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

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

Input

DICOM Study

Primary Outputs

Talo-1st MT axis       

Secondary Outputs 

Normal vs. Forefoot Varus vs. Forefoot Valgus   

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