Joel G. Fletcher

OBSTETRIC TRAUMA, PELVIC FLOOR INJURY AND FECAL INCONTINENCE: A POPULATION-BASED CASE-CONTROL STUDY

OBJECTIVES:Current concepts based on referral center data suggest that pelvic floor injury from obstetric trauma is a major risk factor for fecal incontinence (FI) in women. In contrast, a majority of community women only develop FI decades after vaginal delivery, and obstetric events are not independent risk factors for FI. However, obstetric events are imperfect surrogates for anal and pelvic floor injury, which is often clinically occult. Hence, the objectives of this study were to evaluate the relationship between prior obstetric events, pelvic floor injury, and FI among community women.METHODS:In this nested case–control study of 68 women with FI (cases; mean age 57 years) and 68 age-matched controls from a population-based cohort in Olmsted County, MN, pelvic floor anatomy and motion during voluntary contraction and defecation were assessed by magnetic resonance imaging. Obstetric events and bowel habits were recorded.RESULTS:By multivariable analysis, internal sphincter injury (cases—28%, controls—6%; odds ratio (OR): 8.8; 95% confidence interval (CI): 2.3–34) and reduced perineal descent during defecation (cases—2.6±0.2u2009cm, controls—3.1±0.2u2009cm; OR: 1.7; 95% CI: 1.2–2.4) increased FI risk, but external sphincter injury (cases—25%, controls—4%; P<0.005) was not independently predictive. Puborectalis injury was associated (P<0.05) with impaired anorectal motion during squeeze, but was not independently associated with FI. Grades 3–4 episiotomy (OR: 3.9; 95% CI: 1.4–11) but not other obstetric events increased the risk for pelvic floor injury. Heavy smoking (≥u200920 pack-years) was associated (P=0.052) with external sphincter atrophy.CONCLUSIONS:State-of-the-art imaging techniques reveal pelvic floor injury or abnormal anorectal motion in a minority of community women with FI. Internal sphincter injury and reduced perineal descent during defecation are independent risk factors for FI. In addition to grades 3–4 episiotomy, smoking may be a potentially preventable, risk factor for pelvic floor injury.

Pelvic organ prolapse in defecatory disorders.

Objective: To compare the prevalence of pelvic organ prolapse in subjects with defecatory disorders with that in control subjects. Methods: In 55 subjects with fecal incontinence, 42 subjects with obstructed defecation, and 45 healthy subjects without defecatory symptoms, a urogynecologist assessed pelvic organ prolapse by the pelvic organ prolapse quantification system, and a gastroenterologist evaluated perineal descent during simulated evacuation. A multiple logistic regression model evaluated whether obstetric-gynecological variables, including pelvic organ prolapse, could discriminate among controls, subjects with fecal incontinence, and subjects with obstructed defecation. Results: Fifty-five percent of controls, 42% of those with obstructed defecation, and 29% of those with fecal incontinence had stage II or greater prolapse by clinical examination. Eleven percent of controls, 7% of those with obstructed defecation, and 47% of subjects with fecal incontinence had a forceps delivery. Eighteen percent of controls, 31% of those with obstructed defecation, and 64% of those with fecal incontinence had a hysterectomy. Even after controlling for a higher prevalence of obstetric risk factors and hysterectomy, fecal incontinence was associated with a lower risk of stage II or greater pelvic organ prolapse (odds ratio for fecal incontinence in ≥ stage II pelvic organ prolapse relative to stage 0 pelvic organ prolapse = 0.1, 95% confidence interval 0.01–0.53). In contrast, pelvic organ prolapse severity was not associated with control versus obstructed defecation status. Seven percent of controls, 18% of subjects with obstructed defecation, and 7% of those with fecal incontinence had increased perineal descent during simulated evacuation. Excessive perineal descent was associated (P < .01) with pelvic organ prolapse. Conclusion: Despite a higher prevalence of risk factors for pelvic floor injury, pelvic organ prolapse severity was lower in those with fecal incontinence than in subjects without bowel symptoms. However, a subset of subjects with defecatory disorders, predominantly obstructed defecation, have excessive perineal descent, which is associated with pelvic organ prolapse. Level of Evidence: II-3

Validation of a lower radiation computed tomography enterography imaging protocol to detect Crohn's disease in the small bowel

