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Doppler Ultrasound in Gynecology
3
Similar considerations apply to the early diagnosis of
ectopic pregnancy (Figs.
ing of the course of an ectopic pregnancy by medical
treatment with systematically administered
methotrexate.Note that the perfusion of the corpus luteum is also profuse, so that a suspected ectopic pregnancy could be confused with a normally developed
Fig. 20.5 Intensely vascularized ectopic pregnancy adjacent to
the ovary.
20.3−20.5) and the monitor-
corpus luteum (Fig. 20.6). Hence it is important to display both organs, the ovary and the uterine tube containing the ectopic pregnancy, side by side to ensure
the proper identification of the ectopic pregnancy. In
this case uncritical application of color Doppler can induce a diagnostic error.
When uterine fibroids are treated medically with
gonadotropic-releasing hormone (GnRH) agonists,
Doppler ultrasound display of a reduction in perfusion
can supplement the reduction in size.
Other applications of pulsed and color-coded Doppler ultrasound include the demonstration and documentation of tubal hydroperturbation by ultrasound
contrast media as part of a diagnostic workup for
sterility (Fig. 20.7).
It should be noted that the premature uncritical introduction into clinical practice of a new method such
as color Doppler ultrasound, when not adequately
founded on research, can entail considerable risk. This
is especially true when estimating its validity and
when planning treatment based on this. In this connection special mention should be made of the risk of
laparoscopic surgery when an unexpected adnexal
malignancy is found.
184
Fig. 20.6 Corpus luteum with similarly intense perfusion due
to neovascularization.
Tumor Angiogenesis
As early as 1907 Goldman (The Growth of Malignant
Disease in Man with Reference to Vascular System),
working from arteriographic studies of tumor specimens (Fig 20.8), described the development of newly
formed “tumor vessels” in the periphery of malignant
tumors. Many decades later Folkman (1974) postulated
that tumor growth was only possible when new vessels are formed in the vicinity of the tumor. In 1971
Folkman et al. were able to discover the underlying
Fig. 20.7 Flow of contrast medium through the uterine tube
displayed by color Doppler.
mechanisms of this activity by describing and demonstrating tumor-angiogenesis factors. Increasing new
formation of blood vessels can now be demonstrated
in tumors over 3−5 mm in diameter.
However, new vascularization does not always constitute an unambiguous criterion for the formation of a
tumor, since new vascularizations and changes in
tissue perfusion can also occur during physiological
and benign processes, such as for instance wound heal-
Examination Procedure and Instrumentation for Ultrasound Diagnosis of the Pelvis
ing, ectopic pregnancy (cf. above) and in inflammatory
processes. If in a case presenting a sonographically suspect adnexal finding no vessel can be displayed by ultrasound, the following should be considered:
왘 Flow may be present in the tumor, but very slow
due to small vascular diameters. In this case the
flow may not reach the sensitivity threshold of the
instrument. Thus, there may be a change in perfu-
sion, but the instrument cannot register it for tech-
nical reasons. The introduction of intravenous ultra-
sonic contrast media improves the signal in such
cases and so leads to improvement by displaying
even the smallest vessels. Another possibility suggested by Sohn et al. (1993) is to raise the perfusion
briefly and artificially by raising the blood pressure.
This may, for instance, be achieved without risk by a
controlled physical load.
왘 Since tumors are often only poorly vascularized in
their core, display of tumor vascularization due to
angiogenesis may only be possible in the immediate periphery of the tumor. This effect has been
documented especially in the examination of mammary tumors.
왘 During rapidly increasing tumor growth the center
first becomes strongly vascularized. There follows a
secondary central compression of the newly formed
20.9). The consequence of such
vessels (
diminished central tissue perfusion may be necro-
sis. Thus, in the core of the tumor avascular areas
may alternate with some that are well perfused and
necrotic. Such changes are not, however, pathognomic for malignant tumors: Central necroses may
be observed not only in rapidly growing malignant
tumors, but are also characteristic of rapidly growing fibroid tumors.
Fig.
Fig. 20.8 Arteriographic cast of the uterus displaying the
blood vessels, modified after Fleischer et al.
