Introduction

Imaging techniques play a crucial role in the diagnosis and management of disease. They are most widely used for diagnostic purposes and are normally undertaken well before surgical interventions. Increasingly, they are being used in the immediate (within 24 h) preoperative period to refine the surgical technique or immediate postoperative period to ensure correct performance of surgery or exclude operative adverse events. In this chapter, we focus on intraoperative imaging, with a brief reference to techniques used immediately before and after surgery, and cover the following imaging modalities: X-ray; interventional radiology; computed tomography; magnetic resonance (MRI); radionuclide imaging; positron emission tomography (PET); and ultrasound with or without contrast agents.

As far back as 1960, urinary tract stones were located by intraoperative radiofluoroscopy illumination with the aid of the roentgen image intensifier. On the other hand, intraoperative ultrasound (IOUS), using A-mode or non-real-time B-mode imaging, which was also introduced in the 1960s, was not widely accepted because of the difficulty in image interpretation. The introduction of B-mode scanning in the late 1970s, however, and the ease with which images were interpreted, changed the attitudes and its use among the surgical specialties increased. Specially developed operative probes became more widely available from the 1980s onwards, and the use of IOUS spread worldwide in a number of surgical fields (i.e. hepatobiliary pancreatic surgery, neurosurgery and cardiovascular surgery) ( Fig. 1 ). Intraoperative ultrasound changed hepatic surgery dramatically because it was the only modality that was capable of delineating and examining the interior of the liver during surgery. In the 1990s, colour Doppler became available, and laparoscopic techniques were introduced at around the same time, resulting in the incorporation of laparoscopic ultrasound into the operative procedure ( Fig. 2 ). Clearly, this highlights the need for educating surgeons in the use of ultrasound for better surgical practice. Ultrasound-guided procedures were reported in the 1970s, such as percutaneous fine-needle aspiration biopsy for the definitive diagnosis of pancreatic carcinoma. Other modalities were added, such as intraoperative intracardiac echocardiography during left ventriculomyotomy, myectomy for hypertrophic subaortic stenosis, and intraoperative skeletal scintigraphy for localisation of osteoid-osteoma in the spine.

Intraoperative ultrasound probes: (a) T probe; (b) ‘I’ shaped array; (c) an end-firing array; (d) a curved array, particularly useful for hepatic scanning with access to the dome of the liver; and (e) the back of the curved array is shaped to take the sonographer’s fingers.

A laparoscopic ultrasound probe with a linear array configuration. The probe is flexible in two planes by manipulating the control at the handle.

In gynaecology, ultrasound-guided oocyte retrieval by percutaneous aspiration was reported in 1985 and, in the same year, transvaginal ultrasound-guided egg recovery was reported.

X-ray and magnetic resonance imaging of the abdomen and pelvis

In spite of the many advances in imaging techniques, plain X-ray still plays an important role intraoperatively in situations that the gynaecological surgeon may encounter. Examples of this include locating lost needles, instruments or swabs during surgery, or lost intrauterine contraceptive devices that pelvic ultrasound scans fail to locate inside the uterus or in the pelvis. For this purpose, removing lost intrauterine contraceptive devices or foreign bodies was achieved laparoscopically with the aid of fluoroscopic image intensifier, which has the advantage of showing the images in real time and increasing diagnostic accuracy. This approach has proven to be cost-effective, rapid, and allows endoscopic removal of these devices, therefore reducing the need for laparotomy.

Another important use of the X-ray is to aid the placement of ureteric stents at the beginning of complex pelvic surgery for extensive endometriosis (where ureterolysis may well be required). They are also used in gynaecological–oncology procedures where tumours infiltrate the parametrium, causing a high risk of ureteral damage during the extensive pelvic dissection required for pelvic clearance. These complex surgical procedures carry the delayed risks of developing ureteric stricture, fistulae, or hydronephrosis. These risks can be reduced with elective ureteric identification and stenting at the beginning of these procedures. The insertion of ‘double J ureteric stents’ in these cases is usually combined with retrograde urogram in theatre at the start of the operation. The same technique with some modifications to it may occasionally be adapted when ureteric injury is already suspected to confirm or refute the damage during difficult hysterectomies or caesarean sections with extension of the incision to the uterine angles.

