Ultrasound in Pelvic Floor Physiotherapy

Model

Footprint

Frequency

Penetration

Use in physiotherapy

C60nReal time 2D-convex transducer

60 mm

5–2 MHz

30 cm

Perineal ultrasound

Abdominal muscles

Supra-pubic ultrasound for residual volume and bladder movement

ICTxIntra-cavity 2D-transducer

8–5 MHz

13 cm

Perineal/introital ultrasound

L38xiReal time 2D-linear transducer

38 mm

10–5 MHz

9 cm

Abdominal muscles ultrasound in women with less subcutaneous tissue

To evaluate abdominal muscles, the ultrasound probe should be placed medial to the anterior superior spine to allow a transverse view of the three abdominal muscles (transverse abdominal, internal and external oblique abdominal muscles). For this technique the same convex probe as for pPFUS can be used. For better image quality, a higher frequency linear probe can be used, but only on women with lower body mass index (BMI) or with less abdominal adipose tissue. It has been shown in recent studies that with a correct PFM contraction, a co-contraction of only the transverse abdominal muscle is physiological. Therefore the co-contraction of the superficial muscles should be eliminated. This can be assessed by ultrasound, corrected by terminal ultrasound biofeedback, and reassessed by further ultrasound biofeedback [4].

In the early 2000s, physiotherapists performed ultrasound suprapubically to assess the movement of the bladder. Bladder scans were developed for evaluating the residual volume of the bladder non-invasively (without catheterization). This method was used by physiotherapists to assess bladder movement can be performed by a bladder scan, suprapubically with all curved/abdominal ultrasound probes (2D/3D/4D). This method gives an insight into bladder movement as well. The disadvantage of this ultlrasound technique is due to its limited validation and the influence of the IAP on probe stability during functional tasks such as straining and coughing. Furthermore there is no posiblity to scan when the bladder is empty. The advantage of this method, for example, for back pain patients, (and a collaborating diagnosis of pelvic floor disorders) and for children is that with this method patients are not required to undress fully.

Abdominal ultrasound to visualize the bladder by a supra-pubic or supra-symphysal approach has been performed by Sherburn et al. [27]. This technique was first described by Avery et al. at the International Federation of Orthopaedic Manipulative Therapistst conference in Perth, Australia [28]. Sherburn et al. established the interrater and intrarater reliability of assessment of voluntary pelvic floor contractions (validity study, n = 10 women and reliability study, n = 20 women). The method of supra-pubic or supra-symphysal ultrasound was later used for functional investigations and daily life activities. One big issue was the increase in IAP during these functional tasks and a lack of validation for these activities. Currently, there are only subjective observations; there is no validation of these tasks by the ultrasound methods. A 2005 study was designed (1) to assess the reliability of transabdominal (TA) and pPFUS during a PFM contraction and Valsalva maneuver and (2) to compare TA ultrasound with TP ultrasound for predicting the direction and magnitude of bladder neck movement in a mixed subject population. A qualified sonographer assessed 120 women using both TA and pPFUS. Ten women were tested on two occasions for reliability. The reliability during PFM was excellent for both methods. pPFUS was more reliable than TA ultrasound during Valsalva. The percentage agreement between TA and pPFUS for assessing the direction of movement was 85% during PFM contraction, 100% during Valsalva. There were significant correlations between the magnitude of the measurements taken using TA and pPFUS and significant correlations with PFM strength assessed by digital palpation [29].

For the scanning of abdominal muscles, all machines and 3D/4D curved/abdominal ultrasound probes can be used. The 3D/4D convex transducers are normally used in obstetrics for intra-uterine/pre-natal diagnosis and often available in greater or specialized clinics/practices (e.g., in multidisciplinary teams). These probes can be used and are equal to 2D transducers, but this technology is higher and therefore more expensive and absolutely not necessary for abdominal PT.

Pelvic Floor Ultrasound Techniques

Machines and probes that are widely available and used in gynecology, urogynecology, urology, coloproctology, or general medicine can also be used by physiotherapists (for example in an interdisciplinary clinical setting). At the minimum a 2D ultrasound probe is essential for clinical use, for assessing the dynamics of the pelvic floor, for patient education, and for visual biofeedback. For assessment, pPFUS (with a curved abdominal probe) or a vaginal probe/transducer (intra-cavity probe) can be used. It is easier and can be used also for the abdominal muscles for the physiotherapist to use the curved probe and, it can be used while either standing or sitting (Fig. 16.1). The image obtained may have variable clarity depending on probe technology and the footprint (Fig. 16.2).

