Vascular and Nonvascular Mimics of the CT Angiography “Spot Sign” in Patients With Secondary Intracerebral Hemorrhage
Bibliographic record
Abstract
BACKGROUND AND PURPOSE: The newly-described computed tomography angiography (CTA) Spot Sign is present in about one third of patients with acute primary intracerebral hemorrhage (PICH) and predicts hematoma expansion. This sign has not been systematically evaluated in patients with secondary causes of ICH, and mimics have not been characterized. The purpose of this study was to assess for the presence of the Spot Sign in secondary ICH and to document potential mimics of the Spot Sign and their distinguishing features. METHODS: We performed a retrospective chart review of consecutive patients presenting with ICH to our regional stroke center between January 2002 and May 2007. Ninety-six ICH patients underwent a CT stroke protocol including CTA. CTA documented a secondary cause for hemorrhage in 30 patients (31%). Each patient was assessed for the presence or absence of the CTA Spot Sign or a mimic by 2 blinded neuroradiologists. Clinical and radiological features of PICH and secondary ICH were compared. RESULTS: No patients with secondary ICH had a true CTA Spot Sign, but several Spot Sign mimics were identified including: micro AVM, posterior communicating artery aneurysm, Moya Moya, and neoplasm-associated calcification. The secondary ICH group was younger (P=0.0001) and less likely to be hypertensive at presentation (P=0.0114). Significant hematoma expansion (>33% increase from baseline volume) occurred in 20% of secondary ICH patients and 28% of PICH patients (P=0.2463). CONCLUSIONS: This study describes mimics of the CTA Spot Sign and classifies them as vascular (microAVM, aneurysm, Moya Moya) or nonvascular (tumor and choroid plexus calcification). Evaluation of the noncontrast CT together with the CTA source images is an essential part of the evaluation for the Spot Sign. Vessels entering the hematoma from the periphery are indicative of an underlying vascular lesion. Our findings suggest that the Spot Sign may be rare in secondary ICH and most specific for PICH.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".