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.