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REVIEW ARTICLE
R. Tunn ÆG. Schaer ÆU. Peschers ÆW. Bader
A. Gauruder ÆE. Hanzal ÆH. Koelbl ÆD. Koelle
D. Perucchini ÆE. Petri ÆP. Riss ÆB. Schuessler
V. Viereck
Updated recommendations on ultrasonography in urogynecology
Received: 23 March 2004 / Accepted: 6 August 2004 / Published online: 16 October 2004
ÓInternational Urogynecology Journal 2004
Abstract Ultrasound is a supplementary, indispensable
diagnostic procedure in urogynecology; perineal, intro-
ital, and endoanal ultrasound are the most recom-
mended techniques. The position and mobility of the
bladder neck can be demonstrated. In patients under-
going diagnostic work-up for urge symptoms, ultra-
sound occasionally demonstrates urethral diverticula,
leiomyomas, and cysts in the vaginal wall. These findings
will lead to further diagnostic assessment. The same
applies to the demonstration of bladder diverticula,
foreign bodies in the bladder, and bullous edema. With
endoanal ultrasound, different parts of the sphincter ani
muscle can be evaluated. Recommendations for the
standardized use of urogenital ultrasound are given.
Keywords Incontinence ÆProlapse ÆUltrasound
Introduction
Ultrasonography has become an established procedure
in the diagnostic evaluation of female incontinence and
functional disorders of the pelvic floor and has replaced
X-ray procedures to a large extent. A review of the
international literature shows that the majority of recent
morphologic studies of the female lower urinary tract
have been conducted using ultrasound. However,
investigators use different sonographic techniques and
measurement procedures, which often preclude com-
parison of the findings obtained in different studies.
After the first consensus meeting on ultrasonography
in urogynecology, which was held in Zurich, Switzerland
in 1995, established the first recommendations for
standardizing urogynecologic ultrasound examinations,
a second meeting took place in Berlin on 15 and 16
November 2003. The aim of this meeting was to revise
the recommendations based on the current state of re-
search as presented in the international literature in this
field. The focus was on ultrasonography alone without
taking into consideration other imaging modalities used
in the diagnostic work-up of incontinence and prolapse.
Endoanal sonography has been newly incorporated into
the updated recommendations.
Sonographic techniques
A basic distinction can be made between two sono-
graphic techniques based on the mode of probe appli-
cation:
1. Endosonographic techniques: endoanal sonography
2. External techniques: perineal, introital, and transab-
dominal sonography
The endosonographic techniques are associated with
probe-induced changes in bladder anatomy [1]. Trans-
abdominal ultrasound has been replaced by other
external techniques, except for the determination of
residual urine. The decision in favor of a method de-
pends above all on the ultrasound equipment and probes
available. A reason why mainly introital and perineal
techniques are in use is that these examinations can be
performed with the same probes as obstetric and gyne-
cologic ultrasound examinations. The ultrasound fre-
quencies used depend on the probe and method chosen.
R. Tunn ÆU. Peschers (&)ÆW. Bader
A. Gauruder ÆH. Koelbl ÆE. Petri ÆV. Viereck
Association of Urogynecology and Pelvic Floor Repair, Germany
E-mail: ursula.peschers@amperkliniken.de
Tel.: +49-8131-728324
Fax: +49-8131-728250
G. Schaer ÆD. Perucchini ÆB. Schuessler
Association of Urogynecology, Switzerland
E. Hanzal ÆD. Koelle ÆP. Riss
Association of Urogynecology
and Reconstructive Pelvic Floor Surgery, Austria
U. Peschers
Department of Obstetrics and Gynecology,
Amperkliniken, Konrad-Adenauer-Str. 30,
85221 Dachau, Germany
Int Urogynecol J (2005) 16: 236–241
DOI 10.1007/s00192-004-1228-7
The frequencies are 3.5–5 MHz in perineal ultrasound
and 5–7.5 MHz in introital ultrasound.
This consensus paper presents recommendations for
performing perineal and introital ultrasound, which are
the most widely used techniques, and endoanal ultra-
sound. As the paper is not a review paper, it does not give
a complete overview about the past and current research
trends in the field and does not deal with experimental
techniques such as endourethral and three-dimensional
ultrasound, color Doppler in urogynecology, and
contrast ultrasound.