Hysterosalpingography (HSG) has been carried out for many years to exclude tubal blockage as an essential part of the investigations of the infertile couples. It additionally has the ability to detect intrauterine filling defects resulting from polyps and submucous fibroids, detect intrauterine adhesions, and can identify Müllerian duct anomalies, such as arcuate, septate, and bicornuate uterus, but with the disadvantage of not outlining the outer uterine contour, which is essential in defining some types of these anomalies. Three-dimensional transvaginal ultrasonography, however, seems to be superior to HSG, and is discussed later in this chapter.

The field of interventional radiology in gynaecology has been progressing steadily over the past 2 decades. An important application of it is in uterine artery embolisation (UAE) for the management of uterine leiomyomas, especially for diffuse uterine leiomyomatosis. This is proposed as a preferred fertility-preserving management option in cases where surgery is either not feasible or declined by the woman. It is also preferred if the risk of hysterectomy is too high if myomectomy surgery is attempted in women who have not yet completed their family. Patient selection for this technique is of utmost importance, and this is vastly aided by pelvic MRI at an earlier stage, which will help the patient counselling process on management options. The pre-operative assessment of these women with MRI falls outside the remit of this chapter and will not be discussed here. Many studies have confirmed the safety and efficacy of this technique of UAE in the short and long term. A recent Cochrane systematic review concluded that UAE seems to have an overall patient satisfaction rate similar to hysterectomy and myomectomy, and has a shorter hospital stay and a quicker return to routine activities ; this is in addition to the obvious advantage of being a fertility-preserving procedure. Another minimally invasive technique for the treatment of symptomatic fibroids is magnetic resonance–guided focused ultrasound surgery. This technique results in short-term symptom reduction for women with symptomatic uterine leiomyomas, with an excellent safety profile. Intermediate and long-term benefits are awaited.

A new innovative minimally invasive technique for the treatment of symptomatic fibroids is laparoscopic radiofrequency volumetric thermal ablation. Laparoscopic IOUS is used to map the uterine fibroids and determine the location and size of all fibroids present. Each fibroid is then destroyed by applying energy through a small needle array. The surrounding normal tissue is not affected. The destroyed tissue may then be completely reabsorbed. Early results suggest that this technique results in significant improvement of symptom severity and quality-of-life scores, and provides a minimally invasive uterine-sparing option for the treatment of fibroids.

Uterine artery embolisations was also successfully used to ablate arterio-venous malformations of the uterus, resulting in excessive menometrorrhagia. These are occasionally caused by previous surgical interventions, as a result of placenta accreta or percreta, and after gestational trophoblastic disease. Additionally, this therapeutic technique has been successfully used in selected cases of massive postpartum haemorrhage as an alternative to obstetric hysterectomy and internal iliac artery ligation.

X-ray and magnetic resonance imaging of the abdomen and pelvis

In spite of the many advances in imaging techniques, plain X-ray still plays an important role intraoperatively in situations that the gynaecological surgeon may encounter. Examples of this include locating lost needles, instruments or swabs during surgery, or lost intrauterine contraceptive devices that pelvic ultrasound scans fail to locate inside the uterus or in the pelvis. For this purpose, removing lost intrauterine contraceptive devices or foreign bodies was achieved laparoscopically with the aid of fluoroscopic image intensifier, which has the advantage of showing the images in real time and increasing diagnostic accuracy. This approach has proven to be cost-effective, rapid, and allows endoscopic removal of these devices, therefore reducing the need for laparotomy.

Another important use of the X-ray is to aid the placement of ureteric stents at the beginning of complex pelvic surgery for extensive endometriosis (where ureterolysis may well be required). They are also used in gynaecological–oncology procedures where tumours infiltrate the parametrium, causing a high risk of ureteral damage during the extensive pelvic dissection required for pelvic clearance. These complex surgical procedures carry the delayed risks of developing ureteric stricture, fistulae, or hydronephrosis. These risks can be reduced with elective ureteric identification and stenting at the beginning of these procedures. The insertion of ‘double J ureteric stents’ in these cases is usually combined with retrograde urogram in theatre at the start of the operation. The same technique with some modifications to it may occasionally be adapted when ureteric injury is already suspected to confirm or refute the damage during difficult hysterectomies or caesarean sections with extension of the incision to the uterine angles.

