Comparison of radiologists' confidence in excluding significant colorectal neoplasia with multidetector-row CT colonography compared with double contrast barium enema.

The aim of this study was to compare the confidence of experienced radiologists in excluding colonic neoplasia with CT colonography (CTC) compared with barium enema. 78 patients (median age 70 years, range 61-87 years, 44 women) underwent same day CTC and barium enema. Two radiologists experienced in reporting barium enema assessed whether the examination had excluded a polyp 6 mm or greater as "yes", "probably" or "no" for each of 6 colonic segments. Two different radiologists experienced in CTC independently performed the same assessment on the CT datasets. Responses were compared using a paired exact test. Formal barium enema and CT reports were compared with any endoscopic examination performed within 1 year. Studies reporting polyps 6 mm+ in patients not subsequently undergoing endoscopy were reviewed by two independent observers. Radiologists stated they had confidently excluded a significant lesion in 314 (71%) and 382 (86%) of 444 segments with barium enema and CTC, respectively (p<0.001). Confidence was significantly higher with CTC in the in the descending and ascending colon (p = 0.02 and p<0.001, respectively), and caecum (p<0.001). 22 patients underwent some form of endoscopy. Of five patients with proven colorectal neoplasia (including two with cancer), CTC and barium enema correctly identified five and three, respectively. In 56 patients not undergoing endoscopy, CTC reported 17 polyps 6 mm+, of which 16 were retrospectively classified as definite or probable. 11 could not be identified on the barium enema, even in retrospect. Confidence in excluding polyps 6 mm or larger is significantly greater with CT colonography particularly in the proximal colon.

Anal sphincter dysfunction in Parkinson's disease.

Striated anal sphincter function was studied electrophysiologically and radiologically in six patients with Parkinson's disease and chronic constipation. In five cases, there was paradoxic anal sphincter muscle contraction during simulated defecation straining resembling anismus-type pelvic outlet obstruction. Radiologic studies showed functional improvement of the defecatory mechanism following the administration of the dopamine receptor agonist apomorphine in four patients. Dysfunction of the striated anal sphincter musculature may be a significant cause of constipation in some parkinsonian patients, occurring as part of the generalized extrapyramidal motor disorder.

Varied light and scanning electron microscopic appearances of barium sulphate in smears and histological sections.

The various light and scanning electron microscopic appearances of barium sulphate in smears and in histopathological lesions in sections are illustrated. One type of barium sulphate (E-Z-HD) includes much larger, bright birefringent particles and has very different appearances from other widely used types. Such larger particles in sections were not originally suspected to be barium sulphate and were identified only by energy dispersive x ray analysis in a scanning electron microscope. This form of barium sulphate is used for double contrast upper gastrointestinal radiography, and is not thought to have been responsible for the lesions in which it has been observed by us.

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.

Transperineal repair of symptomatic rectocele with Marlex mesh: a clinical, physiological and radiologic assessment of treatment.

BACKGROUND: The aim of this study was to evaluate the operative repair of rectoceles in a defined group of women by a technique designed to deal with the cause (failure of the rectovaginal septum) rather than the effect (rectal and vaginal wall bulging). STUDY DESIGN: Only women whose defecation was aided by vaginal digitation and who had large rectoceles on proctography were included. Any other clinical symptoms in the absence of vaginal digitation, even when proctography demonstrated a rectocele, were not taken as indicators for surgery in this study. There were nine women, median age 50 years (range, 32 to 61). The rectovaginal septum was repaired with Marlex mesh through a perineal approach by one surgeon. The median follow-up period was 29 months. RESULTS: Eight of the nine women achieved successful evacuation after surgery without the need for vaginal digitation. Rectocele size, depth, and the percent of barium trapped in the rectocele on proctography were all improved. Anorectal physiology measurements were unchanged by surgery. CONCLUSIONS: Operative repair of the rectovaginal septum removes the need for vaginal digitation in most women with large rectoceles on proctography. Further studies in well-defined groups of women are needed to establish how well rectocele repair aids women with a variety of other pelvic and perineal symtoms.

A radiological study after parenteral nutrition through silicone rubber catheters: fibrin sleeves without thrombosis.

Injection of contrast material through 38 central silicone rubber catheters at the time of withdrawal after a mean catheter life of 55 days (range 5-369) has shown no evidence of occult venous thrombosis despite the presence of a fibrin sleeve around the whole length of the intravascular portion in 37 cases. The presence of this fibrin sleeve appears to have been harmless. The absence of thrombosis suggests that silicone rubber is the material of choice for central venous feeding catheters and that the addition of heparin to the infusion fluid is unnecessary.

Unwanted anal penetration as a physical cause of faecal incontinence.

