Detection of Acute Infarct on DWI Images

Purpose	The purpose of this proposal is to automatically detect acute infarcts on diffusion-weighted images (DWI) on brain MRI. Another goal is to simplify the language while reporting the lesions with diffusion restriction.
Tag(s)
Panel	Neuroradiology Panel
Define-AI ID	19020008
Originator	Achint Singh
Lead	Achint Singh
Panel Chair	Alexander Norbash
Panel Reviewers	Neuroradiology Panel
License	Creative Commons 4.0
Status	Public Commenting
RadElement Set	RDES97

Clinical Implementation

Value Proposition

Diffusion refers to the random microscopic movement of the water molecules in the tissues. DWI provides a quantitative measure of this molecular motion in three dimensional space. DWI is the most sensitive MR imaging sequence for the detection of acute infarct. Diffusion restriction is defined as increased signal on the diffusion weighted images and low signal on the ADC images. Diffusion restriction is usually seen in hyperacute infarct within the first 3 hours however, can be seen as early as 11 minutes. Low signal is usually seen on the ADC map up to 7-10 days after which the signal starts to increase, which is known as pseudonormalization.

Diffusion restriction can also be seen in other conditions such as

Abscess
CJD
Herpes or other encephalitis
Lymphoma
GBM
Epidermoid cyst
DAI
Hemorrhage
Seizures
Drug toxicity

Narrative(s)

A 30-year-old male comes with non-specific symptoms of left arm weakness, possible seizures, and altered mental state. CT head is negative for hemorrhage. CTA did not show large vessel occlusion. tPA was not given due to non-specificity of symptoms and a fast MRI was obtained which shows an acute infarct. Automatic detection of this infarct could be helpful in this patient for timely tPA administration.

Workflow Description

The patient receives a CT scan for suspected signs of stroke. If there is no hemorrhage on the CT then the patient receives a stroke protocol MRI with DWI images along with an ADC map. The algorithm receives the MR dataset. The algorithm tries to determine if there is true diffusion restriction based on the signal on DWI and ADC images. If diffusion restriction is present, then an alert should notify the user.

The algorithm also tries to characterize the abnormality as described below in the output section. The algorithm is integrated with the dictation system to automatically populate the results. The representative image is also saved on the PACS system.

Considerations for Dataset Development

Procedures	MR brain (axial DWI and ADC)
Sex at Birth	Male and Female
Age	All Ages
DWI	Hyperintense signal in comparison to the adjacent gray matter (True and False)
ADC	low signal in comparison to the adjacent region (True or False)

Technical Specifications

Inputs

DICOM Study

Procedure	MR, Head
Views	Axial
Data Type	DICOM
Modality	MR
Body Region	Head
Anatomic Focus	Brain
Scenario	axial DWI and ADC

Primary Outputs

Diffusion Restriction

RadElement ID	RDE591
Definition	Determine if high signal on DWI is true diffusion restriction or T2 shine through by analyzing ADC signal
Data Type	Categorical
Value Set	No Yes Unknown
Units	N/A

Shape of Area with Diffusion Restriction

RadElement ID	RDE592
Definition	Categorize the shape of the area with diffusion restriction
Data Type	Categorical
Value Set	No Yes Unknown
Units	N/A

Distribution of Diffusion Restriction

RadElement ID	RDE593
Definition	Categorize the distribution of the diffusion restriction in the lesion
Data Type	Categorical
Value Set	Whole lesion Central Peripheral Rim
Units	N/A

Count of lesions with diffusion restriction

RadElement ID	RDE589
Definition	Count the number of lesion(s) with diffusion restriction
Data Type	Numeric
Value Set	N/A
Units	Number of lesions

Lesion location with diffusion restriction

RadElement ID	RDE597
Definition	Location of the lesion(s) with diffusion restriction
Data Type	Categorical
Value Set	0 - Frontal 1 - Parietal 2 - Occipital 3 - Temporal 4 - Deep gray Nuclei (Basal Ganglia/Thalami) 5 - White matter 5A: Periventricular WM 5B: Deep WM 5C: Subcortical WM 5D: Corticospinal tract 5E: Cerebellar Peduncles 6 - Brainstem 6A: Midbrain 6B: Pons 6C: Medulla 7 - Cerebellum
Units	N/A

Laterality of lesion

RadElement ID	RDE598
Definition	Define the side of the lesion
Data Type	Categorical
Value Set	Right Left Midline
Units	N/A

2D Lesion Size

RadElement ID	RDE587
Definition	Size of the lesion in two dimensions
Data Type	Numeric
Value Set	N/A
Units	mm2

Lesion Volume

RadElement ID	RDE588
Definition	Volume of the lesion
Data Type	Numeric
Value Set	N/A
Units	mm3

Signal Characteristics

RadElement ID	RDE594
Definition	Signal characteristics of the lesion
Data Type	Categorical
Value Set	Homogeneous Heterogeneous
Units	N/A

Future Development Ideas

Analyze the associated features and clinical features with diffusion restriction so that the model is able to give reasonable differential diagnoses
Associated susceptibility artifacts: Primary hemorrhage
Peripheral diffusion restriction : PML
Solid ring enhancement with diffusion restriction in the solid portion : GBM
Ring enhancement with diffusion restriction in the center: Abscess
Focal gyriform diffusion restriction: Status epilepticus
Peripheral cortical areas with rapidly progressive dementia: CJD

Related Datasets

No known related public datasets at this time, please alert us if you know of any.