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Biomedical subjects

S Halligan

Publications and source records attributed to S Halligan.

At least 37 records · Page 2Linked to original sources
PubMed2003

[Endoanal MR imaging: diagnostic assessment].

Endoanal MR imaging is an alternative to anal endosonography for the acquisition of high-resolution images of the external and internal anal sphincter. A dedicated anal receiver coil is placed in the anus so that it spans the sphincter complex. Highly detailed images of the sphincters can be obtained in any plane and the morphological abnormalities found in various types of anal incontinence can be demonstrated. Whilst MR demonstrates external sphincter disruption with an efficacy similar to that of endosonography, it is better able to demonstrate external sphincter atrophy that is presumed secondary to neuropathy. The finding of coexisting muscular atrophy on MR may prejudice the effects of anal sphincter repair for obstetric disruption.

Anal Canal↗
PubMed2003

CT colonography: methods, pathology and pitfalls.

Computed tomography colonography (CTC) is a relatively new technique that is currently challenging more established methods of large bowel imaging. Several workers have suggested CTC surpasses the barium enema and approaches conventional endoscopy for detection of colorectal neoplasia. Accurate diagnosis relies on technically good studies, the main aim of which is adequate bowel cleansing and distension. Furthermore, the learning curve is steep and normal colonic anatomy has to be re-learned in a CT context. This review aims to describe the technique, revise the imaging features of both normal and pathological colon, and to highlight potential diagnostic pitfalls and their avoidance.

Colitis↗
PubMed2003

Optimizing bowel preparation for multidetector row CT colonography: effect of Citramag and Picolax.

AIM: To compare the adequacy and acceptability of Picolax and Citramag bowel cleansing agents for CT colonography. MATERIALS AND METHODS: Multidetector row CT colonography was performed in 124 subjects; 43 had been prepared with Picolax and 81 with Citramag. Datasets were assessed for retained fluid and solid residue, and overall adequacy of segmental visualization. Preparation acceptability was also assessed. RESULTS: There was significantly less retained fluid with Picolax. The odds of being in the next higher category for retained fluid when using Picolax were 0.33 (CI: 0.22-0.50, p<0.0001) when compared with Citramag, for all segments combined. However there was significantly more retained solid residue with Picolax. The odds of being in the next higher category for retained residue when using Picolax were 2.44 (CI: 1.41-4.24, p=0.002) when compared with Citramag, for all segments combined. There was no significant difference with respect to overall segmental visualization: the odds of a segment being adequately visualized when using Picolax were 1.52 (CI: 0.88-2.65, p=0.14) when compared with Citramag. There was no significant difference with respect to acceptability. CONCLUSION: Picolax results in a significantly drier colon than Citramag and associated with more retained residue. We found Picolax the more suitable preparation for CT colonography.

Adenoma↗
PubMed2003

Use of multidetector-row CT colonography for detection of colorectal neoplasia in patients referred via the Department of Health "2-Week-wait" initiative.

AIM: Patients referred under the Department of Health 2-week wait initiative with symptoms of colorectal cancer frequently undergo whole-colon examination. We investigated the use of computed tomography (CT) colonography as an alternative to colonoscopy in this scenario. MATERIALS AND METHODS: Fifty-four consecutive patients, referred via the 2-week wait initiative and scheduled for colonoscopy, consented to undergo multidetector CT colonography immediately before endoscopy. The site and morphology of any polyp or cancer detected by CT was noted and comparison made with subsequent colonoscopy. RESULTS: Colonoscopy detected polyps or cancer in 29 patients (53.7%). CT colonography prospectively detected 18 of 41 (44%) polyps of 1-5 mm, three of four (75%) polyps of 6-9 mm, four of four (100%) polyps 10 mm or larger, and five of six (83%) cancers. The missed cancer occurred early in the series and was a perceptive error. The overall sensitivity, specificity, positive predictive value and negative predictive value of CT colonography for cancer and polyps 10 mm or greater on a per patient basis were 90, 100, 100 and 98%, respectively. CT detected one renal cancer and one colonic cancer, initially missed due to incomplete colonoscopy. CONCLUSION: CT colonography is a robust technique for investigation of symptomatic patients. The learning curve must be overcome for optimal performance.

Adult↗
PubMed2003

Observer variation in the detection of colorectal neoplasia on double-contrast barium enema: implications for colorectal cancer screening and training.

