Three-dimensional Endosonography Research Articles

Stage and size using magnetic resonance imaging and endosonography in neoadjuvantly-treated rectal cancer

To assess the stage and size of rectal tumours using 1.5 Tesla (1.5T) magnetic resonance imaging (MRI) and three-dimensional (3D) endosonography (ERUS). In this study, patients were recruited in a phase I/II trial of neoadjuvant chemotherapy for biopsy-proven rectal cancer planned for surgical resection with or without preoperative radiotherapy. The feasibility and accuracy of 1.5T MRI and 3D ERUS were compared with the histopathology of the fixed surgical specimen (pathology) to determine the stage and size of the rectal cancer before and after neoadjuvant chemotherapy. A Philips Intera 1.5T with a cardiac 5-channel synergy surface coil was used for the MRI, and a B-K Medical Falcon 2101 EXL 3D-Probe was used at 13 MHz for the ERUS. Our hypothesis was that the staging accuracy would be the same when using MRI, ERUS and a combination of MRI and ERUS. For the combination, MRI was chosen for the assessment of the lymph nodes, and ERUS was chosen for the assessment of perirectal tissue penetration. The stage was dichotomised into stage I and stage II or greater. The size was measured as the supero-inferior length and the maximal transaxial area of the tumour. The staging feasibility was 37 of 37 for the MRI and 29 of 36 for the ERUS, with stenosis as a limiting factor. Complete sets of investigations were available in 18 patients for size and 23 patients for stage. The stage accuracy by MRI, ERUS and the combination of MRI and ERUS was 0.65, 0.70 and 0.74, respectively, before chemotherapy and 0.65, 0.78 and 0.83, respectively, after chemotherapy. The improvement of the post-chemotherapy staging using the combination of MRI and ERUS compared with the staging using MRI alone was significant (P = 0.046). The post-chemotherapy understaging frequency by MRI, ERUS and the combination of MRI and ERUS was 0.18, 0.14 and 0.045, respectively, and these differences were non-significant. The measurements of the supero-inferior length by ERUS compared with MRI were within 1.96 standard deviations of the difference between the methods (18 mm) for tumours smaller than 50 mm. The agreement with pathology was within 1.96 standard deviations of the difference between imaging and pathology for all tumours with MRI (15 mm) and for tumours that did not exceed 50 mm with ERUS (22 mm). Tumours exceeding 50 mm in length could not be reliably measured by ERUS due to the limit in the length of each recording. MRI is preferable to use when assessing the size of large or stenotic rectal tumours. However, staging accuracy is improved by combining MRI with ERUS.

Interobserver and Intraobserver Variation of Two-Dimensional and Three-Dimensional Anal Endosonography in the Evaluation of Recurrent Anal Cancer

This study was designed to evaluate the interobserver and intraobserver agreement of two-dimensional (2-D) and three-dimensional (3-D) anal endosonography for the detection of local recurrence anal carcinoma. Thirty-six patients were treated for anal carcinoma, and seven had recurrent disease. They were investigated by using 3-D endosonography at Rigshospitalet from July 2001 to January 2005 because of suspected local recurrence. The 3-D endosonographic examinations were reviewed from the hard disc by two observers who twice reviewed all 2-D examinations (the axial projection) as well as all 3-D examinations (the axial, as well as the reconstructed coronal and sagittal projections). The observers scored each examination according to the following scale regarding presence of local recurrence: 1 = no finding/benign findings; 2 = properly benign findings; 3 = suspicious findings/malignant findings. Kappa statistic-statistic was used to evaluate interobserver and intraobserver variation. Three-dimensional endosonography achieved better interobserver agreement than 2-D endosonography: kappa 3-D 0.34-047 vs. kappa 2-D 0.15-0.28 and better intraobserver agreement: kappa 3-D 0.34-0.62 vs. kappa 2-D 0.22-0.28. These differences showed P < 0.05. Three-dimensional endosonography proved to have significantly better interobserver and intraobserver agreement than 2-D endosonography concerning detection of recurrent anal cancer. Three-dimensional endosonography seems to be less dependent of the individual examiner than 2-D endosonography.

