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Jaap Stoker

Publications and source records attributed to Jaap Stoker.

At least 37 records · Page 2Linked to original sources
PubMed2006

MR Enteroclysis of inflammatory small-bowel diseases.

OBJECTIVE: MR enteroclysis has been introduced in the workup of small-bowel diseases. The major advantage of this technique over others is the combined visualization of luminal, mural, and extramural abnormalities. In this article we propose an MR enteroclysis protocol, present a stepwise approach for evaluation of these examinations, and discuss the different inflammatory conditions that can be detected. CONCLUSION: MR enteroclysis can be considered the current first-line imaging technique for inflammatory small-bowel disorders.

Adult↗
PubMed2005

Functional changes after physiotherapy in fecal incontinence.

BACKGROUND: Physiotherapy 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. AIM: The 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. METHODS: Consenting 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. RESULTS: On 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). CONCLUSIONS: Physiotherapy improves squeeze pressure, urge sensation, and maximum tolerable volume. However, improved anorectal function does not always result in a decrease in fecal incontinence complaints.

Anal Canal↗
PubMed2005

Colorectal liver metastases: CT, MR imaging, and PET for diagnosis--meta-analysis.

PURPOSE: To perform a meta-analysis to obtain sensitivity estimates of computed tomography (CT), magnetic resonance (MR) imaging, and fluorine 18 fluorodeoxyglucose (FDG) positron emission tomography (PET) for detection of colorectal liver metastases on per-patient and per-lesion bases. MATERIALS AND METHODS: MEDLINE, EMBASE, Web of Science, and CANCERLIT databases and Cochrane Database of Systematic Reviews were searched for relevant original articles published from January 1990 to December 2003. Criteria for inclusion of articles were as follows: Articles were reported in the English, German, or French language; CT, MR imaging, or FDG PET was performed to identify and characterize colorectal liver metastases; histopathologic analysis (surgery, biopsy, or autopsy), intraoperative observation (manual palpatation, intraoperative ultrasonography [US]), and/or follow-up US was the reference standard; and data were sufficient for calculation of true-positive or false-negative values. A random-effects linear regression model was used to obtain sensitivity estimates in assessment of liver metastases. RESULTS: Of 165 identified relevant articles, 61 fulfilled all inclusion criteria. Sensitivity estimates on a per-patient basis for nonhelical CT, helical CT, 1.5-T MR imaging, and FDG PET were 60.2%, 64.7%, 75.8%, and 94.6%, respectively; FDG PET was the most accurate modality. On a per-lesion basis, sensitivity estimates for nonhelical CT, helical CT, 1.0-T MR imaging, 1.5-T MR imaging, and FDG PET were 52.3%, 63.8%, 66.1%, 64.4%, and 75.9%, respectively; nonhelical CT had lowest sensitivity. Estimates of gadolinium-enhanced MR imaging and superparamagnetic iron oxide (SPIO)-enhanced MR imaging were significantly better, compared with nonenhanced MR imaging (P = .019 and P < .001, respectively) and with helical CT with 45 g of iodine or less (P = .02 and P < .001, respectively). For lesions of 1 cm or larger, SPIO-enhanced MR imaging was the most accurate modality (P < .001). CONCLUSION: FDG PET had significantly higher sensitivity on a per-patient basis, compared with that of the other modalities, but not on a per-lesion basis. Sensitivity estimates for MR imaging with contrast agent were significantly superior to those for helical CT with 45 g of iodine or less.

Colorectal Neoplasms↗
PubMed2005

Anal sphincter defects in patients with fecal incontinence: endoanal versus external phased-array MR imaging.

PURPOSE: To prospectively compare external phased-array magnetic resonance (MR) imaging with endoanal MR imaging in depicting external and internal anal sphincter defects in patients with fecal incontinence and to prospectively evaluate observer reproducibility in the detection of external and internal anal sphincter defects with both MR imaging techniques. MATERIALS AND METHODS: The medical ethics committees of both participating hospitals approved the study, and informed consent was obtained. Thirty patients (23 women, seven men; mean age, 58.7 years; range, 37-78 years) with fecal incontinence underwent MR imaging with both endoanal and external phased-array coils. MR images were evaluated by three radiologists with different levels of experience for external and internal anal sphincter defects. Measures of inter- and intraobserver agreement of both MR imaging techniques and of differences between both imaging techniques were calculated. RESULTS: Both MR imaging techniques did not significantly differ in the depiction of external (P > .99) and internal (P > .99) anal sphincter defects. The techniques corresponded in 25 (83%) of 30 patients for the depiction of external anal sphincter defects and in 28 (93%) of 30 patients for the depiction of internal anal sphincter defects. Interobserver agreement was moderate to good for endoanal MR imaging and poor to fair for external phased-array MR imaging. Intraobserver agreement ranged from fair to very good for both imaging techniques. CONCLUSION: External phased-array MR imaging is comparable to endoanal MR imaging in the depiction of clinically relevant anal sphincter defects. Because of the weak interobserver agreement, both MR imaging techniques can be recommended in the diagnostic work-up of fecal incontinence only if sufficient experience is available.