Background: The purpose was to validate a lower radiation dose computed tomography enterography (CTE) imaging protocol to detect the presence of Crohns disease (CD) in the small bowel using two different reference standards and to identify a prediction model based on CTE signs for the presence of active CD. Methods: This retrospective study included patients with known or suspected CD who underwent CTE between January and October 2006 according to a lower radiation dose protocol. Two gastrointestinal radiologists blindly and independently classified each CTE as being active or inactive. Reference standards included ileocolonoscopy ± biopsy and a comprehensive clinical reference standard (retrospectively created by a gastroenterologist, also including history, physical, follow‐up course, and subsequent endoscopy, imaging, or surgery). Logistic regression was used to identify CTE findings that predicted the presence of active CD based on the combined clinical reference standard. Results: In all, 137 patients underwent CTE and ileocolonoscopy. Using an endoscopic reference standard, the sensitivity of CTE to detect active CD for the two readers was 81% and 89%, respectively. Using the clinical reference standard, the sensitivity of CTE to detect active CD was 89% and 98%, respectively. For both readers the sensitivity of CTE increased by 8%–9% when using the comprehensive reference standard. Multivariate analysis showed that a combination of mural thickness and hyperenhancement best predicted active CD (area under the curve [AUC] = 0.92–0.93, P < 0.0001). Conclusions: Lower radiation dose CTE exams are sensitive for the detection of active small bowel CD. The combination of mural thickness and hyperenhancement are the best radiologic predictors of active CD. (Inflamm Bowel Dis 2011;)

Temporal Trends in the Incidence and Natural History of Diverticulitis: A Population-Based Study

OBJECTIVES:Data on the incidence and natural history of diverticulitis are largely hospital-based and exclude the majority of diverticulitis patients, who are treated in an outpatient setting for uncomplicated diverticulitis. We assessed temporal trends in the epidemiology of diverticulitis in the general population.METHODS:Through the Rochester Epidemiology Project we reviewed the records of all individuals with a diagnosis of diverticulitis from 1980 to 2007 in Olmsted County, Minnesota, USA.RESULTS:In 1980–1989, the incidence of diverticulitis was 115/100,000 person-years, which increased to 188/100,000 in 2000–2007 (P<0.001). Incidence increased with age (P<0.001); however, the temporal increase was greater in younger people (P<0.001). Ten years after the index and second diverticulitis episodes, 22% and 55% had a recurrence, respectively. This recurrence rate was greater in younger people (hazard ratio (HR) per decade 0.63; 95% confidence interval (CI), 0.59–0.66) and women (HR 0.68; 95% CI, 0.58–0.80). Complications were seen in 12%; this rate did not change over time. Recurrent diverticulitis was associated with a decreased risk of complications (P<0.001). Age was associated with increased risk of local (odds ratio (OR) 1.27 per decade; 95% CI, 1.04–1.57) and systemic (OR 1.83; 95% CI, 1.20–2.80) complications. Survival after diverticulitis was lower in older people (P<0.001) and men (P<0.001) and worsened over time (P<0.001). The incidence of surgery for diverticulitis did not change from 1980 to 2007.CONCLUSIONS:The incidence of diverticulitis has increased by 50% in 2000–2007 compared with 1990–1999, and more so in younger people. Complications are relatively uncommon. Recurrent diverticulitis is frequent but typically uncomplicated. Younger people with diverticulitis have less severe disease, more recurrence, and better survival.

Polyp Measurement with CT Colonography: Multiple-Reader, Multiple-Workstation Comparison

OBJECTIVEnThe risk of invasive colorectal cancer in colorectal polyps correlates with lesion size. Our purpose was to define the most accurate methods for measuring polyp size at CT colonography (CTC) using three models of workstations and multiple observers.nnnMATERIALS AND METHODSnSix reviewers measured 24 unique polyps of known size (5, 7, 10, and 12 mm), shape (sessile, flat, and pedunculated), and location (straight or curved bowel segment) using CTC data sets obtained at two doses (5 mAs and 65 mAs) and a previously described colonic phantom model. Reviewers measured the largest diameter of polyps on three proprietary workstations. Each polyp was measured with lung and soft-tissue windows on axial, 2D multiplanar reconstruction (MPR), and 3D images.nnnRESULTSnThere were significant differences among measurements obtained at various settings within each workstation (p < 0.0001). Measurements on 2D images were more accurate with lung window than with soft-tissue window settings (p < 0.0001). For the 65-mAs data set, the most accurate measurements were obtained in analysis of axial images with lung window, 2D MPR images with lung window, and 3D tissue cube images for Wizard, Advantage, and Vitrea workstations, respectively, without significant differences in accuracy among techniques (0.11 < p < 0.59). The mean absolute error values for these optimal settings were 0.48 mm, 0.61 mm, and 0.76 mm, respectively, for the three workstations. Within the ultralow-dose 5-mAs data set the best methods for Wizard, Advantage, and Vitrea were axial with lung window, 2D MPR with lung window, and 2D MPR with lung window, respectively. Use of nearly all measurement methods, except for the Vitrea 3D tissue cube and the Wizard 2D MPR with lung window, resulted in undermeasurement of the true size of the polyps.nnnCONCLUSIONnUse of CTC computer workstations facilitates accurate polyp measurement. For routine CTC examinations, polyps should be measured with lung window settings on 2D axial or MPR images (Wizard and Advantage) or 3D images (Vitrea). When these optimal methods are used, these three commercial workstations do not differ significantly in acquisition of accurate polyp measurements at routine dose settings.