Fig. 16.1

A physiotherapist evaluating a patient with perineal pelvic floor ultrasound in standing position

Fig. 16.2

Perineal pelvic floor ultrasound . The image on the right is labeled for easy identification. Bladder (B), pubic symphysis (PS), urethra (U), vagina (V), anus (A), levator plate (LP). © Shobeiri

3D and 4D ultrasound pPFUS methods are important when measuring muscle thickness and when genital hiatus is of interest. To answer Questions related to patho-mechanisms, which are often dynamic questions, there is no need for a 3D and 4D ultrasound probe. Further more because movements are often too quick and contractions have to be maintained too long to obtain a good ultrasound image 3D and 4D technology is not posible. For example, we found [max submax paper – see in references] that a maximal pelvic floor contraction can be held for 10 s in healthy and incontinent women, but approximately 30 s is necessary to receive a good 3D ultrasound volume regardless of the technique used.

When performing a 3D endovaginal ultrasound , an intravaginal BK 8838 probe (BK Ultrasound, Analogic, Peabody, MA, USA) obtains images every 0.5° to create a 3D volume from about 800 scans in 30 s. One can decrease the time by scanning every 2°, but the quality suffers. It is, however, important to emphasize that, although visualizing LAM defects is possible with GE, Phillips, or similar transperineal 3D pPFUS requiring squeeze or Valsalva, endovaginal 3D BK ultrasound can visualize the LAM defects in resting position without any dynamic manuvers because of its high resolution and proximity to the LAM tissue. A 2D transperineal ultrasound images the levator plate in relationship to the pubic bone. This is akin to looking at the shadow of a wall (the levator ani muscle) (Fig. 16.3) [30]. In reality pelvic floor musculature is a dynamic 3D structure and needs to be evaluated in totality (Fig. 16.4) [31]. A 3D pPFUS is like looking at the wall at its ends (Fig. 16.5). Employing Valsalva through 4D brings the face of the wall to the sonographer to see any ballooning or warping. A 3D endovaginal probe obviates the need for 4D viewing as it is placed against the belly of the levator ani muscle visualizing the iliococcygeal and the pubococcygeal portions that are normally obscured by the puborectal fibers during pPFUS (Fig. 16.6) not topic of this chapter?

Fig. 16.3

(a) The orthogonal coordinate system fixed on the symphysis pubis. The two orthogonal components (ventral-dorsal and cephalad-caudad components) of the tissues displacements reflect pelvic floor functions of squeezing the urethra and supporting the bladder, respectively. (b) The orthogonal coordinates shown on a 2D perineal pelvic floor ultrasound. (From Peng et al. [30] with permission)

Fig. 16.4

The deformation of the rectum under different pelvic floor muscle (PFM) pressures. (a) The anorectal angle (ARA) is acute when the PFM is narrow and the strength of the PFM contraction is strong. (b) The ARA is acute when the PFM is narrow and the strength of the PFM contraction is not very strong. The deformation is also affected by the stiffness of the rectum and the content within it. (From Constantinou et al. [31], with permission)

Fig. 16.5

(a) A transperineal probe placed at the introitus looks at the levator ani muscle (LAM) at its end. The most caudad portion of the LAM is the puborectalis muscle which is best seen by perineal pelvic floor ultrasound (pPFUS). The medial portion of the LAM attachment to the pubic bone is the pubococcygeus, and this portion may be obscured by more distal puborectalis. (b) In the case of avulsion where both the puborectalis and pubococcygeus are torn, an avulsion can be clearly seen by pPFUS. (c) In cases where the iliococcygeus or pubococcygeus are torn but the puborectalis is intact, the torn muscles may not be visible by pPFUS. © Shobeiri

Fig. 16.6

(a) An endovaginal probe placed in the vagina looks at the levator ani muscle at its entirety. (b) As such, even minor defects in the iliococcygeus or pubococcygeus muscles are visible by endovaginal ultrasound. © Shobeiri

Ultrasound Tips and Techniques

Room for Scanning

It is important to perform ultrasound in a room that can be darkened in order to obtain the best image quality. Direct solar irradiation should be avoided. Enclosed rooms that enable privacy (and because of the intimacy of the entire treatment) are preferred.

Preparation and Hygiene

For pPFUS, as with any ultrasound imaging, use of coupling gel is a critical step, as ultrasound waves do not pass through air. Whether transabdominal, transperineal, or endovaginal transducers are used, the gel should be placed between the transducer and covering. For endovaginal transducers, a disposable cover (e.g., ultrasound cover—not a male condom), and for curved abdominal transducers a glove or plastic wrap can be used (some ultrasound condoms are flexible enough and also fit abdominal transducers). It is not necessary to use sterile gel and sterile hygienic condoms to cover the ultrasound transducer because the region of scanning (perineum) is not sterile. Additional gel should be applied to the perineum to allow for better coupling. Warming the gel in a commercial warming device improves patient comfort. After each use, transducers should be cleaned and disinfected according to manufacturer recommendations to maximize the transducer’s performance and product life. For abdominal scans, there may be no need for covering the transducer.