Adult↗
PubMed2005

MRI in Crohn's disease.

Technological developments have extended the role of MRI in the evaluation of the gastrointestinal tract. The potential of MRI to evaluate disease activity in Crohn's disease has been investigated extensively, as MRI has intrinsic advantages over other techniques, including noninvasiveness and the absence of ionizing radiation. For perianal fistulizing disease MRI has become a mainstay in evaluation of disease, as localization and extent of disease can be very well appreciated using both T2-weighted and T1-weighted sequences, fat suppression, and intravenous contrast medium. Imaging of the small bowel and colon in Crohn's disease is more complicated due to bowel peristalsis and respiratory movement. However, using fast breathhold sequences and intravenous spasmolytic medication, images of good diagnostic quality can be acquired. To obtain sufficiently distended bowel, which in our estimation is a prerequisite for evaluation of the bowel, MR enteroclysis can be performed. However, applicability of different oral contrast media has been studied, as a noninvasive method for bowel distension would be preferable. Abdominal MRI is a valuable imaging technique for evaluation of luminal, transmural, and extraintestinal manifestations of Crohn's disease as degree of disease activity, presence of luminal pathology (e.g., stenoses), and extraintestinal manifestations of disease (e.g., abscesses, fistulas) can be accurately assessed.

Crohn Disease↗
PubMed2005

Selecting an outcome measure for evaluating treatment in fecal incontinence.

PURPOSE: Various 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. METHODS: We 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. RESULTS: There 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). CONCLUSION: Severity measures are best related to patients' subjective perception of relief.

Aged↗
PubMed2005

Magnetic resonance imaging compared with ileocolonoscopy in evaluating disease severity in Crohn's disease.

BACKGROUND & AIMS: Abdominal magnetic resonance imaging (MRI) has shown promising results in the detection of Crohn's disease (CD)-related lesions. The purpose of this study was to assess the value of MRI in measuring disease activity in CD patients in comparison with ileocolonoscopy. METHODS: Thirty-one patients undergoing ileocolonoscopy because of suspicion of relapsing CD underwent MRI with water as intraluminal contrast medium. At endoscopy, disease severity was graded (4-point scale), and Crohn's Disease Endoscopic Index of Severity (CDEIS) was determined. Two radiologists independently interpreted the MRI scans. Radiologic grading (4-point scale) was compared with endoscopic grading of disease severity and CDEIS (overall, for all segments). Wall thickness and enhancement were compared with CDEIS. Patient experience and preference were determined. RESULTS: In, respectively, 14 and 14 patients (radiologist 1) and 16 and 11 patients (radiologist 2) an exact match or 1 level of difference in grading was scored with the endoscopist. Correlation between severity rated at MRI and CDEIS was moderate to strong with r = 0.61 (P < .001) for observer 1 and r = 0.63 (P < .001) for observer 2. Per segment, best correlation was seen in the terminal ileum (r = 0.63; P < .001, for both observers). Wall thickness correlated moderately to strongly with CDEIS (r = 0.57, P < .001 and r = 0.50, P < .001 for observers 1 and 2), whereas enhancement correlated weakly to moderately (r = 0.45, P < .001 and r = 0.42, P < .001). Patients experienced more pain during endoscopy, and all patients except 2 preferred MRI to endoscopy. CONCLUSION: MRI can correctly identify disease severity in patients with CD and is a patient-friendly alternative to ileocolonoscopy.

Adolescent↗
PubMed2005

Costs of outpatients with fecal incontinence.

