CT angiographic spot sign (intracerebral hemorrhage)
Citation, DOI & article data
The spot sign is a CTA sign in acute intracerebral hemorrhage and representing the focal accumulation/pooling/extravasation of contrast containing blood within the hematomas. It is an important feature to identify during the evaluation of acute intracerebral hemorrhage as it significantly increases the likelihood of hematoma growth.
The spot sign generally defined as a unifocal region of contrast enhancement resulting in focal increased density compared to the surrounding hematoma on CT angiography. The shape is not important and it can be spherical, linear or branching.
The spot sign should not be confused with the dot sign consisting of a hyperdense thrombus within an artery seen in cross-section (e.g. MCA branches within the Sylvian fissure on axial imaging).
Of those patients scanned within 6 hours of symptom onset, about 30% will demonstrate the spot sign 2. This will depend, however, on the technique used; higher in dynamic CTA and lower in delayed CTA.
The exact etiology of the spot sign remains unclear and multiple processes may be involved. Generally, it is believed that it represents active extraluminal accumulation/extravasation of contrast, although this does not imply active bleeding as only a subset of patients with a spot sign will demonstrate hemorrhage growth 4,6.
It is worth noting that the term has been used perhaps imprecisely by some authors who have included false aneurysms arising from a damaged vessel and visible on angiography 5 or group small "contained" foci of enhancement with larger regions of extravasation 4.
The spot sign is seen on CTA source images or delayed images as a small focal region of contrast enhancement within the hematoma. Research studies have applied additional definitional criteria:
- discontinuous with any visible vessels (normal or abnormal) around the hematoma 2,12
- attenuation greater than twice that of the surrounding hematoma 2 or at least 120 HU 12
- measures 1-2 mm 1 or at least 1.5 mm diameter 2
- not corresponding to a hyperdensity on the noncontrast CT 2
A region of lower attenuation may be seen at its location representing non-clotted blood. The presence of these hypodensities on non-contrast studies is not well correlated with the spot sign and their presence is an independent predictor of hematoma growth 11. They are similar and probably equivalent to a focal swirl sign.
Treatment and prognosis
The spot sign is an independent predictor of intracerebral hemorrhage growth and poor outcome 2. Multiple spot signs correlate with increased risk of hematoma growth 9. The converse is also true, and the absence of a spot sign suggests that the hematoma is unlikely to significantly increase in size 10.
Trials of hemostatic therapy — e.g. recombinant activated factor VII (SPOTLIGHT and STOP-IT) and tranexamic acid (STOP-AUST) — in intracerebral hemorrhage patients have utilized the 'spot sign' to identify patients who are most likely to benefit from therapy. They have, however, so far failed to demonstrate a clear benefit from either therapy although this may be due to timing of therapy 7,8.
History and etymology
The sign was first formally described by Wada et al. in 2007 1, but the phenomenon was recognized much earlier on conventional angiographic studies performed on intracerebral hemorrhage patients in the pre-CT era 3.
- 1. Wada R, Aviv R, Fox A et al. CT Angiography “Spot Sign” Predicts Hematoma Expansion in Acute Intracerebral Hemorrhage. Stroke. 2007;38(4):1257-62. doi:10.1161/01.str.0000259633.59404.f3 - Pubmed
- 2. Demchuk AM, Dowlatshahi D, Rodriguez-Luna D et-al. Prediction of haematoma growth and outcome in patients with intracerebral haemorrhage using the CT-angiography spot sign (PREDICT): a prospective observational study. Lancet Neurol. 2012;11 (4): 307-14. doi:10.1016/S1474-4422(12)70038-8 - Pubmed citation
- 3. Mizukami M, Araki G, Mihara H et-al. Arteriographically visualized extravasation in hypertensive intracerebral hemorrhage. Report of seven cases. Stroke. 1973;3 (5): 527-37. Pubmed citation