Hysterosalpingography (HSG) has been carried out for many years to exclude tubal blockage as an essential part of the investigations of the infertile couples. It additionally has the ability to detect intrauterine filling defects resulting from polyps and submucous fibroids, detect intrauterine adhesions, and can identify Müllerian duct anomalies, such as arcuate, septate, and bicornuate uterus, but with the disadvantage of not outlining the outer uterine contour, which is essential in defining some types of these anomalies. Three-dimensional transvaginal ultrasonography, however, seems to be superior to HSG, and is discussed later in this chapter.

The field of interventional radiology in gynaecology has been progressing steadily over the past 2 decades. An important application of it is in uterine artery embolisation (UAE) for the management of uterine leiomyomas, especially for diffuse uterine leiomyomatosis. This is proposed as a preferred fertility-preserving management option in cases where surgery is either not feasible or declined by the woman. It is also preferred if the risk of hysterectomy is too high if myomectomy surgery is attempted in women who have not yet completed their family. Patient selection for this technique is of utmost importance, and this is vastly aided by pelvic MRI at an earlier stage, which will help the patient counselling process on management options. The pre-operative assessment of these women with MRI falls outside the remit of this chapter and will not be discussed here. Many studies have confirmed the safety and efficacy of this technique of UAE in the short and long term. A recent Cochrane systematic review concluded that UAE seems to have an overall patient satisfaction rate similar to hysterectomy and myomectomy, and has a shorter hospital stay and a quicker return to routine activities ; this is in addition to the obvious advantage of being a fertility-preserving procedure. Another minimally invasive technique for the treatment of symptomatic fibroids is magnetic resonance–guided focused ultrasound surgery. This technique results in short-term symptom reduction for women with symptomatic uterine leiomyomas, with an excellent safety profile. Intermediate and long-term benefits are awaited.

A new innovative minimally invasive technique for the treatment of symptomatic fibroids is laparoscopic radiofrequency volumetric thermal ablation. Laparoscopic IOUS is used to map the uterine fibroids and determine the location and size of all fibroids present. Each fibroid is then destroyed by applying energy through a small needle array. The surrounding normal tissue is not affected. The destroyed tissue may then be completely reabsorbed. Early results suggest that this technique results in significant improvement of symptom severity and quality-of-life scores, and provides a minimally invasive uterine-sparing option for the treatment of fibroids.

Uterine artery embolisations was also successfully used to ablate arterio-venous malformations of the uterus, resulting in excessive menometrorrhagia. These are occasionally caused by previous surgical interventions, as a result of placenta accreta or percreta, and after gestational trophoblastic disease. Additionally, this therapeutic technique has been successfully used in selected cases of massive postpartum haemorrhage as an alternative to obstetric hysterectomy and internal iliac artery ligation.

Ultrasound scanning in benign gynaecology

Ultrasound scan imaging has been used in gynaecology for many decades. We are practising in an era in which many gynaecologists will regard the gynaecological assessment to be incomplete without a pelvic ultrasound scan. A number of procedures in gynaecology are carried out under direct ultrasound guidance, while others are undertaken with the assistance of immediate preoperative ultrasound assessment.

Reproductive medicine was one of the first fields in gynaecology to carry out ultrasound-guided procedures. These includes tests for fallopian tubes patency, such as colour Doppler hysterosalpingography and hystero-contrast-sonography, which have been shown to be reliable, effective and well tolerated, with results similar to HSG. In addition to confirming tubal patency, hystero-contrast-sonography can successfully identify intrauterine lesions (i.e.) polyps, and submucous fibroids in a similar way to hysterosalpingography. It also has the advantage of providing additional information on the relative proportion of the intracavity and intramyometrial components of submucous myomas, which HSG cannot provide. If tubal patency is not the focus of the investigation, hydrosonography (the injecting of saline into the uterine cavity, causing distension and fluid tissue interface) will clearly identify intracavitary lesions. The technique, also referred to as saline-infusion sonography increases the sensitivity of two-dimensional ultrasound in detecting or excluding the presence of endometrial lesions (i.e. polyps) in women with postmenopausal bleeding, thus reducing false-positive results and reducing unnecessary surgical interventions. Three-dimensional ultrasound was reported to be superior to two-dimensional ultrasound and comparable to hysteroscopy at detecting intrauterine lesions.

