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9.03: Zone C1 – Superior Lateral Region

YOUR ASSIGNMENT FOR THIS LESSON

✅ Step #1: Review all content below.

✅ Step #2: Image the C1 zone on your own with your ultrasond, and using the checklist provided on this page, check off all key structures to be identified in this location

TRANSDUCER POSITION AT C1

Note: Clip is sped up.

STANDARD C1 ORIENTATION:
TRANSVERSE & LONGITUDINAL

The intersection of the vertical line from lateral canthus to the horizontal line from the superior alar groove is the location of C1.

QUICK TIP
  • First identify the periosteum. Then attempt to identify the layers of tissue to be seen.
    • There are muscles and fat to be seen at C1. Below the dermis you will see the superficial medial cheek fat, below this will run the obicularis oculi muscle. Directly under this muscle is the fat of the SOOF. 
    • A hypoechoic region often in contact with the bone at C1 will be the zygomaticus major muscle.
  • If you slightly angulate the probe while in longitudinal, you will be in the same plane as the zygomaticus minor muscle and you will be able to identify more of it.

EXAMPLE OF TRANSVERSE IMAGE ACQUIRED AT C1

Standard image acquired at C1. (Transverse| Left side is patient's lateral right). See key below for lables.*

ANATOMICAL LEGEND FOR C1 LOCATION IN TRANSVERSE

*Standard image acquired at C1 labeled with key anatomical structures.

EXAMPLE OF LONGITUDINAL IMAGE ACQUIRED AT C1

Standard image acquired at C1. (Longitudinal | Left side is deep). See key below for lables.*

ANATOMICAL LEGEND FOR C1 LOCATION IN LONGITUDINAL

*Standard image acquired at C1 labeled with key anatomical structures.
Superficial Fat Compartments
Deep Fat Compartments

DOPPLER IMAGES ACQUIRED AT C1 OF KEY VESSELS

Play Video
QUICK TIP
  • There are few vessels in this area relative to most other regions of the face. If you do identify Doppler flow, it is likely a superficial perforator vessel.
    • These vessels have slower flow.  Power doppler can be useful here, also if using color doppler turn your sensitivity to 2cm/s to detect the slower flow. Just be mindful of motion artifacts.
    • These vessels will be superficial and travel in the superficial fat. 

DO IT YOURSELF CHECKLIST

Structures to Identify on Ultrasound for C1

Once you have completed this checklist, mark this part of the lesson as complete.