- 4. Brouwers HB, Raffeld MR, van Nieuwenhuizen KM, Falcone GJ, Ayres AM, McNamara KA, Schwab K, Romero JM, Velthuis BK, Viswanathan A, Greenberg SM, Ogilvy CS, van der Zwan A, Rinkel GJ, Goldstein JN, Klijn CJ, Rosand J. CT angiography spot sign in intracerebral hemorrhage predicts active bleeding during surgery. (2014) Neurology. 83 (10): 883-9. doi:10.1212/WNL.0000000000000747 - Pubmed
- 5. Cho JS, Kim SU, Lee HJ, Yang JH, Lee IW, Sung JH. The Role of digital subtraction angiography in the ventricular spot sign on the computed tomography angiography. (2019) Journal of cerebrovascular and endovascular neurosurgery. 21 (1): 24-32. doi:10.7461/jcen.2019.21.1.24 - Pubmed
- 6. Meretoja A, Churilov L, Campbell BC, Aviv RI, Yassi N, Barras C, Mitchell P, Yan B, Nandurkar H, Bladin C, Wijeratne T, Spratt NJ, Jannes J, Sturm J, Rupasinghe J, Zavala J, Lee A, Kleinig T, Markus R, Delcourt C, Mahant N, Parsons MW, Levi C, Anderson CS, Donnan GA, Davis SM. The spot sign and tranexamic acid on preventing ICH growth--AUStralasia Trial (STOP-AUST): protocol of a phase II randomized, placebo-controlled, double-blind, multicenter trial. (2014) International journal of stroke : official journal of the International Stroke Society. 9 (4): 519-24. doi:10.1111/ijs.12132 - Pubmed
- 7. David J. Gladstone, Richard I. Aviv, Andrew M. Demchuk, Michael D. Hill, Kevin E. Thorpe, Jane C. Khoury, Heidi J. Sucharew, Fahad Al-Ajlan, Ken Butcher, Dar Dowlatshahi, Gord Gubitz, Stephanie De Masi, Judith Hall, David Gregg, Muhammad Mamdani, Michel Shamy, Richard H. Swartz, C. Martin del Campo, Brett Cucchiara, Peter Panagos, Joshua N. Goldstein, Janice Carrozzella, Edward C. Jauch, Joseph P. Broderick, Matthew L. Flaherty, for the SPOTLIGHT and STOP-IT Investigators and Coordinators. Effect of Recombinant Activated Coagulation Factor VII on Hemorrhage Expansion Among Patients With Spot Sign–Positive Acute Intracerebral Hemorrhage: The SPOTLIGHT and STOP-IT Randomized Clinical Trials. (2019) JAMA Neurology. 76 (12): 1493. doi:10.1001/jamaneurol.2019.2636 - Pubmed
- 8. Meretoja A, Yassi N, Churilov L, et al The Spot Sign and Tranexamic Acid on Preventing ICH Growth - Australasia Trial (STOP-AUST): A Multicenter, Randomized, Double-blind, Placebo-controlled Trial ICS 2020 abstract
- 9. Thien J. Huynh, Andrew M. Demchuk, Dar Dowlatshahi, David J. Gladstone, Özlem Krischek, Alex Kiss, Michael D. Hill, Carlos A. Molina, David Rodriguez-Luna, Imanuel Dzialowski, Yolanda Silva, Anna Czlonkowska, Cheemun Lum, Jean-Martin Boulanger, Gord Gubitz, Rohit Bhatia, Vasantha Padma, Jayanta Roy, Carlos S. Kase, Richard I. Aviv. Spot Sign Number Is the Most Important Spot Sign Characteristic for Predicting Hematoma Expansion Using First-Pass Computed Tomography Angiography. (2013) Stroke. doi:10.1161/strokeaha.111.000410
- 10. Javier M Romero, Rania Hito, Andre Dejam, Laia Sero Ballesteros, Camilo Jaimes Cobos, J Ortiz Liévano, Viesha A Ciura, Isabelle Barnaure, Marielle Ernst, Afonso P Liberato, Gilberto R Gonzalez. Negative spot sign in primary intracerebral hemorrhage: potential impact in reducing imaging. (2017) Emergency Radiology. 24 (1): 1. doi:10.1007/s10140-016-1428-8 - Pubmed
- 11. Andrea Morotti, Gregoire Boulouis, Andreas Charidimou, Kristin Schwab, Christina Kourkoulis, Christopher D. Anderson, M. Edip Gurol, Anand Viswanathan, Javier M. Romero, Steven M. Greenberg, Jonathan Rosand, Joshua N. Goldstein. Integration of Computed Tomographic Angiography Spot Sign and Noncontrast Computed Tomographic Hypodensities to Predict Hematoma Expansion. (2018) Stroke. 49 (9): 2067-2073. doi:10.1161/STROKEAHA.118.022010 - Pubmed
- 12. Delgado Almandoz J, Yoo A, Stone M et al. Systematic Characterization of the Computed Tomography Angiography Spot Sign in Primary Intracerebral Hemorrhage Identifies Patients at Highest Risk for Hematoma Expansion. Stroke. 2009;40(9):2994-3000. doi:10.1161/strokeaha.109.554667 - Pubmed