Three-dimensional endoluminal ultrasound-guided interstitial brachytherapy in patients with anal cancer

New techniques using image guidance other than computed tomography (CT) and traditional two-dimensional (2D) endosonography might improve interstitial brachytherapy in patients with anal cancer. To investigate a new technique guided by three-dimensional (3D) endosonography used in our institution. Seventeen patients with anal carcinoma were referred to interstitial brachytherapy under 3D endosonographic guidance after external radiotherapy. The procedure was initiated by anal endosonography performed with a 10-MHz rotating endoprobe. Cross-sectional images of the anal sphincters were stored on a 3D system during retraction of the endoprobe through the anal canal. Afterward, any projection could be reconstructed. From this scanning, the optimal positioning of the needles was determined. The needles were inserted through holes in an externally fixated anal template. A repeated endosonography assured that optimal tumor coverage could be obtained by adjusting the number, dwell positions, and/or position of the needles. In all patients, endosonography was able to visualize the extension of the tumors and the position of each needle in 3D. 3D endosonography guidance of interstitial brachytherapy in anal carcinoma seems to optimize the implant procedure and offer better information for dose planning.

The Advantages of Volume Rendering in Three-Dimensional Endosonography of the Anorectum

Anorectal diseases require imaging for proper case management. At present, endoanal ultrasonography and endorectal ultrasonography have become important parts of diagnostic workup of patients with fecal incontinence, perianal fistulas, and rectal cancer and provides sufficient information for clinical decision-making in many cases. However, with the currently available ultrasonographic equipment and techniques, a good deal of relevant information may remain hidden. The advent of high-resolution three-dimensional endoluminal ultrasound, constructed from a synthesis of standard two-dimensional cross-sectional images, and of "Volume Render Mode," a technique to analyze information inside a three-dimensional volume by digitally enhancing individual voxels, promises to revolutionize diagnosis of pelvic floor disorders. By use of the different postprocessing display parameters, the volume-rendered image provides better visualization performance when there are not large differences in the signal levels of pathologic structures compared with surrounding tissues. The anatomic structures in the pelvis, the axial and longitudinal extension of anal sphincter defects, the anatomy of the fistulous tract in complex perianal sepsis, and the presence of slight or massive submucosal invasion in early rectal cancer may be imaged in greater detail. This additional information will bring an improvement for both planning and conduct of surgical procedures.

A novel procedure to assess anismus using three‐dimensional dynamic anal ultrasonography

This study aimed to determine the value of three-dimensional (3D) dynamic endosonography in the assessment of anismus. Sixty-one women submitted to anorectal manometry were enrolled including 40 healthy women and 21 patients with anismus diagnosed by manometry. Patients were submitted to 3D endosonography. Images were acquired at rest and during straining and analysed in axial and midline longitudinal planes. Sphincter integrity was quantified. The angle between the internal edge of the puborectalis with a vertical line according to the anal canal axis was calculated at rest and during straining. The angle increased in 39 of the 40 normal individuals and decreased in all patients with anismus during straining compared with the angle at rest (88.36 degrees ) and straining (98.65 degrees ) in normal individuals. In the anismus group, the angle decreased at rest (90.91 degrees ) and straining (84.89 degrees ). The difference between angle sizes in normal and anismus patients during straining was statistically significant (P < 0.5). Three-dimensional endosonography is a useful method to assess patients with anismus confirming the anorectal manometric results.

Elastic band ligation of hemorrhoids: Flexible gastroscope or rigid proctoscope?

