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Biomedical subjects

S Halligan

Publications and source records attributed to S Halligan.

At least 55 records · Page 3Linked to original sources

Dose reduction in evacuation proctography.

The goal of this study was to reduce the patient radiation dose from evacuation proctography. Ninety-eight consecutive adult patients referred for proctography to investigate difficult rectal evacuation were studied using a digital imaging system with either a standard digital program for barium examinations, a reduced dose digital program (both with and without additional copper filtration), or Video fluoroscopy. Dose-area products were recorded for each examination and the groups were compared. All four protocols produced technically acceptable examinations. The low-dose program with copper filtration (median dose 382 cGy cm2) and Video fluoroscopy (median dose 705 cGy cm2) were associated with significantly less dose than other groups (p < 0.0001). Patient dose during evacuation proctography can be reduced significantly without compromising the diagnostic quality of the examination. A digital program with added copper filtration conveyed the lowest dose.

Adult↗

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.

Adolescent↗

Assessment of external anal sphincter morphology in idiopathic fecal incontinence with endocoil magnetic resonance imaging.

The failure of external anal sphincter repair may relate to sphincter atrophy where muscle fibers are replaced by fat, seen on MRI due to the differing signals returned by fat and muscle tissue. Manometry, electrophysiology, and MRI with an endocoil were performed on 34 fecally incontinent patients with intact sphincters on endosonography. The area of the external sphincter was measured in the midcoronal plane, and the percentage fat content calculated. Sphincter muscle area correlated strongly with squeeze pressure (P < 0.001) but not with percentage fat content. There was no relationship between percentage fat and age, weight, anal sensation, squeeze pressure, sphincter length or width, or pudendal nerve terminal motor latency. There was a trend for smaller sphincters to contain a higher percentage fat content (P = 0.059). MRI has established a relationship between function and external sphincter bulk, but not fat content, although smaller muscles may contain more fat.

Adolescent↗

Endocoil magnetic resonance imaging quantification of external anal sphincter atrophy.

BACKGROUND: Anal function depends on the integrity and quality of the sphincter muscles. The diagnosis of external anal sphincter atrophy on endocoil magnetic resonography has been associated with poor outcome from sphincter repair, although the imaging criteria for atrophy remain unclear. METHODS: Women with intact sphincters on endosonography and either normal (more than 60 cm H(2)O) (n = 9) or low (n = 16) squeeze pressures had endocoil magnetic resonography and electromyography. The area and fat content of the external anal sphincter and puborectalis were measured on mid-coronal magnetic resonography and images were graded as showing normal, intermediate or advanced atrophy. The definition of the external anal sphincter on endosonography and the thickness of the internal anal sphincter were also assessed. RESULTS: Women with a normal anal squeeze pressure had a larger external anal sphincter cross-sectional area (mean(s.d.) 240(56) versus 193(62) mm(2); P = 0.01) with a lower mean fat content (mean(s.d.) 23(4) versus 30(6) per cent; P < 0.001) than those with low squeeze pressures. There was an overall correlation between squeeze pressure, cross-sectional area (r = 0.32, P = 0.02) and fat content (r = - 0.51, P < 0.001). Patients with a thin (less than 2 mm) internal anal sphincter and/or a poorly defined external sphincter on endosonography were more likely to have atrophy (positive predictive value 74 per cent). CONCLUSION: : Potential endosonographic markers for external anal sphincter atrophy are suggested, and a visual scale for endocoil magnetic resonographic assessment has been validated.

Adult↗

Multiplanar anal endosonography--normal anal canal anatomy.

INTRODUCTION: Volume acquisition during anal ultrasound enables multiplanar imaging of the anal canal. The normal ultrasonic multiplanar appearance of the anal canal is described and gender differences in canal anatomy are highlighted. METHODS: Ten male and 12 female normal volunteers (mean ages 31.5 years (s.d. 5.9) and 31.2 (s.d. 6.7)) had three-dimensional anal endosonography (3-D AES). Each volume dataset was seeded in the axial plane facilitating multiplanar identification of known anatomical structures. RESULTS: The anterior external anal sphincter (EAS) was significantly longer in men than women 30.1 mm (3.9) vs 16.9 mm (7.4) (P < 0.001). There was no difference in the length of the puborectalis 24.7 mm (6.4) vs 24 mm (5) (P=0.78) in men compared with women. The cranial extent of the anterior EAS was tilted forward in both sexes. The angle formed by the anterior EAS and the longitudinal axis of the anal canal was more acute in men than in women (11.1 degrees vs 18.6 degrees; P=0.007). Dataset volume seeding of familiar structures in the axial plane allowed the multiplanar endosonographic anatomy to be described. CONCLUSIONS: Multiplanar AES has enabled detailed longitudinal measurement of the components of the anal canal and has revealed important gender differences. The multiplanar ultrasonic appearance of the normal anal canal has been described for the first time.

