Currently, several types of CT classification systems exist to prognosticate and stratify TBI patients. Introduced in 1991, the Marshall CT classification 1) categorizes injuries as different levels of diffuse lesions, based on basal cistern compression and midline shift, or focal lesions, depending on whether lesion volume exceeds 25 cm3. Despite somewhat arbitrarily chosen cutoffs, this classification is still considered to be somewhat of a “gold standard” for TBI classification. While components of the Marshall CT classification have been shown to contribute to outcome prediction in TBI 2), the Marshall CT classification was not originally designed as a prognostic tool. Thus, in 2005, the Rotterdam CT score was introduced, reweighting components of the Marshall CT classification and adding traumatic subarachnoid hemorrhage (tSAH) and intraventricular hemorrhage 3) , creating an ordinal score. Components from the Rotterdam CT score are today an integral part of the International Mission for Prognosis and Analysis of Clinical Trials in TBI (IMPACT) outcome model for TBI patients 4).
More recently, new CT classifications have emerged, including the Stockholm CT score in 2010 5) and the Helsinki CT score in 2014 6). The Stockholm CT score uses midline shift as a continuous variable (as compared to the Marshall CT classification’s and Rotterdam CT score’s threshold of ≥5 mm) and has a separate scoring for tSAH 7). It is also the only scoring system that takes diffuse axonal injury (DAI) visible on CT into consideration 8). Moreover, the Stockholm CT score remains the only scoring system that is based on many features of CT scans examined prospectively using an extended protocol, to identify information content. The Helsinki CT score is based on components from both the Marshall CT classification and Rotterdam CT score, but additionally focuses more on the types of intracranial injuries present 9). Thus, the Stockholm and Helsinki CT scoring systems more comprehensively analyze different components of the admission CT scan, and have both been shown to be better outcome predictors than the Marshall CT classification and Rotterdam CT score 10) 11).
The Stockholm and Helsinki CT scores provide more information on the damage sustained, and give a more accurate outcome prediction, than earlier classification systems. The strong independent predictive value of tSAH may reflect an underrated component of TBI pathophysiology. A change to these newer CT scoring systems may be warranted 12).
Marshall head computed tomography (CT) classification for traumatic brain injury is widely used as a predictor of outcome. However, this grading system lacks the following variables, which are found to be useful predictors: subarachnoid/intraventricular hemorrhage, extradural hematoma, and extent of basal cistern compression. A new classification called the Rotterdam CT score, incorporating the above variables, was proposed later.
As the Rotterdam system also includes additional variables like subarachnoid hemorrhage, it may be preferable, particularly in patients with diffuse injury 14).
Use of the novel Helsinki CT score improved outcome prediction accuracy, and the Helsinki CT score is a feasible alternative to the Rotterdam and Marshall CT systems. External validation of the Helsinki CT score is advocated to show generalizability 15).