To compare rigid proctoscope and flexible endoscope for elastic band ligation of internal hemorrhoids. Patients between 18 and 80 years old, with chronic complaints (blood loss, pain, itching or prolapse) of internal hemorrhoids of grade 1-3, were randomized to elastic band ligation by rigid proctoscope or flexible endoscope (preloaded with 7 bands). Patients were re-treated every 6 wk until the cessation of complaints. Evaluation by three-dimensional anal endosonography was performed. Forty-one patients were included (median age 52.0, range 27-79 years, 20 men). Nineteen patients were treated with a rigid proctoscope and twenty two with a flexible endoscope. Twenty-nine patients had grade 1 hemorrhoids, 9 patients had grade 2 hemorrhoids and 3 patients had grade 3 hemorrhoids. All patients needed a minimum of 1 treatment and a maximum of 3 treatments. A median of 4.0 bands was used in the rigid proctoscope group and a median of 6.0 bands was used in the flexible endoscope group (P < 0.05). Pain after ligation tended to be more frequent in patients treated with the flexible endoscope (first treatment: 3 vs 10 patients, P < 0.05). Three-dimensional endosonography showed no sphincter defects or alterations in submucosal thickness. Both techniques are easy to perform, well tolerated and have a good and fast effect. It is easier to perform more ligations with the flexible endoscope. Additional advantages of the flexible scope are the maneuverability and photographic documentation. However, treatment with the flexible endoscope might be more painful and is more expensive.

Three-Dimensional Anal Endosonography May Improve Detection of Recurrent Anal Cancer

In our center since 2001, follow-up examination has included three-dimensional endosonography in all patients with suspicion of local recurrence of anal cancer. This study was designed to investigate whether three-dimensional endosonography surpassed two-dimensional endosonography as a diagnostic tool for patients with suspected local recurrence. This prospective study included 38 consecutive patients who have had anal carcinoma and were investigated using three-dimensional endosonography in combination with anoscopy and digital rectal examination at Rigshospitalet from July 2001 to January 2005 under suspicion of local recurrence. All endosonographic examinations-two-dimensional, three-dimensional, and three-dimensional in combination with anoscopy and digital rectal examination-were evaluated by blinded observers. The observers scored each examination according to a five-point scale in which a score from 1 to 3 was regarded as benign endosonographic findings and a score from 4 to 5 was regarded as malignant endosonographic findings. The endosonographic diagnosis for each examination was compared with histologic evaluation or when no biopsy had been taken with a follow-up period of at least six months. If a patient showed no signs of local recurrence in the follow-up period, no local recurrence was considered to be present at the time of the investigation. The sensitivity was 1.0 for three-dimensional endosonography in combination with palpation, 0.86 for three-dimensional endosonography alone, and 0.57 for two-dimensional endosonography. The differences between two-dimensional endosonography and three-dimensional endosonography alone as well as two-dimensional endosonography and three-dimensional endosonography + anoscopy and digital rectal examination both reached significance with P values <0.05. This study indicates that three-dimensional endosonography surpasses two-dimensional endosonography in the evaluation of patients with suspicion of local recurrence of anal cancer especially in combination with anoscopy and digital rectal examination.

Detection Rate of Periintestinal Lymph Nodes

Compared to standard two-dimensional (2D) endosonography, three-dimensional (3D) endosonography has been presented as a possible improvement regarding imaging of the gastrointestinal (G-I) tract and detection of metastatic lymph nodes. The aim of this study was to evaluate the efficacy of detecting periintestinal lymph nodes in surgical specimens using 3D endosonography. Surgical specimens from 31 patients with malignant G-I tumours were investigated by 3-D endosonography and histology with focus on the presence of periintestinal lymph nodes and presence of metastasis. The specimens were scanned submerged into water. Position and size of the lymph nodes were mapped on a photo of the specimen both by the pathologist and the examiners. Three-dimensional endosonography detected 48 out of 60 malignant lymph nodes (80.0 %), and 110 out of 219 benign lymph nodes (50.2 %). The positive predictive value for an endosonographic finding interpreted as a lymph node was 0.97. The detection rates for periintestinal lymph nodes were relatively high and seemed superior to the one usually assigned to 2D endosonography. Although distinguishing between metastatic and non-metastatic lymph nodes remains a problem, all patients with histologically confirmed metastasis to lymph nodes were detected by 3D endosonography, and the technique thus seems suitable for grouping of patients prior to surgery.