Journal Article↗

Pelvic floor imaging.

A greater awareness of the therapies now available for pelvic floor dysfunction has increased demand for specialized imaging of this region. Some of the techniques required are available at relatively few centers, and the purpose of this review is to introduce the emerging subspecialty of pelvic floor imaging to a more general readership. Pelvic floor anatomy is complex and is being unraveled by means of magnetic resonance (MR) imaging. This is discussed in detail by using a global, rather than a compartmentalized, anatomic approach. The physiology of normal urinary and anal function and the routine clinical tests applied to them are outlined. The imaging techniques involved include MR imaging, endosonography, and fluoroscopy. The main investigations include video urodynamic imaging, evacuation proctography, dynamic cystoproctography, dynamic MR imaging of the pelvic floor, and endoluminal imaging of the anal sphincters with MR imaging and ultrasonography. These are described in detail, and their role with regard to the main pathologic conditions of the pelvic floor--urinary and anal incontinence, constipation, and prolapse--are discussed.

Anal Canal↗

Predictive value of impaired evacuation at proctography in diagnosing anismus.

OBJECTIVE: We aimed to determine the positive predictive value of impaired evacuation during evacuation proctography for the subsequent diagnosis of anismus. SUBJECTS AND METHODS: Thirty-one adults with signs of impaired evacuation (defined as the inability to evacuate two thirds of a 120 mL contrast enema within 30 sec) during evacuation proctography underwent subsequent anorectal physiologic testing for anismus. A physiologic diagnosis of anismus was based on a typical clinical history of the condition combined with impaired rectal balloon expulsion or abnormal surface electromyogram. RESULTS: Twenty-eight (90%) of the 31 patients with impaired proctographic evacuation were found to have anismus at subsequent physiologic testing. Among the 28 were all 10 patients who evacuated no contrast medium and all 11 patients with inadequate pelvic floor descent, giving evacuation proctography a positive predictive value of 90% for the diagnosis of anismus. A prominent puborectal impression was seen in only three subjects during proctography, one of whom subsequently showed no physiologic sign of anismus. CONCLUSION: Impaired evacuation during evacuation proctography is highly predictive for diagnosis of anismus.

Adult↗

Gender differences in the longitudinal pressure profile of the anal canal related to anatomical structure as demonstrated on three-dimensional anal endosonography.

BACKGROUND: Anal canal squeeze pressure is assumed to be due to external sphincter contraction, but the contribution of other muscles has not been explored. METHODS: Ten male and ten nulliparous female asymptomatic subjects had three-dimensional anal endosonography and manometry. Incremental squeeze pressures at 0. 5-cm intervals, expressed as a percentage of the maximum pressure recorded anywhere in the canal, were related to the following anatomical levels: puborectalis, overlap between external anal sphincter (EAS) and puborectalis, external and internal anal sphincters, and external anal sphincter only. Levels were determined by coronal and sagittal endosonographic reconstructions. RESULTS: Puborectalis was the same length in men and women (median 23.9 versus 27.1 mm) but represented a greater proportion of the anal canal in women (45 versus 61 per cent; P = 0.02). At the level of puborectalis alone, the pressure generated as a proportion of maximum anal canal pressure was 71 (range 32-100) per cent in men and 62 (range 32-100) per cent in women. At the level of the EAS alone, the pressure was 60 (4-98) per cent in men and 82 (41-100) per cent in women; where the external sphincter was overlapped by puborectalis, the pressure was 98 (60-100) per cent in men and 75 (47-100) per cent in women. CONCLUSION: Maximal anal canal squeeze pressure is found where the puborectalis overlaps the EAS. This segment represents a significant proportion of anal canal length in women.

Anal Canal↗

The effect of timing of intravenous muscle relaxant on the quality of double-contrast barium enema.

