Radiographic Evaluation of Congenital and Acquired Foot Deformities: Talo-1st MT Axis

Purpose

Characterization of congenital and acquired foot deformities on radiographs

Tag(s)

 bilateral foot, foot, x-rays, radiographs, congenital foot, pes, feet, forefoot, talo-1st MT angle, weight-bearing

Panel

Pediatric

Define-AI ID

20010011

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 RDES201 
                               

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 this 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 measuring the AP talo-1st metatarsal (MT) angle to evaluate the forefoot alignment on weight-bearing or simulated weight-bearing radiographs. Additional use cases include the AP and lateral talocalcaneal angles, Intermetatarsal angle, talonavicular axis, calcaneal pitch, 1st metatarsophalangeal angle,, and the tibial-calcaneal angle.

Narrative(s)


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

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

Workflow Description


Weight-bearing or simulated weight-bearing radiographs of the foot/feet are ordered, obtained, sent to PACS and the algorithm is triggered.


The algorithm delivers the following outputs: talo-1st MT angle, normal vs. increased/decreased angle

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, Supine

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

 

Talo-1st MT axis       

RadElement ID

RDE1333 

Definition

The axis of the base of the first metatarsal (distal bone) relative to the talus (proximal bone) on weight-bearing AP foot radiograph.

Data Type

Categorical

Value Set

  • midline (normal)

  • medial (forefoot varus)

  • lateral (forefoot valgus)

Units

N/A


Secondary Outputs 

 

Normal vs. Forefoot Varus vs. Forefoot Valgus   

RadElement ID

RDE1334 

Definition

Normal talo-1st MT axis is “midline”. Forefoot varus is “medial.” Forefoot valgus is “lateral.”

Data Type

Categorical

Value Set

  • midline (normal)

  • medial (forefoot varus)

  • lateral (forefoot valgus)

Units

N/A



Future Development Ideas


As mentioned in the Value Proposition, future development ideas include

  • Additional angle measurements

  • Bony relationships in the foot

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

  • Improvement from prior studies if comparisons are available

  • Extrapolation to another imaging modality, such as CT