Advanced Topics
Essential Considerations for Clinical Practice
Complete absence of connected vessels or sporadic
color pixels in a display speaks against the presence
of angiogenesis associated with a tumor and hence at
the same time against the presence of a malignant
tumor.
Fig. 20.9 Marginal blood vessels in a mammary carcinoma.
If the display of a suspicious area shows multiple signals with a variable, but above all a low resistance
index (RI), such abnormal perfusion tends to favor the
presence of a malignant tumor.
Examination Procedure and Instrumentation for Ultrasound Diagnosis of the Pelvis
Besides a valid clinical question, Doppler examination
of the internal genital area requires in every case a
vaginal examination and B-mode vaginal sonography
for a three-dimensional view of the relations of the or-
20.10).
Fig.
gans (
In B-mode sonography the uterus is imaged first for
orientation and is displayed in longitudinal and cross
section (
structural changes in the myometrium and the endometrium, and for free fluid in the pouch of Douglas.
The thickness and condition of the endometrium
should be recorded. The search for the adnexa begins
laterally at the pelvic wall near the iliac vessels. The
search may be made difficult by reduced ovarian
Fig. 20.11). The display should be examined for
185
Doppler Ultrasound in Gynecology
3
volume and superposition of gas-filled intestinal loops,
especially after menopause. The ovary is localized and
its morphology recorded (size or volume, follicles, cystic or solid constituents), using a score if necessary. Its
vascularization can then be displayed by color Doppler.
Depending on the diagnostic question, a variety of
Doppler systems may be used for this purpose. If the
large vessels (iliac a.) are to be displayed, a high velocity up to 1 m/s must be taken into account: Perfusion in
this case can be displayed with the usual direction-dependent, frequency-coded, color flow mapping (CFM)
mode. These vessels are displayed easily because of the
high intensity and high pulsatility of the flow signals.
In contrast, the actual ovarian vessels are often difficult
to display. The right ovarian a. originates from the right
renal a., the left from the aorta. However, the ovarian
aa. are of subordinate significance in the evaluation of
Fig. 20.10 Three-dimensional representation of the pelvic organs.
the ovarian perfusion proper, since in clinical practice
only vessels within the limits of the organ itself can be
assigned to that organ with any certainty. When displaying the actual perfusion of an organ or establishing
the presence of tumor vessels, anatomical features
such as very small vascular diameters and very slow
blood flows must be taken into account. Hence a display using an amplitude-coded, direction-dependent
power Doppler is preferred, for in favorable situations
this allows displays of very slow flows of as low as a
few millimeters per second. In such cases the small arteries with low vascular resistance inside the organ are
displayed rather than the larger vessels supplying the
organ.
Evaluation
This addresses in the first place qualitative impressions
of the vascularization of the organ. The record should
include the number and density of the color pixels displayed, the diameter of the vessel, the number of vessels displayed, the presence and number of vascular
branchings. Next the sample volume is placed in the
vessel to be examined or the abnormal color pixel
group, and the pulsed Doppler inserted. In quantitative
measurements, besides measuring flow velocity, the
derived flow curve is described by the use of indices;
the most commonly used indices are the RI (V
V
min/Vmax
V
time average
Carter et al. (1995), it is better to dispense with the precise alignment of the angle of incidence, since the
direction of the tumor vessels can often not be determined.
(1994) showed that the values RI and PI are highly
correlated. The correlation coefficient was 0.99. The diagnostic significance of both parameters seems to be
equivalent. Consequently in our clinic we prefer documenting the RI because it is easier to determine and
plot.
) and the pulsatility index (PI) (V
).
According to studies by Valentin et al. (1994) and
Statistical analysis of results by Prömpler’s group
max
max−Vmin
−
/
186
Fig. 20.11 Longitudinal section through the uterus showing
thin endometrium, scanty serometra.
Ovarian Diagnosis
Conventional Ultrasound Examination of the Ovary: Procedure and Results
Since 1983 Campbell et al. have been reporting continuously on a voluntary screening program using
transabdominal sonography on 5497 women. Asymptomatic women only received annual ultrasound. In
1990 they published these results: 336 (5.9%) women
were found to have abnormal sonograms. In the subsequent exploratory operation five women had ovarian
carcinoma. Hence detection of a malignant ovarian
tumor by ultrasound examination carries a positive
predictive value or accuracy of merely 1:26. The probability of discovering a primary ovarian carcinoma was
therefore just 1:50.
