2. Zygomatic arches_212d47bf6f5edbfa2781a3a6f48c795f

Page 1

• R DPPA201

Page 2: Facial Bones - Frontal View

• Left Nasal Bone

• Left Lacrimal Bone

• Left Zygoma

• Left Inferior Nasal Concha

• Left Maxilla

• Mandible

Page 3: Facial Bones - Lateral View

• Lacrimal Bone

• Nasal Bone

• Zygoma

• Maxilla

• Mandible

Page 4: Facial Bones - Lateral View - Bontrager

• R

• A

• C

• B QPONML

• D

• E

• F

• G

• TH

Page 5: Facial Bones - Inferior View Label

• A

• D

• B

• C D

Page 6: Radiographic Anatomy - Label

• A

• D

• B

• C D

• R

Page 7: SMV - Label

• N

• M

• K-

• H

• R

• E

• F

Page 8: Radiographic Anatomy Continued

• Zygomatic Bone

• Zygomatic Arch

• Temporal Bone

• Mandibular Symphysis Over Frontal Bone

Page 9: Clinical Indications

• Neoplastic or inflammatory processes

• Fractures of zygomatic arch

• CT: 3° RCLOUD

• Radiologic Methods: CT Spine Cervical with Facial Bones - Helical 1.25

• Window Level: 325/

• Segmentation

Page 10: Technical Factors and Patient Preparation

• Technical Factors:

  • Minimum SID: 40 inches (100 cm)

  • IR size: 18 × 24 cm (8 × 10 inches), orientation may vary

• Exposure Factors:

  • Analog: 60 to 70 kV range

  • Digital: 70 to 80 kV range

• Other Considerations:

  • Shield radiosensitive tissues outside the region of interest

  • Remove metallic/plastic objects from head and neck

  • Patient position: erect or supine (erect may be more comfortable)

Page 11: Basic Projections

• Basic Projections:

  • SMV

  • AP axial (modified Towne method)

  • Note: AP axial can be a basic or special projection based on protocol

• Special Projection:

  • Oblique inferosuperior (tangential)

Page 12: SMV Technical Details

• Settings guidelines:

  • 1103

  • 18x24

  • No AEC

Page 13: SMV Part Positioning

• Positioning Instructions:

  • Raise chin, hyperextend neck until IOML is parallel to IR

  • Rest head on vertex of skull

• CR Alignment:

  • Align CR perpendicular to IR

  • Center midway between zygomatic arches, level 4 cm inferior to mandibular symphysis

  • Ensure IR is parallel to IOML

• Collimation:

  • Collimate to outer margins of zygomatic arches

• Note: Modify technique for patients who cannot extend neck adequately

Page 14: Evaluation Criteria - SMV

• Anatomy Demonstrated:

  • Zygomatic arches visible laterally from each mandibular ramus

• Positioning:

  • Correct IOML/CR relationship evidenced by overlapping of mandibular symphysis on frontal bone

  • No rotation indicated by symmetric zygomatic arches

  • Proper collimation to area of interest

• Exposure:

  • Comprehensible contrast and density to visualize zygomatic arches

  • Sharp bony margins indicate absence of motion

• Labelling:

  • Anatomical marker and patient’s name visible

Page 15: Oblique Inferosuperior (Tangential)

• Specifications:

  • 24

  • 18

  • No AEC

Page 16: Oblique Inferosuperior (Tangential) Part Position

• Positioning Instructions:

  • Raise chin, hyperextending neck until IOML is parallel to IR

  • Rest head on vertex of skull

  • Rotate head and chin 15° towards the examined side

• CR Alignment:

  • Align CR perpendicular to IR and IOML

  • Center to zygomatic arch of interest

• Collimation Recommendations:

  • Collimate closely to zygomatic bone and arch

• Note: Modify technique for those unable to extend neck; complete timely

Page 17: Evaluation Criteria - Oblique Inferosuperior

• Anatomy Demonstrated:

  • Single zygomatic arch displayed free of superimposition

• Positioning:

  • Correct patient position shows zygomatic arch free from parietal bone or mandible superimposition

  • Proper collimation to area of interest

• Exposure:

  • Sufficient contrast and brightness for visualization

  • Sharp bony margins indicating no motion

• Labelling:

  • Anatomical marker and patient’s name visible

Page 18: AP Axial (Modified Towne Method)

• Specifications:

  • 30

  • 18

  • 24

  • L

Page 19: AP Axial (Modified Towne Method) Part Position

• Positioning Instructions:

  • Patient's posterior skull against erect Bucky

  • Tuck chin (OML or IOML perpendicular to IR)

  • Align MSP perpendicular to midline to prevent rotation/tilt

• CR Alignment:

  • Angle CR 30° caudad to OML or 37° to IOML

  • Center CR 2.5 cm superior to glabella at gonion level

• Collimation:

  • Collimate to outer margins of zygomatic arches

Page 20: Evaluation Criteria - AP Axial

• Anatomy Demonstrated:

  • Bilateral zygomatic arches free of superimposition

• Positioning:

  • Zygomatic arches visible without rotation, indicated by symmetric appearance

  • Proper collimation

• Exposure:

  • Adequate contrast and density for visualization

  • Sharp bony margins indicating no motion

• Labelling:

  • Anatomical marker and patient’s name visible.