Uterine malformations and Müllerian-duct anomalies are a big heterogeneous group of malformations that affect the female genital tract with varying effects on reproductive function. Their management vastly depends on correct diagnosis and classification. Some types can have a significant effect on reproductive potential. It is critical to establish the correct diagnosis so that the most appropriate management option can be recommended. Although two-dimensional ultrasound has been used for this purpose for some time, three-dimensional transvaginal ultrasonography has been found to be extremely accurate in the diagnosis of bicornuate, septate, and arcuate uterus, compared with hysterosalpingography or office hysteroscopy. It provides visualisation of the uterine cavity with similar or better accuracy than standard HSG in the office, with lower cost and morbidity, in addition to outlining the outer uterine contour, which HSG cannot achieve. Three-dimensional transvaginal ultrasonography was proposed as the only mandatory step in the assessment of the uterine cavity in women with a suspected septate or bicornuate uterus. Recently, it has been reported that the combined findings during hysteroscopy and the three-dimensional reconstructed coronal view of the uterus can avoid the need for laparoscopic assessment to check the outer uterine contour in women undergoing hysteroscopic metroplasty. Some surgeons even prefer to carry out hysteroscopic metroplasty and uterine septum resection with simultaneous real-time transabdominal two- and three-dimensional ultrasonography to improve the safety of the procedure and reduce the risk of uterine perforation by identifying a safe resection distance of the uterine septum. Magnetic resonance imaging is more effective at diagnosis, classification and surgical planning of more complex Müllerian-duct anomalies, including vaginal septa or atresia.

Reports of uterine wall injury, wall perforation, or the creation of a false passage after the use of endometrial ablation devices led the Medicines and Healthcare products Regulatory Agency to issue recommendations that clinicians should follow for hysteroscopy before insertion of the ablation device to establish the condition of the uterus, and for ultrasound to ensure correct uterine placement of the ablation device. If the device uses a balloon, this should remain inflated during the ultrasound scan.

Oocyte retrieval for in-vitro fertilisation cycles (IVF) is carried out almost exclusively now under transvaginal two-dimensional ultrasonography guidance. This has almost completely replaced the earlier use of laparoscopic oocyte retrieval. Further advances in the field of assisted reproduction have witnessed the routine introduction of real-time ultrasound-guided embryo transfer. Two- and three-dimensional ultrasound has been used for this purpose to target the maximum implantation potential point during embryo transfer, which can increase pregnancy rate and reduce ectopic pregnancy rate. Studies have confirmed that ultrasound-guided embryo transfer improves the chance of clinical pregnancy and implantation rate, as well as the live birth rate in IVF cycles. Consequently, it is hard to justify using the ‘clinical touch’ approach for embryo transfer, and ultrasound guidance is currently viewed as best practice in assisted reproduction centres.

Transrectal ultrasound has been used frequently in women with endometriosis, especially in recto-vaginal disease or nodules, to explore the involvement of the rectal wall in the disease, and hence the need for segmental bowel resection. This is undertaken before rather than after surgery, and will determine if a multidisciplinary approach is required.

Ultrasound has also been used in sexual and reproductive health clinics to locate misplaced or deeply inserted hormonal contraceptive implants (Implanon). The removal of these implants can be challenging, and using ultrasound guidance has proven to be very successful at accurately locating these non-palpable implants before making the skin incision. This approach aids the procedure, shortens its time, and reduces patient discomfort. Correct placement of Essure microinsert system (Essure Permanent Birth Control; Conceptus, San Carlos, CA) is critical for the success of this tubal sterilisation technique. Hysterosalpingography has traditionally been the method of choice to check for this; however, it is now widely accepted that three-dimensional ultrasound is a simple and reproducible technique to assess the position of the microinsert, and seems to protect most women from the negative aspects of pelvic radiography and of HSG ( Fig. 3 ).