Importância do ultra-som tridimensional na avaliação anorretal

Anorectal endosonography is actually the main image exam to evaluate some anorectal diseases. To show the three-dimensional endosonography importance in the anal canal anatomic evaluation and the anorectal diseases diagnosis. Seventy four anorectal ultrasound were performed, 23 normal individuals (13 women) and 51 patients (33 women) with benign and malignant diseases. All the patients were examined with a 3-D equipment with 360 degrees transducer. Normal individuals were evaluated in midline sagittal plane concerning to the length of the anal canal, the internal anal sphincter, the external anal sphincter and the anatomic defect in the anterior quadrant. There were no differences in the anal canal and the internal anal sphincter length between men and women. Otherwise, the external anal sphincter length is longer in men and the anatomic defect is longer in women. In those with anorectal diseases, 11 sphincter injuries, 8 anal fistulas, 7 abscess, 1 perirectal endometriosis, 1 pre-sacral cyst, 3 anal canal and 10 rectal malignant neoplasias were diagnosed. The surgical findings confirmed the ultrasound diagnosis in all the patients. Three-dimensional endosonography demonstrated the anatomic differences between male and female anal canal, justifying the larger incidence of pelvic floor disorders in female patients. It was possible to diagnose the anorectal diseases, in multi-plane, with high spatial resolution, adding also important informations about the therapeutic decision. Such characteristics become it similar to nuclear magnetic resonance with intra-rectal coil, with the advantages to be easier, quicker, low cost and better tolerated.

Three-dimensional anal endosonography may improve diagnostic confidence of detecting damage to the anal sphincter complex

The aim of study was to investigate the differences between three-dimensional (3D) endosonography and two-dimensional (2D) endosonography in visualizing damage to the anal sphincter complex. 33 patients with a history of damage to the anal sphincters were examined with a 10 MHz rotating endoprobe. Cross-sectional images of the anal sphincters were stored on a 3D system during retraction of the endoprobe through the anal canal. Cross-sectional images (2D) were compared with reconstructed projections (3D) according to five parameters relating to damage of different parts of the sphincter muscles as well as scar-tissue formation in the rectovaginal septum. Depending on whether the investigator felt confident in diagnosis of scar tissue being present or not a numerical value of 1 or 0 was assigned. In this way a scale from 0 to 5 points was achieved, which ideally should be identical in 3D and 2D. Overall both observers felt diagnostic confidence in a median of five parameters (range 4-5) using 3D, compared with a median of four parameters (range 3-5) using 2D (p=0.001). When only assessing the four parameters relating to damage of different parts of the sphincter-muscles the observers felt diagnostic confidence in eight more cases using 3D than 2D. This difference did not reach statistical significance. The overall agreement between the two observers comparing all five parameters was 98.2% using 3D and 87.9% using 2D. 3D anal endosonography improves diagnostic confidence in detecting damage to the anal sphincter complex. The agreement between the two observers was acceptable using 2D but better when using 3D. The 3D method may improve the selection of patients for surgical repair of the anal sphincter complex.

Anal sphincter damage after vaginal delivery using three-dimensional endosonography

Objective: To determine the incidence and functional consequences of external sphincter trauma compared with other perineal structures using a novel imaging technique, three-dimensional endosonography. Methods: Fifty-five nulliparous women (mean age 30 years, range 18–47 years) had three-dimensional anal endosonography, anal manometry, and questionnaire assessment of continence at a median gestation of 33 weeks (23–42 weeks) and 10 weeks (7–22 weeks) after delivery. Results: There was ultrasound evidence of postpartum trauma in 13 of 45 women who had a vaginal delivery (29%, confidence interval [CI] 16%, 44%), involving the external sphincter in five (11%, CI 4%, 24%), the puboanalis in nine (20%, CI 10%, 35%), and the transverse perineii in three (7%, CI 1%, 18%). In four, more than one structure was damaged. External sphincter trauma was associated with a significant decrease in squeeze pressure ( P = .035) and an increase in incontinence score ( P = .02) compared with those without trauma. Tears to the puboanalis or transverse perineii only did not affect pressure or incontinence scores. Coronal imaging of the external anal sphincter was a useful adjunct to the assessment of trauma. Conclusion: The overall incidence of trauma to the sphincter complex was similar to that of previous reports, although actual damage to the external sphincter was less common and represented the only functionally significant component.

