Automated Leg Length Discrepancy Assessment CT Scanogram

Purpose

Quantify the lower extremity limb lengths on CT scanograms

Tag(s)

 

Panel

Musculoskeletal Panel

Define-AI ID

19050020

Originator

David Sandman
Lead David Sandman

Panel Chair

Jay Patti

Panel Reviewers

Musculoskeletal Panel

License

Creative Commons 4.0 
Status Public Commenting
RadElement Set RDES134
                               

Clinical Implementation


Value Proposition


Leg or lower extremity limb length discrepancy is a correctable problem affecting the pediatric and adult populations. Several methods of measuring the lower extremities have been described, each of which is prone to both intra-reader and inter-reader variability and can be a tedious task to complete. Automated measurements of the lower extremities can provide an accurate and reproducible measuring technique and result.

Narrative(s)


65 year old male with severe medial compartment osteoarthritis of the left knee. Total knee arthroplasty is planned, goals of which include attaining limb length equality and physiologic alignment. A CT scanogram is ordered as part of the preoperative work-up. An algorithm measures the lower extremity lengths, auto-populating the data when a radiologist or other clinician reviews the study.

Workflow Description


Images obtained from the CT scanner are sent to PACS and the AI engine. The images are analyzed by AI. Coordinates of areas of interest are assessed using a measuring tool. Annotated measurements are saved as an image along with a summary of the measurement data set (similar to CT radiation dosing data).


Considerations for Dataset Development



Procedures(s)

{CT scanogram}

View(s)

{supine-CT scanogram}

Sex at Birth

{Male,Female}

Age

[0,90]

Technical Specifications


Inputs


DICOM Study

Procedure

CT scanogram

Views

AP Views

Data Type

DICOM

Modality

CT

Body Region

Lower Extremity

Anatomic Focus

Hip, thigh, knee, leg, ankle


Primary Outputs


Bilateral Lower Extremity Length

RadElement ID

RDE881

Definition

Distance from top of femoral head to mid tibial plafond

Data Type

Numeric

Value Set

N/A

Units

cm


Bilateral Femur Length

RadElement ID

RDE882

Definition

Distance from top of femoral head to medial condyle articular surface

Data Type

Numeric

Value Set

N/A

Units

cm



Bilateral Tibia Length

RadElement ID

RDE883

Definition

Distance from top of tibial intercondylar eminence to the mid-tibial plafond

Data Type

Numeric

Value Set

N/A

Units

cm


Bilateral Bone Length

RadElement ID

RDE884

Definition

Femur length + tibia length

Data Type

Numeric

Value Set

N/A

Units

cm