Quantitative Measurements

      (1)  Border Identification:

      IVUS can identify the boundaries of different layers of blood vessel, such as intima,

      internal elastic lamina, media, external elastic lamina (EEM), and adventia.

　

     (2)  Lumen Measurement:

     The area of lumen is measured by the identified border of intima and lumen. 

    The following parameters can derived from this measurement:

     -  Lumen cross-sectional area (CSA)       -  Minimum lumen diameter

     -  Maximum lumen diameter                    -  Lumen eccentricity

     -  Lumen area stenosis  

        (Reference lumen CSA-minimum lumen CAS) / (Reference lumen CSA)

    

     (3)  External Elastic Lamina (EEM) CSA Measurement

     - The maximum diameter and minimum diameter of EEM can be utilized to

       diagnose atherosclerotic arteries. 

　

     (4)  Atheroma Measurement

     IVUS cannot really identify atheroma, but it can calculate surrogate atheroma trough

     EEM and lumen CSA measurements, i.e., the plaque plus media area.  The following

     parameters can be performed from this calculation:

      -  Plaque plus media (or atheroma) CSA

      -  Maximum plaque plus media (or atheroma) thickness

      -  Minimum plaque plus media (or atheroma) thickness

      -  Plaque plus media (or atheroma) eccentricity

      -  Plaque (or atheroma) burden

   

(5)  Calcium Measurement

     IVUS is the most sensitive method that can detect coronary calcium.  This is because

     calcium obstructs the acoustic beam and perform a bright echoes in IVUS image. 

     Since ultrasound cannot penetrate calcium, IVUS cannot determine the thickness of

     calcium.  But the arc of calcium layer can be identified.

    

      (6)  Stent Measurement

      Because implanted stent are made by metal, it serves a strong reflection layer for

     ultrasound.  Thus, IVUS can give a clear image of the stent and can provide the

     following parameters.

     -  Maximum stent diameter          -  Stent symmetry              -  Stent CSA

     -  Minimum stent diameter           -  Stent expansion

　

      (7)  Reference Segment Measurement

      IVUS can measure a segment of blood vessel with slow pullback.

      

      (8)  Remolding

      With the quantitative data retrieved, IVUS can determine the positive or negative

      remolding of atheroma development via measurement EEM area.

　

      (9)  Length measurement

       The length of plaque can be measured by the motorized transducer pullback function.

              The following is an example of quantitative data drained by IVUS image.

　

            Link to Example of Quantitative Measurement

                  (Original source )