Patrick M. M. Bossuyt

A comparison of the Accuracy of Ultrasound and Computed Tomography in common diagnoses causing acute abdominal pain

ObjectivesHead-to-head comparison of ultrasound and CT accuracy in common diagnoses causing acute abdominal pain.Materials and methodsConsecutive patients with abdominal pain for >2xa0h and <5xa0days referred for imaging underwent both US and CT by different radiologists/radiological residents. An expert panel assigned a final diagnosis. Ultrasound and CT sensitivity and predictive values were calculated for frequent final diagnoses. Effect of patient characteristics and observer experience on ultrasound sensitivity was studied.ResultsFrequent final diagnoses in the 1,021 patients (mean age 47; 55% female) were appendicitis (284; 28%), diverticulitis (118; 12%) and cholecystitis (52; 5%). The sensitivity of CT in detecting appendicitis and diverticulitis was significantly higher than that of ultrasound: 94% versus 76% (pu2009<u20090.01) and 81% versus 61% (pu2009=u20090.048), respectively. For cholecystitis, the sensitivity of both was 73% (pu2009=u20091.00). Positive predictive values did not differ significantly between ultrasound and CT for these conditions. Ultrasound sensitivity in detecting appendicitis and diverticulitis was not significantly negatively affected by patient characteristics or reader experience.ConclusionCT misses fewer cases than ultrasound, but both ultrasound and CT can reliably detect common diagnoses causing acute abdominal pain. Ultrasound sensitivity was largely not influenced by patient characteristics and reader experience.

Feasibility study of computed tomography colonography using limited bowel preparation at normal and low-dose levels study

The purpose was to evaluate low-dose CT colonography without cathartic cleansing in terms of image quality, polyp visualization and patient acceptance. Sixty-one patients scheduled for colonoscopy started a low-fiber diet, lactulose and amidotrizoic-acid for fecal tagging 2xa0days prior to the CT scan (standard dose, 5.8–8.2xa0mSv). The original raw data of 51 patients were modified and reconstructed at simulated 2.3 and 0.7xa0mSv levels. Two observers evaluated the standard dose scan regarding image quality and polyps. A third evaluated the presence of polyps at all three mSv levels in a blinded prospective way. All observers were blinded to the reference standard: colonoscopy. At three times patients were given questionnaires relating to their experiences and preference. Image quality was sufficient in all patients, but significantly lower in the cecum, sigmoid and rectum. The two observers correctly identified respectively 10/15 (67%) and 9/15 (60%) polyps ≥10xa0mm, with 5 and 8 false-positive lesions (standard dose scan). Dose reduction down to 0.7xa0mSv was not associated with significant changes in diagnostic value (polyps ≥10xa0mm). Eighty percent of patients preferred CT colonography and 13% preferred colonoscopy (P<0.001). CT colonography without cleansing is preferred to colonoscopy and shows sufficient image quality and moderate sensitivity, without impaired diagnostic value at dose-levels as low as 0.7xa0mSv.

Electrical stimulation and pelvic floor muscle training with biofeedback in patients with fecal incontinence: a cohort study of 281 patients

PurposePelvic floor rehabilitation is an appealing treatment for patients with fecal incontinence but reported results vary. This study was designed to assess the outcome of pelvic floor rehabilitation in a large series of consecutive patients with fecal incontinence caused by different etiologies.MethodsA total of 281 patients (252 females) were included. Data about medical history, anal manometry, rectal capacity measurement, and endoanal sonography were collected. Subgroups of patients were defined by anal sphincter complex integrity, and nature and possible underlying causes of fecal incontinence. Subsequently patients were referred for pelvic floor rehabilitation, comprising nine sessions of electric stimulation and pelvic floor muscle training with biofeedback. Pelvic floor rehabilitation outcome was documented with Vaizey score, anal manometry, and rectal capacity measurement findings.ResultsVaizey score improved from baseline in 143 of 239 patients (60 percent), remained unchanged in 56 patients (23 percent), and deteriorated in 40 patients (17 percent). Mean Vaizey score reduced with 3.2 points (P < 0.001). A Vaizey score reduction of ≥ 50 percent was observed in 32 patients (13 percent). Mean squeeze pressure (+5.1xa0mmHg; P = 0.04) and maximal tolerated volume (+11xa0ml; P = 0.01) improved from baseline. Resting pressure (P = 0.22), sensory threshold (P = 0.52), and urge sensation (P = 0.06) remained unchanged. Subgroup analyses did not show substantial differences in effects of pelvic floor rehabilitation between subgroups.ConclusionsPelvic floor rehabilitation leads overall to a modest improvement in severity of fecal incontinence, squeeze pressure, and maximal tolerated volume. Only in a few patients, a substantial improvement of the baseline Vaizey score was observed. Further studies are needed to identify patients who most likely will benefit from pelvic floor rehabilitation.

