What
This study shows an easy way for using three-dimensional (3D) ultrasound in the detection and evaluation of many uterine anomalies in everyday clinical work.
A coronal plane view, which encompasses the entire endometrial cavity is usually impossible to obtain using a traditional 2D ultrasound. However, it can be easily displayed using 3D ultrasound reconstruction. Many uterine anomalies are initially suspected on 2D ultrasound. 3D ultrasound reconstruction can then be used to define the lesion much more accurately and is recognized as the standard method for the diagnosis of congenital uterine malformations. Several publications have demonstrated the high level of accuracy in diagnosing and defining uterine anomalies using such a standardized approach. In the hands of an experienced sonographer, the diagnosis of uterine anomalies by 3D ultrasound has been shown be as accurate as an MRI [ 1 ]. Additionally, 3D ultrasound performs better than routine 2D ultrasound in diagnosing and defining endometrial pathologies, leiomyomata uteri, and is better in localization of an IUD [ 2 , 3 ]. The Ultrasound Societies of German speaking countries have based their latest guidelines and quality requirements with these realities in mind [ 4 , 5 ]. An additional benefit of having a stored 3D volume available is that it can be reviewed offline by other experts to provide a second opinion. This increases the diagnostic value of the examination [ 6 ].
The goal of the following presentation is to summarize the best method for obtaining a uterine volume for diagnostic purposes in an everyday gynecological practice. The focus is on reconstruction of the coronal view of the entire endometrial cavity as this allows for the best assessment of the presence and the type of a congenital uterine malformation. Optimally, the endometrial thickness should be at least 5 mm, or the timing of the examination should fall between day 17–25 of the menstrual cycle [ 6 , 7 ]. Underlying conditions such as leiomyomata or adenomyosis and the presence of an IUD may compromise the evaluation of the endometrial contour. Examination of the endometrial cavity during pregnancy or menstrual bleeding should be avoided for the same reason (Tables 1 , 2 , 3 , 4 and 5 ).
Step 1: Obtaining uterus midsagittal plane in 2D (Table 1 ; Figure 1 ) Table 1 Requirements for optimal plane Requirements for optimal plane Sufficient magnification Continuity of endometrium in midsagittal plane Fig. 1 Midsagittal plane of the uterus
Requirements for optimal plane
Midsagittal plane of the uterus
Step 2: Acquisition of standardized multi-planar view. (Table 2 , Figure 2 ) Table 2 Suggestions for an optimal acquisition Suggestions for an optimal acquisition Patient should hold breath and do not move during the process Maximum sweep angle of 180° Fig. 2 Multi-planar view contains four separate planes: midsagittal ( A ), transversal ( B ), coronal ( C ) and 3D view of the uterus
Suggestions for an optimal acquisition
Multi-planar view contains four separate planes: midsagittal ( A ), transversal ( B ), coronal ( C ) and 3D view of the uterus
Step 3: Adjusting the multi-planar view using the “Z rotation” technique [ 8 ]. (Table 3 , Figure 3 ) Table 3 Steps for the Application of the Z Technique Steps for the Application of the Z Technique Step 1. Place the reference/rotational point in the midlevel of the endometrial stripe in the sagittal plane Step 2. Use the Z rotation to align the long axis of the endometrial stripe along the horizontal axis in the sagittal plane of the uterus Step 3. Place the reference/rotational point in the midlevel of the endometrial stripe in the transverse plane Step 4. Use the Z rotation to align the endometrial stripe with the horizontal axis in the transverse plane of the uterus Step 5. After step 4, the midcoronal plane of the uterus will be displayed in coronal plane, apply Z rotation on coronal plane to display the midcoronal plane in the traditional orientation Fig. 3 Multi-planar view of the uterus
Steps for the Application of the Z Technique
Multi-planar view of the uterus
Step 4: Obtaining correct coronal plane of the uterus. (Table 4 , Figures 4 , 5 , 6 ) Table 4 Suggestions for an optimal coronal plane Suggestions for an optimal coronal plane Visualization of endometrial-myometrial junction zone If possible, visualization of tubal insertion Fig. 4 Coronal view of the uterus Fig. 5 Coronal view of the uterus using trace line in “omni view” function Fig. 6 Coronal view of a septate uterus using trace line in “omni view” function
Suggestions for an optimal coronal plane
Coronal view of the uterus
Coronal view of the uterus using trace line in “omni view” function
Coronal view of a septate uterus using trace line in “omni view” function
In case of extreme retroflexion or other untypical positions of the uterus you can also use the “omni view” function with a trace line. This is a means to optimize the view of uterine cavity including the cervix.
Using these steps, you will easily obtain the basic three-dimensional ultrasound of the uterus coronal plane.
Currently, there is no clear consensus among three leading societies (ASRM [ 9 ], ESHRE/ESGE [ 10 ], CUME [ 11 ]) on the classification of congenital uterine anomalies, in particular, of a septate vs. normal uterus. Due to the lack of a consensus it is advised to choose one of the classifications and apply it in everyday gynaecological practice. Following table (Table 5 and Figure 7 ) shows overview of the societies on the definition of a septate uterus. Table 5 Classification of congenital uterine anomalies among three leading societies (ASRM [ 9 ], ESHRE/ESGE [ 10 ], CUME [ 11 ]) Society Criteria for septate uterus ASRM-2016 [ 9 ] Internal fundal indentation depth ≥ 1.5 cm Indentation angle < 90° External fundal indentation depth 50% of uterine-wall thickness External fundal indentation depth < 50% of uterine-wall thickness When uterine-wall thickness measured above interostial/intercornual line CUME-2018 [ 11 ] Internal fundal indentation depth ≥ 1 cm Indentation angle < 140° External fundal indentation depth < 1 cm Fig. 7 Septate uterus according to the three different societies ASRM american society for reproductive medicine, CUME congenital uterine malformation by experts, ESHRE/ESGE European society of human reproduction and embryology/European society for gynecological endoscopy a intercornual line b internal fundal indentation c indentation angle d uterine-wall thickness
Classification of congenital uterine anomalies among three leading societies (ASRM [ 9 ], ESHRE/ESGE [ 10 ], CUME [ 11 ])
Internal fundal indentation depth ≥ 1.5 cm
Indentation angle < 90°
External fundal indentation depth 50% of uterine-wall thickness
External fundal indentation depth < 50% of uterine-wall thickness
When uterine-wall thickness measured above interostial/intercornual line
Internal fundal indentation depth ≥ 1 cm
Indentation angle < 140°
External fundal indentation depth < 1 cm
Septate uterus according to the three different societies ASRM american society for reproductive medicine, CUME congenital uterine malformation by experts, ESHRE/ESGE European society of human reproduction and embryology/European society for gynecological endoscopy a intercornual line b internal fundal indentation c indentation angle d uterine-wall thickness