When ultrasound screening by transvaginal sono-
graphy was performed for ovarian carcinoma, several
criteria were evaluated. Those given special attention
included:
왘 Ovarian size (Campbell et al. 1989, Duda et al. 1990):
Premenopausal volume 쏜18 mL, postmenopausal
volume 쏜8 mL were considered suspicious. As a
general rule length × breadth × height × 0.53 was
used as an approximate estimate of volume.
왘 Pathological structure of the ovary: The evaluation
included changes in echogenicity, the appearance of
cystic formations, appearance of solid parts, and
20.12). All study groups agree
F
blurred contours (
that the appearance of a solid segment in a cystic
adnexal structure is the criterion that best distinguishes benign from malignant tumors.
왘 Difference in size of the ovaries (Campbell et al.
1989, Duda et al. 1990): Using this criterion an
ovary that was more than double the size of the
contralateral ovary was considered suspicious.
The study groups of Higgins and van Nagell in 1989
identified 31 cases of equivocal adnexal findings
during prospective examinations of 1000 asymptomatic patients. During confirmatory surgery on 24
patients only one case of metastatic colon cancer was
found. Hence the accuracy of detection of a malignant
ovarian tumor in this study was 1:24.
Duda et al. (1990), in a study of 221women with normal findings by palpation, found 13 cases with inconclusive ovarian findings. Surgical exploration revealed
one case of ovarian metastasis. This corresponds to an
accuracy of 1:13.
Toimprove the accuracy of ovariandiagnosis, a number of study groups have in the past suggested different scores (e.g., Sassone et al. 1991, Schilliger et al.
1989) that included a varying number of morphological criteria (
Table 20.1).
ig.
Ovarian Diagnosis
Fig. 20.12 Inhomogeneous ovary, partly hypoechoic, partly
echoic. Suspected endometriosis
When equivocal premenopausal and postmenopausal tumors were classified in this way transvaginal sonography attained a sensitivity of about 80−
100% and a specificity between 69 % and 93% (
20.2).
In evaluating the results of such studies it must be
borne in mind that the patient population examined
was mostly confined to symptomatic patients. The results can therefore only be viewed in the light of a
general screening of normal populations.
Table 20.1 Tumor score after Schillinger (1989)
Score
I Well-demarcated solitary cysts
II Other well-demarcated homogeneous tumors
III Minimally inhomogeneous tumors (small tumor areas
differ in consistency)
IV Inhomogeneous cystic−solid or solid−cystic tumors
V Completely inhomogeneous tumors with bizarre
formations
Table 20.2 Preoperative staging using sonographic scoring
systems
Authors Number of
patients (n)
Herrmann et al. 1987 241 82 93
Benacerraf et al. 1990 100 80 87
Granberg et al. 1990 180 82 92
Sassone et al. 1991 143 100 83
Hata et al. 1992 63 85 69
Kurjak et al. 1992 1000 48 98
Weiner et al. 1992 53 94 69
Sensitivity
(%)
Table
Specificity (%)
Advanced Topics
187
Doppler Ultrasound in Gynecology
3
Another point to be noted is that, while transvaginal
sonography is relatively reliable with a sensitivity of
over 90% for scores of 1 and 2 (unremarkable/slightly
suspicious) and 5 (highly suspicious), it is much less
accurate in evaluating the prognosis in groups 3 and 4
(tumors that are partly cystic and partly solid). A number of study groups (Lerner et al. 1994) have therefore
tried to improve sensitivity and specificity by differentiating ovarian findings by color Doppler sonography.