OBJECTIVE: To investigate sexual abuse as a cause of faecal incontinence. PATIENTS: Seven patients (two men and five women) with a history of sexual abuse, including anal penetration, and faecal incontinence. METHODS: Anorectal physiological techniques and anal endosonography were used for patient assessment. RESULTS: All seven patients had evidence of internal sphincter disruption and three had additional external anal sphincter dysfunction. CONCLUSION: Unwanted anal penetration can cause permanent structural anal sphincter damage.

The radiological demonstration of adhesions following surgery for inflammatry bowel disease.

Adhesions were demonstrated by small bowel meal in six patients with symptoms of intermittent small bowel obstruction following surgery for inflammatory bowel disease. The radiographic criteria for the diagnosis of adhesions and the distincton from recurrent Crohn's disease are discussed.

The radiological diagnosis of polyps in the presence of diverticular disease.

The double contrast barium enemas in 20 patients with endoscopically proven polyps within a segment of diverticular disease have been reviewed. Ninety per cent of the polyps were detected. The increased density sign and negative shadow filling defect proved valuable in their detection. Antispasmodics are advised to distend the sigmoid and allow double contrast views to be obtained. With severe diverticular changes it may be impossible to exclude a polyp, and if the patient complains of rectal bleeding, endoscopy is indicated.

The effect of oral magnesium-containing bowel preparation agents on mucosal coating by barium sulphate suspensions.

Alteration in the quality of mucosal coating by barium sulphate suspension observed during double-contrast barium enema (DCBE) examinations when an oral magnesium-containing purgative (Picolax) was used as sole bowel preparation has been investigated in vivo. Small amounts of Picolax were found to produce a linear increase in apparent viscosity and thixotropy, due to flocculation. The effect of equivalent concentrations of acid was significantly less (p less than 0.01), and of magnesium chloride was significantly greater (p less than 0.05), whereas magnesium citrate was comparable to Picolax, demonstrating the deflocculating effect of citrate on the flocculating action of magnesium ions. It is suggested that colonic residue from orally ingested magnesium-containing purgatives may contain sufficient magnesium ions to increase viscosity of the barium suspension and visibly affect its coating during DCBE.

Vaginal endosonography to diagnose enterocoele.

Radiological diagnosis of enterocoele is possible using evacuation proctography, but the standard technique must be modified to reveal the small bowel. Since prolapsed bowel is interposed between the vagina and rectum, diagnosis may be possible using vaginal endosonography. We describe a simple ultrasound technique to diagnose enterocoele, which has been validated by comparison with proctography. 17 women were examined with vaginal endosonography, and a diagnosis of enterocoele made if bowel was visualized in the rectovaginal space when bearing down. The findings were compared with subsequent proctography. In eight cases (47%) bowel prolapsed into the rectogenital space during straining, obscuring the rectum, while this did not occur in the remaining nine subjects (53%). Proctography confirmed an enterocoele in six of the eight cases in whom it had been diagnosed on endosonography, and confirmed the absence of enterocoele in all of the nine cases negative on endosonography. These values gave vaginal endosonography a sensitivity of 100% and specificity of 82%, with a positive predictive value of 75%, and negative predictive value of 100% for a prevalence of abnormality of 0.35. Vaginal endosonography is a quick, easy and convenient alternative to evacuation proctography for the radiological diagnosis of enterocoele.

Magnetic resonance imaging of fistula-in-ano: STIR or SPIR?

Patients with clinically suspected anorectal sepsis were studied using MRI in order to determine if T2 weighted sequences with fat suppression conveyed any additional benefit over conventional short tau inversion recovery (STIR) sequences. 23 consecutive patients (16 male) undergoing MRI for suspected perianal sepsis were studied prospectively using a 1.0 T whole body system and body coil. Axial and coronal T1 weighted turbo spin echo sequences were obtained, followed by STIR and T2 weighted spectral fat saturation inversion recovery (SPIR) sequences. Images were assessed for the presence of sepsis or fistula, and information provided by the sequences compared. Active disease was diagnosed in 17 patients, 14 of whom had fistula-in-ano; one intersphincteric, 10 transsphincteric and three extrasphincteric. Internal openings were identified in all of these 14 patients; anal in 10, rectal in two, and both in two. Diagnosis and fistula classification was possible in all of these 14 subjects on the basis of STIR sequences alone. The anal sphincters and pelvic floor musculature were better resolved by STIR than SPIR, leading to easier and more confident determination of fistula anatomy in eight of the 14 (57%). In no case did STIR sequences fail to resolve inflammation seen subsequently on SPIR, despite reduced track intensity. T1 weighted sequences were generally non-contributory. Both STIR and SPIR sequences are adequate to classify fistula-in-ano, but classification was easier with STIR due to superior resolution of pelvic floor structures.