Anatomy visualized by ultrasound
The following structures and organs can be visualized
with ultrasound: bladder, urethra, symphysis pubis, va-
gina, rectum, and uterus. However, the examiner must
be aware that there are differences according to the
method used. The visualization crucially relies on the
frequency and the angle of projection. Introital and
perineal ultrasound provide panoramic views of the true
pelvis.
The recent advances in ultrasound technology have
improved the resolution and hence the visualization of
pelvic structures to such an extent that it is no longer
necessary, for instance, to mark the urethra with a Foley
catheter.
Image orientation
Most state-of-the-art ultrasound scanners use software
that enables rotation of sonographic images. These
scanners can therefore display cranial parts in the upper
part of the images. In accordance with the DEGUM
[German Ultrasound Association], it is recommended
that urogynecologic ultrasound images be presented
with cranial parts shown on top (Fig. 1). This is the most
widely used way of presenting gynecologic endovaginal
ultrasound images [2] and also corresponds to the ori-
entation recommended by Merz [3] and Bernaschek [2].
Measurement methods
The results of ultrasound examinations of the female
lower urinary tract comprise quantitative and qualitative
findings. Quantitative parameters are important for pre-
and postoperative comparisons, and therefore also for
quality assurance and scientific investigations. We rec-
ommend to determine the retrovesical angle and the
position of the internal urethral orifice. For determina-
tion of the internal urethral orifice, different methods
had been previously investigated and their reproduc-
ibility analyzed [4,5,6]. In perineal ultrasound, the
pubic bone is used as a stable pelvic landmark for
drawing a reliable reference line (central line of the
symphysis, Fig. 2). In introital ultrasound, the prolon-
gation of the axis of the ultrasound probe serves as the
reference line. A good reproducibility and repeatability
has been demonstrated for both methods [4,5,6,7]. An
optimal reference line is defined in relation to a repro-
ducible anatomic landmark. In scientific publications,
the reference line used needs to be defined in a precise
and reproducible manner. The qualitative parameters to
be determined and described are funneling of the blad-
der neck and the position and mobility (fixed, hyper-
mobile) of the urethra and bladder base (vertical,
rotational, or no descent]. These are descriptive terms
that lack a precise definition (Table 1). Since introital
and endovaginal ultrasound do not usually visualize the
entire symphysis pubis, the lower point of the symphysis
has so far been used as a reference point with these
techniques (Fig. 3)[7,8,9,10]. However, to obtain
reliable results with this method, care must be taken to
hold the ultrasound probe in the same position at rest
and during the Valsalva maneuver, coughing, and pelvic
floor contraction. Both introital and endovaginal ultra-
sound are established techniques in clinical routine and
scientific studies alike and are used as they are available.
Examination position
The patient’s position affects the measurement results:
the internal urethral orifice lies lower and the retrovesi-
cal angle is larger in the standing position [11]. However,
the differences are altogether small and negligible in
clinical assessment as long as one consistently performs
the measurements on ultrasound images obtained in the
same position [11]. With regard to the qualitative
parameters, funneling is seen more frequently and des-
cent of the bladder base is more pronounced when the
Fig. 1 Illustration of ultrasound images according to the recom-
mendations of Merz and Bernaschek on vaginal sonography in
gynecology. Cranial structures are shown above, caudal structures
below, ventral structures on the right, and dorsal structures on the
left side. Please note that this schematic drawing does not provide
accurate anatomic details
237
examination is performed with the patient standing. We
advocate examination with the patient supine on the
gynecologic chair (lithotomy position). Only if ultra-
sound in this position fails to demonstrate bladder neck
funneling is it necessary to repeat the examination with
the patient standing.
Bladder filling
Bladder volume has only little effect on the distance and
angle measurements [12,13]. However, according to
Dietz, mobility of the bladder neck is increased when the
bladder is empty [14]. Only standardized bladder vol-
umes allow reliable comparison of pre- and postopera-
tive findings or comparisons of data from different
centers.
