Добавил:
Sekretar
kiopkiopkiop18@yandex.ru
t.me/Prokururor I Вовсе не секретарь, но почту проверяю
Опубликованный материал нарушает ваши авторские права? Сообщите нам.
Вуз:
Предмет:
Файл:Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_5817_Библиотеки_им_академика_М_И_Перельмана-1.pdf
Doppler Ultrasound in Gynecology
The two largest studies addressing endometrial
changes in an asymptomatic population (Kurjak et al.
1994, Schulman et al. 1994) showed that ultrasound
examination could be expected to detect
왘 Three endometrial carcinomas,
왘 Five endometrial hyperplasias,
왘 Five polyps per 1000 patients.
Could these results be improved by the addition of
color Doppler ultrasound? More specifically, can the
relatively high rate of false positive results when looking only at endometrial thickness be improved?
Possibly detection can be improved by instilling fluid
into the uterine cavity (saline infusion sonography),
such as the sonohysterography of Cullinan et al. (1995).
In this procedure the instillation of fluid into the
uterine cavity markedly improves the quality of the
3
image in B-mode as well as in Doppler ultrasound.
Bourne et al. reported in 1990 and 1991 that resistance in the uterine vascular supply was considerably lower than in control groups when an endometrial
neoplasm was present. In all carcinomas of the endometrium the PI in the uterine a. was below 1.8. The
Fig. 20.27 B-mode image of an endometrial carcinoma, confirmed by histology.
authors attributed the difference to angiogenesis in the
endometrium and the adjoining myometrium.
Hata and his collaborators (1991) examined 10
patients with endometrial carcinoma. They found an
elevated blood flow in the region of the tumor itself
with a PI of 0.535 (앧 0.158). In the course of the same
study blood flows in a total of 291 benign and 17 malignant uterine tumors were compared: The RI was 0.58
(앧 0.12) in uterine myomas and 0.34 (앧 0.03) in en-
dometrial carcinoma. The authors concluded that
below a cutoff level for the RI of 0.4 an equivocal lesion
should be considered to be malignant, while those between 0.4 and 0.5 were considered to be suspicious.
Bourne and his collaborators (1992) examined
uterine blood flow in 227 postmenopausal patients—
72 patients with uterine bleeding and 155 who were
asymptomatic. In this study patients with endometrial
carcinoma had an average endometrial thickness of
20.2 mm, while in asymptomatic patients the endometrium was atrophied, and the average thickness
was 1.35 mm. In endometrial carcinoma the PI was
relatively low at 1.0, while in atrophic endometrium it
was 3.8.
In a color Doppler ultrasound analysis of endometrial blood flow published in 1995, Sheth and his
co-workers found no difference between malignant
and benign tumors.
Will color Doppler examination, then, play a role in
the future when a decision is made regarding how to
proceed with the investigation? Granberg and Bourne
(1997) answered the question in the negative, pointing
out that when endometrial thickening is found it must
be followed by histological examination of the endometrium, regardless of the Doppler ultrasound findings. This opinion may be countered by the finding that
the common endometrial changes found during
tamoxifen treatment, i.e., endometrial thickening and
sclerosis in Fleischer’s subendometrial zone 1 (cf.
above), can mimic endometrial hyperplasia. In such
cases the B-mode image may resemble endometrial
194
a b
Fig. 20.28a, b Endometrial carcinomas in color Doppler.
Endometrial Diagnosis
thickening that actually does not exist in this form.
Curettage only yields tiny particles of an essentially
atrophic endometrium. In 1995 Exacoustos et al. described four possible sonographic changes in the endometrial pattern of patients taking tamoxifen (20−
30 mg q.d.):
왘 Echogenic endometrium with good boundaries,
subendometrial halo, and homogeneous struc-
tured;
왘 Echogenic endometrium with good boundaries,
containing small echo-free cysts;
왘 Echogenic endometrium with nonhomogeneous
structure, small cystic parts, and blurring of the
boundary between the endometrium and the subendometrial layer;
왘 Echogenic endometrium with nonhomogeneous ar-
chitecture, blurred boundaries, and partly interrupted halo, i.e., increased density or sclerosis in
the subendometrial layer.
