Arthur C. Fleischer, Bernadette Keefe, Peter S. Cartwright,

MD #{149} Rebecca G. Pennell, MD2 #{149} Mary S. McKee, MD3 #{149} Carl M. Herbert, MD #{149} George A. Hill, MD MD #{149} Donna M. Kepple, RT, RDMS

Ectopic Pregnancy: at Transvaginal A retrospective review of the transvaginal sonograms of 50 women with laparoscopically confirmed ectopic pregnancy was performed to determine whether certain sonographic findings can be detected to confirm the diagnosis. Forty-seven of the 50 pregnancies were tubal. A tubal ring (a 1-3-cm mass consisting of a 2-4-mm concentric, echogenic rim of tissue surrounding a hypoechoic center) was seen in 23 of 34 (68%) ectopic pregnancies in which the fallopian tube had not ruptured, and the tubal ring could be distinguished from a corpus luteum cyst in most cases. Transvaginal sonography also depicted simple (n 22) or particulate (bloody) (n 13) peritoneal fluid associated with ectopic pregnancy. In each case in the series, at least one abnormal uterine, adnexal, or peritoneal finding was detected at transvaginal sonography. Because of its improved resolution of uterine and adnexal structures, transvaginal sonography is recommended as a means for detailed evaluation of patients suspected of having an ectopic pregnancy. terms:

nancy,

ectopic,

ies,

Fallopian

tubes,

856.823

853.8232

#{149} Preg-

#{149} Pregnancy.

US

stud-

85.12989

Radiology

1990;

S

EVERAL

studies

From

I

the

Departments

Radiological

Sciences

D.M.K.) (A.C.F., University 37232, sound,

Center,

(R.G.P.,

September

reprint

requests

3

Doylestown Current

University ( RSNA,

JAW.,

From

Received August

Hospital, address: of North 1990

the

study

to

characterize

the

from transvaginal relatively large

September

with

proved

ectopic

The findings levels of the chonionic when

in a

Address

Department

of

Doylestown. Department

Radiology, Penn.

of Radiology. Chapel

Hill.

MD

combining ferson (R.G.P.,

the

was

experience

University BK.), and

obtained

had

had test

UniversiTenn period. All

5-10

positive

(serum

Jef-

Philadelphia

experienced

amenorrhea,

by

at Thomas

Hospital,

at Vanderbilt ty Medical Center, Nashville, (A.C.F., M.S.M.), over a 2-year patients

weeks

results /3-hCG

of a

levels

roscopy, graphic

were

laparotomy, findings

obtained

phers

and/or

mension,

than

or

both. The retrospectively

sonograms of ectopic reviewed.

by experienced

mass, yolk

and

mm

luteum, tubal

echoic ian

re-

with

ring

sac or embryo,

di-

was

eccentrically

rimmed

delineated

and

hypo-

intraluminal

classified as simple late if it contained

4, 5). Intrafluid

(anechoic) low-level

was

or particuechoes pre-

clotted blood were diagnosed

structures

that

(Fig

i) (7).

cornua

by ovar-

(Figs

arose

from

A cornual

the ec-

refers structure

within serosa

lated

with

when values

approximately (Fig 8). A

to a hypoechoic surrounded

by

findings

were

preoperative

/3-hCG

they were available. were obtained with

radioimmunoassay

tubal

ring

corre-

values

Calif),

International Reference

milli-International A linear regression

versus

intraecho-

The fl-hCG the Clinetics

(Tustin,

uses the Second (0.6 X International

the ec-

which

Standard Preparaunits per of f3-hCG

size

was

mil-

1ev-

plotted,

and

50

and

were

unruptured

tubes

calculated

t test. Only day of the

and

and

compared

the tests sonographic

performed study

tubal

abortions

by using

a

within 1 were evalu-

ated.

Of the 50 proved ectopic pregnancies in this study, 47 were tubal ectopic pregnancies. Of these, 34 were unruptumed and 13 were ruptured. Three of the pregnancies were connual. Of the 13 ruptured ectopic preg-

adnexal

or without

or embryo

cyst

of

for a mid-se(5), a “pseudilated

nonspecific (with

luteum

a predominantly

was

penitoneal

tis-

center

RESULTS

a variety

anteropostenior

of echogenic

(6). A corpus

area

tissue

ex-

of a con-

a hypoechoic when

sonograwith

which is expected phase endometrium) fluid in the cul-de-sac,

cretory dosac,” tube, corpus

1-3)

mm

A

the correlation coefficient was calculated. The range, mean, and standard deviation of fl-hCG levels in women with ruptured

sono-

obtained in pregnancy were The sonograms

sonologists

i2

(Figs

rounded

consisting

of 2-4

diagnosed

els

had

in 16), and had proved on the basis of lapa-

were

ring surrounding

tion in liliter).

of

been determined ectopic pregnancies

Transvaginal proved cases retrospectively

centric sue

a 1-3-cm

genic tissue. The sonographic

METHODS

population

was

(4) (Figs 1-6). by Timor-Tritsch

structure

centrically located 5 mm of the uterine

(9-hCG)

AND

patient

Rottem,

traovarian

pseudosac uterine

PATIENTS

heart activity) as defined

topic pregnancy was diagnosed when gestational sac seemed to be unusually

available.