Normal Findings in the Doppler Ultrasound Examination of the Ovaries
Marked changes in perfusion can be noted in normal
ovaries in the course of the menstrual cycle. While it is
difficult to display any perfusion of the organ during
the follicular phase, signals from the ovary increase
markedly after ovulation, when the erstwhile follicle is
transformed into the corpus luteum. The cause of this
is a physiological “angiogenesis,” which is the consequence of rapid vascular invasion into the corpus luteum of very small vessels without a muscular layer,
resulting in increased end-diastolic perfusion. This
phenomenon is reminiscent both of tumor-specific
perfusion changes and changes resulting from the implantation of a tubal ectopic pregnancy, with either of
F
ig.
which it could be confused (
As a rule the high vascular resistance in the normal
ovarian vessels results in a sharp systolic rise in the
flow curve, followed by a steep decline with an early
diastolic notch, after which the curve declines slowly
to low end-diastolic flow velocities. The resulting RIs in
the blood vessels of the normal premenopausal ovary
are of the order of 0.7 to 0.9. In the region supplied by
tumor vessels, the angiogenetic vessels formed resemble capillary clef ts with sudden increases in caliber
and a lack of the usual vascular musculature that
20.13).
would normally control vascular resistance in a vascular bed. This results in a bed with low flow resistance
and increased continuous flow. Hence the vascular bed
of a tumor often shows a reduction in the measured RIs
to values clearly below 0.7.
After menopause as a rule no blood vessels can be
demonstrated in a healthy ovary of normal size
(volume 쏝8 mL).
Significance of Color-Coded Doppler Ultrasound
In 1993 Bourne et al. published what is to date the only
screening study, examining 1600 asymptomatic
women with a positive family history of ovarian carcinoma. Fifty-eight women with positive morphological
ultrasound findings were also examined by color Dop-
F
ig.
pler (
ian carcinomas were found. The detection rate was
therefore 1:9 by vaginal ultrasound, but 1:2.5 after the
search was refined by the insertion of color Doppler.
However, because of its design this study cannot be
compared with the usual case studies of symptomatic
patients.
Doppler ultrasound were initially presented by the
study groups working with Kurjak (1991), Bourne et al.
(1989), and Campbell (1989). They tried primarily to
find a cutoff level in the measured perfusion indices (RI
or PI) that would effectively differentiate between
benign and malignant tumors. Table
after Voigt 1995) presents an overview of the results of
various study groups.
the studies presented there is a wide overlap between
the Doppler indices for benign and malignant tumors.
For instance, a cutoff level of 0.5 would result in a num-
20.14). On subsequent laparotomy five ovar-
Statistically validated results of transvaginal color
20.3 (modified
On inspection of the results it is noticeable that in
188
Fig. 20.13 Corpus luteum. Fig. 20.14 Color Doppler sonogram of a profusely perfused
ovary.
Ovarian Diagnosis
Table 20.3 Preoperative staging using color-coded Doppler ultrasound
Authors Patients
(n)
Kurjak et al. 1991 680 56/624 RI 0,4 96 99 99
Fleischer et al. 1991 43 11/32 PI 1,0 100 83 100
Weiner et al. 1992 53 17/36 PI 1,0 94 97 −
Kawai et al. 1992 24 9/15 PI 1,25 − − 96
Tekay et al. 1992 72 11/61 RI 0,6 82 72 74
Kurjak et al. 1992 174 38/136 RI − 97 100 99
Timor-Tritsch et al. 1993 115 16/99 RI − 93,8 98,7 −
Prömpeler et al. 1994 129 45/84 RI 0,5 85 77 84
Voigt et al. 1995 186 49/137 PI 1,0 87 93 90
Malignant/
benign
Index Cutoff level Sensitivity
(%)
Specificity
(%)
Accuracy
ber of false positives and also, with a more frequent
fatal outcome, false negatives.
We must add, moreover, that, whereas some study
groups initially found very high values for sensitivity
and specificity in detecting ovarian carcinoma accurately, these results could not be reproduced by other
workers in subsequent years. After a certain initial euphoria, figures for sensitivity and specificity settled at
a level of about 90 %.
In 1996 the group working with Prömpeler analyzed
the validity of transvaginal ultrasound compared to
transvaginal color Doppler sonography and compared
to a combination of both procedures. They essentially
classified their findings as benign if the Schillinger
score was 1 or 2, and malignant if it was 5. Scores of 3
and 4 did not permit separation into benign and malignant tumors. These tumors were then separated according to menopausal status and further differentiated by color Doppler examination.