In our own study of 20 patients, so far unpublished, we
found that in an endometrium which was found to be
쏜 10 mm thick by transvaginal sonography (corresponding to Exacoustos’s fourth pattern), there was no
corresponding finding by hysteroscopy or histology.
On the contrary, the uterine cavity contained only
atrophic endometrium, and this was confirmed by histological examination of targeted tissue areas. It seems
likely that in such a patient population ultrasound control would find the appearance of endometrial hyperplasia immediately after curettage, since the increased
subendometrial density that mimics endometrial hyperplasia continues to be present. In such cases the introduction of color Doppler might be successful in discriminating between suspicious findings: By our criteria renewed operative intervention would only be indicated if abnormal vessels supervene.
Essential Considerations for Clinical Practice
The results of color Doppler ultrasound for endometrial diagnosis are not yet solid to the point
where they could be used materially to determine
treatment decisions in clinical practice. Endometrial
thickness of less than 5 mm speaks against the existence of an endometrial carcinoma with a high
degree of probability. If the thickness of the endometrium 쏜 8 mm, display of vessels in general and
high diastolic flow with a RI 쏝 0.4 is highly suspicious
of a malignancy.
In conclusion,I would like to quote an apt commentary by S. Granville, which I consider rather punctilious
but to the point:
“Transvaginal sonography, including color Doppler
sonography, offers a very sensitive glimpse into the
pathological changes of the female pelvis. It is evident
that the limits of the procedure often lie in the examiner rather than in the procedure or the instrumentation. Hence delicate inquiries should be undertaken
only by experienced examiners. Ultrasound is learnt
neither by acquiring numerous certificates in endless
courses, nor by reading overview articles like the present one. Experience can only be gained by insonating
thousands of patients, by comparing one’s own findings with those of the facility, and by results confirmed
in surgery. It is only from such experience that a ‘feeling’ can be developed for what conclusions a procedure can and cannot support.”
This is the sense in which I would like to urge those
of my colleagues who are active in using ultrasound to
add color Doppler ultrasound to many of their inquiries.
Advanced Topics
195
3
196
21 Diagnosis of the Uterine Tube
by Transvaginal Sonography
One in five couples in the United States is infertile;
there are about 60−80 million such couples worldwide.
Infertility is defined as the inability of a couple to conceive after one year of unprotected intercourse. Etiologic factors affect the woman in about 45 % of cases,
the man in 40 %, while 15% remain undiagnosed. A distinction is made between primary infertility, if the
couple has never conceived, and secondary infertility,
if there has been a prior pregnancy (Runnebaum and
Rabe 1994).
Investigation of the oviduct plays a cardinal role in
the diagnostic workup of infertility. Besides hormonal
and cervical factors, as well as factors relating to the
man, the patency and functionality of the fallopian
tube is the organic prerequisite for a successful meeting of the ovum and spermatozoon. In 30−40 % of cases
the uterine tube is the factor responsible for female infertility. In secondary infertility the involvement of the
oviduct rises to 60 %. The reasons for this might be
genital infections, such as an asymptomatic salpingitis,
or tubal endometriosis (Runnebaum and Rabe 1994).
Application of Ultrasound in Diagnosis of the Uterine Tube
The uterus and ovaries can be displayed by B-mode imaging without difficulty. Unless they are altered by
pathology the uterine tubes are not accessible to this
diagnostic procedure. For their investigation a fluid
must be instilled through the cervix into the uterine
cavity and thence into the lumens of the oviducts to
make them echogenic for display by B-mode imaging
(Rimbach et al. 1995).
Sonographic diagnosis of the fallopian tube by transcervical instillation of contrast medium has in the past
few years become an ambulatory alternative to fluoroscopic hysterosalpingography and chromolaparoscopy.
The use of ultrasound for tubal diagnosis allows the affected patients to avoid the stresses of iodine-containing contrast media, radiographs, or anesthesia and
surgery. Since the procedure does not use major resources either in terms of personnel or instrumentation, it can easily be integrated into routine clinical
practice (Degenhardt 1995).
Display of the Tube by Contrast Sonography
This procedure uses an opalescent solution made up of
microparticles of galactose and an aqueous galactose
solution. The solution is made up just before the procedure by vigorously shaking D-galactose granules
with a 20 % aqueous D-galactose solution for 5 seconds.