AIM: To assess inter-observer error for the diagnosis of neoplasia on double contrast barium enema (DCBE) in the light of claims that no additional interpretative training would be needed for implementation in a national screening programme. MATERIALS AND METHODS: 10 experts, 10 consultants, and 10 experienced trainees each reported 20 DCBE studies, of which two showed cancer, three showed large polyps, four showed small polyps, and 12 were normal. Inter-observer variation was compared using odds ratios with the trainee group as reference (baseline group). RESULTS: Experts were significantly more likely to correctly identify neoplasia on DCBE than trainees. The odds of a correct diagnosis for experts were 2.79 (95% CI 2.04, 3.81) for cancer, 2.36 (1.88, 2.97) for large polyps, and 3.50 (1.98, 6.18) for small polyps. While consultants were more likely to correctly diagnose a large polyp than trainees, 1.45 (1.15, 1.84), there was no significant difference between these two groups for the correct diagnosis of either cancer, 1.24 (0.52, 2.96), or small polyps, 1.26 (0.83, 1.90). A cancer was missed by 6 (60%) experts, 9 (90%) consultants, and 8 (80%) trainees. Large polyps were missed by 4 (40%) experts, 5 (50%) consultants, and 6 (60%) trainees. There was no significant difference between any group when false positive diagnoses were considered. CONCLUSIONS: There is considerable inter-observer perceptive error for the diagnosis of neoplasia on DCBE. Experts performed significantly better than other observers but the overall standard of performance was poor, even amongst experts.

Aged↗
PubMed2003

Response of fistulating Crohn's disease to infliximab treatment assessed by magnetic resonance imaging.

AIMS: To assess fistula track healing after infliximab treatment using magnetic resonance imaging. METHODS: Magnetic resonance imaging and clinical evaluation were performed before and after three infliximab infusions given over a 6-week period. Magnetic resonance images were evaluated for abscesses and fistula tracks. Paired magnetic resonance image examinations were rated 'better', 'unchanged' or 'worse'. Magnetic resonance imaging and clinical outcomes were then compared. RESULTS: Of the 12 referred patients, pre-treatment magnetic resonance imaging detected abscesses in three (two not treated). Of the 10 treated patients, seven had peri-anal fistulas, two of whom also had recto-vaginal fistulas, and three had abdominal wall entero-cutaneous fistulas. After infliximab, four were in remission, one had a response and five were non-responders. One developed a peri-anal abscess. Magnetic resonance imaging improved in six, was unchanged in two and was worse in two. In four of the six with improvement in magnetic resonance imaging, the fistula track resolved, but two of these had clinically persistent entero-cutaneous fistulas. The clinical outcome and magnetic resonance imaging correlated in seven of the 10 patients; in three (two entero-cutaneous and one peri-anal), there was discordance. CONCLUSIONS: Magnetic resonance imaging identifies clinically silent sepsis. Fistulas may persist despite clinical remission. Clinical response to infliximab and clinical correlation with magnetic resonance imaging were poor in patients with abdominal entero-cutaneous fistulas.

Abscess↗
PubMed2003

Transvaginal power Doppler ultrasound in pelvic congestion.

PURPOSE: Pelvic congestion is diagnosed by transuterine venography, an invasive procedure requiring sedation and irradiation. Ultrasound may be an alternative but is hindered by slow flow within pelvic veins. In an attempt to counter this, we investigated the possible role of transvaginal power Doppler ultrasound. MATERIAL AND METHODS: 42 women with a clinical suspicion of pelvic congestion underwent transvaginal ultrasound. Adnexal veins were examined and a congestion score established. Planimetric measurements of adnexal vessels were obtained using power Doppler ultrasound, and uterine and ovarian morphology noted. All women then underwent transuterine venography and agreement with the ultrasound congestion score and morphologic features was determined. RESULTS: There was a trend towards weak positive correlation between ultrasound and venography congestion scores (r = 0.29, p = 0.06). However, agreement between scores was poor on an individual basis (95% limits of agreement, -3.9 to +2.7). Planimetric power Doppler assessments of adnexal vascularity were unrelated to venographic congestion. Instead, there was correlation between the number and diameter of ovarian follicles and venographic congestion: women with congestion tended to have significantly more (0.04) and smaller follicles (p = 0.001). CONCLUSION: There was poor individual agreement between ultrasound and venographic estimates of congestion. However, there was a direct relationship between venographic congestion score and ovarian morphology.

Adnexa Uteri↗
PubMed2002

Endosonographic anatomy of the normal anal canal compared with endocoil magnetic resonance imaging.

PURPOSE: This study was designed to clarify the sonographic anatomy of the normal anal canal by comparison with endoanal magnetic resonance imaging, to determine agreement between these imaging modalities and interobserver error in measuring layer thickness. METHODS: Three-dimensional endosonographic and endocoil magnetic resonance images of the anal canal were obtained in four males and five nulliparous females aged 22 to 34 years. Images were analyzed at similar levels throughout the canal using a graphics-overlay technique to compare sonographic with magnetic resonance images. Measurements were taken at one level for agreement analysis between modalities and for interobserver variability in the measurement of the thickness of the main anal canal layers. RESULTS: The muscularis submucosae ani, muscle bundles in the longitudinal muscle layer, and puboanalis were identified on sonography. The outer border of the external sphincter was demarcated by an interface reflection with ischioanal fat. Clarification of the external sphincter anatomy allowed excellent correlation (Ri = 0.96) for the assessment of thickness. There was excellent correlation for the interobserver measurement of the external and internal sphincters and the submucosal width on endosonography, but there was poor correlation for the longitudinal muscle (0.12). CONCLUSION: The overlay technique has improved endosonographic interpretation, and measurement of external sphincter thickness has been validated both by comparison with magnetic resonance and on interobserver agreement.