AIM: To determine whether the timing of buscopan administration during double-contrast barium enema examination (DCBE) affects diagnostic quality. MATERIALS AND METHODS: In a prospective setting, 100 consecutive adult out-patients referred for DCBE received 20 mg buscopan (hyoscine-N-butylbromide) intravenously, either before infusion of barium suspension (Group A) or after barium infusion and gas insufflation (Group B). A subjective assessment of ease of contrast medium infusion was made at the time of examination and the films subsequently analysed by two radiologists unaware of the mode of relaxant administration, who noted the quality of mucosal coating and made subjective and objective measurements of segmental distension. RESULTS: There was no significant difference in screening times, infusion difficulty or colonic contrast medium coating between the two groups. Subjective assessment of distension of the caecum, ascending colon, transverse colon and rectum were not significantly different. Patients receiving intravenous relaxant after barium and gas infusion had less subjective descending (P = 0. 05) and sigmoid (P = 0.04) colon distension, but there was no significant difference with respect to maximal bowel diameter in any of the segments measured. CONCLUSION: The timing of intravenous administration during DCBE is likely to have no significant effect on the diagnostic quality of the study.

Adult↗

Transvaginal ultrasound examination of women with and without pelvic venous congestion.

AIM: To determine if transvaginal ultrasound, including power Doppler examination, can distinguish between women with and without pelvic congestion. MATERIALS AND METHODS: Thirty-six women with pelvic congestion were prospectively examined using transvaginal ultrasonography and standard uterine and ovarian measurements made. Additionally, planimetric measurements of each ovary were taken using an image analysis program to determine the cross-sectional area of ovarian stroma and follicles, if any. Power Doppler images of adnexal vessels were obtained and planimetric estimates of surface area calculated. A congestion score was assigned to each patient, based on vein number, diameter and morphology on grey-scale scanning. Identical measurements were obtained from 19 asymptomatic women and results compared. RESULTS: There was no significant difference between women with pelvic congestion and controls with respect to power Doppler or grey-scale images of adnexal vessels, or congestion score. However, women with pelvic congestion had significantly larger and multicystic ovaries when compared to controls. CONCLUSIONS: Transvaginal ultrasound measurements of adnexal vasculature, including power Doppler measurements, cannot reliably distinguish women with pelvic congestion from controls. However, ultrasound may remain useful for diagnosis of pelvic congestion, predominantly because it is able to visualize multi-cystic ovaries in these patients.

Adult↗

Dynamic MR imaging of the pelvic floor in asymptomatic subjects.

OBJECTIVE: Dynamic MR imaging may be used as an alternative to dynamic cystoproctography for the evaluation of pelvic floor prolapse and configuration. MR criteria for normality are derived from proctographic studies because no large MR study of asymptomatic individuals has been performed. Our study aimed to define the normal range of dynamic pelvic MR appearances in a large group of asymptomatic individuals. SUBJECTS AND METHODS: Fifty healthy adult volunteers (25 men and 25 women; age range, 20-66 years; mean age, 34 years) were prospectively recruited and examined using dynamic MR imaging. All subjects were interviewed and established as healthy using a validated questionnaire. Axial, coronal, and sagittal MR imaging was performed at rest and during maximum pelvic strain using a static 1.0-T unit and a fast-field-echo sequence, providing 10 slices in 31 sec. Standardized measurements of pelvic configuration were taken, and rest and strain imaging were compared to determine the range of normal appearances. RESULTS: Three women developed a cystocele during maximum pelvic strain, two of whom also showed grade 1 uterocervical prolapse, which was also seen in another woman. Three men showed posterior pelvic floor descent in excess of 3 cm during straining. No rectocele, enterocele, rectal prolapse, or perineal hernia was seen in any subject. CONCLUSION: The normal range of pelvic organ descent in asymptomatic subjects seen on dynamic MR imaging included cystocele, uterocervical prolapse, and excessive anorectal junction descent. Although we encountered pelvic prolapse in seven volunteers, it was infrequent and low grade, suggesting that criteria for abnormality derived from proctography are generally applicable to MR imaging.

Adult↗

Prospective assessment of accuracy of endoanal MR imaging and endosonography in patients with fecal incontinence.

