Biomedical subjects

Dirk Vanbeckevoort

Publications and source records attributed to Dirk Vanbeckevoort.

10 recordsLinked to original sources

PubMed2006

Progressive growth of a pelvic collection five years after endovascular aneurysm repair: an atypical presentation of an asymptomatic contained rupture.

We report a case of an unusual and late presentation of an asymptomatic contained rupture after modular stent-graft implantation to treat an aortobiiliac aneurysm. Follow-up computed tomography (CT) scans 4 and 5 years after endovascular aneurysm repair showed a homogeneous, nonenhancing, but clearly growing, pelvic collection. CT-guided drainage of the collection was performed, and cultures of the evacuated brown fluid were negative for any infection. Control CT scan after drainage showed a complete collapse of both the collection and the previously excluded iliac aneurysms. A direct communication between the sterile pelvic collection and the excluded iliac aneurysm was suggested on this CT imaging and confirmed afterwards by surgery. From these imaging and surgical findings, this pelvic collection can be considered as an atypical presentation of an asymptomatic contained rupture of the excluded aneurysm.

Aged↗

PubMed2005

Clinical validation of high-resolution fast spin-echo MR colonography after colon distention with air.

To evaluate the feasibility of MR colonography (MRC) with air using two-dimensional (2D) T1-weighted fast spin-echo (T1wFSE) in patients scheduled for conventional colonoscopy (CC) after classic bowel preparation, and assess the ability of the technique to detect colonic lesions. The distention was sufficient for diagnosis, and the technique provided adequate delineation of the wall in the majority of segments. Residual fluid obscured the wall in different segments, especially in the ascending and descending colon (supine position) and in the cecum, transverse, and sigmoid colon (prone position). These findings were consistent with CT colonography. MRC visualized three lesions, missed one lesion >10 mm, visualized none of four lesions <5 mm, and yielded one false-positive lesion (5-10 mm). Missed lesions can be due to inconsistency in the slice positions between consecutive breath-holds, which is inherent to the multishot technique. Residual fluid may have obscured the smaller lesions. The shortcomings of the technique are limited coverage and signal drop-off at the borders of the field of view (FOV). Before multishot 2D T1wFSE colonography can become a valid screening method, improved patient preparation and a more practical technique are needed.

Adult↗

PubMed2005

Translumbar thrombin embolization of an aortic pseudoaneurysm complicating lumbar disk surgery.

We report a case of translumbar embolization of an aortic pseudoaneurysm complicating lumbar disk surgery. The iatrogenic pseudoaneurysm was initially treated by open repair, but due to failure of this treatment, we opted for direct translumbar thrombin injection under computed tomography (CT) guidance. The patient recovered completely, and follow-up CT scans showed progressive shrinkage of the residual retroperitoneal hematoma. This minimally invasive treatment should be considered in selected cases as a valuable treatment option for pseudoaneurysms that arise from the aorta.

Aneurysm, False↗

PubMed2004

Dynamic contrast-enhanced MRI of the pancreas: initial results in healthy volunteers and patients with chronic pancreatitis.

PURPOSE: To characterize pancreatic perfusion in volunteers and patients with chronic pancreatitis (CP) by dynamic contrast-enhanced (DCE) MRI. MATERIALS AND METHODS: Pancreatic enhancement after bolus injection of Gd-DTPA with a three-dimensional ultrafast partial-Fourier radiofrequency (RF) spoiled gradient-echo (GE) acquisition was examined prospectively. An acquisition volume of the pancreatic parenchyma was obtained every 4.2 seconds during a single breath-hold in 31 volunteers and 19 patients with CP. We calculated the wash-in rate and a newly defined parameter, the "time-to-inflow deceleration" (TID). A statistical analysis of the differences between both groups was performed with the use of Student's t-test. RESULTS: Significant differences in the TID and wash-in rate were found for the head and body of the pancreas: the TID was 22.4 sec +/- 4.4 sec and 23.5 sec +/- 6.1 sec in the pancreatic head and body of the healthy volunteers, and 29.8 sec +/- 8.6 sec and 29.4 sec +/- 3.8 sec in patients with CP. The wash-in rate was 96 +/- 37 sec(-1) and 101 +/- 27 sec(-1) in controls, and 62 +/- 17 sec(-1) and 75 +/- 27 sec(-1) in CP. CONCLUSION: CP can be identified by semiquantitative changes on DCE-MRI. Whether DCE-MRI of the pancreas can be used to detect early CP remains to be validated.