The shaking induces air microbubbles to settle on the
surface of the galactose microparticles and initiates
changes in the way sound is displayed sonographically.
These changes include simple backscatter effects and
an increase in contrast, caused by the oscillations induced by ultrasound in the air microbubbles.
One property essential for the clinical application of
the contrast medium is stability under pressure while
it is being introduced and during ultrasound examination. This property is not changed materially by the microbubbles in the suspension (Degenhardt 1995).
Undesirable side effects occurring during use in
more than 1000 patients were mainly related to vasovagal reactions, such as vertigo, nausea, sweating,
and transient mild pain. During the examinations
there have been no known allergic reactions to date
(Degenhardt 1995). The only contraindication to the
use of the substance is hereditary galactosemia (incidence 1:30 000).
Contrast-enhanced sonographic examination of the
uterine tubes can be undertaken if a genital infection
such as colpitis, endometritis, or salpingitis can be excluded and the serum white cell count is 쏝 10000/µL.
Lactic acid suppositories may be inserted to prepare
the vagina, but they are not essential, since the vagina
will be disinfected with povidone-iodone or some similar preparation immediately before the tube is displayed by contrast ultrasound examination.
In order not to endanger a possible early pregnancy,
sonographic display of the oviducts should be performed in the first half of the menstrual cycle, i. e., between the sixth and tenth day of the cycle. At that time
the cervix is of course slightly dilated, so that instrumental dilatation is as a rule not necessary (Degenhardt 1995, Deichert et al. 1988).
Advanced Topics
197
Diagnosis of the Uterine Tube by Transvaginal Sonography
For the placement of the balloon catheter a self-retaining speculum helps to visualize the external os of
the cervix. The catheter can usually be introduced into
the cervical canal with a forceps without grasping the
cervix. The balloon is inflated in the uterine cavity with
3−4 mL room air or normal saline solution and the
catheter fixed above the internal os by light traction. As
a rule the fixation of the catheter is not painful. At the
same time an assistant can prepare the suspension,
draw it into a syringe, and attach this to the catheter
(Degenhardt 1995).
The vaginal probe used for this procedure should
reach frequencies of 5−10 MHz to achieve a high resolution. After the patient has been prepped the vaginal
ultrasonic probe can be introduced into the vagina
next to the narrow-lumen transcervical catheter.
Firstly, the uterus is displayed in longitudinal view. The
3
contrast medium first reaches the uterine cavity and
there can serve to highlight any malformations. As a
rule 2−5 mL of the contrast medium are sufficient to
outline the cavity. The cross section of the uterine fundus is then imaged and, to begin with, careful intermittent release of the contrast medium will display the intramural section of the fallopian tube, followed by the
isthmus and the ampulla (Degenhardt 1995, Rimbach
et al. 1995). The sequence of this examination is repeated on the contralateral side. As a rule less than
10mL of the contrast medium is required for this ex-
amination, so that the 15 mL of contrast medium
generally available from the suspension provides an
adequate reserve.
If the tubes are occluded bilaterally, the procedure
can be uncomfortable or painful. The patient should be
warned about this possibility. In such cases pressure
builds in the cavity, so that there appears to be resistance to the application of contrast medium. If the
tubal occlusion is confirmed sonographically, the contrast medium should be reaspirated, in order to avoid
any undesirable side effect (Degenhardt 1995).
In B-mode sonography the contrast medium provides precise information about the structure and caliber of the lumens of the uterine tubes and their
patency within a few minutes. If a tube is patent, the
contrast medium escapes from the ampullary segment
of the tube into the abdominal cavity and can be demonstrated in the space of Douglas. The galactose solution is absorbed from the abdominal cavity within 24
hours. If the fallopian tube is obstructed proximally,
the only portions displayed are the uterine cavity and
intramural segment of the pathologically altered tube.
In the presence of a sactosalpinx the contrast medium
collects in the distal portion of the uterine tube, but no
discharge from the tube can be displayed. The findings
should be documented by still or video imaging.
Supplementation by Doppler
If escape of the contrast medium cannot be displayed
by B-mode imaging, color Doppler can be used to
supplement the procedure. The flow of contrast medium at the transition from the infundibulum to the
abdominal cavity can be confirmed positively by color
display (Degenhardt 1995, Rimbach et al. 1995). For
uncomplicated examinations display by color Doppler
does not shorten the duration of the examination (Deichert et al. 1988).