Comparative Performance of Two Polyp Detection Systems on CT Colonography

OBJECTIVEnThe purpose of our study was to evaluate two current automatic polyp detection systems to determine their sensitivity and false-positive rate in patients who have undergone CT colonography and subsequent endoscopy.nnnMATERIALS AND METHODSnWe evaluated two polyp detection systems--Polyp Enhanced Viewing (PEV) and the Summers computer-aided detection (CAD) system (National Institutes of Health [NIH]) using a unique cohort of CT colonography examinations: 31 examinations with true-positive lesions identified by radiologists and 34 examinations with false-positive lesions incorrectly identified by radiologists. All patients had reference-standard colonoscopy within 7 days of CT. Candidate lesions were compared with the endoscopic reference standard and prospective radiologist interpretation. The sensitivity and false-positive rates were calculated for each system.nnnRESULTSnThe NIH system had a higher sensitivity than the PEV tool for polyps > or = 1 cm (22/23, 96%; 78-99%, 95% CI vs 14/23, 61%; 38-81%, 95% CI; p = 0.008, respectively). There was no significant difference in the detection of medium-sized polyps 6-9 mm in size (8/13 vs 6/13, p = 0.68, respectively). The PEV tool had an average of 1.18 false-positive detections per patient, whereas the NIH tool had an average of 5.20 false-positive detections per patient, with the PEV tool having significantly fewer false-positive detections in both patient groups (p < 0.001).nnnCONCLUSIONnOne polyp detection system tended to operate with a higher sensitivity, whereas the other tended to operate with a lower false-positive rate. Prospective trials using polyp detection systems as a primary or secondary means of CT colonography interpretation appear warranted.

Implementation of iterative metal artifact reduction in the pre-planning-procedure of three-dimensional physical modeling

BackgroundTo assess the impact of metal artifact reduction techniques in 3D printing by evaluating image quality and segmentation time in both phantom and patient studies with dental restorations and/or other metal implants. An acrylic denture apparatus (Kilgore Typodent, Kilgore International, Coldwater, MI) was set in a 20xa0cm water phantom and scanned on a single-source CT scanner with gantry tilting capacity (SOMATOM Edge, Siemens Healthcare, Forchheim, Germany) under 5 scenerios: (1) Baseline acquisition at 120xa0kV with no gantry tilt, no jaw spacer, (2) acquisition at 140xa0kV, (3) acquisition with a gantry tilt at 15°, (4) acquisition with a non-radiopaque jaw spacer and (5) acquisition with a jaw spacer and a gantry tilt at 15°. All acquisitions were reconstructed both with and without a dedicated iterative metal artifact reduction algorithm (MAR). Patients referred for a head-and-neck exam were included into the study. Acquisitions were performed on the same scanner with 120xa0kV and the images were reconstructed with and without iterative MAR. Segmentation was performed on a dedicated workstation (Materialise Interactive Medical Image Control Systems; Materialise NV, Leuven, Belgium) to quantify volume of metal artifact and segmentation time.ResultsIn the phantom study, the use of gantry tilt, jaw spacer and increased tube voltage showed no benefit in time or artifact volume reduction. However the jaw spacer allowed easier separation of the upper and lower jaw and a better display of the teeth. The use of dedicated iterative MAR significantly reduced the metal artifact volume and processing time. Same observations were made for the four patients included into the study.ConclusionThe use of dedicated iterative MAR and jaw spacer substantially reduced metal artifacts in the head-and-neck CT acquisitions, hence allowing a faster 3D segmentation workflow.