CT colonography with limited bowel preparation for the detection of colorectal neoplasia in an FOBT positive screening population

PurposeAim was to evaluate the accuracy of computed tomography colonography (CTC) for detection of colorectal neoplasia in a Fecal Occult Blood Test (FOBT) positive screening population.MethodsIn three different institutions, consecutive FOBT positives underwent CTC after laxative free iodine tagging bowel preparation followed by colonoscopy with segmental unblinding. Each CTC was read by two experienced observers. For CTC and for colonoscopy the per-polyp sensitivity and per-patient sensitivity and specificity were calculated for detection of carcinomas, advanced adenomas, and adenomas.ResultsIn total 22 of 302 included FOBT positive participants had a carcinoma (7%) and 137 had an adenoma or carcinoma ≥10xa0mm (45%). CTC sensitivity for carcinoma was 95% with one rectal carcinoma as false negative finding. CTC sensitivity for advanced adenomas was 92% (95% CI: 88–96) vs. 96% (95% CI: 93–99) for colonoscopy (Pxa0=xa00.26). For adenomas and carcinomas ≥10xa0mm the CTC per-polyp sensitivity was 93% (95% CI: 89–97) vs. 97% (95% CI: 94–99) for colonoscopy (Pxa0=xa00.17). The per-patient sensitivity for the detection of adenomas and carcinomas ≥10xa0mm was 95% (95% CI: 91–99) for CTC vs. 99% (95% CI: 98–100) for colonoscopy (Pxa0=xa00.07), while the per-patient specificity was 90% (95% CI: 86–95) and 96% (95% CI: 94–99), respectively (Pxa0<xa00.001).ConclusionCTC with limited bowel preparation performed in an FOBT positive screening population has high diagnostic accuracy for the detection of adenomas and carcinomas and a sensitivity similar to that of colonoscopy for relevant lesions.

Selecting an outcome measure for evaluating treatment in fecal incontinence

PURPOSEVarious outcome measures exist to evaluate treatment in fecal incontinence, including descriptive, severity (fecal incontinence scoring systems), and impact (quality-of-life questionnaires) and diagnostic measures. We studied associations between changes after treatment for a number of outcome measures and compared them to patients’ subjective perception of relief.METHODSWe analyzed data of 66 patients (92 percent female; mean age, 62 years) (Vaizey score, Wexner score, two impact scales, utility, resting pressure, and maximal incremental squeeze pressure) at baseline and after physiotherapy. In a standardized interview by phone, we asked patients to compare their situation before and after treatment. Correlations between changes in outcome measures were calculated. These changes were compared with patients’ subjective perception.RESULTSThere was a high correlation between the changes in the Vaizey and the Wexner scores (r = 0.94, P < 0.01). Changes in Vaizey and Wexner scores correlated moderately with changes in maximum incremental squeeze pressure (r = −0.29, −0.30, both P < 0.05). Changes in utility and resting pressure were not correlated with changes in any of the other measurements (all r values between −0.086 and 0.18). Average severity scores (Vaizey and Wexner) were 1 point lower for patients who rated their situation as worse or equal (62 percent), 4 points lower for patients who reported their situation to be better (21 percent), and 9 points lower in patients who rated their situation much better (17 percent) (P < .05).CONCLUSIONSeverity measures are best related to patients’ subjective perception of relief.

Can the outcome of pelvic-floor rehabilitation in patients with fecal incontinence be predicted?

PurposePelvic-floor rehabilitation does not provide the same degree of relief in all fecal incontinent patients. We aimed at studying prospectively the ability of tests to predict the outcome of pelvic-floor rehabilitation in patients with fecal incontinence.Materials and methodsTwo hundred fifty consecutive patients (228 women) underwent medical history and a standardized series of tests, including physical examination, anal manometry, pudendal nerve latency testing, anal sensitivity testing, rectal capacity measurement, defecography, endoanal sonography, and endoanal magnetic resonance imaging. Subsequently, patients were referred for pelvic-floor rehabilitation. Outcome of pelvic-floor rehabilitation was quantified by the Vaizey incontinence score. Linear regression analyses were used to identify candidate predictors and to construct a multivariable prediction model for the posttreatment Vaizey score.ResultsAfter pelvic-floor rehabilitation, the mean baseline Vaizey score (18, SDu2009±u20093) was reduced with 3.2 points (pu2009<u20090.001). In addition to the baseline Vaizey score, three elements from medical history were significantly associated with the posttreatment Vaizey score (presence of passive incontinence, thin stool consistency, primary repair of a rupture after vaginal delivery at childbed) (R2, 0.18). The predictive value was significantly but marginally improved by adding the following test results: perineal and/or perianal scar tissue (physical examination), and maximal squeeze pressure (anal manometry; R2, 0.20; pu2009=u20090.05).ConclusionAdditional tests have a limited role in predicting success of pelvic-floor rehabilitation in patients with fecal incontinence.