The indices determined by color Doppler are shown
in Table
20.4.
The table shows clearly that, while the mean values
of benign and malignant tumors can be distinguished
statistically, the broad overlap of the RIs determined
for benign and malignant tumors precludes a definite
distinction between such tumors in individual cases.
Table 20.5 summarizes more studies comparing the di-
agnostic power of ultrasound examination with color
Doppler examination and with a combination of both
procedures (
F
Kurjak and Predanic, for in-
ig. 20.15).
stance, in their 1992 study, were able to amplify the
morphological ultrasound discrimination of tumors by
adding color Doppler sonography. On the other hand,
Valentin and his group (1994) attained a better discrimination by transvaginal ultrasound than by color
Doppler,by determining that all tumors with solid portions should be classified as potentially malignant.
Thus, because of the small number of cases in these
studies, a definitive, precise evaluation of the validity
of color Doppler ultrasound is currently not yet
possible.
Table 20.4 Doppler index values of 36 premenopausal and
52 postmenopausal tumors with scores (after Schillinger) of
3 and 4
Criterion Benign Tumors Malign Tumors
Premenopausal RI
Postmenopausal RI
Median Range Median Range p =
0.54 0.41−1 0.44 0.3−0.53 0.0154
0.52 0.24−1 0.42 0.22−0.66 0.0351
Advanced Topics
Table 20.5 Test validity differentiating benign from malignant ovarian tumors using only ultrasound (TV-US), color Doppler ultrasound (TV-CFM), or a combination of both (after Prömpeler 1996)
Authors Patients
(n)
Kurjak et al. 1992 83 48/96/90 98/95/95 81/96/93
Kurjak und Predanic 1992 174 92/97/97 95/100/100 94/99/99
Timor-Tritsch et al. 1993 94 94/94/94 87/99/99 88/98/98
Schneider et al. 1993 55 88/94/81 67/56/85 78/67/76
Bromley et al. 1994 33 91/67/67 52/81/81 67/76/76
Valentin et al. 1994 149 100/92/100 73/71/77−83 68/75/−
Sensitivity
(TV-US)/
Specificity
(TV-CFM)/
Accuracy
(TV-CFM + TV-CFM)
189
Doppler Ultrasound in Gynecology
Fig. 20.15 Ovarian tumor partly divided by septa. By histology
this was an ovarian carcinoma, but no flow could be demonstrated by Doppler ultrasound.
3
Doppler Ultrasound and Myomas
Essential Considerations for Clinical Practice
Inconclusive adnexal findings should primarily be
evaluated by transvaginal sonography. The most useful
way to classify ovarian tumors, using either transvaginal sonography or color Doppler, is by reference to
menopausal status. Multivariate analysis of sonomorphological criteria indicates that color Doppler ultrasound appears to provide better evaluation of carcinoma staging after menopause than before.
To date research has predominantly pursued the following goals:
왘 Changes in Doppler indices in relation to size and
growth of myomas,
왘 Changes in Doppler indices during GnRH analog
treatment,
왘 Determination of a cutoff level to distinguish
benign from malignant tumors.
In 1997 Alatas and co-workers compared Doppler indices of a normal population of 60 women whose
uterus was of normal size with a study population of
100 women with an enlarged or fibroid uterus (Table
F
ig.
20.6,
tinctly lower indices in the group with uterine fibroids
than in the normal population. When the uteri showing myomatous changes were divided by weight into
two groups, namely those over and those under 200 g,
20.16). The immediate results showed dis-
Table 20.6 Comparison of Doppler indices RI and PI in a normal population with those in a population with an enlarged
uterus
N = Volume of uterus Range RI PI p =
100 276.2 cm
60 101.4 cm
the indices of the heavier uteri were significantly
below the lighter ones. Statistical elaboration showed
a significant overlap of the results, so that healthy uteri
could not be distinguished with certainty from those
with myomas by using Doppler indices alone. Huang et
al. (1996) postoperatively did a histological examination of the uteri of 39 patients who had had hysterectomies for fibroid uteri. They, too, found a correlation between Doppler indices and tumor size, but there was
no corresponding correlation to rate of proliferation or
angiogenesis.