Orientation of the Ultrasound Picture on the Screen

For PT, there are recommended guidelines for the orientation of the ultrasound picture on the screen [32], which were described in 2005 by Tunn et al. [33]: the best image is obtained with the symphysis pubis right/bottom and the LAM left/bottom (Fig. 16.7). Because ultrasound is used not only for evaluation but also for patient education and visual biofeedback, this orientation is the most logical for patients, even when ultrasound is performed in the standing, sitting, or lithotomy positions.

Fig. 16.7

(a) A typical 2D perineal pelvic floor ultrasound. (b) The outline of the structure and anteroposterior diameter of the minimal levator hiatus (yellow line) between the levator plate (LP) and symphysis (S)

Scan Technique

Perineal pelvic floor ultrasound utilizes ultrasound performed with a curvilinear transducer versus introital pelvic floor ultrasound (iPUS) utilizes ultrasound performed with a vaginal probe placed on the perineum (Fig. 16.8) [11]. The common denominator for all these techniques is placement of transducers externally on the patient’s vulva rather than introduction of the transducer into the vagina or anal canal. pPFUS imaging can be performed with use of either the transabdominal curvilinear transducers or with endovaginal transducer that is typically used for endovaginal gynecologic ultrasound. The curved array transducer is typically 4–8 MHz, whereas endovaginal transducers have frequencies up to 10 MHz. It is important to keep in mind that higher frequency transducers provide superior resolution, but have less tissue penetration. This trade-off is important for achieving images of diagnostic quality. For the purposes of this chapter, ultrasound performed with curved array transducers will be referred to as pPFUS, as the transducer is placed between the labia majora to visualize the anatomic structures.

Fig. 16.8

Introital pelvic floor ultrasound (iPUS) in this patient demonstrates descensus and collapse of the bladder this is a healthy woman!!!!!!. This image should be obtained at rest and maximum Valsalva. A video loop adds much value to the observation

The transducer is placed midsagittal between the labia majora with the on-screen view that includes the pubic symphysis and the ARA and behind the ARA, the puboreactal muscle to have a view of all structures that are important for further therapy. The so-called footprint of the ultrasound transducer has to be large, and this is provided by nearly all convex/abdominal transducers. This is especially important when scanning patients with a large perineum, such as women directly after delivery.

Special Tools of the Ultrasound Machines and Their Use

For different clinical inquiries, specific tools of ultrasound machines can be utilized.

1.

Live scan: This tool is used in all dynamic scanning. It can be frozen, saved as a video or an image, reviewed (see cine loop), and printed as images. It can be repeated and compared at a later time (the end of treatment, next appointment, etc.).
2.

Cine loop: With this special tool, it is possible to save a movie/clip sequence of, for example, 10–15 s while the patient is performing a contraction, cough, cough with a PFM pre-contraction, etc. directly afterwards, the maneuvers can be reviewed together with the patient with the ability to select either single frames or a movie clip, playing them forward or backward with different velocities in order to explain each functionally correct or incorrect performance. Thus, explanation and so-called terminal feedback is possible.

Typically, when utilizing this tool, the decision must be made beforehand regarding the preferred save mode and time specifications (machines have prospective and retrospective saving modalities, and in presets the timing of the sequence to be saved can be chosen).

This tool is perfect for lay-person and patient education, for explaining symptoms, and for describing functional properties
3.

Pre−/post-therapy: In some women, PFM contractions are performed incorrectly or even with too much abdominal muscle activity (higher IAP and descent of the organs, such as bladder neck, cervix, and other organs). It has been shown that a PFM contraction is physiologically performed with transverse abdominus (TrA) activity [4]. Other abdominal muscle activity during a PFM contraction, such as internal oblique (IO) and external oblique (EO), has furthermore shown to increase the IAP, therefore leading to no depression of the pelvic floor and the bladder neck, respectively [4]

In these cases, the performance of the PFM contraction must be corrected with specific physiotherapeutical methods, such as breathing control, relaxation of superficial abdominal muscles and more, sometimes with and sometimes without ultrasound of the abdominal muscles in different positions. For example, abdominal ultrasound may have to be performed with the patient lying on her side, sitting, and lying on her back, each maneuver customized to individual conditions. Once the performance is determined to be functionally correct, then pPFUS can be used as a post-training instrument to check the correctness of the contraction and show it to the patient.

Physical Examination and Evaluation by a Pelvic Floor Therapist

The physical examination performed by a specialist in pelvic floor PT consists of the following:

1.