Effect of probe pressure on findings
The acquisition of ultrasound images requires direct
contact between the probe and the body, which differs
with the technique employed and the site of probe
application. Endosonographic techniques distort the
urethrovesical anatomical relationship more markedly
than do external techniques [1]. Differences in the pres-
sure exerted with the ultrasound probe can change the
measuring results (retrovesical angle and position of the
Fig. 3 Measurement of the height of bladder neck with introital
sonography. A horizontal line is drawn at the lower border of the
symphysis. The height (H) of the bladder neck is determined as the
distance between bladder neck (BN) and this horizontal line. For
reliable measurements at rest, during the Valsalva and pelvic floor
contractions, the position of the ultrasound probe may not be
changed
Fig. 2 Measurement methods for the bladder neck position (BN)
and for the retrovesical angle b.Left, measurement of the bladder
neck position with two distances. A rectangular coordinate system
is set up with the origin at the lower border of the symphysis. The
x-axis is determined by the central line of the symphysis, which runs
between its lower and upper borders. The y-axis is constructed
perpendicular to the x-axis at the lower symphysis border. Dx is
defined as the distance between the y-axis and the bladder neck,
and Dy is defined as the distance between the x-axis and the bladder
neck. For precise localization of the bladder neck, the upper and
ventral point of the urethral wall at the immediate transition into
the bladder is used. Right, measurement of the bladder neck
position with one distance and one angle. The distance between
bladder neck and inferior border of the symphysis and the angle
between this distance line and the central line of the symphysis
(pubourethral angle) is measured. The determination of the
retrovesical angle bis the same for these two methods. One side
of the angle lies along the line connecting the dorsocaudal and
proximal urethra, and the other side is formed by the tangent along
the bladder base
Table 1 Terms used descriptively without having precise defini-
tions
Hypermobility of the bladder neck
Excessive elevation following colposuspension
Urethral kinking
Funneling
Rotational and vertical descent
Cystocele
238
internal urethral orifice) [12]. The examination should be
performed with low pressure, just sufficient to obtain a
good image.
Functional testing
Functional tests (provocation tests) for assessing
incontinence are the Valsalva maneuver and coughing.
These two provocation tests yield different results for the
position of the internal urethral orifice and angle mea-
surements [12]. Bladder neck mobility is greater during
the Valsalva maneuver than during coughing because
the former is associated with relaxation of the pelvic
floor and the latter with contraction [5]. For quantitative
evaluation of mobility, the Valsalva maneuver is pref-
erable to the cough test.
Sonographic examinations should be performed
during four functional states: at rest and during the
Valsalva maneuver, coughing, and pelvic floor contrac-
tion. In the clinical setting, visual biofeedback can be
given by showing the patient how the bladder neck is
elevated during contraction [15,16,17].
When these tests are performed as part of a scientific
study, intra-abdominal pressure during the Valsalva
maneuver or coughing should be measured. It must also
be borne in mind that the analysis may be limited by the
equipment available (e.g., frame rate when the exami-
nation is recorded on videotape), resulting in failure to
register the maximum extent of rapid movements.
Table 1lists the terms that are used descriptively with-
out having precise definitions.
Clinical application
Sonographic findings obtained in the clinical setting
suggest that there is a correlation between the diagnosis
of stress urinary incontinence and the demonstration of
funneling and bladder neck mobility at ultrasound.
Pronounced funneling alone without significant mobility
can only be demonstrated by ultrasound but not by the
clinical examination. Schaer et al. published a descrip-
tive method for evaluating the extent of funneling [18].
Mobility of the bladder neck is likewise associated with
the presence of stress urinary incontinence. However,
there is wide overlap of findings between continent and
incontinent women. A generally accepted definition of
hypermobility is still lacking. In patients undergoing
preoperative evaluation, the significance of the sono-
graphic demonstration of hypermobility should always
be interpreted in conjunction with the clinical findings
and the results of urodynamic testing.
The clinical examination continues to be the gold
standard for the description of descent of different
compartments. Ultrasound can provide supportive evi-
dence and has been shown to correlate with the clinical
findings [19]. There is good sonographic visualization of
descent of the anterior vaginal wall with cystocele for-
mation. Different abnormalities such as paravaginal
defects are demonstrated by abdominal ultrasound [20,
21]. However, there are as yet little data and the clinical
significance of these ultrasound findings remains to be
determined.
In patients undergoing diagnostic work-up for urge
symptoms, ultrasonography occasionally demonstrates
urethral diverticula, leiomyomas, and cysts in the vagi-
nal wall. These findings will lead to further diagnostic
assessment. The same applies to the demonstration of
bladder diverticula, foreign bodies in the bladder, and
bullous edema [22]. Only one study has so far reported a
correlation between thickness of the bladder wall and
urge incontinence [23]. The clinical significance of this
observation is still unclear.