Three-dimensional ultrasound image of the uterine cavity demonstrating the position of each ‘Essure’ microinsert at the cornua.

Surgical evacuation of the uterus and termination of pregnancy have been carried out especially in the second trimester with transabdominal ultrasound scan guidance. This approach was found in case reports to be successful in selective surgical evacuation at the second trimester of multiple pregnancies complicated by spontaneous rupture of the membranes of the lower sac. This has been reported to be safe if carried out with real-time ultrasound guidance and allows for the prolongation of the pregnancy with the remaining sibling twin(s). Additionally, selective surgical termination of cervical heterotopic ectopic pregnancies have been carried out safely under ultrasound guidance accompanied by cervical cerclage at the same time.

In a randomised-controlled trial, first-trimester surgical termination of pregnancies under ultrasound guidance were shown to be associated with lower complication rates compared with a bind conventional procedure. These beneficial effects included reduction in blood loss, procedure time, and convalescence time. This approach, however, has not yet found its way into routine daily practice of surgical evacuation of retained products of gestation or surgical termination of pregnancies procedures. A modification of this scanning approach is the use of transrectal ultrasound, which has been reported to be of great assistance to the gynaecological surgeon in procedures such as completing the evacuation of the products of conception after a confirmed perforation of the uterus and in drainage of postoperative vaginal vault haematomas.

Pelvic floor and urogynaecology surgery

Intraoperative imaging has also been used in a number of pelvic floor operations. It is recognised that ureteric injury may occur during pelvic-floor prolapse surgery, and a number of surgeons undertake routine intraoperative urethrocystoscopy at the end of the procedure to confirm ureteric patency. Where bilateral sacrospinous ligament fixation for stage III vaginal prolapse is undertaken, severe angulation of the distal ureter without complete obstruction may result in renal compromise. Fluoroscopic images of retrograde ureterography carried out before and after release of the sutures were reported to assist the surgeon in assessing the extent of ureteric angulation and confirming its success immediately after surgery.

Intraoperative endosonography has also been used successfully in laparoscopy-assisted colon pull-through for high imperforate anus. In this procedure, endoscopic (12-MHz, 2.5 mm in diameter) and proctoscopic (7.5 MHz, 12 mm in diameter) probes were inserted into the proposed route of dissection intraoperatively to measure the thickness of the surrounding muscle tissue at the levels of the external anal sphincter, the levator ani muscle sling, and the intervening muscle complex, thus greatly enhancing the precision of positioning the pull-through canal.

Introital ultrasound uses a conventional ultrasound transducer placed on the labial skin to visualise the urethra, which appears as a hypoechoic tube, and the rhabdosphincter, which appears as an ovoid hyperechoic structure surrounding the urethra. This technique does not impede movement of the bladder neck or vaginal prolapse during a Valsalva manoeuvre or pelvic floor contraction. Viereck et al. reported their 4-year objective follow-up experience of using perioperative introital ultrasound in women with urodynamically proven stress urinary incontinence undergoing colposuspension surgery. The investigators reported that perioperative ultrasound improved their understanding of the surgical procedure and might have helped to prevent postoperative complications.

In an observational study from the same group, women with urodynamically proven genuine stress urinary incontinence underwent colposuspension of the bladder neck under intraoperative introital ultrasound control to achieve patient-specific individualised vertical height correction of 1–10 mm. At 6 months’ follow up, all postoperative measurements showed a significant reduction of the median linear movement of the bladder neck during straining, and a significant reduction of funnelling and hypermobility, with over 90% of women remaining continent. The investigators concluded that intraoperative introital ultrasound can help to optimise the colposuspension procedure by objectively measuring the height of the correction. The same group reported that ultrasound monitoring might have helped to avoid over elevation of the bladder neck and any associated postoperative complications, such as voiding difficulties and urgency. Of those women who completed 48 months’ follow up (56% of the cohort), 94% were objectively continent at 12-months and 82% were objectively continent at 48-months’ follow up.