Predictors of Durability of Radiological Response in Patients With Small Bowel Crohn’s Disease

BackgroundnThe long-term significance of radiological transmural response (TR) as a treatment goal at the first follow-up scan in small bowel Crohns disease (CD) has been previously shown. We examined the durability of a long-term strategy of treating to a target of radiological TR and the influence of baseline predictors on the maintenance of TR.nnnMethodsnSmall bowel CD patients between January 1, 2002, and December 31, 2014, were identified with serial computed tomography enterography (CTE)/magnetic resonance enterography (MRE) before and after initiation of therapy or on maintenance therapy. Overall TR (inflammatory lesions with/without strictures) w1as characterized by abdominal radiologists in up to 5 small bowel lesions per patient at each serial scan until last follow-up or small bowel resection, as response, partial response, or nonresponse. The rate of conversion between TR states and transition to surgery, including the effect of baseline patient/disease characteristics, was examined using a multistate model (mstate R-package).nnnResultsnCD patients (n = 150, 705 CTE/MRE) with a median of 4 CTE/MRE during 4.6 years of follow-up, 49% with ileal-only distribution, had 260 examined bowel segments. Conversion from response to partial response/nonresponse was 37.4% per year of follow-up with no transitions seen directly from response to surgery. Current smoking status (hazard ratio [HR], 2.2; 95% confidence interval [CI], 1.1-4.3) and internal penetrating disease at baseline scan (HR, 2.2; 95% CI, 1.2-4.1) were associated with a 2-fold increased risk of transition from partial response/nonresponse to surgery.nnnConclusionsnAchievement and maintenance of radiological response is associated with avoidance of small bowel surgery. Continued follow-up with CTE/MRE is recommended to identify loss of response, especially in current smokers and patients with internal penetrating disease at baseline CTE/MRE.

An expert consensus to standardise definitions, diagnosis and treatment targets for anti-fibrotic stricture therapies in Crohn's disease

Fibrotic stricture is a common complication of Crohns disease (CD) affecting approximately half of all patients. No specific anti‐fibrotic therapies are available; however, several therapies are currently under evaluation. Drug development for the indication of stricturing CD is hampered by a lack of standardised definitions, diagnostic modalities, clinical trial eligibility criteria, endpoints and treatment targets in stricturing CD.

MP01-08 USE OF DEDICATED STONE ANALYSIS SOFTWARE TO ASSESS URINARY STONE SIZE: TOWARDS SEMI-AUTOMATED METRICS TO ENHANCE PREDICTION OF SPONTANEOUS STONE PASSAGE

INTRODUCTION AND OBJECTIVES: Computed Tomography (CT) is a clinically established modality to evaluate suspected urinary stones. The maximum stone dimension in the axial reconstruction and stone location are often used to estimate the probability of spontaneous stone passage and potential likelihood of surgical intervention. However, the measured axial dimension of urinary stones can vary considerably owing to irregular shape, obliquity to the imaging plane, non-isotropic imaging voxels, interobserver variability, and volume averaging. This limits the reproducibility of axial stone measurements and the accuracy of predictions based upon maximum axial stone dimension. The present study compared the standard measures of stone size from axial images to those obtained using dedicated stone analysis software, which determined maximal stone dimensions in all planes. METHODS: Non-contrast-enhanced abdominal CT scans from 211 consecutive emergency department patients performed to evaluate flank were retrospectively evaluated. Radiological reports were reviewed for a diagnosis of urolithiasis, the maximum axial stone dimension, and stone location. Corresponding 1 mm thick images were analyzed using dedicated stone analysis software to compute the maximum linear dimension in any direction and stone volume. Descriptive outcomes are reported here (mean (SD)), comparing traditional maximum axial dimension and stone volume (assuming a spherical stone) to measurements made using dedicated software that performed 3D stone segmentation. RESULTS: A total of 228 stones were identified in 143 of the 211 patients. The mean maximum dimension in any direction computed by the software algorithm was 5.0 (3.2) mm, which was significantly higher than the mean maximum dimension of 3.9 (2.9) mm contained in the radiographic reports (p1⁄40.0002). The actual stone volume computed by the algorithm based upon the true stone dimensions and shape was 52.8 (141.5) mm3, while the stone volume calculated assuming a spherical shape was 31.06 (102.16) mm3 (p1⁄40.0628). CONCLUSIONS: Using dedicated stone analysis software, maximal stone dimension in any plane and stone volume were significantly larger than traditional measurements made in the axial plane and the associated volume. Semi-automated 3D measurements of stone size hence may be more accurate and reproducible. Further studies are needed to determine if automated 3D stone size metrics offer improved and more reliable prediction of spontaneous stone passage.