OBJECTIVE: Fecal incontinence is a problem with a high prevalence. Patients generally suffer from their problems for many years. It has been shown that quality of life is negatively affected but health economic data for fecal incontinence are limited. The aim of this study was to estimate the costs associated with fecal incontinence in a large outpatient study group, taking a societal perspective. MATERIAL AND METHODS: Based on questionnaire data, we calculated the costs of health-care resources, out-of-pocket expenses and costs associated with production losses in paid and unpaid work. RESULTS: Data were available for 253 patients, of which 228 (90%) were female and 209 (83%) were treated in an academic medical center. The mean age of patients was 59 years (SD+/-13) with a mean duration of incontinence of 8.5 years (SD+/-8.3). Total costs were estimated on C2169 per fecal incontinent patient per year. Production losses in paid and unpaid work accounted for more than half of the total costs and costs of health-care visits accounted for almost a fifth of total costs. Costs associated with protective material (partially reimbursable and not reimbursable) formed only one-tenth of total costs, while incontinence medication was responsible for only 5% of total costs. CONCLUSIONS: More than half of total costs of fecal incontinence are made up of indirect non-medical costs. The costs associated with the use of incontinence material and other personal expenses are limited.

Absenteeism↗
PubMed2005

Colonography by computed tomography.

Computed tomographic colonography ('virtual colonoscopy') has shown promising results in the detection of large (> or = 10 mm) polyps in populations with a high prevalence of polyps. Recent studies in low prevalence populations, however, show variable results in sensitivity, ranging from 55% to 94% for the detection of patients with polyps measuring 10 mm or longer. Therefore questions have been raised about computed tomographic colonography as a screening method, probably the most valuable use of this technique. This article describes possible causes of these remarkable differences as well as advances in computed tomographic colonography.

Attitude to Health↗
PubMed2005

Esophageal cancer: CT, endoscopic US, and FDG PET for assessment of response to neoadjuvant therapy--systematic review.

PURPOSE: To compare diagnostic accuracy of computed tomography (CT), endoscopic ultrasonography (US), and fluorine 18 fluorodeoxyglucose (FDG) positron emission tomography (PET) for assessment of response to neoadjuvant therapy in patients with esophageal cancer by using a systematic review of the literature. MATERIALS AND METHODS: MEDLINE and EMBASE databases and Cochrane Database of Systematic Reviews were searched for relevant studies. Two reviewers independently assessed the methodological quality of each study. Summary receiver operating characteristic (ROC) analysis was used to summarize and compare the diagnostic accuracy of the three modalities. RESULTS: Four studies with CT, 13 with endoscopic US, and seven with FDG PET met inclusion criteria. Percentages of the maximum score in regard to methodological quality ranged from 15% to 100%. Summary ROC analysis could be performed for three studies with CT, four with endoscopic US, and four with FDG PET. The maximum joint values for sensitivity and specificity were 54% for CT, 86% for endoscopic US, and 85% for FDG PET. Accuracy of CT was significantly lower than that of FDG PET (P < .006) and of endoscopic US (P < .003). Accuracy of FDG PET and that of endoscopic US were similar (P = .839). In all patients, CT was always feasible, whereas endoscopic US was not feasible in 6% of the patients, and FDG PET was not feasible in less than 1%. CONCLUSION: CT has poor accuracy for assessment of response to neoadjuvant therapy in patients with esophageal cancer. Endoscopic US and FDG PET have equivalent good accuracy, but endoscopic US is not always feasible after chemotherapy and radiation therapy. FDG PET seems to be a promising noninvasive tool for assessment of neoadjuvant therapy in patients with esophageal cancer.

Endosonography↗
PubMed2005

Prospective assessment of interobserver agreement for defecography in fecal incontinence.

OBJECTIVE: The primary aim of our study was to determine the interobserver agreement of defecography in diagnosing enterocele, anterior rectocele, intussusception, and anismus in fecal-incontinent patients. The subsidiary aim was to evaluate the influence of level of experience on interpreting defecography. SUBJECTS AND METHODS: Defecography was performed in 105 consecutive fecal-incontinent patients. Observers were classified by level of experience and their findings were compared with the findings of an expert radiologist. The quality of the expert radiologist's findings was evaluated by an intraobserver agreement procedure. RESULTS: Intraobserver agreement was good to very good except for anismus: incomplete evacuation after 30 sec (kappa, 0.55) and puborectalis impression (kappa, 0.54). Interobserver agreement for enterocele and rectocele was good (kappa, 0.66 for both) and for intussusception, fair (kappa, 0.29). Interobserver agreement for anismus: incomplete evacuation after 30 sec was moderate (kappa, 0.47), and for anismus: puborectalis impression was fair (kappa, 0.24). Agreement in grading of enterocele and rectocele was good (kappa, 0.64 and 0.72, respectively) and for intussusception, fair (kappa, 0.39). Agreement separated by experience level was very good for rectocele (kappa, 0.83) and grading of rectoceles (kappa, 0.83) and moderate for intussusception (kappa, 0.44) at the most experienced level. For enterocele and grading, experience level did not influence the reproducibility. CONCLUSION: Reproducibility for enterocele, anterior rectocele, and severity grading is good, but for intussusception is fair to moderate. For anismus, the diagnosis of incomplete evacuation after 30 sec is more reproducible than puborectalis impression. The level of experience seems to play a role in diagnosing anterior rectocele and its grading and in diagnosing intussusception.