The

and

ring,

uterine

were correlated with beta subunit of human

gonadotropin

without tubal

as fusiform

pregnancies.

(more

22.

A. Worrell,

sumably due to partially (Figs 6, 7). Dilated tubes

findings

sonognaphy group of patients

5, 1989;

1988

July

2; revision

Carolina,

conven-

received

TN UltraHospital,

to i\.C.F.

address:

which

transvaginal probes (Toshiba, Tustin, Calif; Diasonics, Milpitas, Calif; Philips, Santa Ana, Calif). The following sonographic features were tabulated: endometrial thickening

Nashville,

BK.).

18; accepted

Current

M.S.M.,

of Diagnostic Un iversity

meeting.

requested

and

and Gynecology P.S.C.), Vanderbilt

Division Jefferson

annual

revision

2

(A.C.F..

Medical and the Thomas

Philadelphia RSNA

of Radiology

and Obstetrics C.M.H., G.A.H.,

in

tional transabdominal sonography was used have shown that the sonographic findings of ectopic pregnancy can be subtle (1,2). Clinical experience with transvaginal sonognaphy has demonstrated that delineation of early intrauterine pregnancy, as well as uterus, ovaries, and fallopian tubes, is enhanced oven that obtamed with transabdominal scanning (3,4). Accordingly, we performed this

viewed by an attending sonologist knowledge of the surgical findings.

174:375-378

#{149} John

Features Sonography’

pregnancy

Index

MD

with

Abbreviation: or

man

chorionic

l-hCG

=

beta

subunit

of hu-

gonadotropin.

375

Figure 1. Transvaginal sonogram 15-mm tubal ring (between + and within a dilated left fallopian hCG level was 721 mIU/mL, mal doubling time.

nancies, six hematosalpinx. The Table

were

a

tube. The fiwith an abnor-

associated

summarizes

shows X cursors)

with the

a

frequen-

cy of the sonognaphic features that were assessed. It was not uncommon for one patient to have more than one finding. In 11 patients intnapenitoneal fluid was associated with a tubal ring, in 12 it was associated with a nonspecific adnexal mass, and in four it was associated with a conpus luteum cyst. In one patient with an unruptured ectopic pregnancy, only fluid and bilateral corpus luteum cysts were detected with transvaginal sonognaphy. The most common findings included a tubal ring (seen in 23 of the 34 [68%] unnuptuned ectopic pregnancies) and fluid, either simple (n = 22) on particulate (n 13), in the cul-desac. In 16 of 47 tubal pregnancies, an embryo on embryonic structures could be identified within a tubal ring. In 20 of 50 cases, the endometnium was thickened and echogenic compared with that expected in a normal secretory phase (4). A pseudosac was seen in seven of 47 tubal pregnancies; all demonstrated an unusually thin (less than 2 mm) decidual reaction, less than that expected in a normal intrauterine pregnancy of comparable gestation (Figs 6, 7). In one of the tubal pregnancies with a pseudosac, low-level echoes on panticulate (bloody) fluid was present within the uterine lumen, indicating acute hemorrhage. The three comnual ectopic pregnancies were recognized by means of their eccentric location within the uterine lumen and their proximity (closer than 5 mm) to the uterine serosa (Fig 8). In Figure 9 the /3-hCG levels are plotted against the size of the measurable tubal ring for 1 1 patients for whom the test results were available within 1 day of the sonography. Even though a particular adnexal mass size 376

#{149} Radiology

Figure

2.

Transvaginal

sonogram

caused the containing

tube to rupture an embryo with

Figure

Transvaginal

ring

3 (arrow)

from

(“unruptured heart motion,

sonogram

surrounded by fluid ruptured ectopic pregnancy. The el 3 days before laparoscopy was mL. Intraperitoneal fluid represented that oozed out of the tube secondary ration of choriodecidua from the

a patient

in whom

the ectopic

pregnancy

ectopic pregnancy”) shows the as evident on M-mode tracing.

tubal

had ring

not

(arrow)

of tubal

Figure

in an un/3-hCG 1ev2,364 mIU/ blood to sepatubal wall.

patient

4. Transvaginal sonogram from a in whom the ectopic pregnancy had

caused

the tube

ic pregnancy”)

row)

within

rounded

to rupture shows

the right

by clotted

(“ruptured

a corpus

ovary, blood

ectop-

luteum

(ar-

which in the

is sun-

cul-de-sac.

was associated with a wide range of /3-hCC levels, the regression of 1hCG levels versus size was linear. Moreover, the f3-hCG values in patients with ruptured ectopic pregnancies were significantly greater than those in patients with unruptuned pregnancies (P .05) (Fig 10).

