|
Purpose |
Characterization of congenital and acquired foot deformities on radiographs |
|
Tag(s) |
Bilateral foot, foot, x-rays, radiographs, congenital foot, pes, feed, Meary's angle, weight-bearing, talus-first metatarsal angle, MT |
|
Panel |
Pediatrics |
|
Define-AI ID |
22010017 |
|
Originator |
Pediatrics Panel |
| Lead |
Viet Le, Alex Towbin |
|
Panel Chair |
Steve Blumer |
|
Panel Reviewers |
Pediatrics Panel |
|
License |
|
| Status | Public Comment |
| RadElement Set | RDES244 |
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 measuring the talus-first metatarsal (Meary’s) angle on lateral weight bearing foot radiographs, which is one method that can be used to evaluate for pes planus or pes cavus deformity. Additional use cases include the AP talo-calcaneal and lateral talo-calcaneal angles, intermetatarsal angle, talo-1st metatarsal angle, 1st metatarsophalangeal angle, tibial-calcaneal angle, talonavicular axis and calcaneal pitch.
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.
6month-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.
Radiographs of the foot/feet are ordered, obtained, sent to PACS and the algorithm is triggered.
The algorithm delivers the following outputs: talus-first metatarsal (Meary’s) angle, normal vs. abnormal angle, and severity of the deformity.
|
Procedures |
{X-ray, Foot Radiograph, Foot} |
|
View(s) |
{Lateral} |
|
Age |
[0,18] |
|
Sex at Birth |
{Male, Female} |
|
Technique |
{Weight-bearing, Simulated weight-bearing, Erect} |
| Anatomy | {Foot} |
|
Confounding Variables |
{Cast, Splint, Brace, Non-weight bearing, Supine, AP, AP Supine} |
DICOM Study
|
Procedure |
X-ray, Foot Radiograph |
|
Views |
Lateral |
|
Data Type |
DICOM |
|
Modality |
X-ray |
|
Body Region |
Lower Extremity |
|
Anatomic Focus |
Foot |
Meary’s Angle
|
RadElement ID |
RDE1583 |
|
Definition |
The angle between a line drawn from the centers of the longitudinal axes of the talus and the first metatarsal on weight-bearing lateral foot radiograph. |
|
Data Type |
Numeric |
|
Value Set |
0-90 |
|
Units |
Degrees |
Normal vs. Abnormal Meary’s Angle
|
RadElement ID |
RDE1584 |
|
Definition |
Normal for Meary’s angle is 0 to 4 degrees. |
|
Data Type |
Categorical |
|
Value Set |
|
|
Units |
N/A |
Convexity of Meary’s Angle
|
RadElement ID |
RDE1585 |
|
Definition |
Meary’s angle (in degrees) can be used to determine pes planus or pes cavus, based on the convexity (down or up, respectively). |
|
Data Type |
Categorical |
|
Value Set |
|
|
Units |
N/A |
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