Adult↗
PubMed2004

CT colonography and colonoscopy: assessment of patient preference in a 5-week follow-up study.

PURPOSE: To prospectively evaluate short- and midterm patient preference of computed tomographic (CT) colonography relative to colonoscopy in patients at increased risk for colorectal cancer and to elucidate determinants of preference. MATERIALS AND METHODS: Consecutive patients at increased risk for colorectal cancer underwent CT colonography prior to scheduled colonoscopy. Patient experience and preference were assessed both directly after the examinations and 5 weeks after the examinations. Differences in pain, embarrassment, discomfort, and preference were assessed with the Wilcoxon signed rank sum test or a binomial test. Potential determinants of preference were investigated with logistic regression analyses. RESULTS: Data for 249 patients were included. Fewer patients experienced severe or extreme pain during CT colonography (seven [3%] of 245) than during colonoscopy (81 [34%] of 241) (P < .001). Directly after both examinations, 168 (71%) of 236 patients preferred CT colonography; 5 weeks later, 141 (61%) of 233 patients preferred CT colonography (P < .001). Initially, a painful colonoscopy examination (odds ratio, 0.17; 95% confidence interval [CI]: 0.08, 0.38) was a determinant of CT colonography preference. Similarly, a painful (odds ratio, 3.70; 95% CI: 1.54, 8.92) or an embarrassing (odds ratio, 4.46; 95% CI: 1.18, 16.88) CT colonography examination was a determinant of colonoscopy preference. After 5 weeks, the presence of polyps emerged as a determinant of colonoscopy preference (odds ratio, 1.94; 95% CI: 1.02, 3.70), while the role of experiences waned. CONCLUSION: Patients preferred CT colonography to colonoscopy; however, this preference decreased in time, while outcome considerations gradually replaced temporary experiences of inconvenience.

Aged↗
PubMed2004

Rectal cancer: local staging and assessment of lymph node involvement with endoluminal US, CT, and MR imaging--a meta-analysis.

PURPOSE: To perform a meta-analysis to compare endoluminal ultrasonography (US), computed tomography (CT), and magnetic resonance (MR) imaging in rectal cancer staging. MATERIALS AND METHODS: Relevant articles published between 1985 and 2002 were included if more than 20 patients were studied, histopathologic findings were the reference standard, and data were presented for 2 x 2 tables; articles were excluded if data were reported elsewhere in more detail. Two reviewers independently extracted data on study characteristics and results. Bivariate random-effects approach was used to obtain summary estimates of sensitivity and specificity for invasion of muscularis propria, perirectal tissue, and adjacent organs and for lymph node involvement. Summary receiver operating characteristic (ROC) curves were fitted for perirectal tissue invasion and lymph node involvement. RESULTS: Ninety articles fulfilled all inclusion criteria. For muscularis propria invasion, US and MR imaging had similar sensitivities; specificity of US (86% [95% confidence interval [CI]: 80, 90]) was significantly higher than that of MR imaging (69% [95% CI: 52, 82]) (P =.02). For perirectal tissue invasion, sensitivity of US (90% [95% CI: 88, 92]) was significantly higher than that of CT (79% [95% CI: 74, 84]) (P <.001) and MR imaging (82% [95% CI: 74, 87]) (P =.003); specificities were comparable. For adjacent organ invasion and lymph node involvement, estimates for US, CT, and MR imaging were comparable. Summary ROC curve for US of perirectal tissue invasion showed better diagnostic accuracy than that of CT and MR imaging. Summary ROC curves for lymph node involvement showed no differences in accuracy. CONCLUSION: For local invasion, endoluminal US was most accurate and can be helpful in screening patients for available therapeutic strategies.

Humans↗
PubMed2004

CT colonography: feasibility of substantial dose reduction--comparison of medium to very low doses in identical patients.

In a feasibility study, the authors compared polyp detection and interobserver variability at computed tomographic (CT) colonography in 15 patients with doses ranging from medium to very low (12.00-0.05 mSv). At levels down to 2% of the medium dose, the mean detection of polyps 5 mm or larger remained at least 74%, while the number of false-positive results decreased and the interobserver agreement remained constant. Initial observations indicate that it is feasible to reduce the radiation dose required for CT colonography. Further studies are needed, however, to investigate the clinical value of very low-dose CT colonography.