DISCUSSION Compared about the

with frequency

previous data of specific findings at transabdominal sonognaphy in ectopic pregnancies, our data from transvaginal sonognaphy demonstrate improved visualization with the technique in several areas. These include the adnexal mass created by

Figure

5.

Transvaginal

sonogram

of an un-

ruptured ectopic pregnancy (arrowhead) adjacent to the corpus luteum (arrow), which contains a few internal interfaces. The 9hCG level 2 days before laparoscopy was 949 mIU/mL.

February

1990

rounding

hypoechoic

intraluminal

fluid.

late fluid

(*).

The

f3-hCG

level

was

8,468

gestational

sac

within

the

uterus.

mIU/mL.

10000

S e

8000-

U

m

6000

-

b I

a 4000

h C G

I

2000 (mIU/ml) I I

I

0 9

12

15

18 Tubal

Figure ruptured

9.

Scatter ectopic

plot

with

pregnancies;

linear

r

21 ring

regression .68, p

24 size

(mean

of /3-hCG

27

30

dimension

levels

versus

33

36

39

42

in mm)

tubal

ring

size

in 1 1 un-

.034.

6.5CC mIU/mI (2nd

IS.)

14000 12000

10000 8000 6000 4000

2000

Unruptured

Ruptured

Tubal

AbOrtiOn

Figure

10. Bar graph of the range, mean, and standard deviation of fl-hCG levels in unruptured and ruptured ectopic pregnancies and tubal abortions. P .053 for ruptured versus unruptured ectopic groups.

ectopic pregnancy, a corpus luteurn cyst, a dilated fallopian tube, and fluid in the cul-de-sac (1,2). Most important, transvaginal sonography can definitively

outline

created

by

the

Volume

174 #{149} Number

the

chorion 2

tubal

mass

in an

ectopic

pregnancy and in most cases allows one to distinguish the mass from a corpus luteum cyst (Figs 1-5). Transvaginal sonography also allows a more definitive differentiation of decidua, which produces a pseudosac, from true choniodecidual reactions in intrauterine pregnancies (Figs 6, 7). The broad range of 3-hCC values associated with a particular size of adnexal mass at transvaginal sonography could be explained by the fact that a ruptured ectopic pregnancy with hemorrhage may create a larger mass and lower f3-hCG values than an intact ectopic pregnancy with viable chonionic villi (8). However, the size of the adnexal mass increased with fihCG values. The discrepancy between the fl-hCG values in patients with unruptured and ruptured ectopic pregnancies is likely a reflection of the greaten probability of rupture in

the more advanced ectopic pregnancy. As recently reported by Bree et al, an intrauterine gestational sac should be apparent when /9-hCG levels are about 500 mIU/mL (9). Several patients had definitive transvaginal sonogmaphic findings of ectopic pregnancy even though their 9-hCG values were low (30-60 mIU/ mL). These data substantiate the notion that tnansvaginal sonography should be performed even when fihCG values are low, since an ectopic pregnancy with only a small amount of functioning trophoblasts may be present. Our study reveals that specific sonographic features can be sought in patients who may have an ectopic pregnancy. Specifically, the tubal ring produced by the ectopic pregnancy itself can be reliably detected in most cases if the tube is unrup-

Radiology

#{149} 377

tuned (Figs 1-3). In addition, the tubal ring can usually be differentiated from a corpus luteum cyst, because the latter tends to be more eccentnically located within the rim of ovanian tissue than the concentric ring created by the ectopic pregnancy surrounding the chomionic sac (Figs 4, 5). Even with the enhanced resolution capabilities of transvaginal sonognaphy, there may be cases in which a definite adnexal mass cannot be delineated. The frequency of this occurring, however, is much lower (0% in our series) than that encountered with transabdominal sonography, where it is reported to be as high as 20% (1). Our results compare favorably with those of other studies that used transvaginal sonography for the detection of ectopic pregnancy. Our findings of a specific tubal ring in 68% of unruptured ectopic pregnancies is similar to that reported by Rempen (10) (adnexal tumor nepresenting the extrauterine gestation in 15 of 21 patients), Nybeng et al (11) (10 extrauterine gestational sacs in 25 patients), Dashefsky et al (12) (88% of patients without an intrauterine pregnancy and with an adnexal mass

378

.

Radiology

had an ectopic gestation), and Cacciatore et al (13) (90% of 39 patients with an ectopic pregnancy demonstrated an abnormal location of the pregnan-

5.

6.

The authors thank for his constructive

MD,

Mendelson

55.

dominal

The results of this study support the practice of using transvaginal sonognaphy in the evaluation of patients with suspected ectopic pregnancies. Our data indicate that certam sonographic features such as a tubal ring and particulate intrapenitoneal fluid are helpful in making the diagnosis of an ectopic pregnancy. U Acknowledgment:

AC,

M, Entman

cy).

Timor-Tritsch,

Fleischer

sonography

8.

Ilan E. review.

9.

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February

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