OBJECTIVE: Endoanal MR imaging was prospectively compared with anal endosonography to determine any superiority in the characterization of sphincter morphology in fecal incontinence. SUBJECTS AND METHODS: Fifty-two consecutive patients with fecal incontinence were examined with anal endosonography and endoanal MR imaging after a detailed bowel history, clinical examination, and complete anorectal physiologic testing. External and internal anal sphincter integrity was noted on both endosonograms and MR images by two radiologists in consensus, who read individual scans in a random order to avoid recall bias. Imaging findings were subsequently compared, and arbitration of any disagreement between endosonography and MR imaging was made in consensus by a surgeon and a gastroenterologist who also had access to the patient's history, clinical examination, and anorectal physiologic testing results. RESULTS: Complete agreement was found between anal endosonographic and MR imaging interpretations in 32 patients (62%): 10 with combined external and internal sphincter injuries, two with isolated internal sphincter injury, and 20 with intact sphincters. Of 20 patients in whom results of the scans were disparate, incorrect interpretation was found on endosonography in six patients, on MR imaging in 15. Overall, one error relating to the internal sphincter was made on endosonography versus 12 on MR imaging (p = 0.002), and five errors relating to the external sphincter were made on endosonography versus six on MR imaging (p = 1.0). CONCLUSION: This study suggests that endoanal sonography and endoanal MR imaging are equivalent in diagnosing external anal sphincter injury, but MR imaging is inferior in diagnosing internal anal sphincter injury.

Adolescent↗

Relationship between anatomic and symptomatic long-term results after rectocele repair for impaired defecation.

PURPOSE: The aim of this study was to determine the long-term symptomatic and anatomic results of rectocele repair for impaired defecation. METHODS: All 26 females operated on during a five-year period in one hospital were reviewed in clinic. Follow-up was available on 22 patients after a median of 27 (range, 5-54) months. Interview, anorectal physiological testing, and evacuation proctography were performed preoperatively and postoperatively. Fifteen patients had a transperineal repair and seven patients had a transanal repair. RESULTS: Sixteen (73 percent) patients felt improved. A feeling of incomplete emptying (19 vs. 10, preoperative vs. postoperative; P = 0.02) and the need to use digital assistance vaginally (13 vs. 6; P = 0.07) were both reduced by surgery, the former being improved significantly more often after transperineal repair. The rectocele width and area were reduced by both types of surgery; however, the rectocele diameter was greater than 2 cm in 16 patients preoperatively and 10 patients postoperatively. There was no significant difference between patients who did or did not feel improved by surgery in the percentage reduction in rectocele width (22 vs. 18 percent; P = 0.95), the percentage reduction in rectocele area (65 vs. 62 percent; P = 0.95), or a rectocele width of more than 2 cm (44 vs. 50 percent; P = 0.80), did vs. did not feel improved, respectively. CONCLUSION: Operative repair symptomatically improves a majority of patients with impaired defecation associated with a large rectocele, but the improvement probably relates at least in part to factors other than the dimensions of the rectocele.

Adult↗

The use of non-ionic water-soluble contrast agents for small bowel follow-through examination.

In certain situations it is preferable to perform small bowel examination using water-soluble contrast agents. Generally, ionic agents are used, but non-ionic agents may be an alternative in certain circumstances. We retrospectively reviewed a consecutive series of small bowel examinations using non-ionic media in order to determine their efficacy. A total of 52 water-soluble non-ionic small bowel follow-through examinations were performed in 42 patients using 100 ml iohexol. Indications for the study and the reasons why barium sulphate suspensions were contraindicated were established. Studies were assessed for radiographic quality and clinical findings were noted, and comparison was made with operative findings and clinical outcome. Obstruction was diagnosed in 12 examinations and the radiological findings were confirmed in all 7 patients surgically treated. Fistulae were identified in 11 examinations and the radiological findings were confirmed in all 8 patients who were treated by laparotomy. Additionally, at laparotomy no obstruction or fistula was found in the 5 patients in whom prior contrast examination had been negative. Non-ionic water-soluble follow-through examination is easily performed and well tolerated, allowing accurate diagnosis of obstruction and fistula when barium suspensions are contraindicated.

Abdomen, Acute↗

Accurate PEG tube placement with magnetic positional imaging.

BACKGROUND: Percutaneous endoscopic gastrostomy (PEG) is a common procedure and accounts for an increasing proportion of an endoscopist's workload. Serious complications can occur from inaccurate abdominal wall puncture. Electronic three-dimensional imaging has been used to aid colonoscopy. We adapted the principles of this technique to PEG insertion in a procedure called magnetic positional imaging. METHODS: Magnetic positional imaging was used to determine the abdominal wall puncture site and angle of insertion that would provide the shortest distance from abdominal wall to the stomach. The pull-through technique was used to perform PEG. RESULTS: PEG insertion with magnetic positional imaging was performed on four patients without complications. The average distance between the internal and external sensors was 5 mm. CONCLUSION: A new technique, magnetic positional imaging, facilitates the pull-through technique for PEG. Additional studies are needed to clarify the potential benefit in endoscopic practice.

Abdominal Muscles↗