Adult↗

PubMed2003

Magnetic resonance imaging of the effects of infliximab on perianal fistulizing Crohn's disease.

OBJECTIVES: Although the clinical efficacy of infliximab as measured by closure of fistulas in Crohn's disease has been demonstrated, its influence on the inflammatory changes in the fistula tracks is less clear. The aim of the present study was to assess the behavior of perianal fistulas before and after infliximab treatment. METHODS: Magnetic resonance imaging (MRI) and clinical evaluation were performed in a total of 18 patients before and after treatment with infliximab. An MRI-based score of perianal Crohn's disease severity was developed using both criteria of local extension of fistulas (complexity, supralavetoric extension, relation to the sphincters and of active inflammation (T2 hyperintensity, presence of cavities/abscesses, and rectal wall involvement). RESULTS: The MRI score was reliable in assessing the fistula tracks, with a good interobserver concordance (p < 0.001). Fistula tracks with signs of active inflammation were found in all 18 patients at baseline and collections in seven. After short-term infliximab treatment, active tracks persisted in eight of 11 patients who had clinically responded to infliximab. After long-term (46 wk) infliximab therapy, MRI signs of active track inflammation had resolved in three of six patients. CONCLUSIONS: We have developed an MRI-based score of perianal Crohn's disease severity to assess the anatomical evolution of Crohn's fistulas. Our study demonstrates that despite closure of draining external orifices after infliximab therapy, fistula tracks persist with varying degrees of residual inflammation, which may cause recurrent fistulas and pelvic abscesses. Whether complete fistula fibrosis occurs over time with repeated infliximab infusions needs further study.

Adult↗

PubMed2002

Dry preparation for virtual CT colonography with fecal tagging using water-soluble contrast medium: initial results.

The purpose of this study was to evaluate the feasibility of a dry bowel preparation, i.e. without laxative fluids, for virtual CT colonography (VCTC), and its impact on patient acceptance compared with conventional colonoscopy (CC). A randomly chosen patient population scheduled for CC ( n=11) was first submitted to VCTC after a dry preparation, consisting of low-residue meals combined with a small amount of a iodinated water-soluble contrast medium during each meal 3 days before VCTC. In different colon segments and between different persons, the degree of tagging in VCTC was evaluated and graded. Patient acceptance and future preference were assessed for both preparations as well as for both investigations. The mixing of the contrast with the intestinal content results in contrast impregnated stool, the tagged feces. The degree of fecal tagging was good in the majority of the patients and the colonic segments, especially in the descending colon and sigmoid. Furthermore, patient acceptance and preference were clearly in favour of VCTC compared with CC merely because of the non-invasiveness of the dry preparation. Dry bowel preparation and VCTC is a promising approach towards a patient-friendly colon cancer-screening setup.

Adult↗

PubMed2002

Combined radiologic and manometric study of rectal filling sensation.