Role of ultrasound in perioperative evaluation
Patients with postoperative bladder voiding disturbance
following tension-free polypropylene tape insertion
should undergo ultrasonography for assessing the posi-
tion of the tape in relation to the urethra. Both the
localization and the configuration of the tape may be
significant [24]. The ultrasound examination should be
performed at rest and during the Valsalva maneuver.
Sonography after colposuspension provides infor-
mation on the position and mobility of the bladder neck
and is used to measure the retrovesical angle. However,
recent data suggest some association of urge symptoms
and disturbed bladder voiding with specific measure-
ment value [25,26]. Postoperative recurrence of stress
incontinence is significantly associated with persistent
hypermobility and funneling [10].
Endoanal ultrasonography
Endoanal sonography is indicated in anal incontinence,
tumors, and anal pain, and for the preoperative and
postoperative evaluation in patients undergoing repair
of the anal sphincter muscle [27,28,29,30,31,32].
The equipment required for endoanal ultrasonogra-
phy is a 10-MHz high-frequency transducer with a 360°
probe. To avoid the use of the special probe, attempts
have been made to visualize the anal sphincter canal
from the perineum using a vaginal probe or a curved
linear array scanner [33,34,35]. These techniques have
never been shown to be equivalent to the endoanal
technique in the detection of defects. Therefore the so-
called exoanal technique is not included.
The examination begins at the level of the U-shaped
sling of the puborectal muscle with the probe being drawn
from cranially to caudally. The findings are described for
three anatomically defined levels of the anal canal.
The specific structures to be evaluated are the
subepithelium, the internal anal sphincter muscle, the
239
longitudinal muscle, and the external anal sphincter
muscle. These structures are described in terms of their
thickness, symmetry, continuity, and echo density.
The internal anal sphincter (IAS) is evaluated for the
following abnormalities:
– IAS >3.5 mm: abnormal at any age
– IAS >5 mm: hereditary myopathy
– Local thickening: e.g., leiomyoma
– IAS <2 mm: muscular atrophy, anal incontinence,
trauma, delivery
– IAS disruption: trauma, delivery
The external anal sphincter (EAS) is evaluated for the
following abnormalities:
– Loss of continuity
– Partial or complete muscle tears
– Changes in echo density: hematoma, calcification
– Sphincter atrophy
The accuracy, specificity, and sensitivity of endoanal
sonography for detecting sphincter defects ranges from
83 to 100% [36]. However, there is no definitive corre-
lation between ultrasound parameters and function of
the anal sphincter complex.
Determination of residual urine volume
Ultrasound is the method of choice for the noninvasive
determination of residual urine volume. The accuracy of
the measurement depends on the level of bladder filling,
the formula used for calculating the residual urine vol-
ume, and on the ultrasound equipment used. Post-void
residual is usually assessed transabdominally [37],
smaller volumes can also be measured transvaginally
[38]. If there is a discrepancy between the sonographi-
cally determined residual urine volume and the clinical
findings, the volume should be determined by catheter-
ization.
Renal ultrasonography
Evaluation of the upper urinary tract in the pre- and
postoperative period is again performed by ultrasound
as the method of choice. Radiographic procedures are
required only in cases where the ultrasound findings are
inconclusive.
Recommendations for ultrasound studies
in urogynecology
To compare the results obtained with two techniques or
in different examinations, it is important to perform
ultrasound under similar conditions in terms of intra-
abdominal pressure (intrarectal pressure), bladder filling
volume, and patient position.
Publications reporting urogynecologic ultrasound
findings should provide the following methodological
information [39]: patient position, bladder filling volume
and medium, type of filling (spontaneous versus instru-
mented), simultaneous pressure measurement, type of
pressure measurement (cystometry, urethrometry, ure-
throcystometry), ultrasound equipment including probe
size (type and manufacturer), ultrasound frequency,
image orientation, and type of ultrasound examination
performed (introital, perineal, endovaginal, endoanal).
Figures presenting ultrasound images should depict
cranial parts above and ventral parts on the right.
Conclusion
Ultrasound is a supplementary diagnostic procedure in
urogynecology, which allows documentation of func-
tional and morphologic findings. The patient’s history,
clinical examination, urodynamic testing, and imaging
continue to be the cornerstones of comprehensive uro-
gynecologic work-up. Training in urogynecologic ultra-
sonography should be included in this program of
functional urogynecologic evaluation.
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