Radiographic Evaluation of Congenital and Acquired Foot Deformities Talo-Navicular Axis

Purpose

 Characterization of congenital and acquired foot deformities on radiographs

Tag(s)

 bilateral foot, foot, x-rays, radiographs, congenital foot, pes, feet, talus, navicular, talonavicular, weight-bearing

Panel

 Pediatric

Define-AI ID

 21010016

Originator

 Pediatrics Panel
Lead Viet Le & Alex Towbin

Panel Chair

 Steven Blumer

Panel Reviewers

 Pediatric Panel

License

 Creative Commons 4.0
Status Public Comment
RadElement Set RDES205 
                           

Clinical Implementation

Value Proposition


Multiple angles and measurements can be used to evaluate abnormal development of the foot, but the task of obtaining these can be cumbersome and time-intensive. An automated method for obtaining a series of angle measurements and bony relationships, which can eventually be used to characterize foot deformities, should improve the radiologists’ workflow.

For our use case(s), we will first focus on automating the measurement of a series of different angles and bony associations on foot radiographs, which can then be compiled to determine the presence vs. absence of a foot deformity. If present, our hope is for the algorithm to further diagnose/characterize the specific foot deformity. Ultimately, this may be expanded to include additional modalities, such as CT.

For this particular use case, we will limit our evaluation to evaluating the relationship of the talus and the navicular bones as part of the evaluation for clubfoot (talipes equinovarus). Additional use cases include the AP and lateral talocalcaneal angles, Intermetatarsal angle, Talo-1st metatarsal angle, calcaneal pitch, 1st metatarsophalangeal angle, Meary’s angle, and the tibial-calcaneal angle.

Narrative(s)


3 year-old female presents to the pediatrician with abnormal gait and in-toeing. Bilateral, weight-bearing 3-view foot radiographs are obtained for evaluation of foot deformities.

6 month-old male presents for contractures/abnormal positioning of the feet. Bilateral, 3-view simulated weight-bearing foot radiographs are obtained for evaluation of foot deformities.


Workflow Description


Radiographs of the foot/feet are ordered, obtained, sent to PACS and the algorithm is triggered.


The algorithm delivers the following outputs: talonavicular association or dissociation.

Considerations for Dataset Development

Procedures

X-ray, Foot

Radiograph, Foot

Gender

Male, Female

Age (years)

0-18

Views

AP

Technique

Weight-bearing or Simulated weight-bearing, Erect

Anatomy

Foot

Confounders

Cast, Splint, Brace, Non-weight-bearing, Sponge used for Simulated weight-bearing, Supine

Identify

Sponge, Wood Board, Ground, Text Detection

Technical Specifications

Input

 

DICOM Study

Procedure

X-ray, Foot Radiograph

Views

AP

Data Type

DICOM

Modality

X-ray

Body Region

Lower Extremity

Anatomic Focus

Foot




Primary Outputs
Talonavicular Alignment       

RadElement ID

RDE1342 

Definition

The bony relationship between the talus and navicular bones on weight-bearing AP foot radiograph.

Data Type

Categorical

Value Set

  • 0 = normal association (midline/180 degrees when a line is drawn along the long axis of the talus and along the short axis of the navicular)

  • navicular bone is medially deviated towards midline while the talus is deviated away from midline (varus dissociation)

    • For the LEFT foot >180 degrees when a line is drawn along the long axis of the talus and along the short axis of the navicular bone

    • For the RIGHT foot, the inverse is true (eg, <180 degrees = varus)

  • navicular bone is laterally deviated away from midline while the talus is deviated towards midline (valgus dissociation)

    • For the LEFT foot <180 degrees when a line is drawn along the long axis of the talus and along the short axis of the navicular bone)

    • For the RIGHT foot, the inverse is true (eg, >180 degrees = valgus)

Units

N/A

Future Development Ideas

As mentioned in the Value Proposition, future development ideas include

  • Additional angle measurements

  • Additional bony relationships in the foot

  • Diagnosis of foot deformities if present (“diagnostic use cases”)

  • Change from prior studies if comparisons are available

  • Extrapolation to another imaging modality, such as CT