Use of pulsed Doppler may also be considered for
supplementation. The Doppler signal seen when the
intramural segment of the fallopian tube is displayed is
characteristic. A narrow sample volume is fixed on the
intramural segment of the uterine tube. When the latter is patent, a slowly rising reflex curve can be seen. In
cases where the segment is occluded the Doppler signal shows a briefly increased resistance, after which it
breaks off abruptly.
This procedure is less suited for the confirmation of
an occluded ampullary segment. The Doppler profile
only changes when resistance is high due to ampullary
occlusion. Initially, the Doppler profile appears unremarkable, since the capacity of the ampulla allows the
contrast medium to enter at a normal velocity. An adequate amount of contrast medium should be held in
reserve before beginning the Doppler examination
(Degenhardt 1995).
198
Comparison to Other Procedures
The most effective procedure for establishing tubal
morphology and patency continues to be chromolaparoscopy with chromoperturbation. The procedure
enables a detailed evaluation of the internal genital organs. Nevertheless, it remains impossible to demonstrate the extrusion of blue dye from the fimbriated
end in cases of extensive pelvic adhesions. A sonographic display using a contrast medium may be of
value in these cases.
Hysteroscopic examination allows the uterine cavity
to be imaged. Synechiae, submucosal fibroids, and the
tubal ostium are accessible for assessment. The course
and patency of the oviduct cannot be assessed (Degenhardt 1995, Rimbach et al. 1995).
The use of conventional hysterosalpingography,
which is mediated by radiological contrast media, is
limited by the effect of radiographs on the pelvic organs. Documentation of the path of the contrast me-
Comparison to Other Procedures
dium requires two to three radiograph films and
fluoroscopy of the true pelvis. The radiation received
by the ovaries amounts to 1−3.6 cGy (Degenhardt
1995).
Scintigraphic examination of tubal motility to assess
functional capacity of the uterine tube (hysterosalpin-
goscintography), as described by Steck et al. (1989), has
not entered routine clinical practice.
We conclude that transvaginal tubal sonography
using a contrast medium is a procedure by which tubal
patency can be assessed without major complications.
Should infertility continue to pose a problem even
when patency of the uterine tube has been demonstrated by ultrasound, investigation should be continued by chromolaparoscopy.
Advanced Topics
199
3
200
22 Diagnostic Sonography of Blood Flow in Breast Tumors
Biological Background
In recent years ultrasonographic examination of blood
flow has been added to the armamentarium used in
the differential diagnosis of breast tumors of uncertain
malignancy.
As early as 1907 Goldman first showed that the
growth of a tumor leads to vascular proliferation in the
surrounding tissue, and that this phenomenon is a response of the host to the growth of the tumor. In 1945
Algire and Chalkley discovered that malignant cells can
elicit vascular proliferation on a continuous basis and
that tumor cells have the property of inducing the
growth of capillary epithelium in vivo. Finally, in 1971,
Folkman et al. were able to isolate the factor responsible for angiogenesis in tumors (Folkman et al.
1971, 1987). Currently some authors assert that vascular proliferation in the tissues surrounding a tumor is
an essential prerequisite for tumor growth. Beyond
that, neovascularization is considered to be a sign of
malignancy in a tumor (Delorme 1993, Kaiser et al.
1993, Plate 1993, Possover et al. 1994, Samejima et. al.
1988, Schild and Fendel 1991, Sohn et al. 1992a, Weidner et al. 1991). The degree of vascularization in a
mammary carcinoma correlates with its invasiveness
and its metastasizing potential (Weidner et al. 1991).
Arteriovenous shunts develop and the newly-formed
vessels can at times show considerable variation in
their caliber, resulting in rather heterogeneous blood
flow patterns (Bouck 1994, Horak et al. 1992).
Since the structure of the newly-formed capillaries
does not include a muscular layer, their vascular resistance is very low, resulting in an extremely low flow
rate (Sohn et al. 1992a, 1993, 1994a, b). It is precisely
these minimal flow rates that can be brought into focus
with the aid of the new color techniques, contributing
to preoperative diagnostic staging.
