validation of an algorithm for non-metallic intraocular foreign bodies’ composition identification...

Validation of an Algorithm for Non-metallic Intraocular

Foreign Bodies’ Composition Identification Based on

Computed Tomography and Magnetic Resonance Imaging

Study Questionnaire

Instructions:• Use the flowchart (Figure 1) to identify the IOFB

material.• All eyes have an IOFB in them.• The best representative scan has been chosen.• All MRI scans are identical in localization.• Analyze by CT, then T1/T2, then GE.• Enlarged on GE = compared to T1/T2.• Any IOFB may be included more than once.• Correct IOFB identifications are on the last slide.

ExampleT1 T2

CTGE

Solution:

• CT = detectable IOFB• T1/T2 = signal void with surrounding

hyperintensityTherefore: Stone material• GE = void with surrounding white ring; artifact

enlarged compared to T1/T2• Bright signal on CTTherefore: Porcelain

#1T1 T2

CT GE

#2T1 T2

CTGE

#3T1 T2

CTGE

#4T1

CTGE

T2

#5T2T1

CT GE

#6T1 T2

CT GE

#7T1 T2

CT GE

#8T1 T2

CT GE

#9T1 T2

CTGE

#10T2

CT

T1

GE

THANK YOU!

Correct IOFB identifications:#1 – Gravel#2 – Plastic#3 – Windshield glass#4 – Porcelain#5 - Wood#6 – Pencil graphite#7 – CR39#8 – Thorn#9 – Concrete#10 – Bottle glass