Adult↗
PubMed2002

Predictive value of internal anal sphincter thickness for diagnosis of rectal intussusception in patients with solitary rectal ulcer syndrome.

BACKGROUND: The aim of this study was to determine any association between a thickened internal anal sphincter (IAS) on anal endosonography and high-grade rectal intussusception on evacuation proctography in patients with solitary rectal ulcer syndrome. METHODS: Anal endosonography was performed in 20 patients with solitary rectal ulcer syndrome and IAS thickness defined as normal or abnormal depending on age. Sphincter thickness was compared with the presence or absence of high-grade intussusception on subsequent evacuation proctography to determine any relationship between the two. RESULTS: Thirteen patients had an abnormally thick IAS, two of whom were unable to evacuate. Of the remaining 11 patients, ten showed high-grade intussusception (positive predictive value 91 per cent). Only three of seven patients with a normal IAS had high-grade intussusception (negative predictive value 57 per cent). Patients with a thick IAS were significantly more likely to have proctographic evidence of high-grade intussusception (P = 0.047). CONCLUSION: Sonographic findings of a thick IAS are highly predictive for high-grade rectal intussusception in patients with solitary rectal ulcer syndrome.

Adolescent↗
PubMed2002

Tailgut cyst associated with a pilonidal sinus: an unusual case and a review.

Tailgut cysts are rare congenital abnormalities in the retrocaecal/presacral region. Clinical diagnosis is difficult and delayed and they can present in childhood and adult life with a variety of clinical symptoms and complications. Differential diagnoses include, rectal duplication cysts, cystic teratoma, epidermal cyst, anal gland cyst and anal gland carcinoma. Magnetic resonance imaging has recently become the modality of choice to image these cysts. Although Tailgut cysts rarely undergo malignant transformation, early surgical resection is presently considered the treatment of choice. Here we report the case of a 34 year old gentleman with a Tailgut cyst associated with a Pilonidal sinus, and review of the literature. We believe that the high incidence of complications associated with operations in the presacral region should be weighed against the generally benign course of these lesions, especially with the quality of modern imaging technology.

Journal Article↗
PubMed2002

The therapeutic impact of abdominal ultrasound in patients with acute abdominal symptoms.

AIM: The technical performance of abdominal ultrasound in the investigation of acute abdominal pain has been thoroughly investigated but its therapeutic effects are less well understood. We aimed to determine the therapeutic effect of abdominal ultrasound in the investigation of acute abdominal pain. MATERIAL AND METHODS: A pre- and post-intervention observational study design was used to determine the diagnostic and therapeutic effects of abdominal ultrasound for acute abdominal pain. Referring clinicians completed a pre-ultrasound questionnaire that detailed their leading diagnosis, confidence in this and intended management in 100 consecutive adult patients. Following ultrasound a second questionnaire was completed. This again detailed the leading diagnosis, confidence in this and their intended management. Clinicians quantified the management contribution of ultrasound both for the individual case in question and in their clinical experience generally. RESULTS: The leading diagnosis was either confirmed or rejected in 72 patients and a new diagnosis provided where no prior differential diagnosis existed in 10. Diagnostic confidence increased significantly following ultrasound (mean score 6.5 pre-ultrasound vs 7.6 post-ultrasound, P < 0.001). Intended management changed following ultrasound in 22 patients; 15 intended laparotomies were halted and a further seven patients underwent surgery where this was not originally intended. Ultrasound was rated either 'very' or 'moderately' helpful in 87% of patients, with 99% of clinicians finding it either 'very' or 'moderately' helpful generally. CONCLUSION: Abdominal ultrasound has considerable diagnostic and therapeutic effect in the setting of acute abdominal pain.

Abdomen, Acute↗
PubMed2002

Alteration of anal sphincter morphology following vaginal delivery revealed by multiplanar anal endosonography.

OBJECTIVE: To assess morphologic change in the anal sphincters in the absence of endosonographic evidence of trauma after vaginal delivery. DESIGN: Prospective observational study. SETTING: District general hospital. POPULATION: Consecutively booked nulliparous pregnant women attending antenatal clinic. METHODS: All women were examined using three-dimensional anal endosonography, simple manometry and had questionnaire assessment of incontinence before and after delivery. MAIN OUTCOME MEASURES: Components of the anal canal were measured in the axial, sagittal and coronal planes and paired pre- and post-delivery examinations were compared. Any changes were related to changes in continence and anal canal manometry. RESULTS: Twenty-two women had a vaginal delivery and no endosonographic evidence of perineal trauma after delivery. After delivery, there was significant shortening of the length of the anterior external anal sphincter [EAS] (mean 21.7 vs 20.5 mm, P = 0.02) when measured in the sagittal plane, which increased in anterior angulation with respect to the axis of the anal canal (10 degrees vs 13.8 degrees, P = 0.03). In the axial plane, no change was seen in the thickness of any of the sphincter components after delivery. None of these morphologic changes correlated with changes in manometry or continence score. CONCLUSIONS: Anal sphincter morphology changes after an otherwise atraumatic vaginal delivery. This change does not correlate with any functional symptoms.

Anal Canal↗