However, some benign conditions, such as proliferative mastopathies, inflammatory processes, or a lactating breast can lead to increased blood perfusion
(Leucht and Madjar 1995, Madjar et al. 1997/98). Due
to the rapid technical developments of the last 10
years, different working groups have at times arrived
at quite contradictory results (Adler et al. 1990, Bell et
al. 1993, Blohmer and Lau 1993, Blohmer et al. 1993a,
1993b, 1994, Britton and Couldon 1990, Burns et al.
1982, Cosgrove 1992, Delorme 1993, Dock 1993, Huber
et al. 1993, Konishi 1992, Madjar and Schillinger 1986,
Madjar et al. 1989, 1991b, Schild and Fendel 1991,
Schild et al. 1993, Sohn et al. 1992b, 1993).
Advanced Topics
Instrumentation
Doppler ultrasound uses the frequency shift in sound
waves emitted from a mobile element to make visible
and measure the motion of erythrocytes in the blood
vessels of a tissue. The degree of frequency shift is recorded and documented in Hertz, or it is used to calculate the flow rate of the erythrocytes in millimeters per
second or centimeters per second.
The frequency shift depends on the frequency of the
sound waves generated and the velocity of blood flow
in the vessels. Because, as noted above, the circulation
in a malignant lesion in the female breast is very slow,
high Doppler frequencies are required to detect blood
flow in a mammary carcinoma (Madjar et al. 1989).
Continuous Wave Doppler
In a continuous wave (CW) Doppler, sound waves are
continuously emitted and simultaneously received
from the transducer. Using a frequency usually of
10MHz, a transducer with a surface diameter of about
1 cm (pencil probe) is moved systematically over the
whole breast. Good skin contact must be maintained
throughout the examination. The results of CW Doppler recording are reproduced as acoustic noise or a
22.1). It is not
Doppler flow curve on the monitor (
feasible to display the tissue under examination in Bmode image. By the same token vessels cannot be displayed at a specific depth. Because of the high frequencies used with the pencil probe, the sensitivity of this
procedure for the display of the breast is very high. Ad-
Fig
201
Diagnostic Sonography of Blood Flow in Breast Tumors
Fig. 22.1 CW Doppler. The results of the measurements are
displayed as a Doppler flow curve.
mittedly, because of the small surface area of the probe
and the type of signal display, the procedure must be
performed absolutely systematically and the examiner
must have a great deal of experiencein the detection of
nonpalpable tumors in the female breast.
Scientific research, in which the display by CW Dop-
3
pler of the vessels in the breast affected by a tumor was
compared with the contralateral side, found a definite
increase in the number of vessels on the malignant
side. Moreover, in most healthy women the course of
the vessels and the blood flow in both breasts were
symmetrical. The research also added information on
the small circulatory changes in the female breast over
the course of the menstrual cycle (Madjar et al. 1998,
1992).
Because of the lack of a visual display as a B-mode
image, and because it is very time-consuming, CW
Doppler is no longer used in routine diagnostic studies
(Madjar et al. 1992, Schild and Fendel 1991, Schild et al.
1993).
from the time interval between sending and receiving
sound waves. Hence it becomes possible to display the
vessels at specific depths. The findings can also be displayed simultaneously in B-mode.
The procedure first uses the B-mode image to look
for a lesion in the breast. Next the Doppler window,
called the “sample volume,” is placed over the region
of interest (ROI). As a consequence the blood vessels at
precisely this depth of penetration can be displayed
with the recorded frequency shift and the corresponding Doppler spectrum can be measured (Sohn et al
22.2).
Fig.
1993;
The following parameters are recorded and analyzed
by PW Doppler:
왘 Maximal systolic velocity (V I<max sys): A
왘 Minimal end-diastolic velocity (V
왘 A/B ratio: Q = A/B
왘 Resistance index (RI): RI = A−B/A
왘 Pulsatility index (PI): PI = A−B/Q
The Doppler spectrum should be recorded at an acute
angle, preferably 쏝60°, since otherwise errors could
creep into the calculation of velocity. The RI and the PI
are largely independent of the angle.
