Lymphedema Ultrasonography: A Technique to Measure the Change in Thickness of an Affected Tissue

All the procedures were reviewed and approved by the Institutional Review Board of Chungnam National University Hospital.

1. Measurement with Ultrasonography

1. Set the posture of the patient.
   1. Lay the patient's arm in a supine position, with both arms on the bed.
2. Determine the measurement sites on the patient's upper limb.
   1. Mark in the mid-point of the wrist crease, the mid-point between the medial and lateral epicondyles at the level of the elbow, and the bicipital groove by a pen.
   2. Using a pen directly connect these three points by a ruler. Mark the two target areas on the upper arm and forearm (Figure 1).
      1. Mark the proximal part, 10 cm proximal to the elbow point along the line between the elbow and bicipital groove.
      2. Mark the distal part, 10 cm distal to the elbow point along the line between the elbow and wrist.
3. Measure the thickness of the subcutaneous tissue and muscle of the upper limb. The procedure should be performed by a skilled sonographer.
   1. Switch on the ultrasound system. Enter 2D mode of soft tissue via the keyboard. Set the depth to 5 cm.
      1. Choose the 14L5 linear array transducer.
      2. Apply sufficient gel to the ultrasound transducer. Focus on the subcutaneous tissue.
   2. Place the ultrasound transducer perpendicularly to the upper limb ventral axis. Use the short-axis view. Capture the image where the thickness of the gel is at least 1 cm and the soft tissue contour is not distorted.
   3. Measure the thicknesses of the muscle and subcutaneous tissue.
      1. Draws a line by selecting the calibrator in the software via the keyboard of the ultrasound system.
      2. Measure the thickness of the muscle, defined as the distance from the highest point on the boundary of the bone to the highest point on the boundary portion of the fascia (Figure 2).
      3. Measure the thickness of the subcutaneous tissue, defined as the distance from the skin to the fascia.

2. Clinical Application of Ultrasonography to BCRL

1. Measure the thickness of the subcutaneous tissue and muscle of the upper limb at baseline.
   1. Perform the baseline measurements in the order shown in Step 1.
2. Instruct the patient to perform a series of PREs using a 0.5 kg dumbbell.
   1. Give the patient a compression stocking or a multilayer bandage to wear. Choose a 0.5 kg dumbbell.
   2. Instruct the patient to perform the PREs in the following order: (1) dumbbell fly, (2) triceps extension, (3) one arm bent-over row, (4) biceps curl, (5) dumbbell side raise, and (6) lifting the arms forward (Figure 3).
      1. Instruct the patient to complete the 6 exercises twice a day, according to the following schedule: 5 times each during the 1^st week, 10 times each during the 2^nd week, 15 times each during the 3^rd week, 20 times each during the 4^th week, and 25 times each during 5^th-8^th weeks (Figure 4).
3. Use ultrasonography to identify the therapeutic effects of PRE compared to conventional therapy.
   1. Measure the thickness of the subcutaneous tissue and muscle of the upper limb at 4 and 8 weeks. Perform the measurements in the order shown in Step 1.
4. Calculate the thickness of the subcutaneous tissue and muscle at baseline, 4 weeks, and 8 weeks.
5. Analyze the data.
   1. Compare the difference between both arms using a paired t-test. Compare the changes in subcutaneous tissue and muscle thickness using a repeated-measures ANOVA.