Clinical, physiological, and radiological study of a new purpose-designed artifical bowel sphincter

Studies of the use of artificial urinary sphincters for faecal incontinence have led to refinement and adaptation of such sphincters to the anatomy of the anal region. We aimed to test this new device.Six women, median age 53 (range 32-58) years, who were unsuitable for sphincter repair, had an artificial bowel sphincter implanted as a one-stage procedure without colostomy cover. Clinical assessment, physiological testing, and endosonography were done before and after the operation. Plain radiography, three-dimensional endosonography, and magnetic-resonance imaging were done after the operation, to define its anatomical location.Median follow-up was 10 (range 5-13) months and the device was functional in five patients. In one patient, the device was removed after ulceration through the skin. Of the patients with intact devices, Wexner incontinence scores improved from a median of 19 (18-20) of 20 before the operation, to 3 (0-6) of 20 after the operation. Median anal pressure at rest significantly increased from 60 (range 30-80) cm H2O to 110 (100-120) cm H2O. Functional anal-canal length varied after the operation from 3.3 cm to 3.8 cm. There was no significant change in the maximum tolerated volume of the rectum (140 [80-230] vs 100 [75-250] mL), or rectal compliance (2.9 [2.8-6.0] cm H2O/mL vs 3.5 [2.3-7.3] cm H2O/mL). All the imaging techniques accurately located the implant relative to the anal canal and pelvic floor in each patient.The new artificial bowel sphincter provided a good functional result in five of the six patients, the surgical procedure was straightforward, and the maximum resting anal pressure rose without affecting rectal function. The ease of visualisation of such implants in situ should aid simple management of complications, should they arise.

Cinical, physiological, and radiological study of a new purpose-designed artifical bowel sphincter

Studies of the use of artificial urinary sphincters for faecal incontinence have led to refinement and adaptation of such sphincters to the anatomy of the anal region. We aimed to test this new device. Six women, median age 53 (range 32-58) years, who were unsuitable for sphincter repair, had an artificial bowel sphincter implanted as a one-stage procedure without colostomy cover. Clinical assessment, physiological testing, and endosonography were done before and after the operation. Plain radiography, three-dimensional endosonography, and magnetic-resonance imaging were done after the operation, to define its anatomical location. Median follow-up was 10 (range 5-13) months and the device was functional in five patients. In one patient, the device was removed after ulceration through the skin. Of the patients with intact devices, Wexner incontinence scores improved from a median of 19 (18-20) of 20 before the operation, to 3 (0-6) of 20 after the operation. Median anal pressure at rest significantly increased from 60 (range 30-80) cm H2O to 110 (100-120) cm H2O. Functional anal-canal length varied after the operation from 3.3 cm to 3.8 cm. There was no significant change in the maximum tolerated volume of the rectum (140 [80-230] vs 100 [75-250] mL), or rectal compliance (2.9 [2.8-6.0] cm H2O/mL vs 3.5 [2.3-7.3] cm H2O/mL). All the imaging techniques accurately located the implant relative to the anal canal and pelvic floor in each patient. The new artificial bowel sphincter provided a good functional result in five of the six patients, the surgical procedure was straightforward, and the maximum resting anal pressure rose without affecting rectal function. The ease of visualisation of such implants in situ should aid simple management of complications, should they arise.