PURPOSE: Sensation is an essential aspect of fecal continence. We aimed to correlate manovolumetric and radiologic changes at successive levels of rectal filling sensation. METHODS: Combined anorectal manometry and proctography were performed in nine volunteers. Images, volumes, and pressures were analyzed at the start of the test, at 20 seconds before first sensation, and at first, constant, urge, and maximum tolerable sensation. RESULTS: Consecutive levels of rectal filling sensation were associated with progressive opening and dilation of the upper anal canal (up to 44 mm) and sliding down of the rectal contents (14 mm), which had already started before the first sensation. This coincided initially with a pressure decrease in the proximal anal canal (from 94 to 42 mmHg). With constant sensation and particularly with urge sensation, rectal pressure increase appeared to be responsible for further proximal anal dilation. This was accompanied by a significant increase of proximal anal pressure (up to 133 mmHg) and sharpening of the angle between the anal axis and the horizontal reference line. CONCLUSION: The proximal anal canal or its surrounding structures play an important role in the desire-to-defecate sensation. They can be activated by a progressive buildup of rectal reservoir pressure in the presence of a competent distal anal sphincter barrier.

Adult↗

PubMed2002

Focal lesions in cirrhotic explant livers: pathological evaluation and accuracy of pretransplantation imaging examinations.

Imaging detection and diagnosis of hepatocellular carcinomas (HCCs) and dysplastic nodules (DNs) in cirrhotic patients is important because the number, size, and type of focal lesions strongly influence patient management. Focal lesions detected by imaging examinations during pretransplantation evaluation were correlated with focal lesions detected during detailed pathological examination of 49 cirrhotic explant livers. Within 6 months before transplantation, color Doppler ultrasonography (US), contrast-enhanced computed tomography (CT), and magnetic resonance (MR) imaging were performed in 94%, 33%, and 55% of patients, respectively. In 2% to 8% of patients, different types of benign focal lesions were present, and a considerable proportion was interpreted as (pre)malignant on imaging examination. US detected only the largest HCCs (patient sensitivity, 40%; specificity, 100%) and no DNs. On a per-patient basis, contrast-enhanced CT and MR imaging had poor sensitivity (20% and 27%, respectively) and good specificity (100% and 94%, respectively) for DNs. Patient sensitivity and specificity of both techniques for HCC were reasonable (50% for CT, 70% for MR imaging) and good (79% for CT, 82% for MR imaging), respectively. Neither technique was able to detect smaller (pre)malignant lesions. As a consequence, 10% of patients underwent transplantation, although they exceeded the tumor number limit. Currently used imaging techniques cannot correctly determine the exact tumor burden in some cirrhotic patients. Regular contrast-enhanced MR examination of cirrhotic patients waiting for liver transplantation is the best tool for the early detection of (pre)malignant lesions.

Adult↗

PubMedDate not supplied

Iatrogenic main renal artery injury: treatment by endovascular stent-graft placement.

We report on a patient who presented with perforation of the left main renal artery as a complication of a percutaneous retroperitoneal drainage procedure. Only a small number of cases of iatrogenic main renal artery perforations have been reported, none of them due to a percutaneous drainage attempt. Endovascular treatment by means of a coronary stent-graft was successful.

Aged↗

PubMedDate not supplied

Stool tagging applied in thin-slice multidetector computed tomography colonography.

OBJECTIVE: To compare thin-slice multidetector computed tomography colonography (CTC) that uses stool tagging with colonoscopy. METHOD: One hundred fifty patients scheduled for colonoscopy underwent high-resolution CTC. An iodinated contrast agent was added to the preparation to tag the residual colonic fluid and stool. The effect of fluid tagging was assessed first. Sensitivity and specificity were calculated for two independent readers. In addition, values were recalculated separately for the first and last 75 patients. RESULTS: Tagging was optimal in 95.3% of the cases, and reader confidence was high. Sensitivities were 64.1%-66.7% (for the 2 readers) for 5- to 9-mm polyps and 91.7% for larger polyps. The overall specificity was 94.2% and 95%. Sensitivity improved during the study for both 5- to 9-mm polyps (from 54.2%-58.3% to 80%) and polyps larger than 9 mm (from 50% to 100%). Specificity changed nonuniformly. CONCLUSION: The combination of fluid tagging and high-resolution scanning in CTC showed high sensitivity and specificity, especially concerning sensitivity for polyps of 10 mm and larger.

Colon↗