Radiograhic Evaluation of Congenital and Acquired Foot Deformities Talo-Calcaneal Angles
| Purpose | Characterization of congenital and acquired foot deformities on radiographs |
| Tag(s) | bilateral foot, foot, x-rays, radiographs,congenital foot, pes,feet, talo-calcaneal angle, weight-bearing |
| Panel | Pediatric |
| Define-AI ID | 21010011 |
| 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 | RDES200 |
| Purpose | Characterization of congenital and acquired foot deformities on radiographs |
| Tag(s) | bilateral foot, foot, x-rays, radiographs, congenital foot, pes, feet, calcaneal pitch, weight-bearing, erect |
| Panel | Pediatric |
| Define-AI ID | 20010013 |
| 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 | RDE203 |
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), the focus will first be placed 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-calcaneal angle and the lateral talo-calcaneal angle. Additional use cases include the talonavicular axis, 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 foot simulated weight-bearing 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: AP talo-calcaneal angle, lateral talo-calcaneal angle, normal vs. increased/decreased angle
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 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 calcaneal pitch. Additional use cases include the AP and lateral talocalcaneal angles, talo-1st metatarsal angle, talonavicular axis, 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: calcaneal pitch, and normal vs. abnormal pitch
Considerations for Dataset Development
| Procedures | X-ray, Foot Radiograph, Foot |
| Gender | Male, Female |
| Age (years) | 0-18 |
| Views | AP, Lateral |
| Technique | Erect, Weight-bearing or Simulated weight-bearing |
| Anatomy | Foot |
| Confounders | Cast, Splint, Brace, Non-weight-bearing, Supine |
Considerations for Dataset Development
| Procedures | X-ray, Foot Radiograph, Foot |
| Gender | Male, Female |
| Age (years) | 0-18 |
| Views | Lateral |
| Technique | Weight-bearing,Simulated weight-bearing or Erect |
| Anatomy | Foot |
| Confounders | Cast, Splint, Brace, Non-weight-bearing, Supine |
Technical Specifications
Inputs
DICOM Study
| Procedure | X-ray, Foot Radiograph |
| Views | AP, Lateral |
| Data Type | DICOM |
| Modality | X-ray |
| Body Region | Lower Extremity |
| Anatomic Focus | Foot |
Primary Outputs
AP Talo-calcaneal Angle
| RadElement ID | |
| Definition | The angle between the lines drawn down the axis of the talus and the calcaneus on weight-bearing AP foot radiograph. |
| Data Type | Numeric |
| Value Set | 0-180 |
| Units | Degrees |
Lateral Talo-calcaneal Angle
| RadElement ID | |
| Definition | The angle formed by the intersection of the line bisecting the talus through the body and through the neck and the line along the axis of the plantar border of the calcaneus (or bisecting the calcaneus) on lateral weight-bearing views. |
| Data Type | Numeric |
| Value Set | 0-180 |
| Units | Degrees |
Secondary Outputs
Normal vs. Decreased vs. Increased AP Talo-calcaneal Angle
| RadElement ID | |
| Definition | Normal range for the AP talo-calcaneal angle is 30 to 45 degrees. |
| Data Type | Categorical |
| Value Set |
|
| Units | N/A |
Normal vs. Decreased vs. Increased Lateral Talo-calcaneal Angle
| RadElement ID | |
| Definition | Normal range for the lateral talo-calcaneal angle is 30 to 50 degrees. |
| Data Type | Categorical |
| Value Set |
|
| Units | N/A |
Technical Specifications
Inputs
DICOM Study
| Procedure | X-ray, Foot Radiograph |
| Views | Lateral |
| Data Type | DICOM |
| Modality | X-ray |
| Body Region | Lower Extremity |
| Anatomic Focus | Foot |
Primary Outputs
Calcaneal Pitch
| RadElement ID | |
| Definition | The angle between the calcaneal inclination axis and the supporting horizontal surface on a weight-bearing AP foot radiograph. |
| Data Type | Numerical |
| Value Set | 0-90 |
| Units | Degrees |
Secondary Outputs
Normal vs. Abnormal
| RadElement ID | |
| Definition | Normal for calcaneal pitch is between 20-30 degrees. |
| Data Type | Categorical |
| Value Set |
|
| Units | N/A |
Pes Planus vs. Pes Cavus
| RadElement ID | |
| Definition | Calcaneal pitch measurement can determine a pes planus or pes cavus |
| Data Type | Categorical |
| Value Set |
|
| 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
-
Detection of post-surgical change e.g. mid foot osteotomies and hardware for correction of malalignment.
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