Three-dimensional endosonography of the pelvic floor: An additional diagnostic tool in surgery for continence problems in children: G. Stuhldreier, H.-J. Kirschner, W. Astfalk, et al. Eur J Pediatr Surg 7:97–102, (April), 1997

Three-dimensional endosonography of the pelvic floor: An additional diagnostic tool in surgery for continence problems in children: G. Stuhldreier, H.-J. Kirschner, W. Astfalk, et al. Eur J Pediatr Surg 7:97–102, (April), 1997

IMO 1602 Three-dimensional (3D) endosonography in inflammatory bowel diseases

IMO 1602 Three-dimensional (3D) endosonography in inflammatory bowel diseases

Evaluation and biopsy of recurrent rectal cancer using three-dimensional endosonography.

The value of endorectal ultrasonography for postoperative follow-up of rectal cancer is limited by the inability to distinguish recurrent malignancy from benign lesions, e.g., fibrotic tissue. This study was conducted to investigate the role of three-dimensional (3D) endosonography for evaluation and biopsy of recurrent rectal cancer. Endorectal ultrasonography was performed in routine follow-up program after resection of rectal cancer. 3D volume scans were recorded using a bifocal multiplane 3D transducer (7.5/10 MHz) with a 100 degrees longitudinal and a 360 degrees transversal scan angle. For transrectal ultrasound-guided biopsy of pararectal lesions, a specially designed targeting device was attached to the endoprobe. Overall pararectal lesions were detected in 28 of 163 patients (17 percent) who were undergoing endorectal ultrasonography for follow-up after resection of rectal cancer. 3D image analysis facilitated assessment of suspicious pararectal lesions by contemporary display of three perpendicular scan planes or volume reconstructions of the scanned area. Ultrasound-guided biopsy was performed in all 28 patients with pararectal lesions identified by endorectal ultrasonography. Biopsy revealed recurrent disease or lymph node metastases in seven and two patients, respectively. Benign lesions explained the endosonographic findings in 17 patients. All patients with benign histology still have no evidence of recurrent disease after a median follow-up of seven months. Nonrepresentative material was obtained in only 2 of 28 patients (accuracy, 93 percent). Histology changed the endosonographic diagnosis in 28 percent of cases. 3D endosonography with ultrasound-guided biopsy improves the diagnosis of extramural recurrence after curative resection of rectal cancer. 3D image display allows precise control of the position of the biopsy needle within the target.

Three-dimensional endorectal ultrasonography for staging of obstructing rectal cancer

Preoperative staging of advanced carcinoma of the rectum by conventional endorectal ultrasonography is often impossible because of the presence of obstruction, which does not allow passage of the endoprobe. In a prospective study, we investigated the value of three-dimensional endorectal ultrasonography for staging of obstructing rectal cancer. This technique permits examination of obstructing rectal tumors because scan planes can be chosen deliberately within a scanned volume. Overall obstructing tumors not accessible for conventional endoprobes were found in 26 of 94 patients who were subjected to endorectal ultrasonography for staging of rectal cancer. Three-dimensional volume scanning was performed using a three-dimensional frontfire transducer or a three-dimensional bifocal multiplane transducer (7.5/10 MHz). Data of the three-dimensional scans were stored on a hard disk for subsequent evaluation with a combison 530 processor. Three-dimensional transrectal endosonography enabled visualization of local tumor spread in all 26 patients. In 18 patients, obstruction was caused by advanced primary rectal carcinoma. Endosonography accurately determined the tumor infiltration depth in three T2 tumors, eight T3 tumors, and three T4 tumors. Overall accuracy for assessment of infiltration depth was 78 percent. Accuracy for assessment of perirectal lymph node involvement was 75 percent. In eight patients, the obstruction was attributable to extramural regrowth of rectal cancer after surgery. Diameter of the lesions ranged between 3 and 6 cm. Although all lesions were clearly depicted by three-dimensional endosonography, only five lesions (62 percent) were detected by computed tomography. Three-dimensional endorectal ultrasonography provides previously unattainable scan planes and enables accurate staging of obstructing rectal tumors. This technique may improve therapy planning in advanced rectal cancer by selecting patients who require preoperative adjuvant therapy.