Pulmonary to Systemic Flow Ratio

Purpose

Automate measurement of pulmonary to systemic flow ratio (Qp:Qs)

Tag(s)

 #Qp:Qs

Panel

 Cardiac

TOUCH-AI ID

 TAI-04180022

Originator

 Benoit Desjardins

Panel Chair

 Carlo De Cecco

Panel Reviewers

 Cardiac Panel

License

 Creative Commons 4.0

Status  Public Commenting

Clinical Implementation


Value Proposition

Measurement of Qp:Qs is a well-established clinical parameter to determine degree of shunting that has fundamental diagnostic, therapeutic, and prognostic implications. Cardiac Magnetic Resonance (CMR) allow accurate assessment of flow parameters. Automated Qp:Qs quantification would save the interpreting physician time via elimination of manual measurements, prevent detection errors, and provide structured quantitative data, which could be used in later studies or risk stratification schemes.

Narrative(s)

All patients undergoing CMR examinations which include flow measurements should have automated quantification of Qp:Qs if data are available, which may then be automatically populated into the radiology report or a report supplement.

Workflow Description

Patient receives MRI of the chest/heart. Algorithm retrieves aortic and pulmonary flow imaging dataset if present and may ingest additional EMR data such as age, sex, and body surface area. Algorithm executes and calculates values of Qp:Qs. Algorithm also determines direction of shunting if shunt is present. Algorithm returns all measurements, which could populate the report (possibly within a supplement containing other quantitative data). Algorithm flags abnormal values.

Considerations for Dataset Development


Procedures(s): MRI, Cardiac

View(s): CMR velocity-encoded phase contrast images, ascending thoracic aorta and pulmonary artery

 

Sex at Birth: {Male, Female}

 

Interventions: Congenital heart disease repair

 

Comorbidities: {Congenital heart disease, ventricular septal defects}

 

Pulmonary artery diameter (mm): [10,50]

 

Body Mass Index: [10,52]

 

Body Surface Area (m2): [1.0,3.5]

 

Other: Aliasing

Clinical Note: Alert radiologist to possible aliasing

Technical Specifications


Inputs

DICOM Study

Procedure

MRI, Cardiac

Views

CMR velocity-encoded phase contrast images, ascending thoracic aorta and pulmonary artery

Data Type

DICOM

Modality

MR

Body Region

Chest

Anatomic Focus

Heart

 

Primary Outputs

Pulmonary to Systemic Flow Ratio

RadElement ID

RDE320

Definition

Measurement of Qp:Qs using aortic and pulmonary flow measurements

Data Type

Numeric

Value Set

[0,5]

Units

N/A

Secondary Outputs

Presence of Aliasing

RadElement ID

RDE319

Definition

Presence of aliasing

Data Type

Categorical

Value Set

0-Unknown

1-Aliasing present

2-Aliasing absent

Units

N/A

Public Commenting


Use cases are meant to be a primary vehicle for distributing clinical information to the developer community. They pinpoint precise scenarios within radiology workflows where potential automation could add noticeable value and establish standards for interpreting and passing corresponding common data elements. Implementing effective standards requires the perspective from all stakeholders. So to that end, we encourage your feedback on use cases.

To submit comments, please email DSIUseCases@acr.org with the use case title(s) and relevant comments by January 1, 2019. If more convenient, you may also download this use case and comment directly on the PDF. Just attach the PDF copy on the email.