Unsuspected sphincter damage following childbirth revealed by anal endosonography.

Anal endosonography was performed in 62 consecutive patients with incontinence of flatus or faeces following obstetric trauma, and in 18 parous controls. Of the incontinent group, 90% had defects in the external sphincter, 65% in the internal sphincter and 44% disruption of the perineal body, compared with none of the controls. This triad of lesions is pathognomonic of obstetric trauma. Anal endosonography revealed a higher prevalence of sphincter damage than expected from anorectal physiology tests, and therefore has a role in screening patients following complicated or difficult deliveries.

Mucocele of the appendix presenting as a sigmoid mass.

Mural tumours of the colon are rare and may be difficult to distinguish from extrinsic lesions. We report a case of an apparent intramural sigmoid tumour due to a mucocele of the appendix and discuss the radiological diagnosis of mural tumours of the large bowel.

Anal sphincter trauma during instrumental delivery.

OBJECTIVES: To determine the incidence of defecatory symptoms, pudendal nerve damage and mechanical trauma to the anal sphincters during vacuum and forceps delivery. METHODS: Anal endosonography, manometry, pudendal nerve terminal motor latency (PNTML) measurements and perineometry were performed in 43 primiparae who had an instrumental delivery (17 vacuum and 26 forceps) and in 47 who had a normal vaginal delivery (controls). RESULTS: Defecatory symptoms developed in 10 (38%) women following a forceps delivery compared with 2 (4%) in the control group (P = 0.0003), and 2 (12%) following a vacuum extraction (P = NS). Anal sphincter defects occurred in 21 (81%) forceps deliveries compared with 17 (36%) controls (P = 0.0005) and 4 (21%) vacuum extractions (P = NS). Anal pressures were lower in those who developed a sphincter defect (P < 0.00001). PNTML was not significantly altered by the mode of delivery. CONCLUSIONS: Compared with vacuum extraction, forceps delivery is associated with significantly more damage to the anal sphincters and hence an increased incidence of defecatory symptoms.

Third degree obstetric anal sphincter tears: risk factors and outcome of primary repair.

OBJECTIVES: To determine (i) risk factors in the development of third degree obstetric tears and (ii) the success of primary sphincter repair. DESIGN: (i) Retrospective analysis of obstetric variables in 50 women who had sustained a third degree tear, compared with the remaining 8553 vaginal deliveries during the same period. (ii) Women who had sustained a third degree tear and had primary sphincter repair and control subjects were interviewed and investigated with anal endosonography, anal manometry, and pudendal nerve terminal motor latency measurements. SETTING: Antenatal clinic in teaching hospital in inner London. SUBJECTS: (i) All women (n = 8603) who delivered vaginally over a 31 month period. (ii) 34 women who sustained a third degree tear and 88 matched controls. MAIN OUTCOME MEASURES: Obstetric risk factors, defecatory symptoms, sonographic sphincter defects, and pudendal nerve damage. RESULTS: (i) Factors significantly associated with development of a third degree tear were: forceps delivery (50% v 7% in controls; P = 0.00001), primiparous delivery (85% v 43%; P = 0.00001), birth weight > 4 kg (P = 0.00002), and occipito-posterior position at delivery (P = 0.003). No third degree tear occurred during 351 vacuum extractions. Eleven of 25 (44%) women who were delivered without instruments and had a third degree tear did so despite a posterolateral episiotomy. (ii) Anal incontinence or faecal urgency was present in 16 women with tears and 11 controls (47% v 13%; P = 0.00001). Sonographic sphincter defects were identified in 29 with tears and 29 controls (85% v 33%; P = 0.00001). Every symptomatic patient had persistent combined internal and external sphincter defects, and these were associated with significantly lower anal pressures. Pudendal nerve terminal motor latency measurements were not significantly different. CONCLUSIONS: Vacuum extraction is associated with fewer third degree tears than forceps delivery. An episiotomy does not always prevent a third degree tear. Primary repair is inadequate in most women who sustain third degree tears, most having residual sphincter defects and about half experiencing anal incontinence, which is caused by persistent mechanical sphincter disruption rather than pudendal nerve damage. Attention should be directed towards preventive obstetric practice and surgical techniques of repair.

Barium radiology.

The role of barium radiology in the diagnosis and assessment of inflammatory bowel disease is discussed. A primary diagnostic role is maintained in the small bowel, though in the colon endoscopy with biopsy is being used more frequently. The instant enema is safer in acute colitis. Advanced and complicated disease are more accurately assessed radiologically, as barium studies map out disease more clearly and show mural and extramural components.