ASPECT Score Calculation for Acute Infraction

Purpose

Detect and define ASPECT Score in setting of acute infarction

Tag(s)

 

Panel

Neuroradiology Panel

Define-AI ID

19020009

Originator

John Tsiouris
Lead John Tsiouris

Panel Chair

Alex Norbash

Panel Reviewers

Neuroradiology Panel

License

Creative Commons 4.0 
Status Public Commenting
RadElement Set RDES108
                               

Clinical Implementation


Value Proposition

In the setting of an acute stroke (under 4.5 hours from symptom presentation), a rapid non-contrast trans-axial CT scan is performed as the standard of scare to assess for acute intracranial hemorrhage and to define the extent of cerebral infarction. These important imaging data points will assist in determining if the patient is a candidate for the intravenous administration of tissue plasminogen activator (tPA) and/or interventional mechanical thrombectomy therapy, both of which have been shown to improve long term neurological outcomes in the setting of a developing ischemic infarction related to large vessel thromboembolic disease. The ASPECT (Alberta Stroke Program Early CT) score is a 10-point quantitative score utilized to assess the extent of early infarction on a non-contrast CT. It was designed to provide a simple, reliable, and reproducible grading system for patients have an anterior circulation middle cerebral artery large vessel occlusion (http://www.aspectsinstroke.com). The scale is used in clinical trials worldwide to quantify and classify the extent of early ischemic changes on a quantitative scale. Rapid automated ASPECT score measurements would provide value to specialists and non-specialists who interpret emergent non-contrast CT scans for patients that present with an acute stroke.

Narrative(s)

A 63-year-old male hypertensive patient presents to a community hospital with 2-hour duration of aphasia and right facial weakness that occurred acutely while driving to work. He is immediately triaged to the acute stroke team in the emergency department, who order an emergent non-contrast CT scan.

Workflow Description

Patient receives an emergent non-contrast CT scan of the head performed on a patient presenting with an acute stroke. An acute ischemic infarction is suspected. Algorithm receives the entire CT dataset. If the algorithm can determine a result, return: the degree of the loss of the normal grey-white differentiation in the left and right middle cerebral artery territories utilizing the standardize ASPECT score.

 

Calculating ASPECT Score

Each area of loss of the normal grey-white differentiation constitutes 1 deducted point from a maximum of 10 points:

Subganglionic Nuclei:

     M1 - Frontal operculum -1

     M2 - Anterior temporal lobe -1

     M3 - Posterior temporal lobe -1

Supraganglionic Nuclei: 

     M4 - Anterior MCA -1

     M5 - Lateral MCA -1

     M6 - Posterior MCA -1

Basal Ganglia: 

     Caudate (C) -1

     Lentiform Nucleus (L) -1

     Insula (I) -1

     Internal Capsule (IC) Post Limb -1

Total ASPECTS Score out of 10

A reliability metric, assessing the accuracy of the measurement, would also be helpful. Additional considerations are as follows: Algorithm executes after exam is verified on PACS in the backend. Algorithm optimally integrates on PACS and dictation or reporting software. The user is able to automatically populate the report or manually input the results. Indicator image may save to PACS as part of the medical record.

Considerations for Dataset Development



Procedures(s):

CT, Head, wo IV contrast

Sex at Birth:

{Male, Female}

Age:

>= 2 years

Loss of grey-white:

Numeric Aspect [0,10]

Comorbidties:

acute intracranial hemorrhage

Laterality:

left, right

Technical Specifications


Inputs

DICOM Study

Procedure

CT, Head, wo IV contrast

Views

All

Data Type

DICOM

Modality

CT

Body Region

Head

Anatomic Focus

Brain

Pharmaceutical

N/A

Scenario

N/A


Primary Outputs

 

ASPECT Score (Left hemisphere)


RadElement ID

RDE692

Definition

Loss of grey-white differentiation in left hemisphere

Data Type

Numeric

Value Set

[0,10]

Units

N/A

 

ASPECT Score (Right hemisphere)

 

 

RadElement ID

RDE693

Definition

Loss of grey-white differentiation in right hemisphere

Data Type

Numeric

Value Set

[0,10]

Units

N/A