Adult↗
PubMed2004

Computed tomographic colonography compared with colonoscopy in patients at increased risk for colorectal cancer.

BACKGROUND & AIMS: To date, computed tomographic (CT) colonography has been compared with an imperfect test, colonoscopy, and has been mainly assessed in patients with positive screening test results or symptoms. Therefore, the available data may not apply to screening of patients with a personal or family history of colorectal polyps or cancer (increased risk). We prospectively investigated the ability of CT colonography to identify individuals with large (>or=10 mm) colorectal polyps in consecutive patients at increased risk for colorectal cancer. METHODS: A total of 249 consecutive patients at increased risk for colorectal cancer underwent CT colonography before colonoscopy. Two reviewers interpreted CT colonography examinations independently. Sensitivity, specificity, and predictive values were determined after meticulous matching of CT colonography with colonoscopy. Unexplained large false-positive findings were verified with a second-look colonoscopy. RESULTS: In total, 31 patients (12%) had 48 large polyps at colonoscopy. This included 8 patients with 8 large polyps that were overlooked initially and detected at the second-look colonoscopy. In 6 of 8 patients, the missed polyp was the only large lesion. With CT colonography, 84% of patients (26/31) with large polyp(s) were identified, paired for a specificity of 92% (200-201/218). Positive and negative predictive values were 59%-60% (26/43-44) and 98% (200-201/205-206), respectively. CT colonography detected 75%-77% (36-37/48) of large polyps, with 9 of the missed lesions being flat. CONCLUSIONS: CT colonography and colonoscopy have a similar ability to identify individuals with large polyps in patients at increased risk for colorectal cancer. The large proportion of missed flat lesions warrants further study.

Aged↗
PubMed2004

Magnetic resonance cholangiopancreatography.

The current imaging technique and clinical application of MR cholangiopancreatography (MRCP) is reviewed. MRCP has evolved into a feasible method of non-invasively evaluating the pancreaticobiliary system and has considerable clinical utility. If endoscopic retrograde cholangiopancreatography (ERCP) is incomplete or has failed, or in patients with biliary and gastrointestinal surgical procedures, MRCP is a useful alternative modality. In the near future, MRCP may supplant diagnostic ERCP such that ERCP is reserved primarily for therapeutic interventions. Furthermore, when MRCP is performed in conjunction with abdominal MR and MR angiography, the 'all-in-one' examination can evaluate the solid organs and vessels of the abdomen as well as the ductal systems.

Bile Ducts↗
PubMed2003

Quantification of bone involvement in Gaucher disease: MR imaging bone marrow burden score as an alternative to Dixon quantitative chemical shift MR imaging--initial experience.

PURPOSE: To develop a semiquantitative magnetic resonance (MR) imaging bone marrow burden (BMB) score with inclusion of both axial and peripheral bone marrow in Gaucher disease as an alternative to MR imaging with the Dixon quantitative chemical shift imaging (QCSI) technique. MATERIALS AND METHODS: Two experienced musculoskeletal radiologists with no experience in evaluating Gaucher disease blindly analyzed MR images of lumbar spines and femora. Interobserver and intraobserver variability were tested. In addition, the BMB score was determined as a parameter to evaluate bone marrow response to enzyme supplementation therapy. Finally, the BMB score was compared with fat fraction measurements obtained with Dixon QCSI. Differences between groups were analyzed by using the nonparametric Mann-Whitney test. A P value of less than.05 was considered to represent significance. Correlation was calculated by using two-tailed nonparametric rank correlation (Spearman rho). RESULTS: In 30 patients (mean age, 39.3 years; age range, 12-71 years) the mean fat fraction was 0.20 (range, 0.08-0.40). The BMB score range was 3-13 points. A significant correlation was found between the two observers when using BMB (rho = 0.91, P <.001). The intraobserver variation showed a significant correlation (rho = 0.99, P <.001). There was a significant correlation between BMB and QCSI (rho = -0.78, P <.001). Although BMB was less sensitive than Dixon QCSI, it showed enough sensitivity to allow detection of bone marrow response to enzyme supplementation therapy. CONCLUSION: BMB is a reproducible semiquantitative scoring system that is easy to use. It combines MR imaging of both axial and peripheral bone marrow and shows a significant correlation with QCSI.

Adolescent↗