Patient history should be taken with a validated pelvic floor questionnaire that includes all domains of female pelvic floor symptoms, such as urinary, bowel, prolapse, and sexual problems. As an example, the Australian Pelvic Floor Questionnaire is available without charge, in both an interviewer-administered [34] and a self (patient)-administered version [35], allowing its implementation in clinic and research
2.

Evaluation of the pelvic floor and especially the PFM with vaginal palpation [23]—muscle integrity (avulsion); functional properties during cough; straining; awareness of the pelvic floor (sensation, perception); voluntary PFM contraction; and voluntary pre-contraction before coughing.
3.

Evaluation of the dynamics of the pelvic floor with pPFUS (automatically and voluntarily)—for example, during coughing, squeezing, and straining
4.

Evaluation of the performance of voluntary PFM contractions—coordination, strength, endurance by pPFUS and confirmation of integrity of muscles by 3D endovaginal ultrasound as necessary
5.

Evaluation of posture, breathing, PFM-contraction performance (co-activation; evasive maneuver of other parts of the body—pelvic tilt, breath hold)

The goal of the physical examination by a physiotherapist should be to find the functional problems behind the individual symptoms and to create a therapy plan based on pathophysiological and dysfunctional finding. Questions related to quality-of-life bothersomeness, patient wishes for her life (social integrity, sports activities, business, etc.), and integration of training/exercises into daily life should guide individual therapy. These issues will affect the patients’s willingness to train, her efficacy/self-efficacy, and her compliance and adherence.

Positioning During Examination: Influences on Therapy

As with gynecologic ultrasound most pPFUS exams are performed with the woman in either lithotomy in a standard gynecologic chair or in a modified lithotomy position on a normal therapy table. For 3D imaging the examiner may also need to prop the patient’s arm or elbow, as the imaging capture time can be as long as 15–20 s and absolute stillness is critical for optimal image quality. It is certainly possible to do the pPFUS with the patient standing, which could be especially useful in patients who are not as successful with dynamic maneuver in supine position. For PT, evaluation and treatment in symptoms-related positions such as standing are essential. There are women who are able to contract their PFM in the supine position but are unable to do so in erect positions, which is important in daily life.

In many countries, examinations by a urogynecologist are performed on a special gynecological chair. Having the patient in a comfortable position, with relaxed muscles, allows for an examination without pain. Most physiotherapists do not have this kind of chair, and the examination is performed with the patient in a supine position on a normal bench or therapy table with her hips and knees slightly flexed. Placing the bench or table directly next to a wall on one side allows the therapist to stand on the other side. When the patient’s legs can be supported by the wall and the therapist, to allow relaxation of the hip muscles, this scenario can assist in a comfortable and pain-free examination position. Resting tone of the muscles and the PFM structure and defects can be evaluated by palpation, and resting position of the organs and their movements during voluntary contractions can be seen on ultrasound.

On the other hand, as patients mostly report symptoms (urine or fecal loss, urge, or prolapse) in upright positions, assessment of PFM properties while standing is important to the therapist because of different findings in the same patient between a supine and standing position. An upright position has both advantages and disadvantages. For example, if a woman is not able to contract her muscles while supine, there might be a problem with her awareness of her pelvic floor, or a functional problem in that position, or even a misunderstanding on the patient’s part regarding a degree of contraction that increases the IAP to the degree that it leads to a downward movement of the pelvic floor. In some women the influence of gravity is necessary to help them perceive the sensation of contracting their PFM, since they know how to contract these muscles only while standing or sitting.

Maneuvers During Evaluation

During evaluation several maneuvers are performed to obtain information. First, the therapist starts with evaluating only automatic/functional/quasi-functional tasks, which are coughing, perfoming a Valsalva maneuver, or straining. Second, the therapist follows with voluntary tasks: contraction, contraction with a cough, and a maintained pre-contraction, in order to find functional deficits.

Palpation and Ultrasound

Palpation and ultrasound are important methods to gain an overview of the patients’s muscular and connective tissue structures. Additional answers can be obtained by using ultrasound as an adjunct to complete the diagnostic picture.

Palpation is used to assess the muscle structurally, (such as tears, lesions, etc.) and its functional properties (such as contractions, strength, endurance, coordination). Dynamic 2D ultrasound can give a visualization of the effects of activations of the muscles during PFM contraction: both voluntarily and involuntarily. The two methods in combination give a complete picture of the problem. Is there a spontaneous contraction at coughing? Is there descent of the bladder neck at coughing? Is it possible for the patient to contract the PFM before a cough, with an influence on the bladder neck that can be maintained during coughing?

While the 2D probe is placed on the perineum, three manuvers should be performed: