Radiographic Evaluation of Congenital and Acquired Foot Deformities: Intermetatarsal Angle

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 intermetatarsal angle. Additional use cases include the AP and lateral talocalcaneal angles, talo-1st metatarsal angle, talonavicular axis, 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: intermetatarsal angle, comparisons from any available prior studies, and normal vs. abnormal angle

Input

DICOM Study

Primary Outputs

Intermetatarsal Angle   

Secondary Outputs 

Normal vs. Abnormal   

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