FIBROID ULTRASONOGRAPHY (USG)

                                                        

Uterine leiomyomas or uterine fibroids are the most common gynaecological tumours and occur in about 20-50% of women around the world. Ultrasonography (USG) is the first-line imaging examination in suspected fibroids and shows high sensitivity and specificity in diagnosing this condition. Ultrasound scans can be performed transvaginally (transvaginal scan – TVS) or transabdominally (transabdominal scan – TAS); both scans have advantages and limitations, but, in general, transvaginal sonography is superior to transabdominal sonography in most cases of pelvic pathology. Whether a leiomyoma is symptomatic or not depends primarily on its size and location. During ultrasound examination, leiomyomas usually appear as well-defined, solid, concentric, hypoechoic masses that cause a variable amount of acoustic shadowing. During the examination of leiomyomas differential diagnosis is important. Some of the most common misdiagnosed pathologies are adenomyosis, solid tumours of adnexa, and endometrial polyps.

The following table describes the differentiating features between fibroid and adenomyosis.    

   

Feature	Typical fibroid	Adenomyosis
Serosal contour of uterus	Lobulated or regular	Often globally enlarged uterus
Definition of lesion	Well‐defined	Ill‐defined in diffuse adenomyosis (adenomyoma may be well‐defined)
Symmetry of uterine walls	Asymmetrical in presence of well‐defined lesion(s)	Myometrial anteroposterior asymmetry
Lesion
Outline	Well‐defined	Ill‐defined
Shape	Round, oval, lobulated	Ill‐defined
Contour	Smooth	Irregular or ill‐defined
Rim	Hypo‐ or hyperechogenic	No rim
Shadowing	Edge shadows, internal shadows (often fan‐shaped shadowing)	No edge shadows, fan‐shaped shadowing67

      

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Feature	Typical fibroid	Adenomyosis
	shaped shadowing)
Echogenicity	Uniform: hyper‐, iso‐, hypoechogenic	Non‐uniform: mixed echogenicity67, 68
	Non‐uniform: mixed echogenicity	Cysts20-24, 62, hyperechogenic islands, subendometrial lines and buds24, 63
Vascularity	Circumferential flow	Translesional flow69
Junctional zone (JZ)
JZ thickness, regularity	Not‐thickened; regular or not visible	Thickened; irregular or ill‐defined9, 61-63
JZ interruption	Interrupted or overstretched JZ in areas with lesions of FIGO types 1–3 (Figure 3)	Interrupted JZ (even in absence of localized lesions) 9

 

 

 

 

 

 

 

 

 

 

 

 

 

 

TYPICAL FIBROID IMAGES                                 

 

 

SUBMUCOSAL FIBROID

 

INTRAMURAL FIBROID

 

 

PEDUNCULATED SUBSEROSAL FIBROID

However some fibroids may have atypical appearance as shown in the figure below.

 

 

Ultrasound images showing fibroids with atypical sonographic features. These fibroids have non‐uniform echogenicity and intralesional anechoic cysts, and some have areas with hyperechogenicity. The FIGO type 1 fibroid (bottom right) has an irregular outline.