Functional changes after physiotherapy in fecal incontinence

BackgroundPhysiotherapy is a common treatment option in patients with fecal incontinence. Although physiotherapy may result in relief of symptoms, to what extent improvement is associated with changes in anorectal function is still unclear.AimThe aim of the present study was to investigate prospectively how anorectal function changes with physiotherapy and whether these changes are related to changes in fecal incontinence score.MethodsConsenting consecutive patients (n=266) with fecal incontinence (91% women; mean age, 59 years) underwent anorectal manometry, anal and rectal mucosal sensitivity measurements, and rectal capacity measurement at baseline and after nine sessions of standardized pelvic floor physiotherapy. These findings were compared with changes in Vaizey incontinence score.ResultsOn follow-up 3 months after physiotherapy, squeeze pressure (p=0.028), as well as urge sensation threshold (p=0.046) and maximum tolerable volume (p=0.018), had increased significantly. The extent of improvement was not related to age, duration of fecal incontinence, menopause, and endosonography findings. All other anorectal functions did not change. An improvement in the Vaizey score was moderately correlated with an increase in incremental squeeze pressure (r=0.14, p=0.04) and a decrease in anal mucosal sensitivity threshold (r=0.20, p=0.01).ConclusionsPhysiotherapy improves squeeze pressure, urge sensation, and maximum tolerable volume. However, improved anorectal function does not always result in a decrease in fecal incontinence complaints.

Comparison of Imaging Strategies with Conditional versus Immediate Contrast-Enhanced Computed Tomography in Patients with Clinical Suspicion of Acute Appendicitis

ABSTRACTObjectivesTo compare the diagnostic accuracy of conditional computed tomography (CT), i.e. CT when initial ultrasound findings are negative or inconclusive, and immediate CT for patients with suspected appendicitis.MethodsData were collected within a prospective diagnostic accuracy study on imaging in adults with acute abdominal pain. All patients underwent ultrasound and CT, read by different observers who were blinded from the other modality. Only patients with clinical suspicion of appendicitis were included. An expert panel assigned a final diagnosis to each patient after 6xa0months of follow-up (clinical reference standard).ResultsA total of 422 patients were included with final diagnosis appendicitis in 251 (60xa0%). For 199 patients (47xa0%), ultrasound findings were inconclusive or negative. Conditional CT imaging correctly identified 241 of 251 (96xa0%) appendicitis cases (95 %CI, 92xa0% to 98xa0%), versus 238 (95xa0%) with immediate CT (95 %CI, 91xa0% to 97xa0%). The specificity of conditional CT imaging was lower: 77xa0% (95 %CI, 70xa0% to 83xa0%) versus 87xa0% for immediate CT (95 %CI, 81xa0% to 91xa0%).ConclusionA conditional CT strategy correctly identifies as many patients with appendicitis as an immediate CT strategy, and can halve the number of CTs needed. However, conditional CT imaging results in more false positives.Key Points• Conditional CT (CT after negative/inconclusive ultrasound findings) can be used for suspected appendicitis.• Half the number of CT examinations is needed with a conditional strategy.• Conditional CT correctly identifies as many patients with appendicitis as immediate CT.• Conditional imaging results in more false positive appendicitis cases.

Prediction of fetal lung immaturity using gestational age, patient characteristics and fetal lung maturity tests: a probabilistic approach

ObjectivesThe lecithin/sphingomyelin (L/S) ratio and the lamellar body count (LBC) can be used to predict respiratory distress syndrome (RDS).DesignWe performed a retrospective cohort study among consecutive women who underwent amniotic fluid sampling for the assessment of fetal lung maturity. Logistic regression was used to construct models for the prediction of RDS in three gestational age categories, with models based on clinical characteristics only, clinical characteristics and the LBC, and on clinical characteristics and L/S ratio.ResultsWhen amniotic fluid was collected <30xa0weeks, the specificity of the LBC was 30% and the sensitivity 100%. Addition of the L/S ratio increased the specifity to 60%, for a sensitivity of 100%. When amniocentesis was performed between 30 and 33xa0weeks, addition of the L/S ratio only marginally improved the performance of the LBC.ConclusionsAt a gestational age <30xa0weeks, the L/S ratio has additional value over the LBC. Above 30xa0weeks of gestation, single use of the LBC seems sufficient.

CT colonography polyp matching: differences between experienced readers

The purpose of this study was to investigate if experienced readers differ when matching polyps shown by both CT colonography (CTC) and optical colonoscopy (OC) and to explore the reasons for discrepancy. Twenty-eight CTC cases with corresponding OC were presented to eight experienced CTC readers. Cases represented a broad spectrum of findings, not completely fulfilling typical matching criteria. In 21 cases there was a single polyp on CTC and OC; in seven there were multiple polyps. Agreement between readers for matching was analyzed. For the 21 single-polyp cases, the number of correct matches per reader varied from 13 to 19. Almost complete agreement between readers was observed in 15 cases (71%), but substantial discrepancy was found for the remaining six (29%) probably due to large perceived differences in polyp size between CT and OC. Readers were able to match between 27 (71%) and 35 (92%) of the 38 CTC detected polyps in the seven cases with multiple polyps. Experienced CTC readers agree to a considerable extent when matching polyps between CTC and subsequent OC, but non-negligible disagreement exists.