It is often difficult in the B-mode image to display
the small vessels of a breast tumor formed by angiogenesis. Hence the detection of blood vessels involves a
“blind” search of the sample volume, just as with CW
Doppler.
min
dias): B
Color-Coded PW Doppler
202
Pulsed Wave Doppler
In pulsed wave (PW) Doppler, sound waves of one
frequency are sent and received alternately at defined
time intervals. Selected tissue depths can be calculated
Fig. 22.2 PW Doppler. The sample volume is placed into the Bmode image in such a way that the Doppler spectrum of the
blood vessels of interest is displayed.
A large proportion of the diagnostic studies of blood
flow in obstetrics and gynecology is currently performed by color-coded PW Doppler ultrasound. This
procedure is especially applicable to sonography of the
breast, because it is able to detect blood vessels of
which the lumen is below the power of resolution of
the B-mode image.
In the color-coded PW Doppler the received Doppler
signals are color-coded, i.e., blood flow velocities are
transformed on the monitor into various colors and
degrees of brightness. In these procedures the direction of flow is meaningless. Depending on the manufacturer of the instrument, the procedure is based on
an analysis of phase shift, runtime, or frequency shift.
In the course of the measuring procedure, a wall filter or high pass filter (HPF) filters out the oscillations of
the vascular wall. However, slow flow components of
the perfusing circulation are also filtered out. For this
reason the wall filter in ultrasound examination of the
breast must be high, so that precisely these slow components of flow velocities can be detected. The PW
Doppler can record and measure a Doppler flow curve
if the sample volume is placed in the vessel that is displayed in color.
Because of the very slow blood flows that need to be
detected in mammary sonography, instrumental settings are very sensitive. Hence the development of artifacts is considerable, not only due to the patient’s respiration and heart beat, but also her spontaneous
movements.
In the procedure the malignant lesion in the
patient’s breast is first displayed in the B-mode image.
Next the Doppler window of the color-coded Doppler
ultrasound is placed over the B-mode image. The
sample volume is set low. The detected blood vessels
22.3). Now the sample
are now displayed in color (
volume can be targeted at an acute angle to the vessel
that is to be examined. The monitor displays a Doppler
flow curve, which can be analyzed. Should measurements be unsuccessful at an angle 쏝60°, it is possible
to resort to angle correction. In this correction the actual angle is used in calculating the velocity.
The following technical aspects of instrumentation
should be addressed when color-coded Doppler ultrasound is to be used:
왘 Color-coded pulsed wave Doppler technology,
왘 Doppler frequencies 쏜 5 MHz,
왘 Synchronous display of B-mode image and Doppler
flow curve,
왘 Variable size of the sample volume,
왘 Variable Doppler angle (it should be adaptable to
the course of the vessel),
왘 Angle correction available,
왘 Low measuring range (쏝 1 cm/s),
왘 Limited expression of flash artifacts (movements in
the surrounding tissue cause color artifacts),
왘 The capability of displaying the Doppler flow curve
at a height at which quantitative measurements can
be performed,
왘 Analysis of the usual Doppler parameters by the
system’s software,
왘 Easily handled, lightweight probe.
Fig.
Diagnostic Sonography of Blood Flow in Breast Tumors
Fig. 22.3 In color-coded Doppler ultrasound the detected
blood vessels are displayed in color.
Advanced Topics
Angio Color, Angio Mode, Power Doppler
The angio color technique is a procedure that, like con-
ventional color Doppler ultrasound, displays blood
flows as a color image superimposed on the B-mode
image in real time. In contrast to the traditional color
Doppler, angio mode analyzes the amplitude of the
echo and consequently provides information concerning the number or density of the erythrocytes reflecting the ultrasonic beam.
As in the various procedures described above, the
examination begins with a B-mode display of the suspected primary lesion in the female breast. Next, the
color Doppler window is made to coincide with the
changes previously outlined by ultrasound. Even very
small blood vessels with low flows can be detected
Fig. 22.4 Breast tumor in angio mode. Even very small blood
vessels with low flows can be displayed by this procedure.
Fig.
using this method (
the PW Doppler can now be placed over such a vessel,
the Doppler flow curve can be recorded, and calculations derived from it.
This system has distinct advantages. Because it uses
amplitude, it is independent of the angle between
blood flow and the incident ultrasonic beam.
Moreover, the amplitude signals include less back-
22.4). The sample volume of
203