In 1995 Yoshioka examined a population of 38
patients with fibroid uterus. He divided the patients
into two groups:
− One group in which circulation could be displayed
in the specimen or in the periphery of the myoma,
− One group in which no blood vessels could be de-
monstrated in the tissue surrounding the myoma.
3
3
65−928 cm30.77 1.69 0.01
36−171 cm30.82 1.97 0.01
190
Fig. 20.16 Blood flow in the myometrium of a uterus of normal size.
Postoperative histological workup of the operative
specimen showed, as expected, that in the patients of
the second group they could demonstrate an increase
in hyalinization and rarefication of blood vessels.
Fifteen of these patients received GnRH analog treatment preoperatively (buserelin 900µg q.d). All these
cases showed a significant reduction in Doppler in-
Endometrial Diagnosis
dices and a significant decline in serum estradiol in the
course of treatment. Volumetry of the myomas performed concurrently with this study revealed that all
six patients in the group with positive flow in the periphery of the myoma achieved significant reduction in
the size of the tumor, but only three out of nine did so
in the group without evidence of blood flow. These results indicate that the combination of pulsed and color
Doppler ultrasound might be helpful in predicting for
which patients GnRH analog therapy is indicated.
Using preoperative color Doppler examination
before elective hysterectomy in 2010 patients, the
group working with Kurjak (1995) tried to determine a
cutoff level between benign and malignant tumors. In
the course of their histological examination of the
specimens they found 10 sarcomas in addition to 1850
uteri with myomatous changes. In all patients with
sarcoma the Doppler indices were significantly lower
(RI = 0.37) preoperatively than in the control group. Assuming a cutoff level for the RI of 0.4, benign and
Endometrial Diagnosis
Currently transvaginal ultrasound permits a detailed
description of the normal endometrium. Nevertheless,
80% of curettages performed for postmenopausal
bleeding lead to a diagnosis of benign endometrial
changes (Lerner et al. 1996). It is also known that the
sensitivity and specificity of curettage for the detection
of endometrial changes is limited. False negative results for the detection of endometrial hyperplasia and
endometrial carcinoma, as well as endometrial polyps,
F
igs.
were found at a level of 2−6% (
(Grimes 1982, Koonings 1990). Hence the question
arose of whether the detection rate for endometrial
changes could be improved by using color Doppler ultrasound, and if by measuring perfusion, the rate of
false positive findings could be reduced. This is even
20.17, 20.18)
malignant uterine tumors were separated with a sensitivity of 90.91%, a specificity of 99.8%, a positive predictive value for the detection of a tumor of 71.43 %,
and a negative predictive value (exclusion of a tumor
by preoperative Doppler ultrasound examination) of
99.96%. In contrast to similar studies with ovarian
tumors, these studies seem to show that a cutoff level
can be establishe d for myomas.
Essential Considerations for Clinical Practice
The diagnosis of uterine myoma continues to be made
by transvaginal B-mode sonography. The demonstration of blood vessels by color Doppler may identify a
group of patients for whom GnRH therapy is indicated.
If the RI is lowered significantly, the possibility of a sarcoma must at least be considered in planning treatment. It remains to be seen whether the hypothesis
that there is a cutoff level can be confirmed by studies
from other groups.
more important since more patients present themselves for investigation of equivocal endometrial
changes now that tamoxifen has been introduced for
treatment of mammary carcinoma (and more recently
even approved by the Food and Drug Administration
[FDA] for prevention of mammary carcinoma).
A good knowledge of the structure of the normal endometrium is a prerequisite for the evaluation of
pathological changes in the endometrium. Blood is
supplied to the endometrium (
the arcuate arteries of the uterus through radially arranged arteries piercing the myometrium (Fig. 20.20).
Scholtes (1989), working with Wladimiroff ’s group,
and Steer (1990) in Campbell’s group were able to
show a correlation between the level of female sex
20.19) laterally from
Fig.
Advanced Topics
Fig. 20.17 Polyp in the body of the uterus. Fig. 20.18 The polyp displayed by color Doppler.
