical impact assessment. Trial registration: ClinicalTrials. gov, no. NCT03745755.

Diffusion-weighted imaging in hyperacute haemorrhagic stroke patients presenting within thrombolysis window.

INTRODUCTION: Diffusion-weighted imaging (DWI) in magnetic resonance imaging (MRI) has been proposed as the first line of neuroimaging for acute ischaemic stroke. The reliability of DWI in detecting intracranial haemorrhage, however, is still unproven, compared with susceptibility-weighted imaging (SWI) and CT scan which being considered the gold standard. This study seeks to establish the reliability of DWI as a first-line imaging modality to detect the intracranial haemorrhage in the patients present within the thrombolysis window. MATERIALS AND METHODS: A retrospective cross-sectional analysis was performed on patients who presented to our institution from April 2020 until July 2021 for acute stroke and had MRI brain as first-line neuroimaging. A total of 31 subjects were included in this study. Two radiologists assessed the signal patterns in DWI sequence and compared them with SWI and CT Brain, whenever available, as the gold standard for observing the presence of intracranial haemorrhage. RESULTS: The majority of patients with hyperacute bleed proven to be revealed on SWI or CT, thus showed characteristics of central hyperintensity and peripheral hypointense rim, on DWI. Slightly more than half (51.6%) presented with mild to moderate NIHSS scores (1-15). The sensitivity, specificity, positive predictive value and negative predictive value of DWI in detecting intracranial intra-axial haemorrhages were exceptionally high. There is strong interobserver level of agreement in identifying central haemorrhagic signal intensity [kappa = 0.94 (0.06), p < 0.05]. CONCLUSION: This study supported the DWI sequence as a reliable sequence in MRI, to detect intracranial haemorrhage in hyperacute stroke.

Differential diagnosis of acute intracranial hemorrhage and calcification by cranial dual-energy computed tomography.

OBJECTIVE: To evaluate the application value of dual-energy computed tomography (DECT) in the differential diagnosis of acute intracranial hemorrhage and calcification. METHODS: This retrospective study involved patients who underwent non-contrast-enhanced cranial DECT in Anhui Wannan Rehabilitation Hospital from January 2015 to November 2022. The processed mixed images obtained after DECT were used as the conventional CT images. Each hyperdense lesion was analyzed based on virtual non-calcium and calcium overlay and classified as calcification or hemorrhage. The sensitivity, specificity, and accuracy of conventional CT and DECT were calculated by the chi-square test according to the unified reference standard. RESULTS: Sixty-six hyperdense intracranial lesions of 60 patients were analyzed; of these lesions, 41 (62.12%) were calcifications and 25 (37.88%) were hemorrhages. The sensitivity, specificity, and accuracy of DECT in identifying hemorrhage were 96.00%, 100%, and 98.48%, respectively, while those of conventional CT were 72.00%, 97.56%, and 87.88%, respectively. Of the 66 lesions, 4 (6.06%) could not be qualitatively identified and 3 (4.55%) were misdiagnosed by conventional CT but correctly identified by DECT. CONCLUSIONS: DECT can accurately distinguish acute intracranial hemorrhage from calcification, especially in cases that are difficult to diagnose by conventional CT.

Coronary Angiography Complicated by Acute Ischaemic Stroke and the Use of Thrombolysis: a Cardiology Perspective and Narrative Review of Current Literature.

PURPOSE OF REVIEW: Coronary angiography-associated acute ischaemic stroke (CAAIS) is an uncommon event but is associated with significant mortality and morbidity. The incidence of CAAIS has increased with a rise in the volume of coronary angiography (CA) and percutaneous coronary intervention (PCI) performed. Intravenous thrombolysis (IVT) is utilized in the general management of acute ischaemic stroke; however, it is associated with a higher risk of intracranial hemorrhage (ICH). As CA or PCI is performed more often in an aging population or high-risk patients that also carry an increased risk of ICH, it is vital to minimize additional complications from the treatment of CAAIS. This article aims to review the pathophysiological mechanisms for CAAIS, clarify the current evidence regarding IVT use in this setting, and thus assist cardiologists in the management of CAAIS. RECENT FINDINGS: The pathophysiology for CAAIS may be different from acute ischaemic stroke in the general population. Embolic phenomena from dislodgement of calcium or other debris during manipulation of instrumentation during CA or PCI are likely mechanisms. This may contribute to altered thrombus composition, which affects the efficacy of IVT as suggested in recent studies. Furthermore, IVT in the management of CAAIS has not been evaluated specifically. The utilization of IVT should be carefully considered in CAAIS given a paucity of evidence demonstrating safety and efficacy in this setting. A multidisciplinary pathway that emphasizes the involvement of cardiologists in the treatment decision-making process would aid in thoughtful risk-benefit evaluation for IVT use in CAAIS and reduce adverse patient outcomes. Future studies to assess the impact of this pathway on CAAIS outcomes would be beneficial.

Cardiac surgery for a right atrial myxoma with traumatic intracranial hemorrhage: a case report.

BACKGROUND: The timing of cardiac surgery with cardiopulmonary bypass (CPB) for intracranial hemorrhage is controversial. CASE PRESENTATION: We report the case of an 82-year-old woman who was transferred to our hospital because of a head injury. Brain computed tomography (CT) revealed traumatic intracranial hemorrhage, and transthoracic echocardiography revealed a giant right atrial myxoma. After confirming the disappearance of intracranial hemorrhage on brain CT, cardiac surgery with CPB was performed, which was uneventful. CONCLUSIONS: For an uneventful surgery, the optimal timing of cardiac surgery with CPB in patients with giant right atrial myxoma and intracranial hemorrhage should be based on brain CT.

Decreasing false-positive detection of intracranial hemorrhage (ICH) using RAPID ICH 3.

INTRODUCTION: The prompt detection of intracranial hemorrhage (ICH) on a non-contrast head CT (NCCT) is critical for the appropriate triage of patients, particularly in high volume/high acuity settings. Several automated ICH detection tools have been introduced; however, at present, most suffer from suboptimal specificity leading to false-positive notifications. METHODS: NCCT scans from 4 large databases were evaluated for the presence of an ICH (IPH, IVH, SAH or SDH) of >0.4 ml using fully-automated RAPID ICH 3.0 as compared to consensus detection from at least two neuroradiology experts. Scans were excluded for (1) severe CT artifacts, (2) prior neurosurgical procedures, or (3) recent intravenous contrast. ICH detection accuracy, sensitivity, specificity, positive predictive value, negative predictive value, and positive and negative likelihood ratios by were determined. RESULTS: A total of 881 studies were included. The automated software correctly identified 453/463 ICH-positive cases and 416/418 ICH-negative cases, resulting in a sensitivity of 97.84% and specificity 99.52%, positive predictive value 99.56%, and negative predictive value 97.65% for ICH detection. The positive and negative likelihood ratios for ICH detection were similarly favorable at 204.49 and 0.02 respectively. Mean processing time was <40 seconds. CONCLUSIONS: In this large data set of nearly 900 patients, the automated software demonstrated high sensitivity and specificity for ICH detection, with rare false-positives.