Ultrasound of the female pelvis Chapter 36 Pediatric Sonography & Non-Gynecologic Pathology Holdorf Ultrasound of the female pelvis

Contents Normal Anatomy Indications for Pediatric Imaging Precocious Puberty Precocious Pseudopuberty Hydrocolpos Non-Gynecological Pelvic Pathology

Sonography is a very good evaluation tool of the pelvic organs in infants, children, and adolescents. The distended bladder is used as an imaging window.

Normal anatomy The uterus and ovaries undergo a series of changes in size and configuration during normal growth and development throughout childhood.

In the newborn female, the normal sonographic features are as follows: Cervix is twice the length of the corpus Brightly echogenic endometrium (due to maternal hormonal influence in utero) Total length is approx. 3cm AP dimension is .5 to 1 cm Ovaries may be found anywhere between the lower pole of the kidneys and the true pelvis.

After 2 to 3 months of age, the uterus regresses, and the following characteristics are seen sonographically until puberty: 2.5-3cm total length, when the cervix and corpus equal in length. Endometrial stripe is not usually delineated Maintains infantile appearance until about age 7 Small cysts may be seen in ovaries, usually <9mm, but possibly as large as 17mm

At puberty, the uterus gradually increases in length, to 5-7cm and the corpus to cervix ratio becomes 3-1. The endometrium echogenicity and thickness vary according to the phase of the menstrual cycle, and the ovaries increase in volume and vary in sonographic appearances as well.

The neonate uterus

A prepubescent uterus

Indications for Pediatric Imaging In the pediatric patient, indications for Sonography are varied depending on clinical findings, and include:

Rule out ovarian cysts or complications of ovarian cysts Assess ovaries when polycystic ovarian disease is suspected Rule out ovarian neoplasms Rule out congenital uterine anomalies Determine the presence or absence of uterus and vagina in newborns and ambiguous genitalia. Evaluate uterus and ovaries in patients precocious puberty Rule out hydro-or Hematocolpos

Precocious Puberty True precocious puberty results from an early but normal pattern of gonadotropin secretion from the pituitary. It may be a sign of hypothalamic disease, but is idiopathic in more than 80% of cases. It results in the development of secondary sexual characteristics, Gonadal enlargement and ovulation before the age of 8 years.

15 y/o with ovarian cyst

Precocious pseudopuberty Is caused by abnormal exposure to estrogen and results in the development of secondary sexual characteristics without gameo-genesis. The cause is most typically an ovarian tumor.

Hydrocolpos Hydrocolpos is a generic term for the collection of fluid, blood or pus within the vagina, but it may extend to include the cervix and uterine cavity. In the pediatric patient, hydrocolpos or Hydrometrocolopos is usually secondary to an imperforate hymen. Hematocolpos frequently goes undetected until after menarche, when the patient may present with a lower abdominal mass.

Hydrometrocolopos can also be seen in older women, especially those undergoing radiation therapy, and the postmenopausal patient. Hydrocolpos accounts for 15% of abdominal masses in newborn females.

The specific location and type of fluid is described by combining the following word roots: Hemato=blood Pyo=pus Hydro=water Metro=uterus Colpos=vagina

Example: Hydrometrocolopos is fluid in the uterus and vagina Hematometracolpos is blood in the uterus and vagina

Sonographic findings: Hypoechoic distention of the endometrial cavity and/or vagina Posterior acoustic enhancement Internal echoes may be present in cases of severe obstruction Attempt should be made to identify possible other genitourinary anomalies  

Hydrometra

Hematometra: Collection of Blood in the uterine cavity

Hematometra

Hematometrocolpos: Ultrasound shows a distended uterus and vagina with complex fluid representing blood products consistent with Hematometrocolpos.

NON-GYNECOLOGIC PELVIC PATHOLOGY   It is important for the Sonographer to be aware of other non-gynecologic entities that could cause symptoms mimicking pathology of the reproductive organs. While these entities may not be definitively diagnosed with Sonography, they should be considered when no uterine or adnexal pathology is found.

URINAY BLADDER ABNORMALITIES Distal ureter stone: Evaluate Ureter Vesical Junction (UVJ) region (endovaginally with small amount of urine in bladder, or transabdominally with full bladder) for shadowing calculi

Distal ureter stone: Distal ureter stone in an 8 year old boy with a dilated urinary tract.

Interstitial cystitis Bladder wall thickening, either focal or diffuse, with patient history of recurrent UTIs.

Interstitial cystitis

Bladder wall neoplasm Region of bladder wall thickening or focal wall mass; confirm neoplasm by demonstrating increased vascular flow to mass.

Bladder wall neoplasm

INTESTIONAL TRACT ABNORMALITIES Bowel wall thickening May be seen with diverticulitis, gastroenteritis, or bowel-related abscesses   Appendicitis Usually right lower quadrant, but consider possibility of a left-sided appendix

Bowel wall thickening

Appendicitis An inflamed appendix has a diameter larger than 6 mm, and is usually surrounded by inflamed fat. The presence of a fecolith or hypervascularity on power Doppler strongly supports inflammation.