191
Doppler Ultrasound in Gynecology
3
Fig. 20.19 Blood supply of the uterus. Schematic representation after Fleischer et al.
hormones and uterine perfusion. Thus, as expected,
uterine perfusion clearly depends on the menstrual
cycle. The uterine aa. supply the arterioles in the basal
layer of the endometrium. These arterioles finally give
rise to the spiral aa. of the endometrium, which supply
the functional layer, and, like the latter, change with
the hormonal changes of the menstrual cycle and are
20.21). Adequate
cast off at menstruation (
development of these spiral aa. seems to play an important role in the implantation of the trophoblast at
the beginning of pregnancy. Hence a number of
authors (Deligdisch 1991, Goswamy et al. 1988) have
connected a significant reduction in blood flow in the
supplying uterine a. with infertility.Blood flow in these
vessels of the endometrium proper is so slow that it
can only be displayed by suitable systems (A-mode,
power Doppler). For more precise localization and
differentiation of endometrial changes, Fleischer et al.
(1997) recommended dividing the endometrium into 4
Fig. 20.22):
zones (
Fig.
Fig. 20.20 Ultrasound display of the blood supply to the my-
ometrium.
왘 Zone 1—A layer about 2 mm thick, hypoechoic, sur-
rounding the endometrium (innermost subendometrial layer of the myometrium), sometimes
known as “halo.”
왘 Zone 2—The hyperechoic outermost layer of the en-
dometrium (basal layer).
왘 Zone 3—The hypoechoic inner layer of the en-
dometrium (functional layer).
왘 Zone 4—The surface of the endometrium, boundary
of the uterine cavity.
The premenopausal cyclic changes in the endometrium may be described as follows:
왘 In the follicular phase the endometrium is still rela-
tively thin and is mildly echogenic. Its total thickness is 2−6 mm.
왘 Around the time of ovulation there is often a trace
of fluid in the cavity (Fig. 20.23).
왘 In the postovulatory phase a hyperechoic basal
layer can b e distinguished from a hypoechoic
functional layer (Fig. 20.24).
192
Fig. 20.21 Endometrial blood supply. Fig. 20.22 Endometrium in B-mode image.
Endometrial Diagnosis
Fig. 20.23 Endometrium at time of ovulation. Fig. 20.24 Endometrium after ovulation.
Advanced Topics
왘 In the luteal phase there is first a thickening of the
hypoechoic functional layer that is then increasingly transformed, becoming more hyperechoic. In
this phase the total thickness of the endometrium
can attain 12−14mm (Fig. 20.25).
The morphological changes in the endometrium after
menopause vary according to the number of years
from the beginning of menopause, the exogenous administration of female sex hormones, and the patient’s
body weight. Normally the endometrium atrophies,
the total thickness being 쏝 5 mm. A trace of mucus or
fluid in the lumen (comparable to the changes seen
around ovulation) with a total thickness of the endometrium 쏝 4−5 mm is often seen in the display and
is not considered abnormal. During simple estrogen
treatment the endometrium proliferates slightly and
attains a diameter of almost premenopausal dimension. In combined estrogen/progesterone therapy proliferation to a total thickness of 6−8 mm may be observed.
The question of at what thickness of the endometrium a histological examination becomes necessary has not yet been answered definitively. In one of
the largest studies, the Nordic trial, using a cutoff level
of 4 mm, a sensitivity of 96 % and a specificity of 68%
were calculated for the detection of endometrial carcinoma. Other groups recommend a histological examination at total endometrial thicknesses of 5−8 mm in
the absence of hormone substitution. Of course in
these recommendations there is a broad overlap between normal and abnormal values when the evaluation addresses only the total thickness of the en-
20.26).
dometrium (
It is known from B-mode sonography as well as hysteroscopic examination that endometrial carcinoma
may develop as a focal lesion in an otherwise normal
endometrium, as a diffuse process, or in endometrial
polyps. Hence the display of irregular perfusion of the
endometrium should be considered a good additional
criterion for the detection of neoplasms (
20.28).
Fig.
Figs. 20.27,
Fig. 20.25 Endometrium in luteal phase. Fig. 20.26 Loose, cystic, thickened endometrium.
193